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  • How to stop a ICMP attack?

    - by cumhur onat
    We are under a heavy icmp flood attack. Tcpdump shows the result below. Altough we have blocked ICMP with iptables tcpdump still prints icmp packets. I've also attached iptables configuration and "top" result. Is there any thing I can do to completely stop icmp packets? [root@server downloads]# tcpdump icmp -v -n -nn tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes 03:02:47.810957 IP (tos 0x0, ttl 49, id 16007, offset 0, flags [none], proto: ICMP (1), length: 56) 80.227.64.183 > 77.92.136.196: ICMP redirect 94.201.175.188 to host 80.227.64.129, length 36 IP (tos 0x0, ttl 124, id 31864, offset 0, flags [none], proto: ICMP (1), length: 76) 77.92.136.196 > 94.201.175.188: [|icmp] 03:02:47.811559 IP (tos 0x0, ttl 49, id 16010, offset 0, flags [none], proto: ICMP (1), length: 56) 80.227.64.183 > 77.92.136.196: ICMP redirect 94.201.175.188 to host 80.227.64.129, length 36 IP (tos 0x0, ttl 52, id 31864, offset 0, flags [none], proto: ICMP (1), length: 76) 77.92.136.196 > 94.201.175.188: [|icmp] 03:02:47.811922 IP (tos 0x0, ttl 49, id 16012, offset 0, flags [none], proto: ICMP (1), length: 56) 80.227.64.183 > 77.92.136.196: ICMP redirect 94.201.175.188 to host 80.227.64.129, length 36 IP (tos 0x0, ttl 122, id 31864, offset 0, flags [none], proto: ICMP (1), length: 76) 77.92.136.196 > 94.201.175.188: [|icmp] 03:02:47.812485 IP (tos 0x0, ttl 49, id 16015, offset 0, flags [none], proto: ICMP (1), length: 56) 80.227.64.183 > 77.92.136.196: ICMP redirect 94.201.175.188 to host 80.227.64.129, length 36 IP (tos 0x0, ttl 126, id 31864, offset 0, flags [none], proto: ICMP (1), length: 76) 77.92.136.196 > 94.201.175.188: [|icmp] 03:02:47.812613 IP (tos 0x0, ttl 49, id 16016, offset 0, flags [none], proto: ICMP (1), length: 56) 80.227.64.183 > 77.92.136.196: ICMP redirect 94.201.175.188 to host 80.227.64.129, length 36 IP (tos 0x0, ttl 122, id 31864, offset 0, flags [none], proto: ICMP (1), length: 76) 77.92.136.196 > 94.201.175.188: [|icmp] 03:02:47.812992 IP (tos 0x0, ttl 49, id 16018, offset 0, flags [none], proto: ICMP (1), length: 56) 80.227.64.183 > 77.92.136.196: ICMP redirect 94.201.175.188 to host 80.227.64.129, length 36 IP (tos 0x0, ttl 122, id 31864, offset 0, flags [none], proto: ICMP (1), length: 76) 77.92.136.196 > 94.201.175.188: [|icmp] 03:02:47.813582 IP (tos 0x0, ttl 49, id 16020, offset 0, flags [none], proto: ICMP (1), length: 56) 80.227.64.183 > 77.92.136.196: ICMP redirect 94.201.175.188 to host 80.227.64.129, length 36 IP (tos 0x0, ttl 52, id 31864, offset 0, flags [none], proto: ICMP (1), length: 76) 77.92.136.196 > 94.201.175.188: [|icmp] 03:02:47.814092 IP (tos 0x0, ttl 49, id 16023, offset 0, flags [none], proto: ICMP (1), length: 56) 80.227.64.183 > 77.92.136.196: ICMP redirect 94.201.175.188 to host 80.227.64.129, length 36 IP (tos 0x0, ttl 120, id 31864, offset 0, flags [none], proto: ICMP (1), length: 76) 77.92.136.196 > 94.201.175.188: [|icmp] 03:02:47.814233 IP (tos 0x0, ttl 49, id 16024, offset 0, flags [none], proto: ICMP (1), length: 56) 80.227.64.183 > 77.92.136.196: ICMP redirect 94.201.175.188 to host 80.227.64.129, length 36 IP (tos 0x0, ttl 120, id 31864, offset 0, flags [none], proto: ICMP (1), length: 76) 77.92.136.196 > 94.201.175.188: [|icmp] 03:02:47.815579 IP (tos 0x0, ttl 49, id 16025, offset 0, flags [none], proto: ICMP (1), length: 56) 80.227.64.183 > 77.92.136.196: ICMP redirect 94.201.175.188 to host 80.227.64.129, length 36 IP (tos 0x0, ttl 50, id 31864, offset 0, flags [none], proto: ICMP (1), length: 76) 77.92.136.196 > 94.201.175.188: [|icmp] 03:02:47.815726 IP (tos 0x0, ttl 49, id 16026, offset 0, flags [none], proto: ICMP (1), length: 56) 80.227.64.183 > 77.92.136.196: ICMP redirect 94.201.175.188 to host 80.227.64.129, length 36 IP (tos 0x0, ttl 50, id 31864, offset 0, flags [none], proto: ICMP (1), length: 76) 77.92.136.196 > 94.201.175.188: [|icmp] 03:02:47.815890 IP (tos 0x0, ttl 49, id 16027, offset 0, flags [none], proto: ICMP (1), length: 56) 80.227.64.183 > 77.92.136.196: ICMP redirect 94.201.175.188 to host 80.227.64.129, length 36 iptables configuration: [root@server etc]# iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination ofis tcp -- anywhere anywhere tcp dpt:mysql ofis tcp -- anywhere anywhere tcp dpt:ftp DROP icmp -- anywhere anywhere Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination DROP icmp -- anywhere anywhere Chain ofis (2 references) target prot opt source destination ACCEPT all -- OUR_OFFICE_IP anywhere DROP all -- anywhere anywhere top: top - 03:12:19 up 400 days, 15:43, 3 users, load average: 1.49, 1.67, 2.61 Tasks: 751 total, 3 running, 748 sleeping, 0 stopped, 0 zombie Cpu(s): 8.2%us, 1.0%sy, 0.0%ni, 87.9%id, 2.1%wa, 0.1%hi, 0.7%si, 0.0%st Mem: 32949948k total, 26906844k used, 6043104k free, 4707676k buffers Swap: 10223608k total, 0k used, 10223608k free, 14255584k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 36 root 39 19 0 0 0 R 100.8 0.0 17:03.56 ksoftirqd/11 10552 root 15 0 11408 1460 676 R 5.7 0.0 0:00.04 top 7475 lighttpd 15 0 304m 22m 15m S 3.8 0.1 0:05.37 php-cgi 1294 root 10 -5 0 0 0 S 1.9 0.0 380:54.73 kjournald 3574 root 15 0 631m 11m 5464 S 1.9 0.0 0:00.65 node 7766 lighttpd 16 0 302m 19m 14m S 1.9 0.1 0:05.70 php-cgi 10237 postfix 15 0 52572 2216 1692 S 1.9 0.0 0:00.02 scache 1 root 15 0 10372 680 572 S 0.0 0.0 0:07.99 init 2 root RT -5 0 0 0 S 0.0 0.0 0:16.72 migration/0 3 root 34 19 0 0 0 S 0.0 0.0 0:00.06 ksoftirqd/0 4 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/0 5 root RT -5 0 0 0 S 0.0 0.0 1:10.46 migration/1 6 root 34 19 0 0 0 S 0.0 0.0 0:01.11 ksoftirqd/1 7 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/1 8 root RT -5 0 0 0 S 0.0 0.0 2:36.15 migration/2 9 root 34 19 0 0 0 S 0.0 0.0 0:00.19 ksoftirqd/2 10 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/2 11 root RT -5 0 0 0 S 0.0 0.0 3:48.91 migration/3 12 root 34 19 0 0 0 S 0.0 0.0 0:00.20 ksoftirqd/3 13 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/3 uname -a [root@server etc]# uname -a Linux thisis.oursite.com 2.6.18-238.19.1.el5 #1 SMP Fri Jul 15 07:31:24 EDT 2011 x86_64 x86_64 x86_64 GNU/Linux arp -an [root@server downloads]# arp -an ? (77.92.136.194) at 00:25:90:04:F0:90 [ether] on eth0 ? (192.168.0.2) at 00:25:90:04:F0:91 [ether] on eth1 ? (77.92.136.193) at 00:23:9C:0B:CD:01 [ether] on eth0

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  • How can I get FreeNAS to respond to libvirt shutdown requests

    - by ptomli
    I have a KVM VM of FreeNAS 0.7.1 Shere (revision 5127) running on Ubuntu Server 10.04 and I'm unable to convince the VM to shutdown from the host virsh shutdown freenas I would expect this to send some ACPI? trigger to the VM and FreeNAS then do what it's told. I'm not a FreeBSD fundi so I don't really know what packages or processes to poke to get this running. I have tried to convince powerd to run, but the VM cpus don't have the required freq entry Sysctl HW $ sysctl hw hw.machine: amd64 hw.model: QEMU Virtual CPU version 0.12.3 hw.ncpu: 1 hw.byteorder: 1234 hw.physmem: 523116544 hw.usermem: 463806464 hw.pagesize: 4096 hw.floatingpoint: 1 hw.machine_arch: amd64 hw.realmem: 536850432 hw.aac.iosize_max: 65536 hw.amr.force_sg32: 0 hw.an.an_cache_iponly: 1 hw.an.an_cache_mcastonly: 0 hw.an.an_cache_mode: dbm hw.an.an_dump: off hw.ata.to: 15 hw.ata.wc: 1 hw.ata.atapi_dma: 1 hw.ata.ata_dma_check_80pin: 1 hw.ata.ata_dma: 1 hw.ath.txbuf: 200 hw.ath.rxbuf: 40 hw.ath.regdomain: 0 hw.ath.countrycode: 0 hw.ath.xchanmode: 1 hw.ath.outdoor: 1 hw.ath.calibrate: 30 hw.ath.hal.swba_backoff: 0 hw.ath.hal.sw_brt: 10 hw.ath.hal.dma_brt: 2 hw.bce.msi_enable: 1 hw.bce.tso_enable: 1 hw.bge.allow_asf: 0 hw.cardbus.cis_debug: 0 hw.cardbus.debug: 0 hw.cs.recv_delay: 570 hw.cs.ignore_checksum_failure: 0 hw.cs.debug: 0 hw.cxgb.snd_queue_len: 50 hw.cxgb.use_16k_clusters: 1 hw.cxgb.force_fw_update: 0 hw.cxgb.singleq: 0 hw.cxgb.ofld_disable: 0 hw.cxgb.msi_allowed: 2 hw.cxgb.txq_mr_size: 1024 hw.cxgb.sleep_ticks: 1 hw.cxgb.tx_coalesce: 0 hw.firewire.hold_count: 3 hw.firewire.try_bmr: 1 hw.firewire.fwmem.speed: 2 hw.firewire.fwmem.eui64_lo: 0 hw.firewire.fwmem.eui64_hi: 0 hw.firewire.phydma_enable: 1 hw.firewire.nocyclemaster: 0 hw.firewire.fwe.rx_queue_len: 128 hw.firewire.fwe.tx_speed: 2 hw.firewire.fwe.stream_ch: 1 hw.firewire.fwip.rx_queue_len: 128 hw.firewire.sbp.tags: 0 hw.firewire.sbp.use_doorbell: 0 hw.firewire.sbp.scan_delay: 500 hw.firewire.sbp.login_delay: 1000 hw.firewire.sbp.exclusive_login: 1 hw.firewire.sbp.max_speed: -1 hw.firewire.sbp.auto_login: 1 hw.mfi.max_cmds: 128 hw.mfi.event_class: 0 hw.mfi.event_locale: 65535 hw.pccard.cis_debug: 0 hw.pccard.debug: 0 hw.cbb.debug: 0 hw.cbb.start_32_io: 4096 hw.cbb.start_16_io: 256 hw.cbb.start_memory: 2281701376 hw.pcic.pd6722_vsense: 1 hw.pcic.intr_mask: 57016 hw.pci.honor_msi_blacklist: 1 hw.pci.enable_msix: 1 hw.pci.enable_msi: 1 hw.pci.do_power_resume: 1 hw.pci.do_power_nodriver: 0 hw.pci.enable_io_modes: 1 hw.pci.host_mem_start: 2147483648 hw.syscons.kbd_debug: 1 hw.syscons.kbd_reboot: 1 hw.syscons.bell: 1 hw.syscons.saver.keybonly: 1 hw.syscons.sc_no_suspend_vtswitch: 0 hw.usb.uplcom.interval: 100 hw.usb.uvscom.interval: 100 hw.usb.uvscom.opktsize: 8 hw.wi.debug: 0 hw.wi.txerate: 0 hw.xe.debug: 0 hw.intr_storm_threshold: 1000 hw.availpages: 127714 hw.bus.devctl_disable: 0 hw.ste.rxsyncs: 0 hw.busdma.total_bpages: 32 hw.busdma.zone0.total_bpages: 32 hw.busdma.zone0.free_bpages: 32 hw.busdma.zone0.reserved_bpages: 0 hw.busdma.zone0.active_bpages: 0 hw.busdma.zone0.total_bounced: 0 hw.busdma.zone0.total_deferred: 0 hw.busdma.zone0.lowaddr: 0xffffffff hw.busdma.zone0.alignment: 2 hw.busdma.zone0.boundary: 65536 hw.clockrate: 2808 hw.instruction_sse: 1 hw.apic.enable_extint: 0 hw.kbd.keymap_restrict_change: 0 hw.acpi.supported_sleep_state: S3 S4 S5 hw.acpi.power_button_state: S5 hw.acpi.sleep_button_state: S3 hw.acpi.lid_switch_state: NONE hw.acpi.standby_state: S1 hw.acpi.suspend_state: S3 hw.acpi.sleep_delay: 1 hw.acpi.s4bios: 0 hw.acpi.verbose: 0 hw.acpi.disable_on_reboot: 0 hw.acpi.handle_reboot: 0 hw.acpi.cpu.cx_lowest: C1 Processes $ ps ax PID TT STAT TIME COMMAND 0 ?? DLs 0:00.00 [swapper] 1 ?? ILs 0:00.00 /sbin/init -- 2 ?? DL 0:00.08 [g_event] 3 ?? DL 0:00.29 [g_up] 4 ?? DL 0:00.33 [g_down] 5 ?? DL 0:00.00 [crypto] 6 ?? DL 0:00.00 [crypto returns] 7 ?? DL 0:00.00 [xpt_thrd] 8 ?? DL 0:00.00 [kqueue taskq] 9 ?? DL 0:00.00 [acpi_task_0] 10 ?? RL 34:12.42 [idle: cpu0] 11 ?? WL 0:01.13 [swi4: clock sio] 12 ?? WL 0:00.00 [swi3: vm] 13 ?? WL 0:00.00 [swi1: net] 14 ?? DL 0:00.04 [yarrow] 15 ?? WL 0:00.00 [swi6: task queue] 16 ?? WL 0:00.00 [swi2: cambio] 17 ?? DL 0:00.00 [acpi_task_1] 18 ?? DL 0:00.00 [acpi_task_2] 19 ?? WL 0:00.00 [swi5: +] 20 ?? DL 0:00.01 [thread taskq] 21 ?? WL 0:00.00 [swi6: Giant taskq] 22 ?? WL 0:00.00 [irq9: acpi0] 23 ?? WL 0:00.09 [irq14: ata0] 24 ?? WL 0:00.11 [irq15: ata1] 25 ?? WL 0:00.57 [irq11: ed0 uhci0] 26 ?? DL 0:00.00 [usb0] 27 ?? DL 0:00.00 [usbtask-hc] 28 ?? DL 0:00.00 [usbtask-dr] 29 ?? WL 0:00.01 [irq1: atkbd0] 30 ?? WL 0:00.00 [swi0: sio] 31 ?? DL 0:00.00 [sctp_iterator] 32 ?? DL 0:00.00 [pagedaemon] 33 ?? DL 0:00.00 [vmdaemon] 34 ?? DL 0:00.00 [idlepoll] 35 ?? DL 0:00.00 [pagezero] 36 ?? DL 0:00.01 [bufdaemon] 37 ?? DL 0:00.00 [vnlru] 38 ?? DL 0:00.14 [syncer] 39 ?? DL 0:00.01 [softdepflush] 1221 ?? Is 0:00.00 /sbin/devd 1289 ?? Is 0:00.01 /usr/sbin/syslogd -ss -f /var/etc/syslog.conf 1608 ?? Is 0:00.00 /usr/sbin/cron -s 1692 ?? Ss 0:00.03 /usr/local/sbin/mDNSResponderPosix -b -f /var/etc/mdn 1730 ?? S 0:00.43 /usr/local/sbin/lighttpd -f /var/etc/lighttpd.conf -m 1882 ?? DL 0:00.00 [system_taskq] 1883 ?? DL 0:00.00 [arc_reclaim_thread] 4139 ?? S 0:00.03 /usr/local/bin/php /usr/local/www/exec.php 4144 ?? S 0:00.00 sh -c ps ax 4145 ?? R 0:00.00 ps ax 1816 v0 Is 0:00.01 login [pam] (login) 1818 v0 I+ 0:00.03 -tcsh (csh) 1817 v1 Is+ 0:00.00 /usr/libexec/getty Pc ttyv1 1402 con- I 0:00.00 /usr/local/sbin/afpd -F /var/etc/afpd.conf 1404 con- S 0:00.00 /usr/local/sbin/cnid_metad 1682 con- I 0:02.78 /usr/local/sbin/mt-daapd -m -c /var/etc/mt-daapd.conf 1789 con- S 0:00.18 /usr/local/bin/fuppesd --config-dir /var/etc --config Libvert snippet <domain type='kvm'> <name>freenas</name> <uuid>********-****-****-****-************</uuid> <memory>524288</memory> <currentMemory>524288</currentMemory> <vcpu>1</vcpu> <os> <type arch='x86_64' machine='pc-0.12'>hvm</type> <boot dev='hd'/> </os> <features> <acpi/> <apic/> <pae/> </features> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>restart</on_crash> <devices> <emulator>/usr/bin/kvm</emulator> Is this possible? Ideally I'd like to be able to stop the host without having to manually deal with shutting down the VM.

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  • Strange Recurrent Excessive I/O Wait

    - by Chris
    I know quite well that I/O wait has been discussed multiple times on this site, but all the other topics seem to cover constant I/O latency, while the I/O problem we need to solve on our server occurs at irregular (short) intervals, but is ever-present with massive spikes of up to 20k ms a-wait and service times of 2 seconds. The disk affected is /dev/sdb (Seagate Barracuda, for details see below). A typical iostat -x output would at times look like this, which is an extreme sample but by no means rare: iostat (Oct 6, 2013) tps rd_sec/s wr_sec/s avgrq-sz avgqu-sz await svctm %util 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16.00 0.00 156.00 9.75 21.89 288.12 36.00 57.60 5.50 0.00 44.00 8.00 48.79 2194.18 181.82 100.00 2.00 0.00 16.00 8.00 46.49 3397.00 500.00 100.00 4.50 0.00 40.00 8.89 43.73 5581.78 222.22 100.00 14.50 0.00 148.00 10.21 13.76 5909.24 68.97 100.00 1.50 0.00 12.00 8.00 8.57 7150.67 666.67 100.00 0.50 0.00 4.00 8.00 6.31 10168.00 2000.00 100.00 2.00 0.00 16.00 8.00 5.27 11001.00 500.00 100.00 0.50 0.00 4.00 8.00 2.96 17080.00 2000.00 100.00 34.00 0.00 1324.00 9.88 1.32 137.84 4.45 59.60 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 22.00 44.00 204.00 11.27 0.01 0.27 0.27 0.60 Let me provide you with some more information regarding the hardware. It's a Dell 1950 III box with Debian as OS where uname -a reports the following: Linux xx 2.6.32-5-amd64 #1 SMP Fri Feb 15 15:39:52 UTC 2013 x86_64 GNU/Linux The machine is a dedicated server that hosts an online game without any databases or I/O heavy applications running. The core application consumes about 0.8 of the 8 GBytes RAM, and the average CPU load is relatively low. The game itself, however, reacts rather sensitive towards I/O latency and thus our players experience massive ingame lag, which we would like to address as soon as possible. iostat: avg-cpu: %user %nice %system %iowait %steal %idle 1.77 0.01 1.05 1.59 0.00 95.58 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn sdb 13.16 25.42 135.12 504701011 2682640656 sda 1.52 0.74 20.63 14644533 409684488 Uptime is: 19:26:26 up 229 days, 17:26, 4 users, load average: 0.36, 0.37, 0.32 Harddisk controller: 01:00.0 RAID bus controller: LSI Logic / Symbios Logic MegaRAID SAS 1078 (rev 04) Harddisks: Array 1, RAID-1, 2x Seagate Cheetah 15K.5 73 GB SAS Array 2, RAID-1, 2x Seagate ST3500620SS Barracuda ES.2 500GB 16MB 7200RPM SAS Partition information from df: Filesystem 1K-blocks Used Available Use% Mounted on /dev/sdb1 480191156 30715200 425083668 7% /home /dev/sda2 7692908 437436 6864692 6% / /dev/sda5 15377820 1398916 13197748 10% /usr /dev/sda6 39159724 19158340 18012140 52% /var Some more data samples generated with iostat -dx sdb 1 (Oct 11, 2013) Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util sdb 0.00 15.00 0.00 70.00 0.00 656.00 9.37 4.50 1.83 4.80 33.60 sdb 0.00 0.00 0.00 2.00 0.00 16.00 8.00 12.00 836.00 500.00 100.00 sdb 0.00 0.00 0.00 3.00 0.00 32.00 10.67 9.96 1990.67 333.33 100.00 sdb 0.00 0.00 0.00 4.00 0.00 40.00 10.00 6.96 3075.00 250.00 100.00 sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.00 0.00 0.00 100.00 sdb 0.00 0.00 0.00 2.00 0.00 16.00 8.00 2.62 4648.00 500.00 100.00 sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2.00 0.00 0.00 100.00 sdb 0.00 0.00 0.00 1.00 0.00 16.00 16.00 1.69 7024.00 1000.00 100.00 sdb 0.00 74.00 0.00 124.00 0.00 1584.00 12.77 1.09 67.94 6.94 86.00 Characteristic charts generated with rrdtool can be found here: iostat plot 1, 24 min interval: http://imageshack.us/photo/my-images/600/yqm3.png/ iostat plot 2, 120 min interval: http://imageshack.us/photo/my-images/407/griw.png/ As we have a rather large cache of 5.5 GBytes, we thought it might be a good idea to test if the I/O wait spikes would perhaps be caused by cache miss events. Therefore, we did a sync and then this to flush the cache and buffers: echo 3 > /proc/sys/vm/drop_caches and directly afterwards the I/O wait and service times virtually went through the roof, and everything on the machine felt like slow motion. During the next few hours the latency recovered and everything was as before - small to medium lags in short, unpredictable intervals. Now my question is: does anybody have any idea what might cause this annoying behaviour? Is it the first indication of the disk array or the raid controller dying, or something that can be easily mended by rebooting? (At the moment we're very reluctant to do this, however, because we're afraid that the disks might not come back up again.) Any help is greatly appreciated. Thanks in advance, Chris. Edited to add: we do see one or two processes go to 'D' state in top, one of which seems to be kjournald rather frequently. If I'm not mistaken, however, this does not indicate the processes causing the latency, but rather those affected by it - correct me if I'm wrong. Does the information about uninterruptibly sleeping processes help us in any way to address the problem? @Andy Shinn requested smartctl data, here it is: smartctl -a -d megaraid,2 /dev/sdb yields: smartctl 5.40 2010-07-12 r3124 [x86_64-unknown-linux-gnu] (local build) Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net Device: SEAGATE ST3500620SS Version: MS05 Serial number: Device type: disk Transport protocol: SAS Local Time is: Mon Oct 14 20:37:13 2013 CEST Device supports SMART and is Enabled Temperature Warning Disabled or Not Supported SMART Health Status: OK Current Drive Temperature: 20 C Drive Trip Temperature: 68 C Elements in grown defect list: 0 Vendor (Seagate) cache information Blocks sent to initiator = 1236631092 Blocks received from initiator = 1097862364 Blocks read from cache and sent to initiator = 1383620256 Number of read and write commands whose size <= segment size = 531295338 Number of read and write commands whose size > segment size = 51986460 Vendor (Seagate/Hitachi) factory information number of hours powered up = 36556.93 number of minutes until next internal SMART test = 32 Error counter log: Errors Corrected by Total Correction Gigabytes Total ECC rereads/ errors algorithm processed uncorrected fast | delayed rewrites corrected invocations [10^9 bytes] errors read: 509271032 47 0 509271079 509271079 20981.423 0 write: 0 0 0 0 0 5022.039 0 verify: 1870931090 196 0 1870931286 1870931286 100558.708 0 Non-medium error count: 0 SMART Self-test log Num Test Status segment LifeTime LBA_first_err [SK ASC ASQ] Description number (hours) # 1 Background short Completed 16 36538 - [- - -] # 2 Background short Completed 16 36514 - [- - -] # 3 Background short Completed 16 36490 - [- - -] # 4 Background short Completed 16 36466 - [- - -] # 5 Background short Completed 16 36442 - [- - -] # 6 Background long Completed 16 36420 - [- - -] # 7 Background short Completed 16 36394 - [- - -] # 8 Background short Completed 16 36370 - [- - -] # 9 Background long Completed 16 36364 - [- - -] #10 Background short Completed 16 36361 - [- - -] #11 Background long Completed 16 2 - [- - -] #12 Background short Completed 16 0 - [- - -] Long (extended) Self Test duration: 6798 seconds [113.3 minutes] smartctl -a -d megaraid,3 /dev/sdb yields: smartctl 5.40 2010-07-12 r3124 [x86_64-unknown-linux-gnu] (local build) Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net Device: SEAGATE ST3500620SS Version: MS05 Serial number: Device type: disk Transport protocol: SAS Local Time is: Mon Oct 14 20:37:26 2013 CEST Device supports SMART and is Enabled Temperature Warning Disabled or Not Supported SMART Health Status: OK Current Drive Temperature: 19 C Drive Trip Temperature: 68 C Elements in grown defect list: 0 Vendor (Seagate) cache information Blocks sent to initiator = 288745640 Blocks received from initiator = 1097848399 Blocks read from cache and sent to initiator = 1304149705 Number of read and write commands whose size <= segment size = 527414694 Number of read and write commands whose size > segment size = 51986460 Vendor (Seagate/Hitachi) factory information number of hours powered up = 36596.83 number of minutes until next internal SMART test = 28 Error counter log: Errors Corrected by Total Correction Gigabytes Total ECC rereads/ errors algorithm processed uncorrected fast | delayed rewrites corrected invocations [10^9 bytes] errors read: 610862490 44 0 610862534 610862534 20470.133 0 write: 0 0 0 0 0 5022.480 0 verify: 2861227413 203 0 2861227616 2861227616 100872.443 0 Non-medium error count: 1 SMART Self-test log Num Test Status segment LifeTime LBA_first_err [SK ASC ASQ] Description number (hours) # 1 Background short Completed 16 36580 - [- - -] # 2 Background short Completed 16 36556 - [- - -] # 3 Background short Completed 16 36532 - [- - -] # 4 Background short Completed 16 36508 - [- - -] # 5 Background short Completed 16 36484 - [- - -] # 6 Background long Completed 16 36462 - [- - -] # 7 Background short Completed 16 36436 - [- - -] # 8 Background short Completed 16 36412 - [- - -] # 9 Background long Completed 16 36404 - [- - -] #10 Background short Completed 16 36401 - [- - -] #11 Background long Completed 16 2 - [- - -] #12 Background short Completed 16 0 - [- - -] Long (extended) Self Test duration: 6798 seconds [113.3 minutes]

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  • Can't connect to smtp (postfix, dovecot) after making a change and trying to change it back

    - by UberBrainChild
    I am using postfix and dovecot along with zpanel and I tried enabling SSL and then turned it off as I did not have SSL configured yet and I realized it was a bit stupid at the time. I am using CentOS 6.4. I get the following error in the mail log. (I changed my host name to "myhostname" and my domain to "mydomain.com") Oct 20 01:49:06 myhostname postfix/smtpd[4714]: connect from mydomain.com[127.0.0.1] Oct 20 01:49:16 myhostname postfix/smtpd[4714]: fatal: no SASL authentication mechanisms Oct 20 01:49:17 myhostname postfix/master[4708]: warning: process /usr/libexec/postfix/smtpd pid 4714 exit status 1 Oct 20 01:49:17 amyhostname postfix/master[4708]: warning: /usr/libexec/postfix/smtpd: bad command startup -- throttling Reading on forums and similar questions I figured it was just a service that was not running or installed. However I can see that saslauthd is currently up and running on my system and restarting it does not help. Here is my postfix master.cf # # Postfix master process configuration file. For details on the format # of the file, see the Postfix master(5) manual page. # # ***** Unused items removed ***** # ========================================================================== # service type private unpriv chroot wakeup maxproc command + args # (yes) (yes) (yes) (never) (100) # ========================================================================== smtp inet n - n - - smtpd # -o content_filter=smtp-amavis:127.0.0.1:10024 # -o receive_override_options=no_address_mappings pickup fifo n - n 60 1 pickup submission inet n - - - - smtpd -o content_filter= -o receive_override_options=no_header_body_checks cleanup unix n - n - 0 cleanup qmgr fifo n - n 300 1 qmgr #qmgr fifo n - n 300 1 oqmgr tlsmgr unix - - n 1000? 1 tlsmgr rewrite unix - - n - - trivial-rewrite bounce unix - - n - 0 bounce defer unix - - n - 0 bounce trace unix - - n - 0 bounce verify unix - - n - 1 verify flush unix n - n 1000? 0 flush proxymap unix - - n - - proxymap smtp unix - - n - - smtp smtps inet n - - - - smtpd # When relaying mail as backup MX, disable fallback_relay to avoid MX loops relay unix - - n - - smtp -o fallback_relay= # -o smtp_helo_timeout=5 -o smtp_connect_timeout=5 showq unix n - n - - showq error unix - - n - - error discard unix - - n - - discard local unix - n n - - local virtual unix - n n - - virtual lmtp unix - - n - - lmtp anvil unix - - n - 1 anvil scache unix - - n - 1 scache # # ==================================================================== # Interfaces to non-Postfix software. Be sure to examine the manual # pages of the non-Postfix software to find out what options it wants. # ==================================================================== maildrop unix - n n - - pipe flags=DRhu user=vmail argv=/usr/local/bin/maildrop -d ${recipient} uucp unix - n n - - pipe flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient) ifmail unix - n n - - pipe flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient) bsmtp unix - n n - - pipe flags=Fq. user=foo argv=/usr/local/sbin/bsmtp -f $sender $nexthop $recipient # # spam/virus section # smtp-amavis unix - - y - 2 smtp -o smtp_data_done_timeout=1200 -o disable_dns_lookups=yes -o smtp_send_xforward_command=yes 127.0.0.1:10025 inet n - y - - smtpd -o content_filter= -o smtpd_helo_restrictions= -o smtpd_sender_restrictions= -o smtpd_recipient_restrictions=permit_mynetworks,reject -o mynetworks=127.0.0.0/8 -o smtpd_error_sleep_time=0 -o smtpd_soft_error_limit=1001 -o smtpd_hard_error_limit=1000 -o receive_override_options=no_header_body_checks -o smtpd_bind_address=127.0.0.1 -o smtpd_helo_required=no -o smtpd_client_restrictions= -o smtpd_restriction_classes= -o disable_vrfy_command=no -o strict_rfc821_envelopes=yes # # Dovecot LDA dovecot unix - n n - - pipe flags=DRhu user=vmail:mail argv=/usr/libexec/dovecot/deliver -d ${recipient} # # Vacation mail vacation unix - n n - - pipe flags=Rq user=vacation argv=/var/spool/vacation/vacation.pl -f ${sender} -- ${recipient} And here is dovecot ## ## Dovecot config file ## listen = * disable_plaintext_auth = no protocols = imap pop3 lmtp sieve auth_mechanisms = plain login passdb { driver = sql args = /etc/zpanel/configs/dovecot2/dovecot-mysql.conf } userdb { driver = sql } userdb { driver = sql args = /etc/zpanel/configs/dovecot2/dovecot-mysql.conf } mail_location = maildir:/var/zpanel/vmail/%d/%n first_valid_uid = 101 #last_valid_uid = 0 first_valid_gid = 12 #last_valid_gid = 0 #mail_plugins = mailbox_idle_check_interval = 30 secs maildir_copy_with_hardlinks = yes service imap-login { inet_listener imap { port = 143 } } service pop3-login { inet_listener pop3 { port = 110 } } service lmtp { unix_listener lmtp { #mode = 0666 } } service imap { vsz_limit = 256M } service pop3 { } service auth { unix_listener auth-userdb { mode = 0666 user = vmail group = mail } # Postfix smtp-auth unix_listener /var/spool/postfix/private/auth { mode = 0666 user = postfix group = postfix } } service auth-worker { } service dict { unix_listener dict { mode = 0666 user = vmail group = mail } } service managesieve-login { inet_listener sieve { port = 4190 } service_count = 1 process_min_avail = 0 vsz_limit = 64M } service managesieve { } lda_mailbox_autocreate = yes lda_mailbox_autosubscribe = yes protocol lda { mail_plugins = quota sieve postmaster_address = [email protected] } protocol imap { mail_plugins = quota imap_quota trash imap_client_workarounds = delay-newmail } lmtp_save_to_detail_mailbox = yes protocol lmtp { mail_plugins = quota sieve } protocol pop3 { mail_plugins = quota pop3_client_workarounds = outlook-no-nuls oe-ns-eoh } protocol sieve { managesieve_max_line_length = 65536 managesieve_implementation_string = Dovecot Pigeonhole managesieve_max_compile_errors = 5 } dict { quotadict = mysql:/etc/zpanel/configs/dovecot2/dovecot-dict-quota.conf } plugin { # quota = dict:User quota::proxy::quotadict quota = maildir:User quota acl = vfile:/etc/dovecot/acls trash = /etc/zpanel/configs/dovecot2/dovecot-trash.conf sieve_global_path = /var/zpanel/sieve/globalfilter.sieve sieve = ~/dovecot.sieve sieve_dir = ~/sieve sieve_global_dir = /var/zpanel/sieve/ #sieve_extensions = +notify +imapflags sieve_max_script_size = 1M #sieve_max_actions = 32 #sieve_max_redirects = 4 } log_path = /var/log/dovecot.log info_log_path = /var/log/dovecot-info.log debug_log_path = /var/log/dovecot-debug.log mail_debug=yes ssl = no Does anyone have any ideas or tips on what I can try to get this working? Thanks for all the help EDIT: Output of postconf -n alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases broken_sasl_auth_clients = yes command_directory = /usr/sbin config_directory = /etc/postfix daemon_directory = /usr/libexec/postfix debug_peer_level = 2 delay_warning_time = 4 disable_vrfy_command = yes html_directory = no inet_interfaces = all mail_owner = postfix mailq_path = /usr/bin/mailq.postfix manpage_directory = /usr/share/man mydestination = localhost.$mydomain, localhost mydomain = control.yourdomain.com myhostname = control.yourdomain.com mynetworks = all newaliases_path = /usr/bin/newaliases.postfix queue_directory = /var/spool/postfix readme_directory = /usr/share/doc/postfix-2.2.2/README_FILES recipient_delimiter = + relay_domains = proxy:mysql:/etc/zpanel/configs/postfix/mysql-relay_domains_maps.cf sample_directory = /usr/share/doc/postfix-2.2.2/samples sendmail_path = /usr/sbin/sendmail.postfix setgid_group = postdrop smtp_use_tls = no smtpd_client_restrictions = smtpd_data_restrictions = reject_unauth_pipelining smtpd_helo_required = yes smtpd_helo_restrictions = smtpd_recipient_restrictions = permit_sasl_authenticated, permit_mynetworks, reject_unauth_destination, reject_non_fqdn_sender, reject_non_fqdn_recipient, reject_unknown_recipient_domain smtpd_sasl_auth_enable = yes smtpd_sasl_local_domain = $myhostname smtpd_sasl_path = private/auth smtpd_sasl_security_options = noanonymous smtpd_sasl_type = dovecot smtpd_sender_restrictions = smtpd_use_tls = no soft_bounce = yes transport_maps = hash:/etc/postfix/transport unknown_local_recipient_reject_code = 550 virtual_alias_maps = proxy:mysql:/etc/zpanel/configs/postfix/mysql-virtual_alias_maps.cf, regexp:/etc/zpanel/configs/postfix/virtual_regexp virtual_gid_maps = static:12 virtual_mailbox_base = /var/zpanel/vmail virtual_mailbox_domains = proxy:mysql:/etc/zpanel/configs/postfix/mysql-virtual_domains_maps.cf virtual_mailbox_maps = proxy:mysql:/etc/zpanel/configs/postfix/mysql-virtual_mailbox_maps.cf virtual_minimum_uid = 101 virtual_transport = dovecot virtual_uid_maps = static:101

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  • Why are my hard drives failing?

    - by WishCow
    I have a small Ubuntu server running at home, with 2 HDDs. There are two software raids (raid1) on the disks, managed by mdadm, which I believe is irrelevant, but mentioning it anyway. Both of the HDDs are Western Digital, and have been used for around 2 years, when one of them started making clicking noises, and died. I figured that maybe it's natural after 2 years, so I bought a new one, and resynced the raid arrays. After about a month, the other drive also died. I didn't get suspicious, since both drives have been bought at the same time, it's not that surprising to see both of them near each other, so I bought another one. So far, 2 old drives failed, and 2 brand new in the system. After one month, one of the new drives died. This is when it started getting suspicious. Since the PC was put together from some really old parts (think AthlonXP), I figured that maybe the motherboard's SATA controller is the culprit. Of course you can't switch parts easily in an old PC like this, so I bought a whole system, new MB, new CPU, new RAM. Took the just failed drive back, since it was under warranty, and got it replaced. So it is up to 2 failed drives from the old ones, and 1 failed drive from the new ones. No problems, for 1 month. After that errors were creeping up again in /var/log/messages, and mdadm was reporting raid array failures. I started tearing my hair out. Everything is new in the system, it's up to the third brand new HDD, it's simply not possible that all of the new drives that I bought were faulty. Let's see what is still common... the cables. Okay, long shot, let's replace the SATA cables. Take HDD back, smile to the guy at the counter and say that I'm really unlucky. He replaces the HDD. I come home, one month passes and one of HDDs fails, again. I'm not joking. Two of the brand new HDDs have failed. Maybe it's a bug in the OS. Let's see what the manufacturer's testing tool says. Download testing tool, burn it to a CD, reboot, leave HDD testing overnight. Test says that the drive is faulty, and I should back up everything, if I still can. I don't know what's happening, but it does not look like a software problem, something is definitely thrashing the HDDs. I should mention now, that the whole system is in a shoebox. Since there are a load of "build your own ikea case" stuff, I thought there shouldn't be any problems throwing the thing in a box, and stuffing it away somewhere. The box is well ventilated, but I thought that just maybe the drives were overheating. There is no other possible answer to this. So I took the HDD back, and got it replaced (for the 3rd time), and bought HDD coolers. And just now, I have heard the sound of doom. click click whizzzzzzzzz. SSH into the box: You have new mail! mail r 1 DegradedArrayEvent on /dev/md0 ... dmesg output: [47128.000051] ata3: lost interrupt (Status 0x50) [47128.000097] end_request: I/O error, dev sda, sector 58588863 [47128.000134] md: super_written gets error=-5, uptodate=0 [48043.976054] ata3: lost interrupt (Status 0x50) [48043.976086] ata3.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen [48043.976132] ata3.00: cmd c8/00:18:bf:40:52/00:00:00:00:00/e1 tag 0 dma 12288 in [48043.976135] res 40/00:00:00:4f:c2/00:00:00:00:00/00 Emask 0x4 (timeout) [48043.976208] ata3.00: status: { DRDY } [48043.976241] ata3: soft resetting link [48044.148446] ata3.00: configured for UDMA/133 [48044.148457] ata3.00: device reported invalid CHS sector 0 [48044.148477] ata3: EH complete Recap: No possibility of overheating 6 drives have failed, 4 of those have been brand new. I'm not sure now that the original two have been faulty, or suffered the same thing that the new ones. There is nothing common in the system, apart from the OS which is Ubuntu Karmic now (started with Jaunty). New MB, new CPU, new RAM, new SATA cables. No, the little holes on the HDD are not covered I'm crying. Really. I don't have the face to return to the store now, it's not possible for 4 drives to fail under 4 months. A few ideas that I have been thinking: Is it possible that I fuck up something when I partition and resync the drives? Can it be so bad that it physicaly wrecks the drive? (since the vendor supplied tool says that the drive is damaged) I do the partitoning with fdisk, and use the same block size for the raid1 partitions (I check the exact block sizes with fdisk -lu) Is it possible that the linux kernel or mdadm, or something is not compatible with this exact brand of HDDs, and thrashes them? Is it possible that it may be the shoebox? Try placing it somewhere else? It's under a shelf now, so humidity is not a problem either. Is it possible that a normal PC case will solve my problem (I'm going to shoot myself then)? I will get a picture tomorrow. Am I just simply cursed? Any help or speculation is greatly appreciated. Edit: The power strip is guarded against overvoltage. Edit2: I have moved inbetween these 4 months, so the possibility of the cause being "dirty" electricity in both places, is very low. Edit3: I have checked the voltages in the BIOS (couldn't borrow a multimeter), and they are all seem correct, the biggest discrepancy is in the 12V, because it's supplying 11.3. Should I be worried about that? Edit4: I put my desktop PC's PSU into the server. The BIOS reported much more accurate voltage readings, and also it has successfully rebuilt the raid1 array, which took some 3-4 hours, so I feel a little positive now. Will get a new PSU tomorrow to test with that. Also, attaching the picture about the box: (disregard the 3rd drive)

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  • Optimize php-fpm and varnish for a powerfull server

    - by Jim
    My setup is: Intel® Core™ i7-2600 and RAM 16 GB DDR3 RAM varnish+nginx+php-fpm+apc for a not very heavy WordPress blog with W3 Total Cache and CDN My problem is that after 55 hits per second according to blitz.io varnish starts giving out timeouts. CPU usage at this time is hardly 1%. Free memory at all time remains 10GB+. I tried benchmarking php-fpm directly with result of 150hits/s without any timeouts. But after that the CPU usage goes 100% and it stops responding. Can you help me optimize it to handle more? As i understand nginx has nothing to do over here so i dont put its config. php-fpm config listen = /tmp/php5-fpm.sock listen.allowed_clients = 127.0.0.1 user = nginx group = nginx pm = dynamic pm.max_children = 150 pm.start_servers = 7 pm.min_spare_servers = 2 pm.max_spare_servers = 15 pm.max_requests = 500 slowlog = /var/log/php-fpm/www-slow.log php_admin_value[error_log] = /var/log/php-fpm/www-error.log php_admin_flag[log_errors] = on apc extension = apc.so apc.enabled=1 apc.shm_size=512MB apc.num_files_hint=0 apc.user_entries_hint=0 apc.ttl=7200 apc.use_request_time=1 apc.user_ttl=7200 apc.gc_ttl=3600 apc.cache_by_default=1 apc.filters apc.mmap_file_mask=/tmp/apc.XXXXXX apc.file_update_protection=2 apc.enable_cli=0 apc.max_file_size=1M apc.stat=1 apc.stat_ctime=0 apc.canonicalize=0 apc.write_lock=1 apc.report_autofilter=0 apc.rfc1867=0 apc.rfc1867_prefix =upload_ apc.rfc1867_name=APC_UPLOAD_PROGRESS apc.rfc1867_freq=0 apc.rfc1867_ttl=3600 apc.include_once_override=0 apc.lazy_classes=0 apc.lazy_functions=0 apc.coredump_unmap=0 apc.file_md5=0 apc.preload_path Varnish VCL backend default { .host = "127.0.0.1"; .port = "8080"; .connect_timeout = 6s; .first_byte_timeout = 6s; .between_bytes_timeout = 60s; } acl purgehosts { "localhost"; "127.0.0.1"; } # Called after a document has been successfully retrieved from the backend. sub vcl_fetch { # Uncomment to make the default cache "time to live" is 5 minutes, handy # but it may cache stale pages unless purged. (TODO) # By default Varnish will use the headers sent to it by Apache (the backend server) # to figure out the correct TTL. # WP Super Cache sends a TTL of 3 seconds, set in wp-content/cache/.htaccess set beresp.ttl = 24h; # Strip cookies for static files and set a long cache expiry time. if (req.url ~ "\.(jpg|jpeg|gif|png|ico|css|zip|tgz|gz|rar|bz2|pdf|txt|tar|wav|bmp|rtf|js|flv|swf|html|htm)$") { unset beresp.http.set-cookie; set beresp.ttl = 24h; } # If WordPress cookies found then page is not cacheable if (req.http.Cookie ~"(wp-postpass|wordpress_logged_in|comment_author_)") { # set beresp.cacheable = false;#versions less than 3 #beresp.ttl>0 is cacheable so 0 will not be cached set beresp.ttl = 0s; } else { #set beresp.cacheable = true; set beresp.ttl=24h;#cache for 24hrs } # Varnish determined the object was not cacheable #if ttl is not > 0 seconds then it is cachebale if (!beresp.ttl > 0s) { # set beresp.http.X-Cacheable = "NO:Not Cacheable"; } else if ( req.http.Cookie ~"(wp-postpass|wordpress_logged_in|comment_author_)" ) { # You don't wish to cache content for logged in users set beresp.http.X-Cacheable = "NO:Got Session"; return(hit_for_pass); #previously just pass but changed in v3+ } else if ( beresp.http.Cache-Control ~ "private") { # You are respecting the Cache-Control=private header from the backend set beresp.http.X-Cacheable = "NO:Cache-Control=private"; return(hit_for_pass); } else if ( beresp.ttl < 1s ) { # You are extending the lifetime of the object artificially set beresp.ttl = 300s; set beresp.grace = 300s; set beresp.http.X-Cacheable = "YES:Forced"; } else { # Varnish determined the object was cacheable set beresp.http.X-Cacheable = "YES"; if (beresp.status == 404 || beresp.status >= 500) { set beresp.ttl = 0s; } # Deliver the content return(deliver); } sub vcl_hash { # Each cached page has to be identified by a key that unlocks it. # Add the browser cookie only if a WordPress cookie found. if ( req.http.Cookie ~"(wp-postpass|wordpress_logged_in|comment_author_)" ) { #set req.hash += req.http.Cookie; hash_data(req.http.Cookie); } } # vcl_recv is called whenever a request is received sub vcl_recv { # remove ?ver=xxxxx strings from urls so css and js files are cached. # Watch out when upgrading WordPress, need to restart Varnish or flush cache. set req.url = regsub(req.url, "\?ver=.*$", ""); # Remove "replytocom" from requests to make caching better. set req.url = regsub(req.url, "\?replytocom=.*$", ""); remove req.http.X-Forwarded-For; set req.http.X-Forwarded-For = client.ip; # Exclude this site because it breaks if cached if ( req.http.host == "sr.ituts.gr" ) { return( pass ); } # Serve objects up to 2 minutes past their expiry if the backend is slow to respond. set req.grace = 120s; # Strip cookies for static files: if (req.url ~ "\.(jpg|jpeg|gif|png|ico|css|zip|tgz|gz|rar|bz2|pdf|txt|tar|wav|bmp|rtf|js|flv|swf|html|htm)$") { unset req.http.Cookie; return(lookup); } # Remove has_js and Google Analytics __* cookies. set req.http.Cookie = regsuball(req.http.Cookie, "(^|;\s*)(__[a-z]+|has_js)=[^;]*", ""); # Remove a ";" prefix, if present. set req.http.Cookie = regsub(req.http.Cookie, "^;\s*", ""); # Remove empty cookies. if (req.http.Cookie ~ "^\s*$") { unset req.http.Cookie; } if (req.request == "PURGE") { if (!client.ip ~ purgehosts) { error 405 "Not allowed."; } #previous version ban() was purge() ban("req.url ~ " + req.url + " && req.http.host == " + req.http.host); error 200 "Purged."; } # Pass anything other than GET and HEAD directly. if (req.request != "GET" && req.request != "HEAD") { return( pass ); } /* We only deal with GET and HEAD by default */ # remove cookies for comments cookie to make caching better. set req.http.cookie = regsub(req.http.cookie, "1231111111111111122222222333333=[^;]+(; )?", ""); # never cache the admin pages, or the server-status page, or your feed? you may want to..i don't if (req.request == "GET" && (req.url ~ "(wp-admin|bb-admin|server-status|feed)")) { return(pipe); } # don't cache authenticated sessions if (req.http.Cookie && req.http.Cookie ~ "(wordpress_|PHPSESSID)") { return(lookup); } # don't cache ajax requests if(req.http.X-Requested-With == "XMLHttpRequest" || req.url ~ "nocache" || req.url ~ "(control.php|wp-comments-post.php|wp-login.php|bb-login.php|bb-reset-password.php|register.php)") { return (pass); } return( lookup ); } Varnish Daemon options DAEMON_OPTS="-a :80 \ -T 127.0.0.1:6082 \ -f /etc/varnish/ituts.vcl \ -u varnish -g varnish \ -S /etc/varnish/secret \ -p thread_pool_add_delay=2 \ -p thread_pools=8 \ -p thread_pool_min=100 \ -p thread_pool_max=1000 \ -p session_linger=50 \ -p session_max=150000 \ -p sess_workspace=262144 \ -s malloc,5G" Im not sure where to start, should i for start optimize php-fpm and then go to varnish or php-fpm is at its max right now so i should start looking for the problem in varnish?

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  • How to set up linux watchdog daemon with Intel 6300esb

    - by ACiD GRiM
    I've been searching for this on Google for sometime now and I have yet to find proper documentation on how to connect the kernel driver for my 6300esb watchdog timer to /dev/watchdog and ensure that watchdog daemon is keeping it alive. I am using RHEL compatible Scientific Linux 6.3 in a KVM virtual machine by the way Below is everything I've tried so far: dmesg|grep 6300 i6300ESB timer: Intel 6300ESB WatchDog Timer Driver v0.04 i6300ESB timer: initialized (0xffffc900008b8000). heartbeat=30 sec (nowayout=0) | ll /dev/watchdog crw-rw----. 1 root root 10, 130 Sep 22 22:25 /dev/watchdog | /etc/watchdog.conf #ping = 172.31.14.1 #ping = 172.26.1.255 #interface = eth0 file = /var/log/messages #change = 1407 # Uncomment to enable test. Setting one of these values to '0' disables it. # These values will hopefully never reboot your machine during normal use # (if your machine is really hung, the loadavg will go much higher than 25) max-load-1 = 24 max-load-5 = 18 max-load-15 = 12 # Note that this is the number of pages! # To get the real size, check how large the pagesize is on your machine. #min-memory = 1 #repair-binary = /usr/sbin/repair #test-binary = #test-timeout = watchdog-device = /dev/watchdog # Defaults compiled into the binary #temperature-device = #max-temperature = 120 # Defaults compiled into the binary #admin = root interval = 10 #logtick = 1 # This greatly decreases the chance that watchdog won't be scheduled before # your machine is really loaded realtime = yes priority = 1 # Check if syslogd is still running by enabling the following line #pidfile = /var/run/syslogd.pid Now maybe I'm not testing it correctly, but I would expecting that stopping the watchdog service would cause the /dev/watchdog to time out after 30 seconds and I should see the host reboot, however this does not happen. Also, here is my config for the KVM vm <!-- WARNING: THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE OVERWRITTEN AND LOST. Changes to this xml configuration should be made using: virsh edit sl6template or other application using the libvirt API. --> <domain type='kvm'> <name>sl6template</name> <uuid>960d0ac2-2e6a-5efa-87a3-6bb779e15b6a</uuid> <memory unit='KiB'>262144</memory> <currentMemory unit='KiB'>262144</currentMemory> <vcpu placement='static'>1</vcpu> <os> <type arch='x86_64' machine='rhel6.3.0'>hvm</type> <boot dev='hd'/> </os> <features> <acpi/> <apic/> <pae/> </features> <cpu mode='custom' match='exact'> <model fallback='allow'>Westmere</model> <vendor>Intel</vendor> <feature policy='require' name='tm2'/> <feature policy='require' name='est'/> <feature policy='require' name='vmx'/> <feature policy='require' name='ds'/> <feature policy='require' name='smx'/> <feature policy='require' name='ss'/> <feature policy='require' name='vme'/> <feature policy='require' name='dtes64'/> <feature policy='require' name='rdtscp'/> <feature policy='require' name='ht'/> <feature policy='require' name='dca'/> <feature policy='require' name='pbe'/> <feature policy='require' name='tm'/> <feature policy='require' name='pdcm'/> <feature policy='require' name='pdpe1gb'/> <feature policy='require' name='ds_cpl'/> <feature policy='require' name='pclmuldq'/> <feature policy='require' name='xtpr'/> <feature policy='require' name='acpi'/> <feature policy='require' name='monitor'/> <feature policy='require' name='aes'/> </cpu> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>restart</on_crash> <devices> <emulator>/usr/libexec/qemu-kvm</emulator> <disk type='file' device='disk'> <driver name='qemu' type='raw'/> <source file='/mnt/data/vms/sl6template.img'/> <target dev='vda' bus='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> </disk> <controller type='usb' index='0'> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/> </controller> <interface type='bridge'> <mac address='52:54:00:44:57:f6'/> <source bridge='br0.2'/> <model type='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> <interface type='bridge'> <mac address='52:54:00:88:0f:42'/> <source bridge='br1'/> <model type='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/> </interface> <serial type='pty'> <target port='0'/> </serial> <console type='pty'> <target type='serial' port='0'/> </console> <watchdog model='i6300esb' action='reset'> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </watchdog> <memballoon model='virtio'> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </memballoon> </devices> </domain> Any help is appreciated as the most I've found are patches to kvm and general softdog documentation or IPMI watchdog answers.

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  • My D-Link's Ethernet bridge downlink just got 10-30x slower?

    - by Jay Levitt
    TL;DR: I unplugged my network to move my desk, and now downloading via my DIR-655's Ethernet LAN bridge is 10-30x slower than the Ethernet switch it's plugged into. Background My network is SMC cable modem <-> Cisco firewall <-> Netgear switch <-> D-Link WiFi† | | | | SMC8014 ASA-5505 GS608v2 gigE DIR-655 rev A3 gigE †The DIR-655 is used as an access point, not a router (although what D-Link calls an access point, I'd call a bridge). The "WAN" port is unused; the Netgear connects to the built-in 4-port Ethernet LAN switch, inside the built- in router/firewall. Endpoints: MacBook Pro 17" mid-2010 iPhone 4S Fedora 12 Linux server running reasonably fast dual-Athlon X2, VelociRaptors, etc. All cables are <10 feet, mostly CAT-5e, some CAT-6, all premade. All WiFi endpoints are within three feet of the D-Link. Yesterday I unplugged and rearranged stuff, and now connecting via the D-Link - even through the wired switch, right next to the incoming network cable - is 30x slower than connecting directly to the Netgear switch, on both my MacBook and iPhone. How I'm measuring "slower" I'm mostly using http://speedtest.net, which of course only really measures broadband speeds. I've also installed http://www.speedtest.net/mini.php on my local server, but can't test the iPhone with that. Results Speedtest.net, closest server over Comcast business-class: CONFIG | PING (ms) | DOWN (Mbps) | UP (Mbps) Mac <-> Ethernet <-> Netgear | 9 | 31.6 | 6.8 Mac <-> Ethernet <-> D-Link | 8 | 4.1 | 6.0 Mac <-> WiFi <-> D-Link | 9 | 1.4 | 2.9 iPhone <-> WiFi <-> D-Link | 67 | 0.4 | 1.6 Speedtest Mini on Linux PC: CONFIG | DOWN (Mbps) | UP (Mbps) Mac <-> Ethernet <-> NetGear | 97.2 | 76.9 Mac <-> Ethernet <-> D-Link | 8.2 | 24.2 Mac <-> WiFi <-> D-Link | 1.0 | 8.6 Slow typing in SSH: Mac <-> Ethernet <-> Netgear <-> Linux PC: smooth Mac <-> Ethernet <-> D-Link <-> Linux PC: choppy Note that D-Link upload speeds are normal on broadband, slower locally (but I'd believe that's a D-Link limitation), and always faster than the downloads! Since ssh is choppy just with slow typing, I don't believe it's a throttling-type problem either; that's not a lot of bandwidth. What I've tried Swapping all "good" and "bad" cables Re-plugging "bad" cable from D-Link to Netgear and watching it be the "good" cable pulling cables away from power lines Verify that the Mac auto-detects the D-Link as gigE Try to verify the link speed of the D-Link <- Netgear connection, but the firmware doesn't report that Verify that the D-Link sees no TX/RX errors or collisions Use different Ethernet ports on both Netgear and D-Link Reset the D-Link to factory settings Upgrade the D-Link firmware from 1.21 to 1.35NA, 2010/11/12, the latest Reboot everything at least once On the Mac, disable Wi-Fi during the Ethernet tests, and unplug Ethernet during the Wi-Fi tests Using iStumbler, verify that the D-Link isn't picking overloaded Wi-Fi channels (usually just 1-5 neighbors on my and adjacent channels, average for my apt building) Verify that the only client connected to the Wi-Fi was the iPhone Verify that nothing was being chatty on my network according to the WISH log Enable and disable all sorts of D-Link settings, including forcing WAN auto-detect to gigE So. I don't mind buying a new access point—I wouldn't mind having a dual-link network—but as a guy who's been networking since gated v4 was a drastic rewrite, and who often used physical sniffers in the days before Wireshark, I'm baffled. I hate being baffled. What could I possibly have changed that would result in this? How can I measure it? All I can think of is a static zap—thick carpet, socks, HVAC—but I didn't feel one, and does that really happen anymore? Can I test if it's Ethernet vs. TCP layer slowness? I'm not familiar with modern network utilities; it's hard to Google without hitting "Q: Why is my network slow? A: Is your microwave on?" If I don't get an answer here, will someone big and powerful help me migrate it to serverfault without getting screamed back here? In the words of Inigo Montoya, "I must know." Don't get all Dread Pirate Roberts on me.

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  • What other tool is using my hotkey?

    - by Sammy
    I use Greenshot for screenshots, and it's been nagging about some other software tool using the same hotkey. I started receiving this warning message about two days ago. It shows up each time I reboot and log on to Windows. The hotkey(s) "Ctrl + Shift + PrintScreen" could not be registered. This problem is probably caused by another tool claiming usage of the same hotkey(s)! You could either change your hotkey settings or deactivate/change the software making use of the hotkey(s). What's this all about? The only software I recently installed is CPU-Z Core Temp Speed Fan HD Tune Epson Print CD NetStress What I would like to know is how to find out what other tool is causing this conflict? Do I really have to uninstall each program, one by one, until there is no conflict anymore? I see no option for customizing any hotkeys in CPU-Z, and according to docs there are only a few keyboard shortcuts. These are F5 through F9, but they are no hotkeys. There is nothing in Core Temp, and from what I can see... nothing in Speed Fan. Is any of these programs known to use Ctrl + Shift + PrintScreen hotkey for screenshots? I am actually suspecting the Dropbox client. I think I saw a warning recently coming from Dropbox program, something to do with hotkeys or keyboard shortcuts. I see that it has an option for sharing screenshots under Preferences menu, but I see no option for hotkeys. Core Temp actually also has an option for taking screenshots (F9) but it's just that - a keyboard shortcut, not a hotkey. And again, there's no option actually for changing this setting in Options/Settings menu. How do you resolve this type of conflicts? Are there any general methods you can use to pinpoint the second conflicting software? Like... is there some Windows registry key that holds the hotkeys? Or is it just down to mere luck and trial and error? Addendum I forgot to mention, when I do use the Ctrl + Shift + PrintScreen hotkey, what happens is that the Greenshot context menu shows up, asking me where I want to save the screenshot. So it appears to be working. But I am still getting the darn warning every time I reboot and log on to Windows?! I actually tried changing the key bindings in Greenshot preferences, but after a reboot it seems to have returned back to the settings I had previously. Update I can't see any hotkey conflicts in the Widnows Hotkey Explorer. The aforementioned hotkey is reserved by Greenshot, and I don't see any other program using the same hotkey binding. But when I went into Greenshot preferences, this is what I discovered. As you can see it's the Greenshot itself that uses the same hotkey twice! I guess that's why no other program was listed above as using this hotkey. But how can Greenshot be so stupid to use the same hotkey more than once? I didn't do this! It's not my fault... I'm not that stupid. This is what it's set to right now: Capture full screen: Ctrl + Skift + Prntscrn Capture window: Alt + Prntscrn Capture region: Ctrl + Prntscrn Capture last region: Skift + Prntscrn Capture Internet Explorer: Ctrl + Skift + Prntscrn And this is my preferred setting: Capture full screen: Prntscrn Capture window: Alt + Prntscrn Capture region: Ctrl + Prntscrn Capture last region: Capture Internet Explorer: I don't use any hotkey for "last region" and IE. But when I set this to my liking, as listed here, Greenshot gives me the same warning message, even as I tab through the hotkey entry fields. Sometimes it even gives me the warning when I just click Cancel button. This is really crazy! On the side note... You might have noticed that I have "update check" set to 0 (zero). This is because, in my experience, Greenshot changes all or only some of my preferences back to default settings whenever it automatically updates to a new version. So I opted to stay off updates to get rid of the problem. It has done so for the past three updates or so. I hoped to receive a new update that would fix the issue, but I think it still reverts back to default settings after each update to a new version, including setting default hotkeys. Update 2 I'll give you just one example of how Greenshot behaves. This is the dialog I have in front of me right now. As you can see, I have removed the last two hotkeys and changed the first one to my own liking. While I was clicking in the fields and removing the two hotkeys I was getting the warning message. So let's say I click in the "capture last region" field. Then I get this: Note that none of the entries include "Ctrl + Shift + PrintScreen" that it's warning about. Now I will change all the hotkeys so I get something like this: So now I'm using QWERTY letters for binding, like Ctrl+Alt+Q, Ctrl+Alt+W and so on. As far as I know no Windows program is using these. While I was clicking through the different fields it was giving me the warning. Now when I try to click OK to save the changes, it once again gives me a warning about "ctrl + shift + printscreen". Update 3 After setting the above key bindings (QWERTY) and saving changes, and then rebooting, the conflict seems to have been resolved. I was then able to set following key bindings. Capture full screen: Prntscrn Capture window: Alt + Prntscrn Capture region: Ctrl + Prntscrn I was not prompted with the warning message this time. Perhaps changing key binding required a system reboot? Sounds far fetched but that appears to be the case. I'm still not sure what caused this conflict, but I know for sure that it started after installing aforementioned programs. It might just have to do with Greenshot itself, and not some other program. Like I said, I know from experience that Greenshot likes to mess with users' settings after each update. I wouldn't be surprised if it was actually silently updated, even though I have specified not to check for updates, then it changed the key bindings back to defaults and caused a conflict with the hotkeys that were registered with the operating system previously. I rarely reboot the system, so that could have added to the conflict. Next time if I see this I will run Hotkey Explorer immediately and see if there is another program causing the conflict.

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  • Backing up my data causes my server to crash using Symantec Backup Exec 12, or How I Came to Loathe Irony

    - by Kyle Noland
    I have a Dell PowerEdge 2850 running Windows Server 2003. It is the primary file server for one of my clients. I have another server also running Windows Server 2003 that acts as the core media server for Symantec Backup Exec 12. I recently upgraded from Backup Exec 11d to 12. This upgrade was necessary because we also just upgraded from Exchange 2003 to Exchange 2007. After the upgrade I had to push-install the new version 12 Backup Exec Remote Agents to each of the servers I am backing up (about 6 total). 5 of my servers are doing just fine, faithfully completing backups every night. My file server routinely crashes. Observations: When the server crashes, it does not blue screen, it just locks up completely. Even the mouse is unresponsive. If you leave the server locked up long enough, it will eventually reboot itself and hang on the Windows splash screen. There is absolutely zero useful Event Viewer evidence of a problem. The logs go from routine logging to an Unexplained Shutdown Event the next morning when I have to hard reset the server to get it to boot. 90% of the time the server does not boot cleanly, it hangs on the Windows splash screen. I don't have any light to shed here. When the server hangs all I can do is hard reset it and try again. Even after a successful boot and chkdsk /r operation, if you reboot the machine, you have a 90% chance it won't back up again cleanly. The back story: This server started crashing during nightly backups about a month ago. I tried everything I could think of to troubleshoot the problem and eventually had to give up because I could not keep coming to the office at 4 AM to try to get the server back online. One Friday I got lucky and the server stayed up for its entire full backup. I took this opportunity to restore the full backup to a temporary server I set up and switched all my users to the temporary. Then I reloaded the ailing file server. I kept all my users on the temporary file server for about 3 weeks. I installed the same Backup Exec Remote Agent and Trend Micro A/V client on the temporary server that I was using on the regular file server. During this time, I had absolutely no problems backing up the temporary server. I tested the reloaded file server extensively. I rebooted the server once an hour every day for 3 weeks trying to make it fail. It never did. I felt confident that the reload was the answer to my problems. I moved all of the data from the temporary server back to the regular server. I got 3 nightly backups out of it before it locked up again and started the familiar failure to boot cleanly behavior. This weekend I decided to monitor the file server through the entire backup job. I RDPd into the file server and also into the server running Backup Exec. On the file server I opened the Task Manager so I could view the processes and watch CPU and memory usage. Everything was running smoothly for about 60GB worth of backup. Then I noticed that the byte count of the backup job in Backup Exec had stopped progressing. I looked back over at my RDP session into the file server, and I was getting real time updates about CPU and memory usage still - both nearly 0%, which is unusual. Backups usually hover around 40% usage for the duration of the backup job. Let me reiterate this point: The screen was refreshing and I was getting real time Task Manager updates - until I clicked on the Start menu. The screen went black and the server locked up. In truth, I think the server had already locked up, the video card just hadn't figured it out yet. I went back into my bag of trick: driving to the office and hard reseting the server over and over again when it hangs up at the Windows splash screen. I did this for 2 hours without getting a successful boot. I started panicking because I did not have a decent backup to use to get everything back onto the working temporary file server. Once I exhausted everything I knew to do, I took a deep breath, booted to the Windows Server 2003 CD and performed a repair installation of Windows. The server came back up fine, with all of my data intact. I can now reboot the server at will and it will come back up cleanly. The problem is that I'm afraid as soon as I try to back that data up again I will back at square one. So let me sum things up: Here is what I've done so far to troubleshoot this server: Deleted and recreated the RAID 5 sets. Initialized the drives. Reloaded the server with a fresh Server 2003 install. Confirmed with Dell that I have installed the latest, Dell approved BIOS and NIC drivers. Uninstalled / reinstalled the Backup Exec Remote Agent. Uninstalled the Trend Micro A/V client. Configured the server not to reboot itself after a blue screen so I can see any stop error. I used to think the server was blue screening, but since I enabled this setting I now know that the server just completely locks up. Run chkdsk /r from the Windows Recovery Console. Several errors were found and corrected, but did not help my problem. Help confirm or deny the following assumptions: There are two problems at work here. Why the server is locking up in the first place, and why the server won't boot cleanly after a lockup. This is ultimately a software problem. The server works fine and can be rebooted cleanly all day long - until the first lockup - following a fresh OS load or even a Repair installation. This is not a problem with Backup Exec in general. All of my other servers back up just fine. For the record, all of the other servers run Server 2003, and some of them house more data than the file server in question here. Any help is appreciated. The irony is almost too much to bear. Backing up my data is what is jeopardizing it.

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  • How to improve Varnish performance?

    - by Darkseal
    We're experiencing a strange problem with our current Varnish configuration. 4x Web Servers (IIS 6.5 on Windows 2003 Server, each installed on a Intel(R) Xeon(R) CPU E5450 @ 3.00GHz Quad Core, 4GB RAM) 3x Varnish Servers (varnish-3.0.3 revision 9e6a70f on Ubuntu 12.04.2 LTS - 64 bit/precise, Kernel Linux 3.2.0-29-generic, each installed on a Intel(R) Xeon(R) CPU E5450 @ 3.00GHz Quad Core, 4GB RAM) The Varnish Servers performance are awfully bad in general, to the point that if we shut down one of them the other two are unable to fullfill all the requests and start to skip beats resulting in pending requests, timeouts, 404, etc. What can we do to improve our Varnish performance? Considering that we're getting less than 5k request per seconds during our max peak, we should be able to serve our pages even with a single one of them without any problem. We use a standard, vanilla CFG, as shown by this varnishadm param.show output: acceptor_sleep_decay 0.900000 [] acceptor_sleep_incr 0.001000 [s] acceptor_sleep_max 0.050000 [s] auto_restart on [bool] ban_dups on [bool] ban_lurker_sleep 0.010000 [s] between_bytes_timeout 60.000000 [s] cc_command "exec gcc -std=gnu99 -g -O2 -pthread -fpic -shared - Wl,-x -o %o %s" cli_buffer 8192 [bytes] cli_timeout 20 [seconds] clock_skew 10 [s] connect_timeout 0.700000 [s] critbit_cooloff 180.000000 [s] default_grace 10.000000 [seconds] default_keep 0.000000 [seconds] default_ttl 120.000000 [seconds] diag_bitmap 0x0 [bitmap] esi_syntax 0 [bitmap] expiry_sleep 1.000000 [seconds] fetch_chunksize 128 [kilobytes] fetch_maxchunksize 262144 [kilobytes] first_byte_timeout 60.000000 [s] group varnish (113) gzip_level 6 [] gzip_memlevel 8 [] gzip_stack_buffer 32768 [Bytes] gzip_tmp_space 0 [] gzip_window 15 [] http_gzip_support off [bool] http_max_hdr 64 [header lines] http_range_support on [bool] http_req_hdr_len 8192 [bytes] http_req_size 32768 [bytes] http_resp_hdr_len 8192 [bytes] http_resp_size 32768 [bytes] idle_send_timeout 60 [seconds] listen_address :80 listen_depth 1024 [connections] log_hashstring on [bool] log_local_address off [bool] lru_interval 2 [seconds] max_esi_depth 5 [levels] max_restarts 4 [restarts] nuke_limit 50 [allocations] pcre_match_limit 10000 [] pcre_match_limit_recursion 10000 [] ping_interval 3 [seconds] pipe_timeout 60 [seconds] prefer_ipv6 off [bool] queue_max 100 [%] rush_exponent 3 [requests per request] saintmode_threshold 10 [objects] send_timeout 600 [seconds] sess_timeout 5 [seconds] sess_workspace 16384 [bytes] session_linger 50 [ms] session_max 100000 [sessions] shm_reclen 255 [bytes] shm_workspace 8192 [bytes] shortlived 10.000000 [s] syslog_cli_traffic on [bool] thread_pool_add_delay 2 [milliseconds] thread_pool_add_threshold 2 [requests] thread_pool_fail_delay 200 [milliseconds] thread_pool_max 2000 [threads] thread_pool_min 5 [threads] thread_pool_purge_delay 1000 [milliseconds] thread_pool_stack unlimited [bytes] thread_pool_timeout 300 [seconds] thread_pool_workspace 65536 [bytes] thread_pools 2 [pools] thread_stats_rate 10 [requests] user varnish (106) vcc_err_unref on [bool] vcl_dir /etc/varnish vcl_trace off [bool] vmod_dir /usr/lib/varnish/vmods waiter default (epoll, poll) This is our default.vcl file: LINK sub vcl_recv { # BASIC recv COMMANDS: # # lookup -> search the item in the cache # pass -> always serve a fresh item (no-caching) # pipe -> like pass but ensures a direct-connection with the backend (no-cache AND no-proxy) # Allow the backend to serve up stale content if it is responding slow. # This defines when Varnish should use a stale object if it has one in the cache. set req.grace = 30s; if (client.ip == "127.0.0.1") { # request from NGINX - do not alter X-Forwarded-For set req.http.HTTPS = "on"; } else { # Add an X-Forwarded-For to keep track of original request unset req.http.HTTPS; unset req.http.X-Forwarded-For; set req.http.X-Forwarded-For = client.ip; } set req.backend = www_director; # Strip all cookies to force an anonymous request when the back-end servers are down. if (!req.backend.healthy) { unset req.http.Cookie; } ## HHTP Accept-Encoding if (req.http.Accept-Encoding) { if (req.http.Accept-Encoding ~ "gzip") { set req.http.Accept-Encoding = "gzip"; } else if (req.http.Accept-Encoding ~ "deflate") { set req.http.Accept-Encoding = "deflate"; } else { unset req.http.Accept-Encoding; } } if (req.request != "GET" && req.request != "HEAD" && req.request != "PUT" && req.request != "POST" && req.request != "TRACE" && req.request != "OPTIONS" && req.request != "DELETE") { /* non-RFC2616 or CONNECT */ return (pipe); } if (req.request != "GET" && req.request != "HEAD") { /* only deal with GET and HEAD by default */ return (pass); } if (req.http.Authorization) { return (pass); } if (req.http.HTTPS ~ "on") { return (pass); } ###################################################### # COOKIE HANDLING ###################################################### # METHOD 1: do not remove cookies, but pass the page if they contain TB_NC if (!(req.url ~ "(?i)\.(png|gif|ipeg|jpg|ico|swf|css|js)(\?[a-z0-9]+)?$")) { if (req.http.Cookie && req.http.Cookie ~ "TB_NC") { return (pass); } } return (lookup); } # Code determining what to do when serving items from the IIS Server sub vcl_fetch { unset beresp.http.Server; set beresp.http.Server = "Server-1"; # Allow items to be stale if needed. This is the maximum time Varnish should keep an object. set beresp.grace = 1h; if (req.url ~ "(?i)\.(png|gif|ipeg|jpg|ico|swf|css|js)(\?[a-z0-9]+)?$") { unset beresp.http.set-cookie; } # Default Varnish VCL logic if (!beresp.cacheable || beresp.ttl <= 0s || beresp.http.Set-Cookie || beresp.http.Vary == "*") { set beresp.ttl = 120 s; return(hit_for_pass); } # Not Cacheable if it has specific TB_NC no-caching cookie if (req.http.Cookie && req.http.Cookie ~ "TB_NC") { set beresp.http.X-Cacheable = "NO:Got Cookie"; set beresp.ttl = 120 s; return(hit_for_pass); } # Not Cacheable if it has Cache-Control private else if (beresp.http.Cache-Control ~ "private") { set beresp.http.X-Cacheable = "NO:Cache-Control=private"; set beresp.ttl = 120 s; return(hit_for_pass); } # Not Cacheable if it has Cache-Control no-cache or Pragma no-cache else if (beresp.http.Cache-Control ~ "no-cache" || beresp.http.Pragma ~ "no-cache") { set beresp.http.X-Cacheable = "NO:Cache-Control=no-cache (or pragma no-cache)"; set beresp.ttl = 120 s; return(hit_for_pass); } # If we reach to this point, the object is cacheable. # Cacheable but with not enough ttl: we need to extend the lifetime of the object artificially # NOTE: Varnish default TTL is set in /etc/sysconfig/varnish # and can be checked using the following command: # varnishadm param.show default_ttl else if (beresp.ttl < 1s) { set beresp.ttl = 5s; set beresp.grace = 5s; set beresp.http.X-Cacheable = "YES:FORCED"; } # Cacheable and with valid TTL. else { set beresp.http.X-Cacheable = "YES"; } # DEBUG INFO (Cookies) # set beresp.http.X-Cookie-Debug = "Request cookie: " + req.http.Cookie; return(deliver); } sub vcl_error { set obj.http.Content-Type = "text/html; charset=utf-8"; if (obj.status == 404) { synthetic {" <!-- Markup for the 404 page goes here --> "}; } else if (obj.status == 500) { synthetic {" <!-- Markup for the 500 page goes here --> "}; } else if (obj.status == 503) { if (req.restarts < 4) { return(restart); } else { synthetic {" <!-- Markup for the 503 page goes here --> "}; } } else { synthetic {" <!-- Markup for a generic error page goes here --> "}; } } sub vcl_deliver { if (obj.hits > 0) { set resp.http.X-Cache = "HIT"; } else { set resp.http.X-Cache = "MISS"; } } Thanks in advance,

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  • Following the Thread in OSB

    - by Antony Reynolds
    Threading in OSB The Scenario I recently led an OSB POC where we needed to get high throughput from an OSB pipeline that had the following logic: 1. Receive Request 2. Send Request to External System 3. If Response has a particular value   3.1 Modify Request   3.2 Resend Request to External System 4. Send Response back to Requestor All looks very straightforward and no nasty wrinkles along the way.  The flow was implemented in OSB as follows (see diagram for more details): Proxy Service to Receive Request and Send Response Request Pipeline   Copies Original Request for use in step 3 Route Node   Sends Request to External System exposed as a Business Service Response Pipeline   Checks Response to Check If Request Needs to Be Resubmitted Modify Request Callout to External System (same Business Service as Route Node) The Proxy and the Business Service were each assigned their own Work Manager, effectively giving each of them their own thread pool. The Surprise Imagine our surprise when, on stressing the system we saw it lock up, with large numbers of blocked threads.  The reason for the lock up is due to some subtleties in the OSB thread model which is the topic of this post.   Basic Thread Model OSB goes to great lengths to avoid holding on to threads.  Lets start by looking at how how OSB deals with a simple request/response routing to a business service in a route node. Most Business Services are implemented by OSB in two parts.  The first part uses the request thread to send the request to the target.  In the diagram this is represented by the thread T1.  After sending the request to the target (the Business Service in our diagram) the request thread is released back to whatever pool it came from.  A multiplexor (muxer) is used to wait for the response.  When the response is received the muxer hands off the response to a new thread that is used to execute the response pipeline, this is represented in the diagram by T2. OSB allows you to assign different Work Managers and hence different thread pools to each Proxy Service and Business Service.  In out example we have the “Proxy Service Work Manager” assigned to the Proxy Service and the “Business Service Work Manager” assigned to the Business Service.  Note that the Business Service Work Manager is only used to assign the thread to process the response, it is never used to process the request. This architecture means that while waiting for a response from a business service there are no threads in use, which makes for better scalability in terms of thread usage. First Wrinkle Note that if the Proxy and the Business Service both use the same Work Manager then there is potential for starvation.  For example: Request Pipeline makes a blocking callout, say to perform a database read. Business Service response tries to allocate a thread from thread pool but all threads are blocked in the database read. New requests arrive and contend with responses arriving for the available threads. Similar problems can occur if the response pipeline blocks for some reason, maybe a database update for example. Solution The solution to this is to make sure that the Proxy and Business Service use different Work Managers so that they do not contend with each other for threads. Do Nothing Route Thread Model So what happens if there is no route node?  In this case OSB just echoes the Request message as a Response message, but what happens to the threads?  OSB still uses a separate thread for the response, but in this case the Work Manager used is the Default Work Manager. So this is really a special case of the Basic Thread Model discussed above, except that the response pipeline will always execute on the Default Work Manager.   Proxy Chaining Thread Model So what happens when the route node is actually calling a Proxy Service rather than a Business Service, does the second Proxy Service use its own Thread or does it re-use the thread of the original Request Pipeline? Well as you can see from the diagram when a route node calls another proxy service then the original Work Manager is used for both request pipelines.  Similarly the response pipeline uses the Work Manager associated with the ultimate Business Service invoked via a Route Node.  This actually fits in with the earlier description I gave about Business Services and by extension Route Nodes they “… uses the request thread to send the request to the target”. Call Out Threading Model So what happens when you make a Service Callout to a Business Service from within a pipeline.  The documentation says that “The pipeline processor will block the thread until the response arrives asynchronously” when using a Service Callout.  What this means is that the target Business Service is called using the pipeline thread but the response is also handled by the pipeline thread.  This implies that the pipeline thread blocks waiting for a response.  It is the handling of this response that behaves in an unexpected way. When a Business Service is called via a Service Callout, the calling thread is suspended after sending the request, but unlike the Route Node case the thread is not released, it waits for the response.  The muxer uses the Business Service Work Manager to allocate a thread to process the response, but in this case processing the response means getting the response and notifying the blocked pipeline thread that the response is available.  The original pipeline thread can then continue to process the response. Second Wrinkle This leads to an unfortunate wrinkle.  If the Business Service is using the same Work Manager as the Pipeline then it is possible for starvation or a deadlock to occur.  The scenario is as follows: Pipeline makes a Callout and the thread is suspended but still allocated Multiple Pipeline instances using the same Work Manager are in this state (common for a system under load) Response comes back but all Work Manager threads are allocated to blocked pipelines. Response cannot be processed and so pipeline threads never unblock – deadlock! Solution The solution to this is to make sure that any Business Services used by a Callout in a pipeline use a different Work Manager to the pipeline itself. The Solution to My Problem Looking back at my original workflow we see that the same Business Service is called twice, once in a Routing Node and once in a Response Pipeline Callout.  This was what was causing my problem because the response pipeline was using the Business Service Work Manager, but the Service Callout wanted to use the same Work Manager to handle the responses and so eventually my Response Pipeline hogged all the available threads so no responses could be processed. The solution was to create a second Business Service pointing to the same location as the original Business Service, the only difference was to assign a different Work Manager to this Business Service.  This ensured that when the Service Callout completed there were always threads available to process the response because the response processing from the Service Callout had its own dedicated Work Manager. Summary Request Pipeline Executes on Proxy Work Manager (WM) Thread so limited by setting of that WM.  If no WM specified then uses WLS default WM. Route Node Request sent using Proxy WM Thread Proxy WM Thread is released before getting response Muxer is used to handle response Muxer hands off response to Business Service (BS) WM Response Pipeline Executes on Routed Business Service WM Thread so limited by setting of that WM.  If no WM specified then uses WLS default WM. No Route Node (Echo functionality) Proxy WM thread released New thread from the default WM used for response pipeline Service Callout Request sent using proxy pipeline thread Proxy thread is suspended (not released) until the response comes back Notification of response handled by BS WM thread so limited by setting of that WM.  If no WM specified then uses WLS default WM. Note this is a very short lived use of the thread After notification by callout BS WM thread that thread is released and execution continues on the original pipeline thread. Route/Callout to Proxy Service Request Pipeline of callee executes on requestor thread Response Pipeline of caller executes on response thread of requested proxy Throttling Request message may be queued if limit reached. Requesting thread is released (route node) or suspended (callout) So what this means is that you may get deadlocks caused by thread starvation if you use the same thread pool for the business service in a route node and the business service in a callout from the response pipeline because the callout will need a notification thread from the same thread pool as the response pipeline.  This was the problem we were having. You get a similar problem if you use the same work manager for the proxy request pipeline and a business service callout from that request pipeline. It also means you may want to have different work managers for the proxy and business service in the route node. Basically you need to think carefully about how threading impacts your proxy services. References Thanks to Jay Kasi, Gerald Nunn and Deb Ayers for helping to explain this to me.  Any errors are my own and not theirs.  Also thanks to my colleagues Milind Pandit and Prasad Bopardikar who travelled this road with me. OSB Thread Model Great Blog Post on Thread Usage in OSB

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  • Meet the New Windows Azure

    - by ScottGu
    Today we are releasing a major set of improvements to Windows Azure.  Below is a short-summary of just a few of them: New Admin Portal and Command Line Tools Today’s release comes with a new Windows Azure portal that will enable you to manage all features and services offered on Windows Azure in a seamless, integrated way.  It is very fast and fluid, supports filtering and sorting (making it much easier to use for large deployments), works on all browsers, and offers a lot of great new features – including built-in VM, Web site, Storage, and Cloud Service monitoring support. The new portal is built on top of a REST-based management API within Windows Azure – and everything you can do through the portal can also be programmed directly against this Web API. We are also today releasing command-line tools (which like the portal call the REST Management APIs) to make it even easier to script and automate your administration tasks.  We are offering both a Powershell (for Windows) and Bash (for Mac and Linux) set of tools to download.  Like our SDKs, the code for these tools is hosted on GitHub under an Apache 2 license. Virtual Machines Windows Azure now supports the ability to deploy and run durable VMs in the cloud.  You can easily create these VMs using a new Image Gallery built-into the new Windows Azure Portal, or alternatively upload and run your own custom-built VHD images. Virtual Machines are durable (meaning anything you install within them persists across reboots) and you can use any OS with them.  Our built-in image gallery includes both Windows Server images (including the new Windows Server 2012 RC) as well as Linux images (including Ubuntu, CentOS, and SUSE distributions).  Once you create a VM instance you can easily Terminal Server or SSH into it in order to configure and customize the VM however you want (and optionally capture your own image snapshot of it to use when creating new VM instances).  This provides you with the flexibility to run pretty much any workload within Windows Azure.   The new Windows Azure Portal provides a rich set of management features for Virtual Machines – including the ability to monitor and track resource utilization within them.  Our new Virtual Machine support also enables the ability to easily attach multiple data-disks to VMs (which you can then mount and format as drives).  You can optionally enable geo-replication support on these – which will cause Windows Azure to continuously replicate your storage to a secondary data-center at least 400 miles away from your primary data-center as a backup. We use the same VHD format that is supported with Windows virtualization today (and which we’ve released as an open spec), which enables you to easily migrate existing workloads you might already have virtualized into Windows Azure.  We also make it easy to download VHDs from Windows Azure, which also provides the flexibility to easily migrate cloud-based VM workloads to an on-premise environment.  All you need to do is download the VHD file and boot it up locally, no import/export steps required. Web Sites Windows Azure now supports the ability to quickly and easily deploy ASP.NET, Node.js and PHP web-sites to a highly scalable cloud environment that allows you to start small (and for free) and then scale up as your traffic grows.  You can create a new web site in Azure and have it ready to deploy to in under 10 seconds: The new Windows Azure Portal provides built-in administration support for Web sites – including the ability to monitor and track resource utilization in real-time: You can deploy to web-sites in seconds using FTP, Git, TFS and Web Deploy.  We are also releasing tooling updates today for both Visual Studio and Web Matrix that enable developers to seamlessly deploy ASP.NET applications to this new offering.  The VS and Web Matrix publishing support includes the ability to deploy SQL databases as part of web site deployment – as well as the ability to incrementally update database schema with a later deployment. You can integrate web application publishing with source control by selecting the “Set up TFS publishing” or “Set up Git publishing” links on a web-site’s dashboard: Doing do will enable integration with our new TFS online service (which enables a full TFS workflow – including elastic build and testing support), or create a Git repository that you can reference as a remote and push deployments to.  Once you push a deployment using TFS or Git, the deployments tab will keep track of the deployments you make, and enable you to select an older (or newer) deployment and quickly redeploy your site to that snapshot of the code.  This provides a very powerful DevOps workflow experience.   Windows Azure now allows you to deploy up to 10 web-sites into a free, shared/multi-tenant hosting environment (where a site you deploy will be one of multiple sites running on a shared set of server resources).  This provides an easy way to get started on projects at no cost. You can then optionally upgrade your sites to run in a “reserved mode” that isolates them so that you are the only customer within a virtual machine: And you can elastically scale the amount of resources your sites use – allowing you to increase your reserved instance capacity as your traffic scales: Windows Azure automatically handles load balancing traffic across VM instances, and you get the same, super fast, deployment options (FTP, Git, TFS and Web Deploy) regardless of how many reserved instances you use. With Windows Azure you pay for compute capacity on a per-hour basis – which allows you to scale up and down your resources to match only what you need. Cloud Services and Distributed Caching Windows Azure also supports the ability to build cloud services that support rich multi-tier architectures, automated application management, and scale to extremely large deployments.  Previously we referred to this capability as “hosted services” – with this week’s release we are now referring to this capability as “cloud services”.  We are also enabling a bunch of new features with them. Distributed Cache One of the really cool new features being enabled with cloud services is a new distributed cache capability that enables you to use and setup a low-latency, in-memory distributed cache within your applications.  This cache is isolated for use just by your applications, and does not have any throttling limits. This cache can dynamically grow and shrink elastically (without you have to redeploy your app or make code changes), and supports the full richness of the AppFabric Cache Server API (including regions, high availability, notifications, local cache and more).  In addition to supporting the AppFabric Cache Server API, it also now supports the Memcached protocol – allowing you to point code written against Memcached at it (no code changes required). The new distributed cache can be setup to run in one of two ways: 1) Using a co-located approach.  In this option you allocate a percentage of memory in your existing web and worker roles to be used by the cache, and then the cache joins the memory into one large distributed cache.  Any data put into the cache by one role instance can be accessed by other role instances in your application – regardless of whether the cached data is stored on it or another role.  The big benefit with the “co-located” option is that it is free (you don’t have to pay anything to enable it) and it allows you to use what might have been otherwise unused memory within your application VMs. 2) Alternatively, you can add “cache worker roles” to your cloud service that are used solely for caching.  These will also be joined into one large distributed cache ring that other roles within your application can access.  You can use these roles to cache 10s or 100s of GBs of data in-memory very effectively – and the cache can be elastically increased or decreased at runtime within your application: New SDKs and Tooling Support We have updated all of the Windows Azure SDKs with today’s release to include new features and capabilities.  Our SDKs are now available for multiple languages, and all of the source in them is published under an Apache 2 license and and maintained in GitHub repositories. The .NET SDK for Azure has in particular seen a bunch of great improvements with today’s release, and now includes tooling support for both VS 2010 and the VS 2012 RC. We are also now shipping Windows, Mac and Linux SDK downloads for languages that are offered on all of these systems – allowing developers to develop Windows Azure applications using any development operating system. Much, Much More The above is just a short list of some of the improvements that are shipping in either preview or final form today – there is a LOT more in today’s release.  These include new Virtual Private Networking capabilities, new Service Bus runtime and tooling support, the public preview of the new Azure Media Services, new Data Centers, significantly upgraded network and storage hardware, SQL Reporting Services, new Identity features, support within 40+ new countries and territories, and much, much more. You can learn more about Windows Azure and sign-up to try it for free at http://windowsazure.com.  You can also watch a live keynote I’m giving at 1pm June 7th (later today) where I’ll walk through all of the new features.  We will be opening up the new features I discussed above for public usage a few hours after the keynote concludes.  We are really excited to see the great applications you build with them. Hope this helps, Scott

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  • Faster, Simpler access to Azure Tables with Enzo Azure API

    - by Herve Roggero
    After developing the latest version of Enzo Cloud Backup I took the time to create an API that would simplify access to Azure Tables (the Enzo Azure API). At first, my goal was to make the code simpler compared to the Microsoft Azure SDK. But as it turns out it is also a little faster; and when using the specialized methods (the fetch strategies) it is much faster out of the box than the Microsoft SDK, unless you start creating complex parallel and resilient routines yourself. Last but not least, I decided to add a few extension methods that I think you will find attractive, such as the ability to transform a list of entities into a DataTable. So let’s review each area in more details. Simpler Code My first objective was to make the API much easier to use than the Azure SDK. I wanted to reduce the amount of code necessary to fetch entities, remove the code needed to add automatic retries and handle transient conditions, and give additional control, such as a way to cancel operations, obtain basic statistics on the calls, and control the maximum number of REST calls the API generates in an attempt to avoid throttling conditions in the first place (something you cannot do with the Azure SDK at this time). Strongly Typed Before diving into the code, the following examples rely on a strongly typed class called MyData. The way MyData is defined for the Azure SDK is similar to the Enzo Azure API, with the exception that they inherit from different classes. With the Azure SDK, classes that represent entities must inherit from TableServiceEntity, while classes with the Enzo Azure API must inherit from BaseAzureTable or implement a specific interface. // With the SDK public class MyData1 : TableServiceEntity {     public string Message { get; set; }     public string Level { get; set; }     public string Severity { get; set; } } //  With the Enzo Azure API public class MyData2 : BaseAzureTable {     public string Message { get; set; }     public string Level { get; set; }     public string Severity { get; set; } } Simpler Code Now that the classes representing an Azure Table entity are defined, let’s review the methods that the Azure SDK would look like when fetching all the entities from an Azure Table (note the use of a few variables: the _tableName variable stores the name of the Azure Table, and the ConnectionString property returns the connection string for the Storage Account containing the table): // With the Azure SDK public List<MyData1> FetchAllEntities() {      CloudStorageAccount storageAccount = CloudStorageAccount.Parse(ConnectionString);      CloudTableClient tableClient = storageAccount.CreateCloudTableClient();      TableServiceContext serviceContext = tableClient.GetDataServiceContext();      CloudTableQuery<MyData1> partitionQuery =         (from e in serviceContext.CreateQuery<MyData1>(_tableName)         select new MyData1()         {            PartitionKey = e.PartitionKey,            RowKey = e.RowKey,            Timestamp = e.Timestamp,            Message = e.Message,            Level = e.Level,            Severity = e.Severity            }).AsTableServiceQuery<MyData1>();        return partitionQuery.ToList();  } This code gives you automatic retries because the AsTableServiceQuery does that for you. Also, note that this method is strongly-typed because it is using LINQ. Although this doesn’t look like too much code at first glance, you are actually mapping the strongly-typed object manually. So for larger entities, with dozens of properties, your code will grow. And from a maintenance standpoint, when a new property is added, you may need to change the mapping code. You will also note that the mapping being performed is optional; it is desired when you want to retrieve specific properties of the entities (not all) to reduce the network traffic. If you do not specify the properties you want, all the properties will be returned; in this example we are returning the Message, Level and Severity properties (in addition to the required PartitionKey, RowKey and Timestamp). The Enzo Azure API does the mapping automatically and also handles automatic reties when fetching entities. The equivalent code to fetch all the entities (with the same three properties) from the same Azure Table looks like this: // With the Enzo Azure API public List<MyData2> FetchAllEntities() {        AzureTable at = new AzureTable(_accountName, _accountKey, _ssl, _tableName);        List<MyData2> res = at.Fetch<MyData2>("", "Message,Level,Severity");        return res; } As you can see, the Enzo Azure API returns the entities already strongly typed, so there is no need to map the output. Also, the Enzo Azure API makes it easy to specify the list of properties to return, and to specify a filter as well (no filter was provided in this example; the filter is passed as the first parameter).  Fetch Strategies Both approaches discussed above fetch the data sequentially. In addition to the linear/sequential fetch methods, the Enzo Azure API provides specific fetch strategies. Fetch strategies are designed to prepare a set of REST calls, executed in parallel, in a way that performs faster that if you were to fetch the data sequentially. For example, if the PartitionKey is a GUID string, you could prepare multiple calls, providing appropriate filters ([‘a’, ‘b’[, [‘b’, ‘c’[, [‘c’, ‘d[, …), and send those calls in parallel. As you can imagine, the code necessary to create these requests would be fairly large. With the Enzo Azure API, two strategies are provided out of the box: the GUID and List strategies. If you are interested in how these strategies work, see the Enzo Azure API Online Help. Here is an example code that performs parallel requests using the GUID strategy (which executes more than 2 t o3 times faster than the sequential methods discussed previously): public List<MyData2> FetchAllEntitiesGUID() {     AzureTable at = new AzureTable(_accountName, _accountKey, _ssl, _tableName);     List<MyData2> res = at.FetchWithGuid<MyData2>("", "Message,Level,Severity");     return res; } Faster Results With Sequential Fetch Methods Developing a faster API wasn’t a primary objective; but it appears that the performance tests performed with the Enzo Azure API deliver the data a little faster out of the box (5%-10% on average, and sometimes to up 50% faster) with the sequential fetch methods. Although the amount of data is the same regardless of the approach (and the REST calls are almost exactly identical), the object mapping approach is different. So it is likely that the slight performance increase is due to a lighter API. Using LINQ offers many advantages and tremendous flexibility; nevertheless when fetching data it seems that the Enzo Azure API delivers faster.  For example, the same code previously discussed delivered the following results when fetching 3,000 entities (about 1KB each). The average elapsed time shows that the Azure SDK returned the 3000 entities in about 5.9 seconds on average, while the Enzo Azure API took 4.2 seconds on average (39% improvement). With Fetch Strategies When using the fetch strategies we are no longer comparing apples to apples; the Azure SDK is not designed to implement fetch strategies out of the box, so you would need to code the strategies yourself. Nevertheless I wanted to provide out of the box capabilities, and as a result you see a test that returned about 10,000 entities (1KB each entity), and an average execution time over 5 runs. The Azure SDK implemented a sequential fetch while the Enzo Azure API implemented the List fetch strategy. The fetch strategy was 2.3 times faster. Note that the following test hit a limit on my network bandwidth quickly (3.56Mbps), so the results of the fetch strategy is significantly below what it could be with a higher bandwidth. Additional Methods The API wouldn’t be complete without support for a few important methods other than the fetch methods discussed previously. The Enzo Azure API offers these additional capabilities: - Support for batch updates, deletes and inserts - Conversion of entities to DataRow, and List<> to a DataTable - Extension methods for Delete, Merge, Update, Insert - Support for asynchronous calls and cancellation - Support for fetch statistics (total bytes, total REST calls, retries…) For more information, visit http://www.bluesyntax.net or go directly to the Enzo Azure API page (http://www.bluesyntax.net/EnzoAzureAPI.aspx). About Herve Roggero Herve Roggero, Windows Azure MVP, is the founder of Blue Syntax Consulting, a company specialized in cloud computing products and services. Herve's experience includes software development, architecture, database administration and senior management with both global corporations and startup companies. Herve holds multiple certifications, including an MCDBA, MCSE, MCSD. He also holds a Master's degree in Business Administration from Indiana University. Herve is the co-author of "PRO SQL Azure" from Apress and runs the Azure Florida Association (on LinkedIn: http://www.linkedin.com/groups?gid=4177626). For more information on Blue Syntax Consulting, visit www.bluesyntax.net.

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  • Display System Information on Your Desktop with Desktop Info

    - by Asian Angel
    Do you like to monitor your system but do not want a complicated app to do it with? If you love simplicity and easy configuration then join us as we look at Desktop Info. Desktop Info in Action Desktop Info comes in a zip file format so you will need to unzip the app, place it into an appropriate “Program Files Folder”, and create a shortcut. Do NOT delete the “Read Me File”…this will be extremely useful to you when you make changes to the “Configuration File”. Once you have everything set up you are ready to start Desktop Info up. This is the default layout and set of listings displayed when you start Desktop Info up for the first time. The font colors will be a mix of colors as seen here and the font size will perhaps be a bit small but those are very easy to change if desired. You can access the “Context Menu” directly over the “information area”…so no need to look for it in the “System Tray”. Notice that you can easily access that important “Read Me File” from here… The full contents of the configuration file (.ini file) are displayed here so that you can see exactly what kind of information can be displayed using the default listings. The first section is “Options”…you will most likely want to increase the font size while you are here. Then “Items”… If you are unhappy with any of the font colors in the “information area” this is where you can make the changes. You can turn information display items on or off here. And finally “Files, Registry, & Event Logs”. Here is our displayed information after a few tweaks in the configuration file. Very nice. Conclusion If you have been looking for a system information app that is simple and easy to set up then you should definitely give Desktop Info a try. Links Download Desktop Info Similar Articles Productive Geek Tips Ask the Readers: What are Your Computer’s Hardware Specs?Allow Remote Control To Your Desktop On UbuntuHow To Get Detailed Information About Your PCGet CPU / System Load Average on Ubuntu LinuxEnable Remote Desktop (VNC) on Kubuntu TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Test Drive Windows 7 Online Download Wallpapers From National Geographic Site Spyware Blaster v4.3 Yes, it’s Patch Tuesday Generate Stunning Tag Clouds With Tagxedo Install, Remove and HIDE Fonts in Windows 7

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  • Unable to boot Windows 7 after installing Ubuntu

    - by Devendra
    I have Windows 7 on my machine and then installed Ubuntu 12.04 using a live CD. I can see both Windows 7 and Ubuntu in the grub menu, but when I select Windows 7 it shows a black screen for about 2 seconds and the returns to the Grub menu. But if I select Ubuntu it's working fine. This is the contents of the boot-repair log: Boot Info Script 0.61.full + Boot-Repair extra info [Boot-Info November 20th 2012] ============================= Boot Info Summary: =============================== => Grub2 (v2.00) is installed in the MBR of /dev/sda and looks at sector 1 of the same hard drive for core.img. core.img is at this location and looks in partition 1 for (,msdos6)/boot/grub. sda1: __________________________________________________________________________ File system: ntfs Boot sector type: Grub2 (v1.99-2.00) Boot sector info: Grub2 (v2.00) is installed in the boot sector of sda1 and looks at sector 388911128 of the same hard drive for core.img. core.img is at this location and looks in partition 1 for (,msdos6)/boot/grub. No errors found in the Boot Parameter Block. Operating System: Windows 7 Boot files: /bootmgr /Boot/BCD /Windows/System32/winload.exe sda2: __________________________________________________________________________ File system: ntfs Boot sector type: Windows Vista/7: NTFS Boot sector info: No errors found in the Boot Parameter Block. Operating System: Boot files: sda3: __________________________________________________________________________ File system: ntfs Boot sector type: Windows Vista/7: NTFS Boot sector info: No errors found in the Boot Parameter Block. Operating System: Boot files: sda4: __________________________________________________________________________ File system: Extended Partition Boot sector type: - Boot sector info: sda5: __________________________________________________________________________ File system: ntfs Boot sector type: Windows Vista/7: NTFS Boot sector info: According to the info in the boot sector, sda5 starts at sector 2048. Operating System: Boot files: sda6: __________________________________________________________________________ File system: ext4 Boot sector type: - Boot sector info: Operating System: Ubuntu 12.10 Boot files: /boot/grub/grub.cfg /etc/fstab /boot/grub/i386-pc/core.img sda7: __________________________________________________________________________ File system: swap Boot sector type: - Boot sector info: ============================ Drive/Partition Info: ============================= Drive: sda _____________________________________________________________________ Disk /dev/sda: 750.2 GB, 750156374016 bytes 255 heads, 63 sectors/track, 91201 cylinders, total 1465149168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes Partition Boot Start Sector End Sector # of Sectors Id System /dev/sda1 * 206,848 146,802,687 146,595,840 7 NTFS / exFAT / HPFS /dev/sda2 147,007,488 293,623,807 146,616,320 7 NTFS / exFAT / HPFS /dev/sda3 293,623,808 332,820,613 39,196,806 7 NTFS / exFAT / HPFS /dev/sda4 332,822,526 1,465,145,343 1,132,322,818 f W95 Extended (LBA) /dev/sda5 461,342,720 1,465,145,343 1,003,802,624 7 NTFS / exFAT / HPFS /dev/sda6 332,822,528 453,171,199 120,348,672 83 Linux /dev/sda7 453,173,248 461,338,623 8,165,376 82 Linux swap / Solaris "blkid" output: ________________________________________________________________ Device UUID TYPE LABEL /dev/sda1 F6AE2C13AE2BCB47 ntfs /dev/sda2 DC2273012272DFC6 ntfs /dev/sda3 1E76E43376E40D79 ntfs New Volume /dev/sda5 5ED60ACDD60AA57D ntfs /dev/sda6 9e70fd16-b48b-4f88-adcf-e443aef83124 ext4 /dev/sda7 52f3dd94-6be7-4a7b-a3ae-f43eb8810483 swap ================================ Mount points: ================================= Device Mount_Point Type Options /dev/sda6 / ext4 (rw,errors=remount-ro) =========================== sda6/boot/grub/grub.cfg: =========================== -------------------------------------------------------------------------------- # # DO NOT EDIT THIS FILE # # It is automatically generated by grub-mkconfig using templates # from /etc/grub.d and settings from /etc/default/grub # ### BEGIN /etc/grub.d/00_header ### if [ -s $prefix/grubenv ]; then set have_grubenv=true load_env fi set default="0" if [ x"${feature_menuentry_id}" = xy ]; then menuentry_id_option="--id" else menuentry_id_option="" fi export menuentry_id_option if [ "${prev_saved_entry}" ]; then set saved_entry="${prev_saved_entry}" save_env saved_entry set prev_saved_entry= save_env prev_saved_entry set boot_once=true fi function savedefault { if [ -z "${boot_once}" ]; then saved_entry="${chosen}" save_env saved_entry fi } function recordfail { set recordfail=1 if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi } function load_video { if [ x$feature_all_video_module = xy ]; then insmod all_video else insmod efi_gop insmod efi_uga insmod ieee1275_fb insmod vbe insmod vga insmod video_bochs insmod video_cirrus fi } if [ x$feature_default_font_path = xy ] ; then font=unicode else insmod part_msdos insmod ext2 set root='hd0,msdos6' if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6 9e70fd16-b48b-4f88-adcf-e443aef83124 else search --no-floppy --fs-uuid --set=root 9e70fd16-b48b-4f88-adcf-e443aef83124 fi font="/usr/share/grub/unicode.pf2" fi if loadfont $font ; then set gfxmode=auto load_video insmod gfxterm set locale_dir=$prefix/locale set lang=en_IN insmod gettext fi terminal_output gfxterm if [ "${recordfail}" = 1 ]; then set timeout=10 else set timeout=10 fi ### END /etc/grub.d/00_header ### ### BEGIN /etc/grub.d/05_debian_theme ### set menu_color_normal=white/black set menu_color_highlight=black/light-gray if background_color 44,0,30; then clear fi ### END /etc/grub.d/05_debian_theme ### ### BEGIN /etc/grub.d/10_linux ### function gfxmode { set gfxpayload="${1}" if [ "${1}" = "keep" ]; then set vt_handoff=vt.handoff=7 else set vt_handoff= fi } if [ "${recordfail}" != 1 ]; then if [ -e ${prefix}/gfxblacklist.txt ]; then if hwmatch ${prefix}/gfxblacklist.txt 3; then if [ ${match} = 0 ]; then set linux_gfx_mode=keep else set linux_gfx_mode=text fi else set linux_gfx_mode=text fi else set linux_gfx_mode=keep fi else set linux_gfx_mode=text fi export linux_gfx_mode if [ "${linux_gfx_mode}" != "text" ]; then load_video; fi menuentry 'Ubuntu' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-9e70fd16-b48b-4f88-adcf-e443aef83124' { recordfail gfxmode $linux_gfx_mode insmod gzio insmod part_msdos insmod ext2 set root='hd0,msdos6' if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6 9e70fd16-b48b-4f88-adcf-e443aef83124 else search --no-floppy --fs-uuid --set=root 9e70fd16-b48b-4f88-adcf-e443aef83124 fi linux /boot/vmlinuz-3.5.0-17-generic root=UUID=9e70fd16-b48b-4f88-adcf-e443aef83124 ro quiet splash $vt_handoff initrd /boot/initrd.img-3.5.0-17-generic } submenu 'Advanced options for Ubuntu' $menuentry_id_option 'gnulinux-advanced-9e70fd16-b48b-4f88-adcf-e443aef83124' { menuentry 'Ubuntu, with Linux 3.5.0-17-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.5.0-17-generic-advanced-9e70fd16-b48b-4f88-adcf-e443aef83124' { recordfail gfxmode $linux_gfx_mode insmod gzio insmod part_msdos insmod ext2 set root='hd0,msdos6' if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6 9e70fd16-b48b-4f88-adcf-e443aef83124 else search --no-floppy --fs-uuid --set=root 9e70fd16-b48b-4f88-adcf-e443aef83124 fi echo 'Loading Linux 3.5.0-17-generic ...' linux /boot/vmlinuz-3.5.0-17-generic root=UUID=9e70fd16-b48b-4f88-adcf-e443aef83124 ro quiet splash $vt_handoff echo 'Loading initial ramdisk ...' initrd /boot/initrd.img-3.5.0-17-generic } menuentry 'Ubuntu, with Linux 3.5.0-17-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.5.0-17-generic-recovery-9e70fd16-b48b-4f88-adcf-e443aef83124' { recordfail insmod gzio insmod part_msdos insmod ext2 set root='hd0,msdos6' if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6 9e70fd16-b48b-4f88-adcf-e443aef83124 else search --no-floppy --fs-uuid --set=root 9e70fd16-b48b-4f88-adcf-e443aef83124 fi echo 'Loading Linux 3.5.0-17-generic ...' linux /boot/vmlinuz-3.5.0-17-generic root=UUID=9e70fd16-b48b-4f88-adcf-e443aef83124 ro recovery nomodeset echo 'Loading initial ramdisk ...' initrd /boot/initrd.img-3.5.0-17-generic } } ### END /etc/grub.d/10_linux ### ### BEGIN /etc/grub.d/20_linux_xen ### ### END /etc/grub.d/20_linux_xen ### ### BEGIN /etc/grub.d/20_memtest86+ ### menuentry "Memory test (memtest86+)" { insmod part_msdos insmod ext2 set root='hd0,msdos6' if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6 9e70fd16-b48b-4f88-adcf-e443aef83124 else search --no-floppy --fs-uuid --set=root 9e70fd16-b48b-4f88-adcf-e443aef83124 fi linux16 /boot/memtest86+.bin } menuentry "Memory test (memtest86+, serial console 115200)" { insmod part_msdos insmod ext2 set root='hd0,msdos6' if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6 9e70fd16-b48b-4f88-adcf-e443aef83124 else search --no-floppy --fs-uuid --set=root 9e70fd16-b48b-4f88-adcf-e443aef83124 fi linux16 /boot/memtest86+.bin console=ttyS0,115200n8 } ### END /etc/grub.d/20_memtest86+ ### ### BEGIN /etc/grub.d/30_os-prober ### menuentry 'Windows 7 (loader) (on /dev/sda1)' --class windows --class os $menuentry_id_option 'osprober-chain-F6AE2C13AE2BCB47' { insmod part_msdos insmod ntfs set root='hd0,msdos1' if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1 F6AE2C13AE2BCB47 else search --no-floppy --fs-uuid --set=root F6AE2C13AE2BCB47 fi chainloader +1 } ### END /etc/grub.d/30_os-prober ### ### BEGIN /etc/grub.d/30_uefi-firmware ### ### END /etc/grub.d/30_uefi-firmware ### ### BEGIN /etc/grub.d/40_custom ### # This file provides an easy way to add custom menu entries. Simply type the # menu entries you want to add after this comment. Be careful not to change # the 'exec tail' line above. ### END /etc/grub.d/40_custom ### ### BEGIN /etc/grub.d/41_custom ### if [ -f ${config_directory}/custom.cfg ]; then source ${config_directory}/custom.cfg elif [ -z "${config_directory}" -a -f $prefix/custom.cfg ]; then source $prefix/custom.cfg; fi ### END /etc/grub.d/41_custom ### -------------------------------------------------------------------------------- =============================== sda6/etc/fstab: ================================ -------------------------------------------------------------------------------- # /etc/fstab: static file system information. # # Use 'blkid' to print the universally unique identifier for a # device; this may be used with UUID= as a more robust way to name devices # that works even if disks are added and removed. See fstab(5). # # <file system> <mount point> <type> <options> <dump> <pass> # / was on /dev/sda6 during installation UUID=9e70fd16-b48b-4f88-adcf-e443aef83124 / ext4 errors=remount-ro 0 1 # swap was on /dev/sda7 during installation UUID=52f3dd94-6be7-4a7b-a3ae-f43eb8810483 none swap sw 0 0 -------------------------------------------------------------------------------- =================== sda6: Location of files loaded by Grub: ==================== GiB - GB File Fragment(s) 162.831275940 = 174.838751232 boot/grub/grub.cfg 1 163.036647797 = 175.059267584 boot/initrd.img-3.5.0-17-generic 1 206.871749878 = 222.126850048 boot/vmlinuz-3.5.0-17-generic 1 163.036647797 = 175.059267584 initrd.img 1 163.036647797 = 175.059267584 initrd.img.old 1 206.871749878 = 222.126850048 vmlinuz 1 =============================== StdErr Messages: =============================== cat: write error: Broken pipe cat: write error: Broken pipe ADDITIONAL INFORMATION : =================== log of boot-repair 2012-12-11__00h59 =================== boot-repair version : 3.195~ppa28~quantal boot-sav version : 3.195~ppa28~quantal glade2script version : 3.2.2~ppa45~quantal boot-sav-extra version : 3.195~ppa28~quantal boot-repair is executed in installed-session (Ubuntu 12.10, quantal, Ubuntu, x86_64) CPU op-mode(s): 32-bit, 64-bit BOOT_IMAGE=/boot/vmlinuz-3.5.0-17-generic root=UUID=9e70fd16-b48b-4f88-adcf-e443aef83124 ro quiet splash vt.handoff=7 =================== os-prober: /dev/sda6:The OS now in use - Ubuntu 12.10 CurrentSession:linux /dev/sda1:Windows 7 (loader):Windows:chain =================== blkid: /dev/sda1: UUID="F6AE2C13AE2BCB47" TYPE="ntfs" /dev/sda2: UUID="DC2273012272DFC6" TYPE="ntfs" /dev/sda3: LABEL="New Volume" UUID="1E76E43376E40D79" TYPE="ntfs" /dev/sda5: UUID="5ED60ACDD60AA57D" TYPE="ntfs" /dev/sda6: UUID="9e70fd16-b48b-4f88-adcf-e443aef83124" TYPE="ext4" /dev/sda7: UUID="52f3dd94-6be7-4a7b-a3ae-f43eb8810483" TYPE="swap" 1 disks with OS, 2 OS : 1 Linux, 0 MacOS, 1 Windows, 0 unknown type OS. Warning: extended partition does not start at a cylinder boundary. DOS and Linux will interpret the contents differently. =================== /etc/default/grub : # If you change this file, run 'update-grub' afterwards to update # /boot/grub/grub.cfg. # For full documentation of the options in this file, see: # info -f grub -n 'Simple configuration' GRUB_DEFAULT=0 #GRUB_HIDDEN_TIMEOUT=0 GRUB_HIDDEN_TIMEOUT_QUIET=true GRUB_TIMEOUT=10 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" GRUB_CMDLINE_LINUX="" # Uncomment to enable BadRAM filtering, modify to suit your needs # This works with Linux (no patch required) and with any kernel that obtains # the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...) #GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef" # Uncomment to disable graphical terminal (grub-pc only) #GRUB_TERMINAL=console # The resolution used on graphical terminal # note that you can use only modes which your graphic card supports via VBE # you can see them in real GRUB with the command `vbeinfo' #GRUB_GFXMODE=640x480 # Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux #GRUB_DISABLE_LINUX_UUID=true # Uncomment to disable generation of recovery mode menu entries #GRUB_DISABLE_RECOVERY="true" # Uncomment to get a beep at grub start #GRUB_INIT_TUNE="480 440 1" =================== /etc/grub.d/ : drwxr-xr-x 2 root root 4096 Oct 17 20:29 grub.d total 72 -rwxr-xr-x 1 root root 7541 Oct 14 23:06 00_header -rwxr-xr-x 1 root root 5488 Oct 4 15:00 05_debian_theme -rwxr-xr-x 1 root root 10891 Oct 14 23:06 10_linux -rwxr-xr-x 1 root root 10258 Oct 14 23:06 20_linux_xen -rwxr-xr-x 1 root root 1688 Oct 11 19:40 20_memtest86+ -rwxr-xr-x 1 root root 10976 Oct 14 23:06 30_os-prober -rwxr-xr-x 1 root root 1426 Oct 14 23:06 30_uefi-firmware -rwxr-xr-x 1 root root 214 Oct 14 23:06 40_custom -rwxr-xr-x 1 root root 216 Oct 14 23:06 41_custom -rw-r--r-- 1 root root 483 Oct 14 23:06 README =================== UEFI/Legacy mode: This installed-session is not in EFI-mode. EFI in dmesg. Please report this message to [email protected] [ 0.000000] ACPI: UEFI 00000000bafe7000 0003E (v01 DELL QA09 00000002 PTL 00000002) [ 0.000000] ACPI: UEFI 00000000bafe6000 00042 (v01 PTL COMBUF 00000001 PTL 00000001) [ 0.000000] ACPI: UEFI 00000000bafe3000 00256 (v01 DELL QA09 00000002 PTL 00000002) SecureBoot disabled. =================== PARTITIONS & DISKS: sda6 : sda, not-sepboot, grubenv-ok grub2, grub-pc , update-grub, 64, with-boot, is-os, not--efi--part, fstab-without-boot, fstab-without-efi, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot, apt-get, grub-install, with--usr, fstab-without-usr, not-sep-usr, standard, farbios, . sda1 : sda, not-sepboot, no-grubenv nogrub, no-docgrub, no-update-grub, 32, no-boot, is-os, not--efi--part, part-has-no-fstab, part-has-no-fstab, no-nt, haswinload, no-recov-nor-hid, bootmgr, is-winboot, nopakmgr, nogrubinstall, no---usr, part-has-no-fstab, not-sep-usr, standard, not-far, /mnt/boot-sav/sda1. sda2 : sda, not-sepboot, no-grubenv nogrub, no-docgrub, no-update-grub, 32, no-boot, no-os, not--efi--part, part-has-no-fstab, part-has-no-fstab, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot, nopakmgr, nogrubinstall, no---usr, part-has-no-fstab, not-sep-usr, standard, farbios, /mnt/boot-sav/sda2. sda3 : sda, not-sepboot, no-grubenv nogrub, no-docgrub, no-update-grub, 32, no-boot, no-os, not--efi--part, part-has-no-fstab, part-has-no-fstab, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot, nopakmgr, nogrubinstall, no---usr, part-has-no-fstab, not-sep-usr, standard, farbios, /mnt/boot-sav/sda3. sda5 : sda, not-sepboot, no-grubenv nogrub, no-docgrub, no-update-grub, 32, no-boot, no-os, not--efi--part, part-has-no-fstab, part-has-no-fstab, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot, nopakmgr, nogrubinstall, no---usr, part-has-no-fstab, not-sep-usr, standard, farbios, /mnt/boot-sav/sda5. sda : not-GPT, BIOSboot-not-needed, has-no-EFIpart, not-usb, has-os, 2048 sectors * 512 bytes =================== parted -l: Model: ATA WDC WD7500BPKT-7 (scsi) Disk /dev/sda: 750GB Sector size (logical/physical): 512B/4096B Partition Table: msdos Number Start End Size Type File system Flags 1 106MB 75.2GB 75.1GB primary ntfs boot 2 75.3GB 150GB 75.1GB primary ntfs 3 150GB 170GB 20.1GB primary ntfs 4 170GB 750GB 580GB extended lba 6 170GB 232GB 61.6GB logical ext4 7 232GB 236GB 4181MB logical linux-swap(v1) 5 236GB 750GB 514GB logical ntfs =================== parted -lm: BYT; /dev/sda:750GB:scsi:512:4096:msdos:ATA WDC WD7500BPKT-7; 1:106MB:75.2GB:75.1GB:ntfs::boot; 2:75.3GB:150GB:75.1GB:ntfs::; 3:150GB:170GB:20.1GB:ntfs::; 4:170GB:750GB:580GB:::lba; 6:170GB:232GB:61.6GB:ext4::; 7:232GB:236GB:4181MB:linux-swap(v1)::; 5:236GB:750GB:514GB:ntfs::; =================== mount: /dev/sda6 on / type ext4 (rw,errors=remount-ro) proc on /proc type proc (rw,noexec,nosuid,nodev) sysfs on /sys type sysfs (rw,noexec,nosuid,nodev) none on /sys/fs/fuse/connections type fusectl (rw) none on /sys/kernel/debug type debugfs (rw) none on /sys/kernel/security type securityfs (rw) udev on /dev type devtmpfs (rw,mode=0755) devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620) tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755) none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880) none on /run/shm type tmpfs (rw,nosuid,nodev) none on /run/user type tmpfs (rw,noexec,nosuid,nodev,size=104857600,mode=0755) gvfsd-fuse on /run/user/dev/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,user=dev) /dev/sda1 on /mnt/boot-sav/sda1 type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096) /dev/sda2 on /mnt/boot-sav/sda2 type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096) /dev/sda3 on /mnt/boot-sav/sda3 type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096) /dev/sda5 on /mnt/boot-sav/sda5 type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096) =================== ls: /sys/block/sda (filtered): alignment_offset bdi capability dev device discard_alignment events events_async events_poll_msecs ext_range holders inflight power queue range removable ro sda1 sda2 sda3 sda4 sda5 sda6 sda7 size slaves stat subsystem trace uevent /sys/block/sr0 (filtered): alignment_offset bdi capability dev device discard_alignment events events_async events_poll_msecs ext_range holders inflight power queue range removable ro size slaves stat subsystem trace uevent /dev (filtered): alarm ashmem autofs binder block bsg btrfs-control bus cdrom cdrw char console core cpu cpu_dma_latency disk dri dvd dvdrw ecryptfs fb0 fb1 fd full fuse hpet input kmsg kvm log mapper mcelog mei mem net network_latency network_throughput null oldmem port ppp psaux ptmx pts random rfkill rtc rtc0 sda sda1 sda2 sda3 sda4 sda5 sda6 sda7 sg0 sg1 shm snapshot snd sr0 stderr stdin stdout uinput urandom v4l vga_arbiter vhost-net video0 zero ls /dev/mapper: control =================== df -Th: Filesystem Type Size Used Avail Use% Mounted on /dev/sda6 ext4 57G 2.7G 51G 6% / udev devtmpfs 1.9G 12K 1.9G 1% /dev tmpfs tmpfs 770M 892K 769M 1% /run none tmpfs 5.0M 0 5.0M 0% /run/lock none tmpfs 1.9G 260K 1.9G 1% /run/shm none tmpfs 100M 44K 100M 1% /run/user /dev/sda1 fuseblk 70G 36G 35G 51% /mnt/boot-sav/sda1 /dev/sda2 fuseblk 70G 66G 4.8G 94% /mnt/boot-sav/sda2 /dev/sda3 fuseblk 19G 87M 19G 1% /mnt/boot-sav/sda3 /dev/sda5 fuseblk 479G 436G 44G 92% /mnt/boot-sav/sda5 =================== fdisk -l: Disk /dev/sda: 750.2 GB, 750156374016 bytes 255 heads, 63 sectors/track, 91201 cylinders, total 1465149168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disk identifier: 0x1dc69d0b Device Boot Start End Blocks Id System /dev/sda1 * 206848 146802687 73297920 7 HPFS/NTFS/exFAT /dev/sda2 147007488 293623807 73308160 7 HPFS/NTFS/exFAT /dev/sda3 293623808 332820613 19598403 7 HPFS/NTFS/exFAT /dev/sda4 332822526 1465145343 566161409 f W95 Ext'd (LBA) Partition 4 does not start on physical sector boundary. /dev/sda5 461342720 1465145343 501901312 7 HPFS/NTFS/exFAT /dev/sda6 332822528 453171199 60174336 83 Linux /dev/sda7 453173248 461338623 4082688 82 Linux swap / Solaris Partition table entries are not in disk order =================== Recommended repair Recommended-Repair This setting will reinstall the grub2 of sda6 into the MBR of sda. Additional repair will be performed: unhide-bootmenu-10s grub-install (GRUB) 2.00-7ubuntu11,grub-install (GRUB) 2. Reinstall the GRUB of sda6 into the MBR of sda Installation finished. No error reported. grub-install /dev/sda: exit code of grub-install /dev/sda:0 update-grub Generating grub.cfg ... Found linux image: /boot/vmlinuz-3.5.0-17-generic Found initrd image: /boot/initrd.img-3.5.0-17-generic Found memtest86+ image: /boot/memtest86+.bin Found Windows 7 (loader) on /dev/sda1 Unhide GRUB boot menu in sda6/boot/grub/grub.cfg Boot successfully repaired. You can now reboot your computer. The boot files of [The OS now in use - Ubuntu 12.10] are far from the start of the disk. Your BIOS may not detect them. You may want to retry after creating a /boot partition (EXT4, >200MB, start of the disk). This can be performed via tools such as gParted. Then select this partition via the [Separate /boot partition:] option of [Boot Repair]. (https://help.ubuntu.com/community/BootPartition)

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  • Why is /dev/rfcomm0 giving PySerial problems?

    - by Travis G.
    I am connecting my Ubuntu box to a wireless readout setup over Bluetooth. I wrote a Python script to send the serial information through /dev/rfcomm0. The script connects fine and works for a few minutes, but then Python will start using 100% CPU and the messages stop flowing through. I can open rfcomm0 in a serial terminal and communicate through it by hand just fine. When I open it through a terminal it seems to work indefinitely. Also, I can swap the Bluetooth receiver for a USB cable, and change the port to /dev/ttyUSB0, and I don't get any problems over time. It seems either I'm doing something wrong with rfcomm0 or PySerial doesn't handle it well. Here's the script: import psutil import serial import string import time sampleTime = 1 numSamples = 5 lastTemp = 0 TEMP_CHAR = 't' USAGE_CHAR = 'u' SENSOR_NAME = 'TC0D' gauges = serial.Serial() gauges.port = '/dev/rfcomm0' gauges.baudrate = 9600 gauges.parity = 'N' gauges.writeTimeout = 0 gauges.open() print("Connected to " + gauges.portstr) filename = '/sys/bus/platform/devices/applesmc.768/temp2_input' def parseSensorsOutputLinux(output): return int(round(float(output) / 1000)) while(1): usage = psutil.cpu_percent(interval=sampleTime) gauges.write(USAGE_CHAR) gauges.write(chr(int(usage))) #write the first byte #print("Wrote usage: " + str(int(usage))) sensorFile = open(filename) temp = parseSensorsOutputLinux(sensorFile.read()) gauges.write(TEMP_CHAR) gauges.write(chr(temp)) #print("Wrote temp: " + str(temp)) Any thoughts? Thanks. EDIT: Here is the revised code, using Python-BlueZ instead of PySerial: import psutil import serial import string import time import bluetooth sampleTime = 1 numSamples = 5 lastTemp = 0 TEMP_CHAR = 't' USAGE_CHAR = 'u' SENSOR_NAME = 'TC0D' #gauges = serial.Serial() #gauges.port = '/dev/rfcomm0' #gauges.baudrate = 9600 #gauges.parity = 'N' #gauges.writeTimeout = 0 #gauges.open() gaugeSocket = bluetooth.BluetoothSocket(bluetooth.RFCOMM) gaugeSocket.connect(('00:06:66:42:22:96', 1)) filename = '/sys/bus/platform/devices/applesmc.768/temp2_input' def parseSensorsOutputLinux(output): return int(round(float(output) / 1000)) while(1): usage = psutil.cpu_percent(interval=sampleTime) #gauges.write(USAGE_CHAR) gaugeSocket.send(USAGE_CHAR) #gauges.write(chr(int(usage))) #write the first byte gaugeSocket.send(chr(int(usage))) #print("Wrote usage: " + str(int(usage))) sensorFile = open(filename) temp = parseSensorsOutputLinux(sensorFile.read()) #gauges.write(TEMP_CHAR) gaugeSocket.send(TEMP_CHAR) #gauges.write(chr(temp)) gaugeSocket.send(chr(temp)) #print("Wrote temp: " + str(temp)) It seems either Ubuntu must be closing /dev/rfcomm0 after a certain time or my Bluetooth receiver is messing things up. Even when the BluetoothError arises, the "connected" light on the receiver stays illuminated, and it is not until I power-cycle to receiver that I can reconnect. I'm not sure how to approach this problem. It's odd that the connection would work fine for a few minutes (seemingly a random amount of time) and then seize up. In case it helps, the Bluetooth receiver is a BlueSmirf Silver from Sparkfun. Do I need to be trying to maintain the connection from the receiver end or something?

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  • How To Personalize the Windows Command Prompt

    - by Matthew Guay
    Command line interfaces can be downright boring, and always seem to miss out on the fresh coats of paint liberally applied to the rest of Windows.  Here’s how to add a splash of color to Command Prompt and make it unique. By default, Windows Command Prompt is white text on a black background. It get’s the job done, but maybe you want to add some color to it.   To get an overview of what we can do with the color command, let’s enter: color /? So, to get the color you want, enter color then the option for the background color followed by the font color.  For example, let’s make an old-fashioned green on black look by entering: color 02   There are a bunch of different combinations you can do, like this black background with red text. color 04 You can’t mess it up too much.  The color command won’t let you set both the font and the background to the same color, which would make it unreadable.  Also, if you want to get back to the default settings, just enter: color Now we’re back to plain-old black and white. Personalize Command Prompt Without Commands If you’d prefer to change the color without entering commands, just click on the Command Prompt icon in the top left corner of the window and select Properties. Select the Colors tab, and then choose the color you want for the screen text and background.  You can also enter your own RGB color combination if you want.   Here we entered the RGB values to get a purple background color like Ubuntu 10.04. Back in the Properties dialog, you can also change your Command Prompt font from the font tab.  Choose any font you want, as long as the one you want is one of the three listed here. Customizations you make via the Properties dialog are saved and will be used any time you open Command Prompt, but any customizations you make with the Color command are only for that session. Conclusion Whether you want to make your command prompt bright enough to cause a sunburn or old-style enough to scare a mainframe operator, with these settings, you can make Command Prompt a bit more unique.   Similar Articles Productive Geek Tips Use "Command Prompt Here" in Windows VistaVerify the Integrity of Windows Vista System FilesKeyboard Ninja: Scrolling the Windows Command Prompt With Only the KeyboardRun a Command as Administrator from the Windows 7 / Vista Run boxStart an Application Assigned to a Specific CPU in Windows Vista TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 How to Add Exceptions to the Windows Firewall Office 2010 reviewed in depth by Ed Bott FoxClocks adds World Times in your Statusbar (Firefox) Have Fun Editing Photo Editing with Citrify Outlook Connector Upgrade Error Gadfly is a cool Twitter/Silverlight app

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  • I can't install using Wubi due to permission denied error

    - by Taksh Sharma
    I can't install ubuntu 11.10 inside my windows 7. It shows permission denied while installation. It gave a log file having the following data: 03-29 20:19 DEBUG TaskList: # Running tasklist... 03-29 20:19 DEBUG TaskList: ## Running select_target_dir... 03-29 20:19 INFO WindowsBackend: Installing into D:\ubuntu 03-29 20:19 DEBUG TaskList: ## Finished select_target_dir 03-29 20:19 DEBUG TaskList: ## Running create_dir_structure... 03-29 20:19 DEBUG CommonBackend: Creating dir D:\ubuntu 03-29 20:19 DEBUG CommonBackend: Creating dir D:\ubuntu\disks 03-29 20:19 DEBUG CommonBackend: Creating dir D:\ubuntu\install 03-29 20:19 DEBUG CommonBackend: Creating dir D:\ubuntu\install\boot 03-29 20:19 DEBUG CommonBackend: Creating dir D:\ubuntu\disks\boot 03-29 20:19 DEBUG CommonBackend: Creating dir D:\ubuntu\disks\boot\grub 03-29 20:19 DEBUG CommonBackend: Creating dir D:\ubuntu\install\boot\grub 03-29 20:19 DEBUG TaskList: ## Finished create_dir_structure 03-29 20:19 DEBUG TaskList: ## Running uncompress_target_dir... 03-29 20:19 DEBUG TaskList: ## Finished uncompress_target_dir 03-29 20:19 DEBUG TaskList: ## Running create_uninstaller... 03-29 20:19 DEBUG WindowsBackend: Copying uninstaller E:\wubi.exe -> D:\ubuntu\uninstall-wubi.exe 03-29 20:19 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi UninstallString D:\ubuntu\uninstall-wubi.exe 03-29 20:19 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi InstallationDir D:\ubuntu 03-29 20:19 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi DisplayName Ubuntu 03-29 20:19 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi DisplayIcon D:\ubuntu\Ubuntu.ico 03-29 20:19 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi DisplayVersion 11.10-rev241 03-29 20:19 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi Publisher Ubuntu 03-29 20:19 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi URLInfoAbout http://www.ubuntu.com 03-29 20:19 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi HelpLink http://www.ubuntu.com/support 03-29 20:19 DEBUG TaskList: ## Finished create_uninstaller 03-29 20:19 DEBUG TaskList: ## Running copy_installation_files... 03-29 20:19 DEBUG WindowsBackend: Copying C:\Users\Home\AppData\Local\Temp\pylB911.tmp\data\custom-installation -> D:\ubuntu\install\custom-installation 03-29 20:19 DEBUG WindowsBackend: Copying C:\Users\Home\AppData\Local\Temp\pylB911.tmp\winboot -> D:\ubuntu\winboot 03-29 20:19 DEBUG WindowsBackend: Copying C:\Users\Home\AppData\Local\Temp\pylB911.tmp\data\images\Ubuntu.ico -> D:\ubuntu\Ubuntu.ico 03-29 20:19 DEBUG TaskList: ## Finished copy_installation_files 03-29 20:19 DEBUG TaskList: ## Running get_iso... 03-29 20:19 DEBUG TaskList: New task copy_file 03-29 20:19 DEBUG TaskList: ### Running copy_file... 03-29 20:23 ERROR TaskList: [Errno 13] Permission denied Traceback (most recent call last): File "\lib\wubi\backends\common\tasklist.py", line 197, in __call__ File "\lib\wubi\backends\common\utils.py", line 202, in copy_file IOError: [Errno 13] Permission denied 03-29 20:23 DEBUG TaskList: # Cancelling tasklist 03-29 20:23 DEBUG TaskList: New task check_iso 03-29 20:23 ERROR root: [Errno 13] Permission denied Traceback (most recent call last): File "\lib\wubi\application.py", line 58, in run File "\lib\wubi\application.py", line 130, in select_task File "\lib\wubi\application.py", line 205, in run_cd_menu File "\lib\wubi\application.py", line 120, in select_task File "\lib\wubi\application.py", line 158, in run_installer File "\lib\wubi\backends\common\tasklist.py", line 197, in __call__ File "\lib\wubi\backends\common\utils.py", line 202, in copy_file IOError: [Errno 13] Permission denied 03-29 20:23 ERROR TaskList: 'WindowsBackend' object has no attribute 'iso_path' Traceback (most recent call last): File "\lib\wubi\backends\common\tasklist.py", line 197, in __call__ File "\lib\wubi\backends\common\backend.py", line 579, in get_iso File "\lib\wubi\backends\common\backend.py", line 565, in use_iso AttributeError: 'WindowsBackend' object has no attribute 'iso_path' 03-29 20:23 DEBUG TaskList: # Cancelling tasklist 03-29 20:23 DEBUG TaskList: # Finished tasklist 03-29 20:29 INFO root: === wubi 11.10 rev241 === 03-29 20:29 DEBUG root: Logfile is c:\users\home\appdata\local\temp\wubi-11.10-rev241.log 03-29 20:29 DEBUG root: sys.argv = ['main.pyo', '--exefile="E:\\wubi.exe"'] 03-29 20:29 DEBUG CommonBackend: data_dir=C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\data 03-29 20:29 DEBUG WindowsBackend: 7z=C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\bin\7z.exe 03-29 20:29 DEBUG WindowsBackend: startup_folder=C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup 03-29 20:29 DEBUG CommonBackend: Fetching basic info... 03-29 20:29 DEBUG CommonBackend: original_exe=E:\wubi.exe 03-29 20:29 DEBUG CommonBackend: platform=win32 03-29 20:29 DEBUG CommonBackend: osname=nt 03-29 20:29 DEBUG CommonBackend: language=en_IN 03-29 20:29 DEBUG CommonBackend: encoding=cp1252 03-29 20:29 DEBUG WindowsBackend: arch=amd64 03-29 20:29 DEBUG CommonBackend: Parsing isolist=C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\data\isolist.ini 03-29 20:29 DEBUG CommonBackend: Adding distro Xubuntu-i386 03-29 20:29 DEBUG CommonBackend: Adding distro Xubuntu-amd64 03-29 20:29 DEBUG CommonBackend: Adding distro Kubuntu-amd64 03-29 20:29 DEBUG CommonBackend: Adding distro Mythbuntu-i386 03-29 20:29 DEBUG CommonBackend: Adding distro Ubuntu-amd64 03-29 20:29 DEBUG CommonBackend: Adding distro Ubuntu-i386 03-29 20:29 DEBUG CommonBackend: Adding distro Mythbuntu-amd64 03-29 20:29 DEBUG CommonBackend: Adding distro Kubuntu-i386 03-29 20:29 DEBUG WindowsBackend: Fetching host info... 03-29 20:29 DEBUG WindowsBackend: registry_key=Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi 03-29 20:29 DEBUG WindowsBackend: windows version=vista 03-29 20:29 DEBUG WindowsBackend: windows_version2=Windows 7 Home Basic 03-29 20:29 DEBUG WindowsBackend: windows_sp=None 03-29 20:29 DEBUG WindowsBackend: windows_build=7601 03-29 20:29 DEBUG WindowsBackend: gmt=5 03-29 20:29 DEBUG WindowsBackend: country=IN 03-29 20:29 DEBUG WindowsBackend: timezone=Asia/Calcutta 03-29 20:29 DEBUG WindowsBackend: windows_username=Home 03-29 20:29 DEBUG WindowsBackend: user_full_name=Home 03-29 20:29 DEBUG WindowsBackend: user_directory=C:\Users\Home 03-29 20:29 DEBUG WindowsBackend: windows_language_code=1033 03-29 20:29 DEBUG WindowsBackend: windows_language=English 03-29 20:29 DEBUG WindowsBackend: processor_name=Intel(R) Core(TM) i3 CPU M 370 @ 2.40GHz 03-29 20:29 DEBUG WindowsBackend: bootloader=vista 03-29 20:29 DEBUG WindowsBackend: system_drive=Drive(C: hd 61135.1523438 mb free ntfs) 03-29 20:29 DEBUG WindowsBackend: drive=Drive(C: hd 61135.1523438 mb free ntfs) 03-29 20:29 DEBUG WindowsBackend: drive=Drive(D: hd 12742.5507813 mb free ntfs) 03-29 20:29 DEBUG WindowsBackend: drive=Drive(E: cd 0.0 mb free cdfs) 03-29 20:29 DEBUG WindowsBackend: drive=Drive(F: cd 0.0 mb free ) 03-29 20:29 DEBUG WindowsBackend: drive=Drive(G: hd 93.22265625 mb free fat32) 03-29 20:29 DEBUG WindowsBackend: drive=Drive(Q: hd 0.0 mb free ) 03-29 20:29 DEBUG WindowsBackend: uninstaller_path=D:\ubuntu\uninstall-wubi.exe 03-29 20:29 DEBUG WindowsBackend: previous_target_dir=D:\ubuntu 03-29 20:29 DEBUG WindowsBackend: previous_distro_name=Ubuntu 03-29 20:29 DEBUG WindowsBackend: keyboard_id=67699721 03-29 20:29 DEBUG WindowsBackend: keyboard_layout=us 03-29 20:29 DEBUG WindowsBackend: keyboard_variant= 03-29 20:29 DEBUG CommonBackend: python locale=('en_IN', 'cp1252') 03-29 20:29 DEBUG CommonBackend: locale=en_IN 03-29 20:29 DEBUG WindowsBackend: total_memory_mb=3893.859375 03-29 20:29 DEBUG CommonBackend: Searching ISOs on USB devices 03-29 20:29 DEBUG CommonBackend: Searching for local CDs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Ubuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Ubuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Kubuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Kubuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Xubuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Xubuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Mythbuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Mythbuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Ubuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Ubuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Kubuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Kubuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Xubuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Xubuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Mythbuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Mythbuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether E:\ is a valid Ubuntu CD 03-29 20:29 DEBUG Distro: parsing info from str=Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111012) 03-29 20:29 DEBUG Distro: parsed info={'name': 'Ubuntu', 'subversion': 'Release', 'version': '11.10', 'build': '20111012', 'codename': 'Oneiric Ocelot', 'arch': 'i386'} 03-29 20:29 INFO Distro: Found a valid CD for Ubuntu: E:\ 03-29 20:29 INFO root: Running the CD menu... 03-29 20:29 DEBUG WindowsFrontend: __init__... 03-29 20:29 DEBUG WindowsFrontend: on_init... 03-29 20:29 INFO WinuiPage: appname=wubi, localedir=C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\translations, languages=['en_IN', 'en'] 03-29 20:29 INFO WinuiPage: appname=wubi, localedir=C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\translations, languages=['en_IN', 'en'] 03-29 20:29 INFO root: CD menu finished 03-29 20:29 INFO root: Already installed, running the uninstaller... 03-29 20:29 INFO root: Running the uninstaller... 03-29 20:29 INFO CommonBackend: This is the uninstaller running 03-29 20:29 INFO WinuiPage: appname=wubi, localedir=C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\translations, languages=['en_IN', 'en'] 03-29 20:29 INFO root: Received settings 03-29 20:29 INFO WinuiPage: appname=wubi, localedir=C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\translations, languages=['en_IN', 'en'] 03-29 20:29 DEBUG TaskList: # Running tasklist... 03-29 20:29 DEBUG TaskList: ## Running Remove bootloader entry... 03-29 20:29 DEBUG WindowsBackend: Could not find bcd id 03-29 20:29 DEBUG WindowsBackend: undo_bootini C: 03-29 20:29 DEBUG WindowsBackend: undo_configsys Drive(C: hd 61135.1523438 mb free ntfs) 03-29 20:29 DEBUG WindowsBackend: undo_bootini D: 03-29 20:29 DEBUG WindowsBackend: undo_configsys Drive(D: hd 12742.5507813 mb free ntfs) 03-29 20:29 DEBUG WindowsBackend: undo_bootini G: 03-29 20:29 DEBUG WindowsBackend: undo_configsys Drive(G: hd 93.22265625 mb free fat32) 03-29 20:29 DEBUG WindowsBackend: undo_bootini Q: 03-29 20:29 DEBUG WindowsBackend: undo_configsys Drive(Q: hd 0.0 mb free ) 03-29 20:29 DEBUG TaskList: ## Finished Remove bootloader entry 03-29 20:29 DEBUG TaskList: ## Running Remove target dir... 03-29 20:29 DEBUG CommonBackend: Deleting D:\ubuntu 03-29 20:29 DEBUG TaskList: ## Finished Remove target dir 03-29 20:29 DEBUG TaskList: ## Running Remove registry key... 03-29 20:29 DEBUG TaskList: ## Finished Remove registry key 03-29 20:29 DEBUG TaskList: # Finished tasklist 03-29 20:29 INFO root: Almost finished uninstalling 03-29 20:29 INFO root: Finished uninstallation 03-29 20:29 DEBUG CommonBackend: Fetching basic info... 03-29 20:29 DEBUG CommonBackend: original_exe=E:\wubi.exe 03-29 20:29 DEBUG CommonBackend: platform=win32 03-29 20:29 DEBUG CommonBackend: osname=nt 03-29 20:29 DEBUG WindowsBackend: arch=amd64 03-29 20:29 DEBUG CommonBackend: Parsing isolist=C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\data\isolist.ini 03-29 20:29 DEBUG CommonBackend: Adding distro Xubuntu-i386 03-29 20:29 DEBUG CommonBackend: Adding distro Xubuntu-amd64 03-29 20:29 DEBUG CommonBackend: Adding distro Kubuntu-amd64 03-29 20:29 DEBUG CommonBackend: Adding distro Mythbuntu-i386 03-29 20:29 DEBUG CommonBackend: Adding distro Ubuntu-amd64 03-29 20:29 DEBUG CommonBackend: Adding distro Ubuntu-i386 03-29 20:29 DEBUG CommonBackend: Adding distro Mythbuntu-amd64 03-29 20:29 DEBUG CommonBackend: Adding distro Kubuntu-i386 03-29 20:29 DEBUG WindowsBackend: Fetching host info... 03-29 20:29 DEBUG WindowsBackend: registry_key=Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi 03-29 20:29 DEBUG WindowsBackend: windows version=vista 03-29 20:29 DEBUG WindowsBackend: windows_version2=Windows 7 Home Basic 03-29 20:29 DEBUG WindowsBackend: windows_sp=None 03-29 20:29 DEBUG WindowsBackend: windows_build=7601 03-29 20:29 DEBUG WindowsBackend: gmt=5 03-29 20:29 DEBUG WindowsBackend: country=IN 03-29 20:29 DEBUG WindowsBackend: timezone=Asia/Calcutta 03-29 20:29 DEBUG WindowsBackend: windows_username=Home 03-29 20:29 DEBUG WindowsBackend: user_full_name=Home 03-29 20:29 DEBUG WindowsBackend: user_directory=C:\Users\Home 03-29 20:29 DEBUG WindowsBackend: windows_language_code=1033 03-29 20:29 DEBUG WindowsBackend: windows_language=English 03-29 20:29 DEBUG WindowsBackend: processor_name=Intel(R) Core(TM) i3 CPU M 370 @ 2.40GHz 03-29 20:29 DEBUG WindowsBackend: bootloader=vista 03-29 20:29 DEBUG WindowsBackend: system_drive=Drive(C: hd 61134.8632813 mb free ntfs) 03-29 20:29 DEBUG WindowsBackend: drive=Drive(C: hd 61134.8632813 mb free ntfs) 03-29 20:29 DEBUG WindowsBackend: drive=Drive(D: hd 12953.140625 mb free ntfs) 03-29 20:29 DEBUG WindowsBackend: drive=Drive(E: cd 0.0 mb free cdfs) 03-29 20:29 DEBUG WindowsBackend: drive=Drive(F: cd 0.0 mb free ) 03-29 20:29 DEBUG WindowsBackend: drive=Drive(G: hd 93.22265625 mb free fat32) 03-29 20:29 DEBUG WindowsBackend: drive=Drive(Q: hd 0.0 mb free ) 03-29 20:29 DEBUG WindowsBackend: uninstaller_path=None 03-29 20:29 DEBUG WindowsBackend: previous_target_dir=None 03-29 20:29 DEBUG WindowsBackend: previous_distro_name=None 03-29 20:29 DEBUG WindowsBackend: keyboard_id=67699721 03-29 20:29 DEBUG WindowsBackend: keyboard_layout=us 03-29 20:29 DEBUG WindowsBackend: keyboard_variant= 03-29 20:29 DEBUG WindowsBackend: total_memory_mb=3893.859375 03-29 20:29 DEBUG CommonBackend: Searching ISOs on USB devices 03-29 20:29 DEBUG CommonBackend: Searching for local CDs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Ubuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Ubuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Kubuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Kubuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Xubuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Xubuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Mythbuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether C:\Users\Home\AppData\Local\Temp\pyl3487.tmp is a valid Mythbuntu CD 03-29 20:29 DEBUG Distro: does not contain C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Ubuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Ubuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Kubuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Kubuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Xubuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Xubuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Mythbuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether D:\ is a valid Mythbuntu CD 03-29 20:29 DEBUG Distro: does not contain D:\casper\filesystem.squashfs 03-29 20:29 DEBUG Distro: checking whether E:\ is a valid Ubuntu CD 03-29 20:29 INFO Distro: Found a valid CD for Ubuntu: E:\ 03-29 20:29 INFO root: Running the installer... 03-29 20:29 INFO WinuiPage: appname=wubi, localedir=C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\translations, languages=['en_IN', 'en'] 03-29 20:29 INFO WinuiPage: appname=wubi, localedir=C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\translations, languages=['en_IN', 'en'] 03-29 20:30 DEBUG WinuiInstallationPage: target_drive=C:, installation_size=8000MB, distro_name=Ubuntu, language=en_US, locale=en_US.UTF-8, username=taksh 03-29 20:30 INFO root: Received settings 03-29 20:30 INFO WinuiPage: appname=wubi, localedir=C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\translations, languages=['en_US', 'en'] 03-29 20:30 DEBUG TaskList: # Running tasklist... 03-29 20:30 DEBUG TaskList: ## Running select_target_dir... 03-29 20:30 INFO WindowsBackend: Installing into C:\ubuntu 03-29 20:30 DEBUG TaskList: ## Finished select_target_dir 03-29 20:30 DEBUG TaskList: ## Running create_dir_structure... 03-29 20:30 DEBUG CommonBackend: Creating dir C:\ubuntu 03-29 20:30 DEBUG CommonBackend: Creating dir C:\ubuntu\disks 03-29 20:30 DEBUG CommonBackend: Creating dir C:\ubuntu\install 03-29 20:30 DEBUG CommonBackend: Creating dir C:\ubuntu\install\boot 03-29 20:30 DEBUG CommonBackend: Creating dir C:\ubuntu\disks\boot 03-29 20:30 DEBUG CommonBackend: Creating dir C:\ubuntu\disks\boot\grub 03-29 20:30 DEBUG CommonBackend: Creating dir C:\ubuntu\install\boot\grub 03-29 20:30 DEBUG TaskList: ## Finished create_dir_structure 03-29 20:30 DEBUG TaskList: ## Running uncompress_target_dir... 03-29 20:30 DEBUG TaskList: ## Finished uncompress_target_dir 03-29 20:30 DEBUG TaskList: ## Running create_uninstaller... 03-29 20:30 DEBUG WindowsBackend: Copying uninstaller E:\wubi.exe -> C:\ubuntu\uninstall-wubi.exe 03-29 20:30 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi UninstallString C:\ubuntu\uninstall-wubi.exe 03-29 20:30 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi InstallationDir C:\ubuntu 03-29 20:30 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi DisplayName Ubuntu 03-29 20:30 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi DisplayIcon C:\ubuntu\Ubuntu.ico 03-29 20:30 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi DisplayVersion 11.10-rev241 03-29 20:30 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi Publisher Ubuntu 03-29 20:30 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi URLInfoAbout http://www.ubuntu.com 03-29 20:30 DEBUG registry: Setting registry key -2147483646 Software\Microsoft\Windows\CurrentVersion\Uninstall\Wubi HelpLink http://www.ubuntu.com/support 03-29 20:30 DEBUG TaskList: ## Finished create_uninstaller 03-29 20:30 DEBUG TaskList: ## Running copy_installation_files... 03-29 20:30 DEBUG WindowsBackend: Copying C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\data\custom-installation -> C:\ubuntu\install\custom-installation 03-29 20:30 DEBUG WindowsBackend: Copying C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\winboot -> C:\ubuntu\winboot 03-29 20:30 DEBUG WindowsBackend: Copying C:\Users\Home\AppData\Local\Temp\pyl3487.tmp\data\images\Ubuntu.ico -> C:\ubuntu\Ubuntu.ico 03-29 20:30 DEBUG TaskList: ## Finished copy_installation_files 03-29 20:30 DEBUG TaskList: ## Running get_iso... 03-29 20:30 DEBUG TaskList: New task copy_file 03-29 20:30 DEBUG TaskList: ### Running copy_file... 03-29 20:34 ERROR TaskList: [Errno 13] Permission denied Traceback (most recent call last): File "\lib\wubi\backends\common\tasklist.py", line 197, in __call__ File "\lib\wubi\backends\common\utils.py", line 202, in copy_file IOError: [Errno 13] Permission denied 03-29 20:34 DEBUG TaskList: # Cancelling tasklist 03-29 20:34 DEBUG TaskList: New task check_iso 03-29 20:34 ERROR root: [Errno 13] Permission denied Traceback (most recent call last): File "\lib\wubi\application.py", line 58, in run File "\lib\wubi\application.py", line 130, in select_task File "\lib\wubi\application.py", line 205, in run_cd_menu File "\lib\wubi\application.py", line 120, in select_task File "\lib\wubi\application.py", line 158, in run_installer File "\lib\wubi\backends\common\tasklist.py", line 197, in __call__ File "\lib\wubi\backends\common\utils.py", line 202, in copy_file IOError: [Errno 13] Permission denied 03-29 20:34 ERROR TaskList: 'WindowsBackend' object has no attribute 'iso_path' Traceback (most recent call last): File "\lib\wubi\backends\common\tasklist.py", line 197, in __call__ File "\lib\wubi\backends\common\backend.py", line 579, in get_iso File "\lib\wubi\backends\common\backend.py", line 565, in use_iso AttributeError: 'WindowsBackend' object has no attribute 'iso_path' 03-29 20:34 DEBUG TaskList: # Cancelling tasklist 03-29 20:34 DEBUG TaskList: # Finished tasklist I have no idea what's the problem is. I'm a kind of newbie. I'm using win7 64bit, and installing as an administrator. Please help me out!

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  • Virtual Box - How to open a .VDI Virtual Machine

    - by [email protected]
     How to open a .VDI Virtual MachineSometimes someone share with us one Virtual machine with extension .VDI, after that we can wonder how and what with?Well the answer is... It is a VirtualBox - Virtual Machine. If you have not downloaded it you can do this easily just follow this post.http://listeningoracle.blogspot.com/2010/04/que-es-virtualbox.htmlor http://oracleoforacle.wordpress.com/2010/04/14/ques-es-virtualbox/Ok, Now with VirtualBox Installed open it and proceed with the following:1. Open the Virtual File Manager. 2. Click on Actions ? Add and select the .VDI file Click "Ok"3. Now we can register the new Virtual Machine - Click New, and Click Next4. Write down a Name for the virtual Machine a proceed to select a Operating System and Version. (In this case it is a Linux (Oracle Enterprise Linux or RedHat)Click Next5. Select the memory amount base for the Virtual Machine (Minimal 1280 for our case) - Click Next6. Select the Disk 11GR2_OEL5_32GB.vdi it was added in the virtual media manager in the step 2. Dont forget let selected Boot hard Disk (Primary Master) . Given it is the only disk assigned to the virtual machine.Click Next7. Click Finish8. This step is important. Once you have click on the settings Button.9. On General option click the advanced settings. Here you must change the default directory to save your Snapshots; my recommendation set it to the same directory where the .Vdi file is. Otherwise you can have the same Virtual Machine and its snapshots in different paths.10. Now Click on System, and proceed to assign the correct memory (If you did not before) Note: Enable "Enable IO APIC" if you are planning to assign more than one CPU to the Virtual Machine.Define the processors for the Virtual machine. If you processor is dual core choose 211. Select the video memory amount you want to assign to the Virtual Machine 12. Associated more storage disk to the Virtual machine, if you have more VDI files. (Not our case)The disk must be selected as IDE Primary Master. 13. Well you can verify the other options, but with these changes you will be able to start the VM.Note: Sometime the VM owner may share some instructions, if so follow his instructions.14. Finally Start the Virtual Machine (Click > Start)

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  • Challenges in multi-player Android Game Server with RESTful Nature

    - by Kush
    I'm working on an Android Game based on Contract Bridge, as a part of my college Summer Internship project. The game will be multi-player such that 4 Android devices can play it, so there's no BOT or CPU player to be developed. At the time of getting project, I realized that most of the students had already worked on the project but none of their works is reusable now (for variety of reasons like, undocumented code and design architecture, different platform implementation). I have experience working on several open source projects and hence I emphasis to work out on this project such that components I make become reusable as much as possible. Now, as the game is multi-player and entire game progress will be handled on server, I'm currently working on Server's design, since I wanted to make game server reusable such that any client platform can use it, I was previously confused in selecting Socket or REST for Game Server's design, but later finalized to work on REST APIs for the server. Now, since I have to keep all players in-sync while they make movements in game, on server I've planned to use Database which will keep all players' progress, specific for each table (in Bridge, 4 players play on single table, and server will handle many such game tables). I don't know if its an appropriate decision to use database as shared medium to track progress of each game table (let me know if there's an appropriate or better option). Obviously, when game is completed for the table, data for that table on server's database is discarded. Now the problem is that, access to REST service is an HTTP call, so as long as client doesn't make any request, server will remain idle, and consider a situation where A player has played a card on his device and the device requests to apply this change on the server. Now, I need to let rest of the three devices know that the player has played a card, and also update view on their device. AFAIK, REST cannot provide a sort-of Push-notification system, since the connection to the server is not persistent. One solution that I thought was to make each device constantly poll the server for any change (like every 56 ms) and when changes are found, reflect it on the device. But I feel this is not an elegant way, as every HTTP request is expensive. (and I choose REST to make game play experience robust since, a mobile device tends to get disconnected from Internet, and if there's Socket-like persistent connection then entire game progress is subject to lost. Also, portability on client-end is important) Also, imagining a situation where 10 game tables are in progress and 40 players are playing, a server must be capable to handle flooded HTTP requests from all the devices which make it every 56 ms. So I wonder if the situation is assumed as DoS attack. So, explaining the situation, am I going on the right track for the server design? I wanted to be sure before I proceed much further with the code.

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  • Advanced TSQL Tuning: Why Internals Knowledge Matters

    - by Paul White
    There is much more to query tuning than reducing logical reads and adding covering nonclustered indexes.  Query tuning is not complete as soon as the query returns results quickly in the development or test environments.  In production, your query will compete for memory, CPU, locks, I/O and other resources on the server.  Today’s entry looks at some tuning considerations that are often overlooked, and shows how deep internals knowledge can help you write better TSQL. As always, we’ll need some example data.  In fact, we are going to use three tables today, each of which is structured like this: Each table has 50,000 rows made up of an INTEGER id column and a padding column containing 3,999 characters in every row.  The only difference between the three tables is in the type of the padding column: the first table uses CHAR(3999), the second uses VARCHAR(MAX), and the third uses the deprecated TEXT type.  A script to create a database with the three tables and load the sample data follows: USE master; GO IF DB_ID('SortTest') IS NOT NULL DROP DATABASE SortTest; GO CREATE DATABASE SortTest COLLATE LATIN1_GENERAL_BIN; GO ALTER DATABASE SortTest MODIFY FILE ( NAME = 'SortTest', SIZE = 3GB, MAXSIZE = 3GB ); GO ALTER DATABASE SortTest MODIFY FILE ( NAME = 'SortTest_log', SIZE = 256MB, MAXSIZE = 1GB, FILEGROWTH = 128MB ); GO ALTER DATABASE SortTest SET ALLOW_SNAPSHOT_ISOLATION OFF ; ALTER DATABASE SortTest SET AUTO_CLOSE OFF ; ALTER DATABASE SortTest SET AUTO_CREATE_STATISTICS ON ; ALTER DATABASE SortTest SET AUTO_SHRINK OFF ; ALTER DATABASE SortTest SET AUTO_UPDATE_STATISTICS ON ; ALTER DATABASE SortTest SET AUTO_UPDATE_STATISTICS_ASYNC ON ; ALTER DATABASE SortTest SET PARAMETERIZATION SIMPLE ; ALTER DATABASE SortTest SET READ_COMMITTED_SNAPSHOT OFF ; ALTER DATABASE SortTest SET MULTI_USER ; ALTER DATABASE SortTest SET RECOVERY SIMPLE ; USE SortTest; GO CREATE TABLE dbo.TestCHAR ( id INTEGER IDENTITY (1,1) NOT NULL, padding CHAR(3999) NOT NULL,   CONSTRAINT [PK dbo.TestCHAR (id)] PRIMARY KEY CLUSTERED (id), ) ; CREATE TABLE dbo.TestMAX ( id INTEGER IDENTITY (1,1) NOT NULL, padding VARCHAR(MAX) NOT NULL,   CONSTRAINT [PK dbo.TestMAX (id)] PRIMARY KEY CLUSTERED (id), ) ; CREATE TABLE dbo.TestTEXT ( id INTEGER IDENTITY (1,1) NOT NULL, padding TEXT NOT NULL,   CONSTRAINT [PK dbo.TestTEXT (id)] PRIMARY KEY CLUSTERED (id), ) ; -- ============= -- Load TestCHAR (about 3s) -- ============= INSERT INTO dbo.TestCHAR WITH (TABLOCKX) ( padding ) SELECT padding = REPLICATE(CHAR(65 + (Data.n % 26)), 3999) FROM ( SELECT TOP (50000) n = ROW_NUMBER() OVER (ORDER BY (SELECT 0)) - 1 FROM master.sys.columns C1, master.sys.columns C2, master.sys.columns C3 ORDER BY n ASC ) AS Data ORDER BY Data.n ASC ; -- ============ -- Load TestMAX (about 3s) -- ============ INSERT INTO dbo.TestMAX WITH (TABLOCKX) ( padding ) SELECT CONVERT(VARCHAR(MAX), padding) FROM dbo.TestCHAR ORDER BY id ; -- ============= -- Load TestTEXT (about 5s) -- ============= INSERT INTO dbo.TestTEXT WITH (TABLOCKX) ( padding ) SELECT CONVERT(TEXT, padding) FROM dbo.TestCHAR ORDER BY id ; -- ========== -- Space used -- ========== -- EXECUTE sys.sp_spaceused @objname = 'dbo.TestCHAR'; EXECUTE sys.sp_spaceused @objname = 'dbo.TestMAX'; EXECUTE sys.sp_spaceused @objname = 'dbo.TestTEXT'; ; CHECKPOINT ; That takes around 15 seconds to run, and shows the space allocated to each table in its output: To illustrate the points I want to make today, the example task we are going to set ourselves is to return a random set of 150 rows from each table.  The basic shape of the test query is the same for each of the three test tables: SELECT TOP (150) T.id, T.padding FROM dbo.Test AS T ORDER BY NEWID() OPTION (MAXDOP 1) ; Test 1 – CHAR(3999) Running the template query shown above using the TestCHAR table as the target, we find that the query takes around 5 seconds to return its results.  This seems slow, considering that the table only has 50,000 rows.  Working on the assumption that generating a GUID for each row is a CPU-intensive operation, we might try enabling parallelism to see if that speeds up the response time.  Running the query again (but without the MAXDOP 1 hint) on a machine with eight logical processors, the query now takes 10 seconds to execute – twice as long as when run serially. Rather than attempting further guesses at the cause of the slowness, let’s go back to serial execution and add some monitoring.  The script below monitors STATISTICS IO output and the amount of tempdb used by the test query.  We will also run a Profiler trace to capture any warnings generated during query execution. DECLARE @read BIGINT, @write BIGINT ; SELECT @read = SUM(num_of_bytes_read), @write = SUM(num_of_bytes_written) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; SET STATISTICS IO ON ; SELECT TOP (150) TC.id, TC.padding FROM dbo.TestCHAR AS TC ORDER BY NEWID() OPTION (MAXDOP 1) ; SET STATISTICS IO OFF ; SELECT tempdb_read_MB = (SUM(num_of_bytes_read) - @read) / 1024. / 1024., tempdb_write_MB = (SUM(num_of_bytes_written) - @write) / 1024. / 1024., internal_use_MB = ( SELECT internal_objects_alloc_page_count / 128.0 FROM sys.dm_db_task_space_usage WHERE session_id = @@SPID ) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; Let’s take a closer look at the statistics and query plan generated from this: Following the flow of the data from right to left, we see the expected 50,000 rows emerging from the Clustered Index Scan, with a total estimated size of around 191MB.  The Compute Scalar adds a column containing a random GUID (generated from the NEWID() function call) for each row.  With this extra column in place, the size of the data arriving at the Sort operator is estimated to be 192MB. Sort is a blocking operator – it has to examine all of the rows on its input before it can produce its first row of output (the last row received might sort first).  This characteristic means that Sort requires a memory grant – memory allocated for the query’s use by SQL Server just before execution starts.  In this case, the Sort is the only memory-consuming operator in the plan, so it has access to the full 243MB (248,696KB) of memory reserved by SQL Server for this query execution. Notice that the memory grant is significantly larger than the expected size of the data to be sorted.  SQL Server uses a number of techniques to speed up sorting, some of which sacrifice size for comparison speed.  Sorts typically require a very large number of comparisons, so this is usually a very effective optimization.  One of the drawbacks is that it is not possible to exactly predict the sort space needed, as it depends on the data itself.  SQL Server takes an educated guess based on data types, sizes, and the number of rows expected, but the algorithm is not perfect. In spite of the large memory grant, the Profiler trace shows a Sort Warning event (indicating that the sort ran out of memory), and the tempdb usage monitor shows that 195MB of tempdb space was used – all of that for system use.  The 195MB represents physical write activity on tempdb, because SQL Server strictly enforces memory grants – a query cannot ‘cheat’ and effectively gain extra memory by spilling to tempdb pages that reside in memory.  Anyway, the key point here is that it takes a while to write 195MB to disk, and this is the main reason that the query takes 5 seconds overall. If you are wondering why using parallelism made the problem worse, consider that eight threads of execution result in eight concurrent partial sorts, each receiving one eighth of the memory grant.  The eight sorts all spilled to tempdb, resulting in inefficiencies as the spilled sorts competed for disk resources.  More importantly, there are specific problems at the point where the eight partial results are combined, but I’ll cover that in a future post. CHAR(3999) Performance Summary: 5 seconds elapsed time 243MB memory grant 195MB tempdb usage 192MB estimated sort set 25,043 logical reads Sort Warning Test 2 – VARCHAR(MAX) We’ll now run exactly the same test (with the additional monitoring) on the table using a VARCHAR(MAX) padding column: DECLARE @read BIGINT, @write BIGINT ; SELECT @read = SUM(num_of_bytes_read), @write = SUM(num_of_bytes_written) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; SET STATISTICS IO ON ; SELECT TOP (150) TM.id, TM.padding FROM dbo.TestMAX AS TM ORDER BY NEWID() OPTION (MAXDOP 1) ; SET STATISTICS IO OFF ; SELECT tempdb_read_MB = (SUM(num_of_bytes_read) - @read) / 1024. / 1024., tempdb_write_MB = (SUM(num_of_bytes_written) - @write) / 1024. / 1024., internal_use_MB = ( SELECT internal_objects_alloc_page_count / 128.0 FROM sys.dm_db_task_space_usage WHERE session_id = @@SPID ) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; This time the query takes around 8 seconds to complete (3 seconds longer than Test 1).  Notice that the estimated row and data sizes are very slightly larger, and the overall memory grant has also increased very slightly to 245MB.  The most marked difference is in the amount of tempdb space used – this query wrote almost 391MB of sort run data to the physical tempdb file.  Don’t draw any general conclusions about VARCHAR(MAX) versus CHAR from this – I chose the length of the data specifically to expose this edge case.  In most cases, VARCHAR(MAX) performs very similarly to CHAR – I just wanted to make test 2 a bit more exciting. MAX Performance Summary: 8 seconds elapsed time 245MB memory grant 391MB tempdb usage 193MB estimated sort set 25,043 logical reads Sort warning Test 3 – TEXT The same test again, but using the deprecated TEXT data type for the padding column: DECLARE @read BIGINT, @write BIGINT ; SELECT @read = SUM(num_of_bytes_read), @write = SUM(num_of_bytes_written) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; SET STATISTICS IO ON ; SELECT TOP (150) TT.id, TT.padding FROM dbo.TestTEXT AS TT ORDER BY NEWID() OPTION (MAXDOP 1, RECOMPILE) ; SET STATISTICS IO OFF ; SELECT tempdb_read_MB = (SUM(num_of_bytes_read) - @read) / 1024. / 1024., tempdb_write_MB = (SUM(num_of_bytes_written) - @write) / 1024. / 1024., internal_use_MB = ( SELECT internal_objects_alloc_page_count / 128.0 FROM sys.dm_db_task_space_usage WHERE session_id = @@SPID ) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; This time the query runs in 500ms.  If you look at the metrics we have been checking so far, it’s not hard to understand why: TEXT Performance Summary: 0.5 seconds elapsed time 9MB memory grant 5MB tempdb usage 5MB estimated sort set 207 logical reads 596 LOB logical reads Sort warning SQL Server’s memory grant algorithm still underestimates the memory needed to perform the sorting operation, but the size of the data to sort is so much smaller (5MB versus 193MB previously) that the spilled sort doesn’t matter very much.  Why is the data size so much smaller?  The query still produces the correct results – including the large amount of data held in the padding column – so what magic is being performed here? TEXT versus MAX Storage The answer lies in how columns of the TEXT data type are stored.  By default, TEXT data is stored off-row in separate LOB pages – which explains why this is the first query we have seen that records LOB logical reads in its STATISTICS IO output.  You may recall from my last post that LOB data leaves an in-row pointer to the separate storage structure holding the LOB data. SQL Server can see that the full LOB value is not required by the query plan until results are returned, so instead of passing the full LOB value down the plan from the Clustered Index Scan, it passes the small in-row structure instead.  SQL Server estimates that each row coming from the scan will be 79 bytes long – 11 bytes for row overhead, 4 bytes for the integer id column, and 64 bytes for the LOB pointer (in fact the pointer is rather smaller – usually 16 bytes – but the details of that don’t really matter right now). OK, so this query is much more efficient because it is sorting a very much smaller data set – SQL Server delays retrieving the LOB data itself until after the Sort starts producing its 150 rows.  The question that normally arises at this point is: Why doesn’t SQL Server use the same trick when the padding column is defined as VARCHAR(MAX)? The answer is connected with the fact that if the actual size of the VARCHAR(MAX) data is 8000 bytes or less, it is usually stored in-row in exactly the same way as for a VARCHAR(8000) column – MAX data only moves off-row into LOB storage when it exceeds 8000 bytes.  The default behaviour of the TEXT type is to be stored off-row by default, unless the ‘text in row’ table option is set suitably and there is room on the page.  There is an analogous (but opposite) setting to control the storage of MAX data – the ‘large value types out of row’ table option.  By enabling this option for a table, MAX data will be stored off-row (in a LOB structure) instead of in-row.  SQL Server Books Online has good coverage of both options in the topic In Row Data. The MAXOOR Table The essential difference, then, is that MAX defaults to in-row storage, and TEXT defaults to off-row (LOB) storage.  You might be thinking that we could get the same benefits seen for the TEXT data type by storing the VARCHAR(MAX) values off row – so let’s look at that option now.  This script creates a fourth table, with the VARCHAR(MAX) data stored off-row in LOB pages: CREATE TABLE dbo.TestMAXOOR ( id INTEGER IDENTITY (1,1) NOT NULL, padding VARCHAR(MAX) NOT NULL,   CONSTRAINT [PK dbo.TestMAXOOR (id)] PRIMARY KEY CLUSTERED (id), ) ; EXECUTE sys.sp_tableoption @TableNamePattern = N'dbo.TestMAXOOR', @OptionName = 'large value types out of row', @OptionValue = 'true' ; SELECT large_value_types_out_of_row FROM sys.tables WHERE [schema_id] = SCHEMA_ID(N'dbo') AND name = N'TestMAXOOR' ; INSERT INTO dbo.TestMAXOOR WITH (TABLOCKX) ( padding ) SELECT SPACE(0) FROM dbo.TestCHAR ORDER BY id ; UPDATE TM WITH (TABLOCK) SET padding.WRITE (TC.padding, NULL, NULL) FROM dbo.TestMAXOOR AS TM JOIN dbo.TestCHAR AS TC ON TC.id = TM.id ; EXECUTE sys.sp_spaceused @objname = 'dbo.TestMAXOOR' ; CHECKPOINT ; Test 4 – MAXOOR We can now re-run our test on the MAXOOR (MAX out of row) table: DECLARE @read BIGINT, @write BIGINT ; SELECT @read = SUM(num_of_bytes_read), @write = SUM(num_of_bytes_written) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; SET STATISTICS IO ON ; SELECT TOP (150) MO.id, MO.padding FROM dbo.TestMAXOOR AS MO ORDER BY NEWID() OPTION (MAXDOP 1, RECOMPILE) ; SET STATISTICS IO OFF ; SELECT tempdb_read_MB = (SUM(num_of_bytes_read) - @read) / 1024. / 1024., tempdb_write_MB = (SUM(num_of_bytes_written) - @write) / 1024. / 1024., internal_use_MB = ( SELECT internal_objects_alloc_page_count / 128.0 FROM sys.dm_db_task_space_usage WHERE session_id = @@SPID ) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; TEXT Performance Summary: 0.3 seconds elapsed time 245MB memory grant 0MB tempdb usage 193MB estimated sort set 207 logical reads 446 LOB logical reads No sort warning The query runs very quickly – slightly faster than Test 3, and without spilling the sort to tempdb (there is no sort warning in the trace, and the monitoring query shows zero tempdb usage by this query).  SQL Server is passing the in-row pointer structure down the plan and only looking up the LOB value on the output side of the sort. The Hidden Problem There is still a huge problem with this query though – it requires a 245MB memory grant.  No wonder the sort doesn’t spill to tempdb now – 245MB is about 20 times more memory than this query actually requires to sort 50,000 records containing LOB data pointers.  Notice that the estimated row and data sizes in the plan are the same as in test 2 (where the MAX data was stored in-row). The optimizer assumes that MAX data is stored in-row, regardless of the sp_tableoption setting ‘large value types out of row’.  Why?  Because this option is dynamic – changing it does not immediately force all MAX data in the table in-row or off-row, only when data is added or actually changed.  SQL Server does not keep statistics to show how much MAX or TEXT data is currently in-row, and how much is stored in LOB pages.  This is an annoying limitation, and one which I hope will be addressed in a future version of the product. So why should we worry about this?  Excessive memory grants reduce concurrency and may result in queries waiting on the RESOURCE_SEMAPHORE wait type while they wait for memory they do not need.  245MB is an awful lot of memory, especially on 32-bit versions where memory grants cannot use AWE-mapped memory.  Even on a 64-bit server with plenty of memory, do you really want a single query to consume 0.25GB of memory unnecessarily?  That’s 32,000 8KB pages that might be put to much better use. The Solution The answer is not to use the TEXT data type for the padding column.  That solution happens to have better performance characteristics for this specific query, but it still results in a spilled sort, and it is hard to recommend the use of a data type which is scheduled for removal.  I hope it is clear to you that the fundamental problem here is that SQL Server sorts the whole set arriving at a Sort operator.  Clearly, it is not efficient to sort the whole table in memory just to return 150 rows in a random order. The TEXT example was more efficient because it dramatically reduced the size of the set that needed to be sorted.  We can do the same thing by selecting 150 unique keys from the table at random (sorting by NEWID() for example) and only then retrieving the large padding column values for just the 150 rows we need.  The following script implements that idea for all four tables: SET STATISTICS IO ON ; WITH TestTable AS ( SELECT * FROM dbo.TestCHAR ), TopKeys AS ( SELECT TOP (150) id FROM TestTable ORDER BY NEWID() ) SELECT T1.id, T1.padding FROM TestTable AS T1 WHERE T1.id = ANY (SELECT id FROM TopKeys) OPTION (MAXDOP 1) ; WITH TestTable AS ( SELECT * FROM dbo.TestMAX ), TopKeys AS ( SELECT TOP (150) id FROM TestTable ORDER BY NEWID() ) SELECT T1.id, T1.padding FROM TestTable AS T1 WHERE T1.id IN (SELECT id FROM TopKeys) OPTION (MAXDOP 1) ; WITH TestTable AS ( SELECT * FROM dbo.TestTEXT ), TopKeys AS ( SELECT TOP (150) id FROM TestTable ORDER BY NEWID() ) SELECT T1.id, T1.padding FROM TestTable AS T1 WHERE T1.id IN (SELECT id FROM TopKeys) OPTION (MAXDOP 1) ; WITH TestTable AS ( SELECT * FROM dbo.TestMAXOOR ), TopKeys AS ( SELECT TOP (150) id FROM TestTable ORDER BY NEWID() ) SELECT T1.id, T1.padding FROM TestTable AS T1 WHERE T1.id IN (SELECT id FROM TopKeys) OPTION (MAXDOP 1) ; SET STATISTICS IO OFF ; All four queries now return results in much less than a second, with memory grants between 6 and 12MB, and without spilling to tempdb.  The small remaining inefficiency is in reading the id column values from the clustered primary key index.  As a clustered index, it contains all the in-row data at its leaf.  The CHAR and VARCHAR(MAX) tables store the padding column in-row, so id values are separated by a 3999-character column, plus row overhead.  The TEXT and MAXOOR tables store the padding values off-row, so id values in the clustered index leaf are separated by the much-smaller off-row pointer structure.  This difference is reflected in the number of logical page reads performed by the four queries: Table 'TestCHAR' logical reads 25511 lob logical reads 000 Table 'TestMAX'. logical reads 25511 lob logical reads 000 Table 'TestTEXT' logical reads 00412 lob logical reads 597 Table 'TestMAXOOR' logical reads 00413 lob logical reads 446 We can increase the density of the id values by creating a separate nonclustered index on the id column only.  This is the same key as the clustered index, of course, but the nonclustered index will not include the rest of the in-row column data. CREATE UNIQUE NONCLUSTERED INDEX uq1 ON dbo.TestCHAR (id); CREATE UNIQUE NONCLUSTERED INDEX uq1 ON dbo.TestMAX (id); CREATE UNIQUE NONCLUSTERED INDEX uq1 ON dbo.TestTEXT (id); CREATE UNIQUE NONCLUSTERED INDEX uq1 ON dbo.TestMAXOOR (id); The four queries can now use the very dense nonclustered index to quickly scan the id values, sort them by NEWID(), select the 150 ids we want, and then look up the padding data.  The logical reads with the new indexes in place are: Table 'TestCHAR' logical reads 835 lob logical reads 0 Table 'TestMAX' logical reads 835 lob logical reads 0 Table 'TestTEXT' logical reads 686 lob logical reads 597 Table 'TestMAXOOR' logical reads 686 lob logical reads 448 With the new index, all four queries use the same query plan (click to enlarge): Performance Summary: 0.3 seconds elapsed time 6MB memory grant 0MB tempdb usage 1MB sort set 835 logical reads (CHAR, MAX) 686 logical reads (TEXT, MAXOOR) 597 LOB logical reads (TEXT) 448 LOB logical reads (MAXOOR) No sort warning I’ll leave it as an exercise for the reader to work out why trying to eliminate the Key Lookup by adding the padding column to the new nonclustered indexes would be a daft idea Conclusion This post is not about tuning queries that access columns containing big strings.  It isn’t about the internal differences between TEXT and MAX data types either.  It isn’t even about the cool use of UPDATE .WRITE used in the MAXOOR table load.  No, this post is about something else: Many developers might not have tuned our starting example query at all – 5 seconds isn’t that bad, and the original query plan looks reasonable at first glance.  Perhaps the NEWID() function would have been blamed for ‘just being slow’ – who knows.  5 seconds isn’t awful – unless your users expect sub-second responses – but using 250MB of memory and writing 200MB to tempdb certainly is!  If ten sessions ran that query at the same time in production that’s 2.5GB of memory usage and 2GB hitting tempdb.  Of course, not all queries can be rewritten to avoid large memory grants and sort spills using the key-lookup technique in this post, but that’s not the point either. The point of this post is that a basic understanding of execution plans is not enough.  Tuning for logical reads and adding covering indexes is not enough.  If you want to produce high-quality, scalable TSQL that won’t get you paged as soon as it hits production, you need a deep understanding of execution plans, and as much accurate, deep knowledge about SQL Server as you can lay your hands on.  The advanced database developer has a wide range of tools to use in writing queries that perform well in a range of circumstances. By the way, the examples in this post were written for SQL Server 2008.  They will run on 2005 and demonstrate the same principles, but you won’t get the same figures I did because 2005 had a rather nasty bug in the Top N Sort operator.  Fair warning: if you do decide to run the scripts on a 2005 instance (particularly the parallel query) do it before you head out for lunch… This post is dedicated to the people of Christchurch, New Zealand. © 2011 Paul White email: @[email protected] twitter: @SQL_Kiwi

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  • Multi-Threaded Application vs. Single Threaded Application

    Why would we use a multi threaded application vs. a single threaded application? First we must define multithreading. Multithreading is a feature of an operating system that allows programs to run subcomponents or threads in parallel. Typically most applications only need to use one thread because they do not perform time consuming tasks. The use of multiple threads allows an application to distribute long running tasks so that they can be executed in parallel. This gives the user the perceived appearance that the application is working faster due to the fact that while one thread is waiting on an IO process the remaining tasks can make use of the available CPU. The allows working threads to execute in tandem so that they can be competed sooner. Multithreading Benefits Improved responsiveness — Users usually report improved responsiveness compared to single thread applications. Faster applications — Multiple threads can lead to improved application performance. Prioritization — Threads can be assigned a priority which would allow higher priority tasks to take precedence over lower priority tasks. Single Threading Benefits Programming and debugging —These activities are easier compared to multithreaded applications due to the reduced complexity Less Overhead — Threads add overhead to an application When developing multi-threaded applications, the following must be considered. Deadlocks occur when two threads hold a monitor that the other one requires. In essence each task is blocking the other and both tasks are waiting for the other monitor to be released. This forces an application to hang or deadlock. Resource allocation is used to prevent deadlocks because the system determines if approving the resource request will render the system in an unsafe state. An unsafe state could result in a deadlock. The system only approves requests that will lead to safe states. Thread Synchronization is used when multiple threads use the same instance of an object. The threads accessing the object can then be locked and then synchronized so that each task can interact with the static object on at a time.

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  • Apple iPad 2 In April, iPhone 5 in June With New Hardware[Rumours]

    - by Gopinath
    Blogs and news sites are buzzing with the rumours of Apple’s next generation iPad and iPhone devices. These rumours interests the bloggers, geeks and end users of Apple devices as Apple maintains very tight lip on the new features of their upcoming products. The gadget blog Engadget has some very interesting rumours on the release of iPad 2 & iPhone 5 as well the new hardware they are going to have. Lets get into the details if you love to read the rumours of high profile blogs iPad 2 Release Date and Specs Apple seems to be all set to release iPad 2 in April, that is almost an year after the release of first iPad. It’s common for Apple to enjoy an one year long time to release a new version of their products. So if at all the rumours are to be believed, I can place an order of iPad 2 in April. Just like many of you out there, I’m also holding my iPad buying instinct and waiting for iPad 2 as it’s going to have at the minimum retina display,  Facetime features and few game changing features in Apple’s style. The report claims, iPad 2 will have a front and back cameras retina display SD Card slot (seems to be no USB) a dual GSM / CDMA chipset, that lets you use it with both GSM(AT &T, Airte) and CDMA(Verizon, Reliance) telecom providers iPhone 5 Release Date and Specs When it comes to iPhone 5 information, the rumour claims that the new iPhone is a completed redesigned device and it’s slated to release in summer of United States(i.e. June 2011). The device is also being tested by senior Apple executives right inside the campus and strictly not allowed to carry it outside. This restriction is to make sure that iPhone 5 will not land land up in a bar and then in the hands of geek blogs like how it happened with iPhone 4 last year. When it comes to the hardware of iPhone 5 Apple’s new A5 CPU (a Cortex A9-based, multi-core chip) a dual GSM / CDMA chipset, that lets you use it with both GSM(AT &T, Airte) and CDMA(Verizon, Reliance) telecom providers via Engadget and cc image credit flickr/mr-blixt This article titled,Apple iPad 2 In April, iPhone 5 in June With New Hardware[Rumours], was originally published at Tech Dreams. Grab our rss feed or fan us on Facebook to get updates from us.

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  • XMPP— openfire,PHP and python web service

    - by mlakhara
    I am planning to integrate real time notifications into a web application that I am currently working on. I have decided to go with XMPP for this and selected openfire server which i thought to be suitable for my needs. The front end uses strophe library to fetch the notifications using BOSH from my openfire server. However the notices are the notifications and other messages are to be posted by my application and hence I think this code needs to reside at the backend. Initially I thougt of going with PHP XMPP libraries like XMPHP and JAXL but then I think that this would cause much overhead as each script will have to do same steps like connection, authentication etc. and I think this would make the PHP end a little slow and unresponsive. Now I am thinking of creating a middle-ware application acting as a web service that the PHP will call and this application will handle the stuff with XMPP service. The benefit with this is that this app(a server if you will) will have to connect just once and the it will sit there listening on a port. also I am planning to build it in a asynchronous way such that It will first take all the requests from my PHp app and then when there are no more requests; go about doing the notification publishing stuff. I am planninng to create this service in Python using SleekXMPP. This is just what I planned. I am new to XMPP and this whole web service stuff ans would like to take your comments on this regarding issues like memory and CPU usage, advantages, disadvantages, scalability issues,security etc. Thanks in advance. PS:-- also if something like this already exists(although I didn't find after a lot of Googling) Please direct me there. EDIT --- The middle-level service should be doing the following(but not limited to): 1. Publishing notifications for different level of groups and community pages. 2. Notification for single user on some event. 3. User registration(can be done using user service plugin though). EDIT --- Also it should like to create pub-sub nodes and subscribe and unsubscribe users from these pub-sub nodes. Also I want to store the notifications and messages in a database(openfire doesn't). Would that be a good choice?

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