Search Results

Search found 1157 results on 47 pages for 'latency'.

Page 42/47 | < Previous Page | 38 39 40 41 42 43 44 45 46 47  | Next Page >

  • Issues connection to Ubuntu via PuTTy

    - by user1787262
    I'm not sure this is the appropriate stack exchange site to post this question on. If not, please flag this for migration. I am trying to use PuTTy ssh into my ubuntu machine which is wirelessly connected to the same network. I originally ran ifconfig to get my ubuntu machines private network IP address. I then verified that ssh was running, I even ssh'd into my school network and then into the ubuntu machine itself. No problems yet. On my windows 8 machine I ran ipconfig to get my private network IPv4 address. I then pinged my ubunty machines IP and 100% of packets were received. I figured, "OK we are ready to use PuTTy to connect to my Ubuntu Machine". Keep in mind this was my first time using PuTTy. I tried entering the IP of my ubuntu machine in the PuTTy Config GUI but I got a connection timeout. At this moment I don't really know what's going on, SSH is running on port 22 of my Ubuntu machine and I can ping the machine why is it not connecting? (I tried [username]@ip too). So I went on my Ubuntu machine and ran nmap -sP 192.168.0.1/24 and found that my windows machines IP did not show up, the host is down. I'm at a lost in something I am not very familiar with. Would anyone be able to help me or direct me to some resources that would trouble shoot my problem? Thank you EDIT (ADDITION): tyler@tyler-Aspire-5250:~$ nmap -v 192.168.0.123 Starting Nmap 6.40 ( http://nmap.org ) at 2014-06-06 01:56 MDT Initiating Ping Scan at 01:56 Scanning 192.168.0.123 [2 ports] Completed Ping Scan at 01:56, 3.00s elapsed (1 total hosts) Nmap scan report for 192.168.0.123 [host down] Read data files from: /usr/bin/../share/nmap Note: Host seems down. If it is really up, but blocking our ping probes, try -Pn Nmap done: 1 IP address (0 hosts up) scanned in 3.14 seconds tyler@tyler-Aspire-5250:~$ nmap -Pn 192.168.0.123 Starting Nmap 6.40 ( http://nmap.org ) at 2014-06-06 01:56 MDT Nmap scan report for 192.168.0.123 Host is up (0.022s latency). Not shown: 998 filtered ports PORT STATE SERVICE 2869/tcp open icslap 5357/tcp open wsdapi Nmap done: 1 IP address (1 host up) scanned in 72.51 seconds

    Read the article

  • Best Processor for MediaSmart Server?

    - by Kent Boogaart
    I'm trying to figure out what the best possible processor is that I can stick in my HP MediaSmart server. I'm clueless when it comes to correlating CPUs to motherboards. I suspect it's the socket type I care about, but I worry that there's more to it. CPU-Z gives me (excerpt): Processors Information ------------------------------------------------------------------------- Processor 1 ID = 0 Number of cores 1 (max 1) Number of threads 1 (max 1) Name AMD Sempron LE-1150 Codename Sparta Specification AMD Sempron(tm) Processor LE-1150 Package Socket AM2 (940) CPUID F.F.1 Extended CPUID F.7F Brand ID 1 Core Stepping DH-G1 Technology 65 nm Core Speed 1000.0 MHz Multiplier x FSB 5.0 x 200.0 MHz HT Link speed 800.0 MHz Stock frequency 2000 MHz Instructions sets MMX (+), 3DNow! (+), SSE, SSE2, SSE3, x86-64 L1 Data cache 64 KBytes, 2-way set associative, 64-byte line size L1 Instruction cache 64 KBytes, 2-way set associative, 64-byte line size L2 cache 256 KBytes, 16-way set associative, 64-byte line size FID/VID Control yes Max FID 10.0x Max VID 1.350 V P-State FID 0x2 - VID 0x12 (5.0x - 1.100 V) P-State FID 0xA - VID 0x0C (9.0x - 1.250 V) P-State FID 0xC - VID 0x0A (10.0x - 1.300 V) K8 Thermal sensor yes K8 Revision ID 6.0 Attached device PCI device at bus 0, device 24, function 0 Attached device PCI device at bus 0, device 24, function 1 Attached device PCI device at bus 0, device 24, function 2 Attached device PCI device at bus 0, device 24, function 3 Chipset ------------------------------------------------------------------------- Northbridge SiS 761GX rev. 02 Southbridge SiS 966 rev. 59 Graphic Interface AGP AGP Revision 3.0 AGP Transfer Rate 8x AGP SBA supported, enabled Memory Type DDR2 Memory Size 2048 MBytes Channels Single Memory Frequency 200.0 MHz (CPU/5) CAS# latency (CL) 5.0 RAS# to CAS# delay (tRCD) 5 RAS# Precharge (tRP) 5 Cycle Time (tRAS) 15 Bank Cycle Time (tRC) 21 Command Rate (CR) 1T DMI ------------------------------------------------------------------------- DMI BIOS vendor Phoenix Technologies, LTD version R03 date 05/08/2008 DMI System Information manufacturer HP product MediaSmart Server version unknown serial CN68330DGH UUID A482007B-B0CC7593-DD11736A-407B7067 DMI Baseboard vendor Wistron model SJD4 revision A.0 serial unknown DMI System Enclosure manufacturer HP chassis type Desktop chassis serial unknown DMI Processor manufacturer AMD model AMD Sempron(tm) Processor LE-1150 clock speed 2000.0 MHz FSB speed 200.0 MHz multiplier 10.0x DMI Memory Controller correction 64-bit ECC Max module size 4096 MBytes DMI Memory Module designation A0 size 2048 MBytes (double bank) DMI Memory Module designation A1 DMI Memory Module designation A2 DMI Memory Module designation A3 DMI Port Connector designation PS/2 Mouse (internal) port type Mouse Port connector PS/2 connector PS/2 DMI Port Connector designation USB0 (external) port type USB DMI Physical Memory Array location Motherboard usage System Memory correction None max capacity 16384 MBytes max# of devices 4 DMI Memory Device designation A0 format DIMM type unknown total width 64 bits data width 64 bits size 2048 MBytes DMI Memory Device designation A1 format DIMM type unknown total width 64 bits data width 64 bits DMI Memory Device designation A2 format DIMM type unknown total width 64 bits data width 64 bits DMI Memory Device designation A3 format DIMM type unknown total width 64 bits data width 64 bits How do I figure out what options I have for an upgrade?

    Read the article

  • Is real-time or synchronous replication possible over WAN link?

    - by johnnyb10
    The company I work for is looking to implement truly real-time file replication with file locking over a WAN link that spans over 2000 miles. We currently have a 16-drive SAN setup in our east coast office. We also have an office out in Colorado that will have the same exact SAN setup. The idea is to have those two SANs contain the same exact data at all times, which will allow us to work with the same data pool, and which will also provide use with an offsite backup solution, should a failure occur on either end. We're running Server 2008. The objective is to enable users in the east coast office to work on files and have those changes be instantly updated on the Colorado SAN as well. We also need there to be file locking so that there will be no conflicts or overwritten changes if users attempt to work on the same file. Is this scenario even possible, at speeds that would make the files usable? And if so, what software would we need to pull this off? As I understand it, DFS-R does not provide file locking, so if we used that, we would need to go with a third-party product like Peerlock. But I don't even know if DFS-R is an option. Can it replicate quickly enough over a WAN link? Can any product? It seems that if we were to use synchronous replication, the programs would be unacceptably slow, as every write would have to wait for confirmation from the other end of the link. But if we used asynchronous replication, what kind of latency would we be looking at? There is a product from GlobalScape called WAFS that claims to provide "File coherence with real-time file locking, file release, and synchronization" and says that "As files are modified, changes are mirrored instantly using intelligent byte-level differencing to minimize the impact on network bandwidth". So this sounds like synchronous replication, but that doesn't even seem possible, given physical limitations such as the speed of light. If anyone has any experience with this kind of setup, or knows whether it's even possible, I'd appreciate your input and suggestions, including recommendations for software that we should check out.

    Read the article

  • RHEL 6.x on Rackspace Cloud and Dedicated hardware experiencing Redis Timeouts

    - by zhallett
    I just recently set up a mixture of RHEL 6.1 Rackspace cloud hosts and RHEL 6.2 dedicated hosts using Rackconnect. I am experiencing intermittent Redis timeouts from within our Rails 3.2.8 app with Redis 2.4.16 running on the RHEL 6.2 dedicated hosts. There is no network latency or packet loss. Also there are no errors on any interfaces on our cloud or dedicated servers or on the managed firewall from Rackspace. When Redis timesout, there is nothing logged within redis even though it is set up to do debug logging. The only error we receive is from Airbrake saying there was a Redis timeout. Network topology: RHEL 6.1 cloud hosts <--> Alert logic IDS <--> Cisco ASA 5510 <--> RHEL 6.2 dedicated hosts (web nodes) (two way NAT) (db hosts running redis) Ping from db host to web host: 64 bytes from 10.181.230.180: icmp_seq=998 ttl=64 time=0.520 ms 64 bytes from 10.181.230.180: icmp_seq=999 ttl=64 time=0.579 ms 64 bytes from 10.181.230.180: icmp_seq=1000 ttl=64 time=0.482 ms --- web1.xxxxxx.com ping statistics --- 1000 packets transmitted, 1000 received, 0% packet loss, time 999007ms rtt min/avg/max/mdev = 0.359/0.535/5.684/0.200 ms Ping from web host to db host: 64 bytes from 192.168.100.26: icmp_seq=998 ttl=64 time=0.544 ms 64 bytes from 192.168.100.26: icmp_seq=999 ttl=64 time=0.452 ms 64 bytes from 192.168.100.26: icmp_seq=1000 ttl=64 time=0.529 ms --- data1.xxxxxx.com ping statistics --- 1000 packets transmitted, 1000 received, 0% packet loss, time 999017ms rtt min/avg/max/mdev = 0.358/0.499/6.120/0.201 ms Redis config: daemonize yes pidfile /var/run/redis/6379/redis_6379.pid port 6379 timeout 0 loglevel debug logfile /var/lib/redis/log syslog-enabled yes syslog-ident redis-6379 syslog-facility local0 databases 16 save 900 1 save 300 10 save 60 10000 rdbcompression yes dbfilename dump-6379.rdb dir /var/lib/redis maxclients 10000 maxmemory-policy volatile-lru maxmemory-samples 3 appendfilename appendonly-6379.aof appendfsync everysec no-appendfsync-on-rewrite no auto-aof-rewrite-percentage 100 auto-aof-rewrite-min-size 64mb slowlog-log-slower-than 10000 slowlog-max-len 1024 vm-enabled no vm-swap-file /tmp/redis.swap vm-max-memory 0 vm-page-size 32 vm-pages 134217728 vm-max-threads 4 hash-max-zipmap-entries 512 hash-max-zipmap-value 64 list-max-ziplist-entries 512 list-max-ziplist-value 64 set-max-intset-entries 512 zset-max-ziplist-entries 128 zset-max-ziplist-value 64 activerehashing yes Redis-cli info: redis-cli info redis_version:2.4.16 redis_git_sha1:00000000 redis_git_dirty:0 arch_bits:64 multiplexing_api:epoll gcc_version:4.4.6 process_id:4174 uptime_in_seconds:79346 uptime_in_days:0 lru_clock:1064644 used_cpu_sys:13.08 used_cpu_user:19.81 used_cpu_sys_children:1.56 used_cpu_user_children:7.69 connected_clients:167 connected_slaves:0 client_longest_output_list:0 client_biggest_input_buf:0 blocked_clients:6 used_memory:15060312 used_memory_human:14.36M used_memory_rss:22061056 used_memory_peak:15265928 used_memory_peak_human:14.56M mem_fragmentation_ratio:1.46 mem_allocator:jemalloc-3.0.0 loading:0 aof_enabled:0 changes_since_last_save:166 bgsave_in_progress:0 last_save_time:1352823542 bgrewriteaof_in_progress:0 total_connections_received:286 total_commands_processed:507254 expired_keys:0 evicted_keys:0 keyspace_hits:1509 keyspace_misses:65167 pubsub_channels:0 pubsub_patterns:0 latest_fork_usec:690 vm_enabled:0 role:master db0:keys=6,expires=0 edit 1: add redis-cli info output

    Read the article

  • Why are the analoge stereo input and output of my M-Audio 24/96 soundcard not available to me in Ubu

    - by user37968
    I have installed Lucid on an old Mac PowerPC G4 desktop with a M-Audio Audiophile 24/96 soundcard. The only inputs and outputs I can select in the audio preferences are digital ones for the digital input and output. "lspci -v" shows the card as so: 0001:10:13.0 Multimedia audio controller: VIA Technologies Inc. ICE1712 [Envy24] PCI Multi-Channel I/O Controller (rev 02) Subsystem: VIA Technologies Inc. Device d634 Flags: bus master, medium devsel, latency 16, IRQ 53 I/O ports at 0440 [size=32] I/O ports at 04b0 [size=16] I/O ports at 04a0 [size=16] I/O ports at 0400 [size=64] Capabilities: <access denied> Kernel driver in use: ICE1712 Kernel modules: snd-ice1712 "cat /proc/asound/cards" as so: 0 [Tumbler ]: PMac Tumbler - PowerMac Tumbler PowerMac Tumbler (Dev 21) Sub-frame 0 1 [M2496 ]: ICE1712 - M Audio Audiophile 24/96 M Audio Audiophile 24/96 at 0x440, irq 53 "aplay -L" shows these as listed: pulse Playback/recording through the PulseAudio sound server front:CARD=Tumbler,DEV=0 PowerMac Tumbler, PowerMac Tumbler Front speakers front:CARD=M2496,DEV=0 M Audio Audiophile 24/96, ICE1712 multi Front speakers surround40:CARD=M2496,DEV=0 M Audio Audiophile 24/96, ICE1712 multi 4.0 Surround output to Front and Rear speakers surround41:CARD=M2496,DEV=0 M Audio Audiophile 24/96, ICE1712 multi 4.1 Surround output to Front, Rear and Subwoofer speakers surround50:CARD=M2496,DEV=0 M Audio Audiophile 24/96, ICE1712 multi 5.0 Surround output to Front, Center and Rear speakers surround51:CARD=M2496,DEV=0 M Audio Audiophile 24/96, ICE1712 multi 5.1 Surround output to Front, Center, Rear and Subwoofer speakers iec958:CARD=M2496,DEV=0 M Audio Audiophile 24/96, ICE1712 multi IEC958 (S/PDIF) Digital Audio Output I believe it is a problem with detecting the analogue input/output. Sometimes I can get sound from the device but it is a sheet of white noise and tinkering makes it go away again I don't know if that is a separate problem or if it is linked to not being able to see the analogue input/outputs in the sound preferences. Any help would be greatly appreciated As for the white noise I have installed the Envy24 control panel and spend lots of time playing with the settings but when I can get the white noise I can never get it to an quality where I can actually hear what is being played. The internal speaker plays audio fine and plugging in a NI Audio 4DJ via usb also plays sound, although with some static but I believe that is due to an underpowered usb2 pci expansion card not being able to get enough electricity to the device. Alternatively I have seen other people with problems with this device so it may be a bug in the driver but that is another matter. I would like to get the M-Audio card working so I can begin to enjoy my music once again. As a note, I do not currently have any audio equipment capable of sending or receiving audio via the digital inputs and output so I can not check if they are working. The sound preferences show a wide range of digital in and out options with various surround sound options but no analogue ins and outs.

    Read the article

  • Why are the analoge stereo input and output of my M-Audio 24/96 soundcard not available to me in Ubuntu Lucid

    - by MIDoubleKO
    I have installed Lucid on an old Mac PowerPC G4 desktop with a M-Audio Audiophile 24/96 soundcard. The only inputs and outputs I can select in the audio preferences are digital ones for the digital input and output. "lspci -v" shows the card as so: 0001:10:13.0 Multimedia audio controller: VIA Technologies Inc. ICE1712 [Envy24] PCI Multi-Channel I/O Controller (rev 02) Subsystem: VIA Technologies Inc. Device d634 Flags: bus master, medium devsel, latency 16, IRQ 53 I/O ports at 0440 [size=32] I/O ports at 04b0 [size=16] I/O ports at 04a0 [size=16] I/O ports at 0400 [size=64] Capabilities: <access denied> Kernel driver in use: ICE1712 Kernel modules: snd-ice1712 "cat /proc/asound/cards" as so: 0 [Tumbler ]: PMac Tumbler - PowerMac Tumbler PowerMac Tumbler (Dev 21) Sub-frame 0 1 [M2496 ]: ICE1712 - M Audio Audiophile 24/96 M Audio Audiophile 24/96 at 0x440, irq 53 "aplay -L" shows these as listed: pulse Playback/recording through the PulseAudio sound server front:CARD=Tumbler,DEV=0 PowerMac Tumbler, PowerMac Tumbler Front speakers front:CARD=M2496,DEV=0 M Audio Audiophile 24/96, ICE1712 multi Front speakers surround40:CARD=M2496,DEV=0 M Audio Audiophile 24/96, ICE1712 multi 4.0 Surround output to Front and Rear speakers surround41:CARD=M2496,DEV=0 M Audio Audiophile 24/96, ICE1712 multi 4.1 Surround output to Front, Rear and Subwoofer speakers surround50:CARD=M2496,DEV=0 M Audio Audiophile 24/96, ICE1712 multi 5.0 Surround output to Front, Center and Rear speakers surround51:CARD=M2496,DEV=0 M Audio Audiophile 24/96, ICE1712 multi 5.1 Surround output to Front, Center, Rear and Subwoofer speakers iec958:CARD=M2496,DEV=0 M Audio Audiophile 24/96, ICE1712 multi IEC958 (S/PDIF) Digital Audio Output I believe it is a problem with detecting the analogue input/output. Sometimes I can get sound from the device but it is a sheet of white noise and tinkering makes it go away again I don't know if that is a separate problem or if it is linked to not being able to see the analogue input/outputs in the sound preferences. Any help would be greatly appreciated As for the white noise I have installed the Envy24 control panel and spend lots of time playing with the settings but when I can get the white noise I can never get it to an quality where I can actually hear what is being played. The internal speaker plays audio fine and plugging in a NI Audio 4DJ via usb also plays sound, although with some static but I believe that is due to an underpowered usb2 pci expansion card not being able to get enough electricity to the device. Alternatively I have seen other people with problems with this device so it may be a bug in the driver but that is another matter. I would like to get the M-Audio card working so I can begin to enjoy my music once again. As a note, I do not currently have any audio equipment capable of sending or receiving audio via the digital inputs and output so I can not check if they are working. The sound preferences show a wide range of digital in and out options with various surround sound options but no analogue ins and outs.

    Read the article

  • XCP Project Kronos syslog error: "irq ... : nobody cared" on Dom0 host

    - by Vlad Fedin
    One of our production clusters driven by XCP suddenly went uresponsive. After restart and some investigation we found such logs in dom0 machine syslog: Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659040] irq 339: nobody cared (try booting with the "irqpoll" option) Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659058] Pid: 0, comm: swapper/3 Tainted: G C O 3.2.0-24-generic #37-Ubuntu Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659060] Call Trace: Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659062] <IRQ> [<ffffffff810db37d>] __report_bad_irq+0x3d/0xe0 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659071] [<ffffffff810db605>] note_interrupt+0x135/0x190 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659074] [<ffffffff810d8e69>] handle_irq_event_percpu+0xa9/0x220 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659078] [<ffffffff8130ff3b>] ? radix_tree_lookup+0xb/0x10 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659081] [<ffffffff810d9031>] handle_irq_event+0x51/0x80 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659084] [<ffffffff810dc187>] handle_edge_irq+0x87/0x140 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659089] [<ffffffff813a8829>] __xen_evtchn_do_upcall+0x199/0x250 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659092] [<ffffffff813aa96f>] xen_evtchn_do_upcall+0x2f/0x50 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659096] [<ffffffff81666d3e>] xen_do_hypervisor_callback+0x1e/0x30 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659097] <EOI> [<ffffffff810013aa>] ? hypercall_page+0x3aa/0x1000 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659104] [<ffffffff810013aa>] ? hypercall_page+0x3aa/0x1000 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659107] [<ffffffff8100a1d0>] ? xen_safe_halt+0x10/0x20 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659110] [<fff IRQ 339 in cat /proc/interrupts: 339: ... xen-pirq-msi-x eth0 where eth0 is hardware NIC. While host machine seems to hang, guest machines continue to work, so our tiny internal monitoring on one of the virtual hosts logged something like that: [2012-10-26 20:31:51] [OK......] 200 OK : 113159149 ns [2012-10-26 20:32:40] [DISASTER] 500 Can't connect to [hostname]:80 (No route to host) : 47763284432 ns ... [2012-10-26 20:34:40] [DISASTER] 500 Can't connect to [hostname]:80 (No route to host) : 46894835070 ns [2012-10-26 20:34:57] [DISASTER] 500 Can't connect to [hostname]:80 (Bad hostname) : 16821741955 ns ... [2012-10-26 20:38:18] [DISASTER] 500 Can't connect to [hostname]:80 (Bad hostname) : 20103298289 ns [2012-10-26 20:38:37] [DISASTER] 500 Can't connect to [hostname]:80 (Bad hostname) : 17895754943 ns Host and guest OS: Ubuntu 12.04 LTS, 05:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection Subsystem: ASUSTeK Computer Inc. Device 8369 Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx+ Latency: 0, Cache Line Size: 64 bytes Interrupt: pin A routed to IRQ 17 Region 0: Memory at fe500000 (32-bit, non-prefetchable) [size=128K] Region 2: I/O ports at e000 [size=32] Region 3: Memory at fe520000 (32-bit, non-prefetchable) [size=16K] Capabilities: <access denied> Kernel driver in use: e1000e Kernel modules: e1000e Any hints how to debug this?

    Read the article

  • how to setup kismet.conf on Ubuntu

    - by Registered User
    I installed Kismet on my Ubuntu 10.04 machine as apt-get install kismet every thing seems to work fine. but when I launch it I see following error kismet Launching kismet_server: //usr/bin/kismet_server Suid priv-dropping disabled. This may not be secure. No specific sources given to be enabled, all will be enabled. Non-RFMon VAPs will be destroyed on multi-vap interfaces (ie, madwifi-ng) Enabling channel hopping. Enabling channel splitting. NOTICE: Disabling channel hopping, no enabled sources are able to change channel. Source 0 (addme): Opening none source interface none... FATAL: Please configure at least one packet source. Kismet will not function if no packet sources are defined in kismet.conf or on the command line. Please read the README for more information about configuring Kismet. Kismet exiting. Done. I followed this guide http://www.ubuntugeek.com/kismet-an-802-11-wireless-network-detector-sniffer-and-intrusion-detection-system.html#more-1776 how ever in kismet.conf I am not clear with following line source=none,none,addme as to what should I change this to. lspci -vnn shows 0c:00.0 Network controller [0280]: Broadcom Corporation BCM4312 802.11b/g [14e4:4315] (rev 01) Subsystem: Dell Device [1028:000c] Flags: bus master, fast devsel, latency 0, IRQ 17 Memory at f69fc000 (64-bit, non-prefetchable) [size=16K] Capabilities: [40] Power Management version 3 Capabilities: [58] Vendor Specific Information <?> Capabilities: [e8] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable- Capabilities: [d0] Express Endpoint, MSI 00 Capabilities: [100] Advanced Error Reporting <?> Capabilities: [13c] Virtual Channel <?> Capabilities: [160] Device Serial Number Capabilities: [16c] Power Budgeting <?> Kernel driver in use: wl Kernel modules: wl, ssb and iwconfig shows lo no wireless extensions. eth0 no wireless extensions. eth1 IEEE 802.11bg ESSID:"WIKUCD" Mode:Managed Frequency:2.462 GHz Access Point: <00:43:92:21:H5:09> Bit Rate=11 Mb/s Tx-Power:24 dBm Retry min limit:7 RTS thr:off Fragment thr:off Encryption key:off Power Managementmode:All packets received Link Quality=1/5 Signal level=-81 dBm Noise level=-90 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:169 Invalid misc:0 Missed beacon:0 So what should I be putting in place of source=none,none,addme with output I mentioned above ?

    Read the article

  • Sharing files between multiple sites using only desktop software

    - by perlyking
    Our organisation has three sites; a head office, where the master copies of company files are stored, plus two branch offices using only workstations and a NAS or two. Currently we're talking about <10GB. At the main office, we have no admin access to the file server, as this is entirely controlled by the larger institution where we are located. For the same reason, we have no VPN remote access to this network. Instead, we simply have access to a network share using over a Novell LAN. Question: how can we share files between offices in way that minimises latency, i.e. that gives us a mirror of the main network share at each site? (There is little likelihood of concurrent editing, and we can live with the odd file conflict now and again). Up to now branch office staff have had to use GotoMyPC-type solutions to remotely access files held at the main office. Or email. I was hoping to use Google Drive on a dedicated workstation at each office to sync the contents of the network share (head office) or NAS (branch offices) via the cloud, but at my last attempt (29 Jun '12), the Google Drive installer would not allow me to designate the remote network share as the "target" folder. (I chose Google Drive over Drobbox et al. as we already use GMail for corporate mail) The next idea was to use a designated workstation at head office to mirror the network share to a local drive, then use Google Drive to push that to the cloud. This seems a step too far. Nor do I have any good ideas about how to achieve this network/local mirroring, as we can't, for example, install the rsync daemon on the server. I do not want to use Google Drive locally on each workstation as this will inconvenience users, and more importantly, move files off the backed-up, well-maintained (UPS, RAID etc) network share at head office. Our budget is only in the £100's. Should we perhaps just ditch the head office server and use something like JungleDisk? At least this presents the user with what appears to be a mapped drive.

    Read the article

  • Can not get sound over hdmi in kubuntu 9.10

    - by user32509
    I have used a hdmi cable to connect my lcd (which is connected with my speakers) with my nvida 275 gtx grafic card. I can not get the sound output to work. The hardware itself is working probably - I tested it under windows. Currently I am running Kubuntu 9.10 64 with Nvidia 190.53. The sound output worked fine before I installed the hdmi connection. (German output - i can change it, if you tell me how :)) aplay -l **** Liste von PLAYBACK Geräten **** Karte 0: Intel [HDA Intel], Gerät 0: ALC889A Analog [ALC889A Analog] Untergeordnete Geräte: 1/1 Untergeordnetes Gerät '0: subdevice #0 Karte 0: Intel [HDA Intel], Gerät 1: ALC889A Digital [ALC889A Digital] Untergeordnete Geräte: 1/1 Untergeordnetes Gerät '0: subdevice #0 aplay -L front:CARD=Intel,DEV=0 HDA Intel, ALC889A Analog Front speakers surround40:CARD=Intel,DEV=0 HDA Intel, ALC889A Analog 4.0 Surround output to Front and Rear speakers surround41:CARD=Intel,DEV=0 HDA Intel, ALC889A Analog 4.1 Surround output to Front, Rear and Subwoofer speakers surround50:CARD=Intel,DEV=0 HDA Intel, ALC889A Analog 5.0 Surround output to Front, Center and Rear speakers surround51:CARD=Intel,DEV=0 HDA Intel, ALC889A Analog 5.1 Surround output to Front, Center, Rear and Subwoofer speakers surround71:CARD=Intel,DEV=0 HDA Intel, ALC889A Analog 7.1 Surround output to Front, Center, Side, Rear and Woofer speakers iec958:CARD=Intel,DEV=0 HDA Intel, ALC889A Digital IEC958 (S/PDIF) Digital Audio Output null Discard all samples (playback) or generate zero samples (capture) pulse Playback/recording through the PulseAudio sound server And i disabled mute in kmix an all channels :) Edit: lspci -v ... 00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 02) Subsystem: Giga-byte Technology Device a022 Flags: bus master, fast devsel, latency 0, IRQ 22 Memory at ea400000 (64-bit, non-prefetchable) [size=16K] Capabilities: [50] Power Management version 2 Capabilities: [60] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable- Capabilities: [70] Express Root Complex Integrated Endpoint, MSI 00 Capabilities: [100] Virtual Channel <?> Capabilities: [130] Root Complex Link <?> Kernel driver in use: HDA Intel Kernel modules: snd-hda-intel ... cat /proc/asound/version Advanced Linux Sound Architecture Driver Version 1.0.20. lsmod | grep snd_hda_intel snd_hda_intel 31880 2 snd_hda_codec 87584 2 snd_hda_codec_realtek,snd_hda_intel snd_pcm 93160 3 snd_hda_intel,snd_hda_codec,snd_pcm_oss snd 77096 16 snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_seq_oss,snd_rawmidi,snd_seq,snd_timer,snd_seq_device snd_page_alloc 10928 2 snd_hda_intel,snd_pcm I think I am missing the something-hdmi module? Is there such a thing?

    Read the article

  • On ESXi, guest machines hang for significant intervals compared to real machines. How can I fix this?

    - by Tarbox
    This is ESXi version 5.0.0. We plan on upgrading to 5.5 eventually. I have four code profiles, two taken on a real, unvirtualized machine, two taken on a virtual machine. Ordering the list of subroutines by time spent in each one, the two real profiles are practically identical. The two virtual profiles are different from each other and from the real profiles: a subset of subroutines are taking a lot more time on the virtual machines, and the subset is different for each run. The two virtual profiles take a similar amount of time, which is 3 times the amount of time the real profiles take. This gross "how long does it take?" result is consistent after hundreds of tests across three different virtual machines on two different host machines -- the virtual machine is just slower. I've only the code profiling on the four, however. Here's the most guilty set of lines: This is the real machine: 8µs $text = '' unless defined $text; 1.48ms foreach ( split( "\n", $text ) ) { This is the first run on the virtual machine: 20.1ms $text = '' unless defined $text; 1.49ms foreach ( split( "\n", $text ) ) { This is the second run on the virtual machine: 6µs $text = '' unless defined $text; 21.9ms foreach ( split( "\n", $text ) ) { My WAG is that the VM is swapping out the thread and then swapping it back in, destroying some level of cache in the process, but these code profiles were taken when the vm in question was the only active vm on the host, so... what? What does that mean? The guest itself is under light load, this is a latency problem for my users rather than throughput. The host is also under a light load, if I knew what resources to assign where, I could do it without worrying about the cost. I've attempted to lock memory, reserve cpu, assign a restrictive affinity, and disable hyperthread sharing. They don't help, it still takes the VM 2-4x the amount of time to do the same thing as the real machine. The host the tests were run on is 6x2.50GHz, Intel Xeon E5-26400 w/ 16gigs of ram. The guest exhibits the same performance under a wide combination of settings. The real machine is 4x2.13GHz, Xeon E5506 w/ 2 gigs of ram. Thank you for all advice.

    Read the article

  • VLAN issues between linux kernels 2.6 / 3.3 in an ESX / Cisco environment

    - by David Griffith
    I shall attempt to explain an issue I have encountered - I have a VM running on esx 4.1 with an interface connected to VLAN800 via an access port on a cisco 3750. It runs linux - kernel 2.6.24, and has about 5 to 10 Mbit of chatter on 10.10.0.0/16 and various multicast addresses to look after. I needed to isolate certain devices from certain other devices on the network, with all of them having to talk to that one VM. No, the address space can't be separated, nor can the networks be easily vlan'd apart. The software on the VM listens to one interface only. Private vlans appear to be the way to go. So as a test, I built a bridge on the VM that globs together the vlans as needed. All good, everything works as expected. But occasionally (sigh) there's some latency that trips up a couple of profinet devices on the network because, you know, you're not really supposed to trunk real-time protocols around the place willy-nilly. I shift it to our test/backup server - works nicely, but I don't want it to be running on the test server as we muck around with that a lot. So I says to myself, "I'll put it on a new VM for testing and tweaking." I download a small linux distro with kernel 3.3, and install as a new VM with a the vlans as separate interfaces for testing. I power up the testing VM - ok. I bring up all the separate interfaces - ok. I can ping the production VM, see all sorts of traffic going past with tshark, etc. I build a bridge and put the primary vlan on it - the production VM running 2.6 immediately loses its multicast traffic - Unicast is fine. (?) I shut down the bridge - still no multicast traffic (!?) I power-cycle the production VM(!?!?) - multicast traffic returns. I trunk everything into the testing VM and create vlan interfaces under linux instead - same result, as soon as I start the bridge.... no multicast on the production VM. Ok, so I take a break and leave things alone. I decide to play with a couple of ubiquiti bullet radios - I'm testing various firmware as a side project. I flash a radio with Open-wrt-12.09. I enable a trunk on a port on a cisco on our network so I can muck around with multiple vlans and SSIDs I power up the radio and connect - ok. I create a vlan interface from the trunk.... the same vlan as the production VM wayyyyy over there, three cisco routers away. Ok. I bridge the vlan interface to the wifi interface and immediately get a phone call. The production VM has (suprise!) lost its multicast traffic. Again, nothing comes back until I power-cycle the VM. What the hell is going on?

    Read the article

  • Network unreachable on Ubuntu guest after trying to set up a host only network on Virtualbox

    - by gkb0986
    I have a Mac OS X host and a bunch of guests including Ubuntu and Arch Linux. I was trying to set up a host-only network at eth1 to let me ssh into the system. But now eth0 isn't working properly either. Ubuntu can no longer connect to remote hosts or browse the internet. It tells me that the network is unreachable. What's gone wrong here? I've included some diagnostics below. $ifconfig lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:10968 errors:0 dropped:0 overruns:0 frame:0 TX packets:10968 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:897264 (897.2 KB) TX bytes:897264 (897.2 KB) Other diagnostic commands and the output: $sudo lspci -n 00:00.0 0600: 8086:1237 (rev 02) 00:01.0 0601: 8086:7000 00:01.1 0101: 8086:7111 (rev 01) 00:02.0 0300: 80ee:beef 00:03.0 0200: 8086:100e (rev 02) 00:04.0 0880: 80ee:cafe 00:05.0 0401: 8086:2415 (rev 01) 00:06.0 0C03: 106B:003F 00:07.0 0680: 8086:7113 (REV 08) 00:0D.0 0106: 8086:2829 (REV 02) $sudo lshw -c network *-network DISABLED description: Ethernet interface product: 82540EM Gigabit Ethernet Controller vendor: Intel Corporation physical id: 3 bus info: pci@0000:00:03.0 logical name: eth0 version: 02 serial: 08:00:27:7d:22:df size: 1Gbit/s capacity: 1Gbit/s width: 32 bits clock: 66MHz capabilities: pm pcix bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=e1000 driverversion=7.3.21-k8-NAPI duplex=full firmware=N/A latency=64 link=no mingnt=255 multicast=yes port=twisted pair speed=1Gbit/s resources: irq:19 memory:f0000000-f001ffff ioport:d010(size=8) $lsmod Module Size Used by nls_utf8 12557 1 isofs 40257 1 vboxsf 43743 2 vesafb 13844 1 snd_intel8x0 38570 2 snd_ac97_codec 134869 1 snd_intel8x0 ac97_bus 12730 1 snd_ac97_codec snd_pcm 97275 2 snd_intel8x0,snd_ac97_codec snd_seq_midi 13324 0 snd_rawmidi 30748 1 snd_seq_midi snd_seq_midi_event 14899 1 snd_seq_midi rfcomm 47604 0 snd_seq 61929 2 snd_seq_midi,snd_seq_midi_event bnep 18281 2 bluetooth 180113 10 rfcomm,bnep ppdev 17113 0 psmouse 97519 0 snd_timer 29990 2 snd_pcm,snd_seq joydev 17693 0 snd_seq_device 14540 3 snd_seq_midi,snd_rawmidi,snd_seq vboxvideo 12622 1 serio_raw 13211 0 snd 79041 11 snd_intel8x0,snd_ac97_codec,snd_pcm,snd_rawmidi,snd_seq,snd_timer,snd_seq_device soundcore 15091 1 snd vboxguest 235498 7 vboxsf parport_pc 32866 0 drm 241971 2 vboxvideo i2c_piix4 13301 0 snd_page_alloc 18529 2 snd_intel8x0,snd_pcm mac_hid 13253 0 lp 17799 0 parport 46562 3 ppdev,parport_pc,lp usbhid 47238 0 hid 99636 1 usbhid e1000 108589 0

    Read the article

  • Wrapping a point-to-point link

    - by user3712955
    I'm using a pair of IP radios (non-WiFi) to bridge my office engineering LAN (172.0.0.0/8) to a lab in another building. The radios work fine, but they expose a web management interface I'd like to hide, and they also generate traffic (ARP, STP, and more) that I need to keep off my (very, very clean) LAN segments. I have some ARM-Linux boards (similar to Beagle/Panda/RasPi) running Ubuntu, and I've put one at each end of the link, between the radio and the LAN. Each of the boards has 2 wired Ethernet interfaces, eth0 and eth1. The LAN segments are connected to eth0, and the radios are connected to eth1. I'd like to accomplish the following: Keep radio-originated traffic off my LAN segments! Hide all services provided by the radio (web, ssh, etc.) Transparently pass all traffic between the LAN segments (including things like ARP). The above also applies to the ARM-Linux boards: No stray traffic my LAN from them either! I'd like the system to look like a switch: LAN packets arriving at one eth0 appear at the other. And neither eth0 should have an IP address: The working system should behave like a CAT6 cable with some latency (instead of ARM boards and radios). Unfortunately, I'm confused about how to properly configure the ARM Ubuntu systems. What I'm guessing I need is a bridge on each board (br0?) and a VLAN (vlan0 or eth0.0?) to isolate the LAN traffic from everything else as it passes through the ARM boards and the radios. Then I need some kind of a firewall to block sending anything out eth0 that isn't from the other eth0 (via the VLAN). I've looked at the ip and ebtables commands (especially -t broute). While the concepts sorta-kinda make sense, I'm completely lost in the details. Edit: In the perverse case that a system on one of my LAN segments has the same IP address as one of the radios, or as eth1 on the ARM-Ubuntu boards, a VLAN won't work. Which I believe means I need to tunnel all traffic between the two eth0 interfaces to get that "like a wire" behavior. Help? Finally, I'd like to have a way to temporarily expose services on the ARM boards (ssh) and the radios (web) for maintenance purposes. Ideally, it would expose an IP address with ssh available on port 22. Once connected, I figure I'd start an X11 session and run a browser on the ARM board to access the radios. Or something. I could login via the console to enable/disable this, or perhaps could use a GPIO to trigger a script. I feel I've identified most of the pieces needed to make all this happen, but I have no idea how to combine them to make a working system. Thanks!

    Read the article

  • Silverlight 5 Hosting :: Features in Silverlight 5 and Release Date

    - by mbridge
    Silverlight 5 is finally announced in the Silverlight FireStarter Event on the 2nd December, 2010. This new version of Silverlight which was earlier labeled as 'Future of Microsoft Silverlight' has now come much closer to go live as the first Silverlight 5 Beta version is expected to be shipped during the early months of 2011. However for the full fledged and the final release of Silverlight 5, we have to wait many more months as the same is likely to be made available within the Q3 2011. As would have been usually expected, this latest edition would feature many new capabilities thereby extending the developer productivity to a whole new dimension of premium media experience and feature-rich business applications. It comes along with many new feature updates as well as the inclusion of new technologies to improve the standard of the Silverlight applications which are now fine-tuned to produce next generation business and media solutions that is capable to meet the requirements of the advanced web-based app development. The Silverlight 5 is all set to replace the previous fourth version which now includes more than forty new features while also dropping various deprecated elements that was prevalent earlier. It has brought around some major performance enhancements and also included better support for various other tools and technologies. Following are some of the changes that are registered to be available under the Silverlight 5 Beta edition which is scheduled to be launched during the Q1 2011. Silverlight 5 : Premium Media Experiences The media features of Silverlight 5 has seen some major enhancements with a lot of optimizations being made to deliver richer solutions. It's capability has now been extended to make things easier, faster and capable of performing the desired tasks in the most efficient manner. The Silverlight media solutions has already been a part of many companies in the recent days where various on-demand Silverlight services were featured but with the arrival of the next generation premium media solution of Silverlight 5, it is expected to register new heights of success and global user acclamation for using it with many esteemed web-based projects and media solutions. - The most happening element in the new Silverlight 5 will be its support for utilizing the GPU based hardware acceleration which is intended to lower down the CPU load to a significant extent and thereby allowing faster rendering of media contents without consuming much resources. This feature is believed to be particularly helpful for low configured machines to run full HD media content without any lagging caused due to processor load. It will hence be one great feature to revolutionize the new generation high quality media contents to be available within the web in a more efficient manner with its hardware decoded video playback capabilities. - With the inclusion of hardware video decoding to minimize the processor load, the Silverlight 5 also comes with another optimization enhancement to also reduce the power consumption level by making new methods to deal with the power-saver settings. With this optimization in effect, the computer would be automatically allowed to switch to sleep mode while no video playback is in progress and also to prevent any screensavers to popup and cause annoyances during any video playback. There would also be other power saver options which will be made available to best suit the users requirements and purpose. - The Silverlight trickplay feature is another great way to tweak any silverlight powered media content as is used for many video tutorial sites or for dealing with any sort of presentations. This feature enables the user to modify the playback speed to either slowdown or speedup during the playback durations based on the requirements without compromising on the quality of output. Normally such manipulations always makes the content's audio to go off-pitch, but the same will not be the case with TrickPlay and the audio would seamlessly progress with the video without skipping any of its part. - In addition to all of the above, the new Silverlight 5 will be featuring wireless control of all the media contents by making use of remote controllers. With the use of such remote devices, it will be easier to handle the various media playback controls thereby providing more freedom while experiencing the premium media services. Silverlight 5 : Business Application Development The application development standard has been extended with more possibilities by bringing forth new and useful technologies and also reviving the existing methods to work better than what it was used to. From the UI improvements to advanced technical aspects, the Silverlight 5 scores high on all grounds to produce great next generation business delivered applications by putting in more creativity and resourceful touch to all the apps being produced with it. - The WPF feature of Silverlight is made more effective by introducing new standards of Databinding which is intended to improve the productivity standards of the Silverlight application developer. It brings in a lot of convenience in debugging the databinding components or expressions and hence making things work in a flawless manner. Some additional features related to databinding includes that of Ancestor RelativeSource, Implicit DataTemplates and Model View ViewModel (MVVM) support with DataContextChanged event and many other new features relating it. - It now comes with a refined text and printing service which facilitates better clarity of the text rendering and also many positive changes which are being applied to the layout pattern. New supports has been added to include OpenType font, multi-column text, linked-text containers and character leading support to name a few among the available features.This also includes some important printing aspects like that of Postscript Vector Printing API which allows to program our printing tasks in a user defined way and Pivot functionality for visualization concerns of informations. - The Graphics support is the key improvements being incorporated which now enables to utilize three dimensional graphics pattern using GPU acceleration. It can manage to provide some really cool visualizations being curved to provide media contents within the business apps with also the support for full HD contents at 1080p quality. - Silverlight 5 includes the support for 64-bit operating systems and relevant browsers and is also optimized to provide better performance. It can support the background thread for the networking which can reduce the latency of the network to a considerable extent. The Out-of-Browser functionality adds the support for utilizing various libraries and also the Win32 API. It also comes with testing support with VS 2010 which is mostly an automated procedure and has also enabled increased security aspects of all the Silverlight 5 developed applications by using the improved version of group policy support.

    Read the article

  • Windows Azure Use Case: Hybrid Applications

    - by BuckWoody
    This is one in a series of posts on when and where to use a distributed architecture design in your organization's computing needs. You can find the main post here: http://blogs.msdn.com/b/buckwoody/archive/2011/01/18/windows-azure-and-sql-azure-use-cases.aspx  Description: Organizations see the need for computing infrastructures that they can “rent” or pay for only when they need them. They also understand the benefits of distributed computing, but do not want to create this infrastructure themselves. However, they may have considerations that prevent them from moving all of their current IT investment to a distributed environment: Private data (do not want to send or store sensitive data off-site) High dollar investment in current infrastructure Applications currently running well, but may need additional periodic capacity Current applications not designed in a stateless fashion In these situations, a “hybrid” approach works best. In fact, with Windows Azure, a hybrid approach is an optimal way to implement distributed computing even when the stipulations above do not apply. Keeping a majority of the computing function in an organization local while exploring and expanding that footprint into Windows and SQL Azure is a good migration or expansion strategy. A “hybrid” architecture merely means that part of a computing cycle is shared between two architectures. For instance, some level of computing might be done in a Windows Azure web-based application, while the data is stored locally at the organization. Implementation: There are multiple methods for implementing a hybrid architecture, in a spectrum from very little interaction from the local infrastructure to Windows or SQL Azure. The patterns fall into two broad schemas, and even these can be mixed. 1. Client-Centric Hybrid Patterns In this pattern, programs are coded such that the client system sends queries or compute requests to multiple systems. The “client” in this case might be a web-based codeset actually stored on another system (which acts as a client, the user’s device serving as the presentation layer) or a compiled program. In either case, the code on the client requestor carries the burden of defining the layout of the requests. While this pattern is often the easiest to code, it’s the most brittle. Any change in the architecture must be reflected on each client, but this can be mitigated by using a centralized system as the client such as in the web scenario. 2. System-Centric Hybrid Patterns Another approach is to create a distributed architecture by turning on-site systems into “services” that can be called from Windows Azure using the service Bus or the Access Control Services (ACS) capabilities. Code calls from a series of in-process client application. In this pattern you move the “client” interface into the server application logic. If you do not wish to change the application itself, you can “layer” the results of the code return using a product (such as Microsoft BizTalk) that exposes a Web Services Definition Language (WSDL) endpoint to Windows Azure using the Application Fabric. In effect, this is similar to creating a Service Oriented Architecture (SOA) environment, and has the advantage of de-coupling your computing architecture. If each system offers a “service” of the results of some software processing, the operating system or platform becomes immaterial, assuming it adheres to a service contract. There are important considerations when you federate a system, whether to Windows or SQL Azure or any other distributed architecture. While these considerations are consistent with coding any application for distributed computing, they are especially important for a hybrid application. Connection resiliency - Applications on-premise normally have low-latency and good connection properties, something you’re not always guaranteed in a distributed and hybrid application. Whether a centralized client or a distributed one, the code should be able to handle extended retry logic. Authorization and Access - In a single authorization environment like a Active Directory domain, security is handled at a user-password level. In a distributed computing environment, you have more options. You can mitigate this with  using The Windows Azure Application Fabric feature of ACS to make the Azure application aware of the App Fabric as an ADFS provider. However, a claims-based authentication structure is often a superior choice.  Consistency and Concurrency - When you have a Relational Database Management System (RDBMS), Consistency and Concurrency are part of the design. In a Service Architecture, you need to plan for sequential message handling and lifecycle. Resources: How to Build a Hybrid On-Premise/In Cloud Application: http://blogs.msdn.com/b/ignitionshowcase/archive/2010/11/09/how-to-build-a-hybrid-on-premise-in-cloud-application.aspx  General Architecture guidance: http://blogs.msdn.com/b/buckwoody/archive/2010/12/21/windows-azure-learning-plan-architecture.aspx   

    Read the article

  • SQLAuthority News – Why VoIP Service Providers Should Think About NuoDB’s Geo Distribution

    - by Pinal Dave
    You can always tell when someone’s showing off their cool, cutting edge comms technology. They tend to raise their voice a lot. Back in the day they’d announce their gadget leadership to the rest of the herd by shouting into their cellphone. Usually the message was no more urgent than “Hi, I’m on my cellphone!” Now the same types will loudly name-drop a different technology to the rest of the airport lounge. “I’m leveraging the wifi,” a fellow passenger bellowed, the other day, as we filtered through the departure gate. Nobody needed to know that, but the subtext was “look at me everybody”. You can tell the really advanced mobile user – they tend to whisper. Their handset has a microphone (how cool is that!) and they know how to use it. Sometimes these shouty public broadcasters aren’t even connected anyway because the database for their Voice over IP (VoIP) platform can’t cope. This will happen if they are using a traditional SQL model to try and cope with a phone network which has far flung offices and hundreds of mobile employees. That, like shouting into your phone, is just wrong on so many levels. What VoIP needs now is a single, logical database across multiple servers in different geographies. It needs to be updated in real-time and automatically scaled out during times of peak demand. A VoIP system should scale up to handle increased traffic, but just as importantly is must then go back down in the off peak hours. Try this with a MySQL database. It can’t scale easily enough, so it will keep your developers busy. They’ll have spent many hours trying to knit the different databases together. Traditional relational databases can possibly achieve this, at a price. Mind you, you could extend baked bean cans and string to every point on the network and that would be no less elegant. That’s not really following engineering principles though is it? Having said that, most telcos and VoIP systems use a separate, independent solution for each office location, which they link together – loosely.  The more office locations, the more complex and expensive the solution becomes and so the more you spend on maintenance. Ideally, you’d have a fluid system that can automatically shift its shape as the need arises. That’s the point of software isn’t it – it adapts. Otherwise, we might as well return to the old days. A MySQL system isn’t exactly baked bean cans attached by string, but it’s closer in spirit to the old many teethed mechanical beast that was employed in the first type of automated switchboard. NuoBD’s NewSQL is designed to be a single database that works across multiple servers, which can scale easily, and scale on demand. That’s one system that gives high connectivity but no latency, complexity or maintenance issues. MySQL works in some circumstances, but a period of growth isn’t one of them. So as a company moves forward, the MySQL database can’t keep pace. Data storage and data replication errors creep in. Soon the diaspora of offices becomes a problem. Your telephone system isn’t just distributed, it is literally all over the place. Though voice calls are often a software function, some of the old habits of telephony remain. When you call an engineer out, some of them will listen to what you’re asking for and announce that it cannot be done. This is what happens if you ask, say, database engineers familiar with Oracle or Microsoft to fulfill your wish for a low maintenance system built on a single, fluid, scalable database. No can do, they’d say. In fact, I heard one shouting something similar into his VoIP handset at the airport. “I can’t get on the network, Mac. I’m on MySQL.” You can download NuoDB from here. “NuoDB provides the ability to replicate data globally in real-time, which is not available with any other product offering,” states Weeks.  “That alone is remarkable and it works. I’ve seen it. I’ve used it.  I’ve tested it. The ability to deploy NuoDB removes a tremendous burden from our support and engineering teams.” Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: NuoDB

    Read the article

  • NoSQL Memcached API for MySQL: Latest Updates

    - by Mat Keep
    With data volumes exploding, it is vital to be able to ingest and query data at high speed. For this reason, MySQL has implemented NoSQL interfaces directly to the InnoDB and MySQL Cluster (NDB) storage engines, which bypass the SQL layer completely. Without SQL parsing and optimization, Key-Value data can be written directly to MySQL tables up to 9x faster, while maintaining ACID guarantees. In addition, users can continue to run complex queries with SQL across the same data set, providing real-time analytics to the business or anonymizing sensitive data before loading to big data platforms such as Hadoop, while still maintaining all of the advantages of their existing relational database infrastructure. This and more is discussed in the latest Guide to MySQL and NoSQL where you can learn more about using the APIs to scale new generations of web, cloud, mobile and social applications on the world's most widely deployed open source database The native Memcached API is part of the MySQL 5.6 Release Candidate, and is already available in the GA release of MySQL Cluster. By using the ubiquitous Memcached API for writing and reading data, developers can preserve their investments in Memcached infrastructure by re-using existing Memcached clients, while also eliminating the need for application changes. Speed, when combined with flexibility, is essential in the world of growing data volumes and variability. Complementing NoSQL access, support for on-line DDL (Data Definition Language) operations in MySQL 5.6 and MySQL Cluster enables DevOps teams to dynamically update their database schema to accommodate rapidly changing requirements, such as the need to capture additional data generated by their applications. These changes can be made without database downtime. Using the Memcached interface, developers do not need to define a schema at all when using MySQL Cluster. Lets look a little more closely at the Memcached implementations for both InnoDB and MySQL Cluster. Memcached Implementation for InnoDB The Memcached API for InnoDB is previewed as part of the MySQL 5.6 Release Candidate. As illustrated in the following figure, Memcached for InnoDB is implemented via a Memcached daemon plug-in to the mysqld process, with the Memcached protocol mapped to the native InnoDB API. Figure 1: Memcached API Implementation for InnoDB With the Memcached daemon running in the same process space, users get very low latency access to their data while also leveraging the scalability enhancements delivered with InnoDB and a simple deployment and management model. Multiple web / application servers can remotely access the Memcached / InnoDB server to get direct access to a shared data set. With simultaneous SQL access, users can maintain all the advanced functionality offered by InnoDB including support for Foreign Keys, XA transactions and complex JOIN operations. Benchmarks demonstrate that the NoSQL Memcached API for InnoDB delivers up to 9x higher performance than the SQL interface when inserting new key/value pairs, with a single low-end commodity server supporting nearly 70,000 Transactions per Second. Figure 2: Over 9x Faster INSERT Operations The delivered performance demonstrates MySQL with the native Memcached NoSQL interface is well suited for high-speed inserts with the added assurance of transactional guarantees. You can check out the latest Memcached / InnoDB developments and benchmarks here You can learn how to configure the Memcached API for InnoDB here Memcached Implementation for MySQL Cluster Memcached API support for MySQL Cluster was introduced with General Availability (GA) of the 7.2 release, and joins an extensive range of NoSQL interfaces that are already available for MySQL Cluster Like Memcached, MySQL Cluster provides a distributed hash table with in-memory performance. MySQL Cluster extends Memcached functionality by adding support for write-intensive workloads, a full relational model with ACID compliance (including persistence), rich query support, auto-sharding and 99.999% availability, with extensive management and monitoring capabilities. All writes are committed directly to MySQL Cluster, eliminating cache invalidation and the overhead of data consistency checking to ensure complete synchronization between the database and cache. Figure 3: Memcached API Implementation with MySQL Cluster Implementation is simple: 1. The application sends reads and writes to the Memcached process (using the standard Memcached API). 2. This invokes the Memcached Driver for NDB (which is part of the same process) 3. The NDB API is called, providing for very quick access to the data held in MySQL Cluster’s data nodes. The solution has been designed to be very flexible, allowing the application architect to find a configuration that best fits their needs. It is possible to co-locate the Memcached API in either the data nodes or application nodes, or alternatively within a dedicated Memcached layer. The benefit of this flexible approach to deployment is that users can configure behavior on a per-key-prefix basis (through tables in MySQL Cluster) and the application doesn’t have to care – it just uses the Memcached API and relies on the software to store data in the right place(s) and to keep everything synchronized. Using Memcached for Schema-less Data By default, every Key / Value is written to the same table with each Key / Value pair stored in a single row – thus allowing schema-less data storage. Alternatively, the developer can define a key-prefix so that each value is linked to a pre-defined column in a specific table. Of course if the application needs to access the same data through SQL then developers can map key prefixes to existing table columns, enabling Memcached access to schema-structured data already stored in MySQL Cluster. Conclusion Download the Guide to MySQL and NoSQL to learn more about NoSQL APIs and how you can use them to scale new generations of web, cloud, mobile and social applications on the world's most widely deployed open source database See how to build a social app with MySQL Cluster and the Memcached API from our on-demand webinar or take a look at the docs Don't hesitate to use the comments section below for any questions you may have 

    Read the article

  • Silverlight 5 &ndash; What&rsquo;s New? (Including Screenshots &amp; Code Snippets)

    - by mbcrump
    Silverlight 5 is coming next year (2011) and this blog post will tell you what you need to know before the beta ships. First, let me address people saying that it is dead after PDC 2010. I believe that it’s best to see what the market is doing, not the vendor. Below is a list of companies that are developing Silverlight 4 applications shown during the Silverlight Firestarter. Some of the companies have shipped and some haven’t. It’s just great to see the actual company names that are working on Silverlight instead of “people are developing for Silverlight”. The next thing that I wanted to point out was that HTML5, WPF and Silverlight can co-exist. In case you missed Scott Gutherie’s keynote, they actually had a slide with all three stacked together. This shows Microsoft will be heavily investing in each technology.  Even I, a Silverlight developer, am reading Pro HTML5. Microsoft said that according to the Silverlight Feature Voting site, 21k votes were entered. Microsoft has implemented about 70% of these votes in Silverlight 5. That is an amazing number, and I am crossing my fingers that Microsoft bundles Silverlight with Windows 8. Let’s get started… what’s new in Silverlight 5? I am going to show you some great application and actual code shown during the Firestarter event. Media Hardware Video Decode – Instead of using CPU to decode, we will offload it to GPU. This will allow netbooks, etc to play videos. Trickplay – Variable Speed Playback – Pitch Correction (If you speed up someone talking they won’t sound like a chipmunk). Power Management – Less battery when playing video. Screensavers will no longer kick in if watching a video. If you pause a video then screensaver will kick in. Remote Control Support – This will allow users to control playback functions like Pause, Rewind and Fastforward. IIS Media Services 4 has shipped and now supports Azure. Data Binding Layout Transitions – Just with a few lines of XAML you can create a really rich experience that is not using Storyboards or animations. RelativeSource FindAncestor – Ancestor RelativeSource bindings make it much easier for a DataTemplate to bind to a property on a container control. Custom Markup Extensions – Markup extensions allow code to be run at XAML parse time for both properties and event handlers. This is great for MVVM support. Changing Styles during Runtime By Binding in Style Setters – Changing Styles at runtime used to be a real pain in Silverlight 4, now it’s much easier. Binding in style setters allows bindings to reference other properties. XAML Debugging – Below you can see that we set a breakpoint in XAML. This shows us exactly what is going on with our binding.  WCF & RIA Services WS-Trust Support – Taken from Wikipedia: WS-Trust is a WS-* specification and OASIS standard that provides extensions to WS-Security, specifically dealing with the issuing, renewing, and validating of security tokens, as well as with ways to establish, assess the presence of, and broker trust relationships between participants in a secure message exchange. You can reduce network latency by using a background thread for networking. Supports Azure now.  Text and Printing Improved text clarity that enables better text rendering. Multi-column text flow, Character tracking and leading support, and full OpenType font support.  Includes a new Postscript Vector Printing API that provides control over what you print . Pivot functionality baked into Silverlight 5 SDK. Graphics Immediate mode graphics support that will enable you to use the GPU and 3D graphics supports. Take a look at what was shown in the demos below. 1) 3D view of the Earth – not really a real-world application though. A doctor’s portal. This demo really stood out for me as it shows what we can do with the 3D / GPU support. Out of Browser OOB applications can now create and manage childwindows as shown in the screenshot below.  Trusted OOB applications can use P/Invoke to call Win32 APIs and unmanaged libraries.  Enterprise Group Policy Support allow enterprises to lock down or up the sandbox capabilities of Silverlight 5 applications. In this demo, he tore the “notes” off of the application and it appeared in a new window. See the black arrow below. In this demo, he connected a USB Device which fired off a local Win32 application that provided the data off the USB stick to Silverlight. Another demo of a Silverlight 5 application exporting data right into Excel running inside of browser. Testing They demoed Coded UI, which is available now in the Visual Studio Feature Pack 2. This will allow you to create automated testing without writing any code manually. Performance: Microsoft has worked to improve the Silverlight startup time. Silverlight 5 provides 64-bit browser support.  Silverlight 5 also provides IE9 Hardware acceleration.   I am looking forward to Silverlight 5 and I hope you are too. Thanks for reading and I hope you visit again soon.  Subscribe to my feed CodeProject

    Read the article

  • CQRS - Benefits

    - by Dylan Smith
    Thanks to all the comments and feedback from the last post I think I have a better understanding now of the benefits of CQRS (separate from the benefits of Event Sourcing). I’m going to try and sum it up here, and point out some areas where I could still use some advice: CQRS Benefits Sounds like the primary benefit of CQRS as an architecture is it allows you to create a simpler domain model by sucking out everything related to queries. I can definitely see the benefit to this, in general the domain logic related to commands is the high-value behavior in the software, but the logic required to service the queries would add a lot of low-value “noise” to the domain model that would dilute the high-value (command) behavior – sorting, paging, filtering, pre-fetch paths, etc. Also the most appropriate domain structure for implementing commands might not be the most optimal for implementing queries. To paraphrase Greg, this usually results in a domain model that is mediocre at both, piss-poor at one, or more likely piss-poor at both commands and queries. Not only will you be able to simplify your domain model by pulling out all the query logic, but at least a handful of commands in most systems will probably be “pass-though” type commands with little to no logic that just generate events. If these can be implemented directly in the command-handler and never touch the domain model, this allows you to slim down the domain model even more. Also, if you were to do event sourcing without CQRS, you no longer have a database containing the current state (only the domain model would) which makes it difficult (or impossible) to support ad-hoc querying and/or reporting that is common in most business software. Of course CQRS provides some great scalability benefits, not only scalability but I have to assume that it provides extremely low latency for most operations, especially if you have an asynchronous event bus. I know Greg says that you get a 3x scaling (Commands, Queries, Client) of your ability to perform parallel development, but IMHO, it seems like it only provides 1.5x scaling since even without CQRS you’re going to have your client loosely coupled to your domain - which is still a great benefit to be able to realize. Questions / Concerns If all the queries against an aggregate get pulled out to the Query layer, what if the only commands for that aggregate can be handled in a “pass-through” manner with the command handler directly generating events. Is it possible to have an aggregate that isn’t modeled in the domain model? Are there any issues or downsides to this? I know in the feedback from my previous posts it was suggested that having one domain model handling both commands and queries requires implementing a lot of traversals between objects that wouldn’t be necessary if it was only servicing commands. My question is, do you include traversals in your domain model based on the needs of the code, or based on the conceptual domain model? If none of my Commands require a Customer.Orders traversal, but the conceptual domain includes the concept of a set of orders belonging to a customer – should I model that in my domain model or not? I like the idea of using the Query side of the architecture as a place to put junior devs where the risk of them screwing something up has minimal impact. But I’m not sold on the idea that you can actually outsource it. Like I said in one of my comments on my previous post, the code to handle a query and generate DTO’s is going to be dead simple, but the code to process events and apply them to the tables on the query side is going to require a significant amount of domain knowledge to know which events to listen for to update each of the de-normalized tables (and what changes need to be made when each event is processed). I don’t know about everybody else, but having Indian/Russian/whatever outsourced developers have to do anything that requires significant domain knowledge has never been successful in my experience. And if you need to spec out for each new query which events to listen to and what to do with each one, well that’s probably going to be just as much work to document as it would be to just implement it. Greg made the point in a comment that doing an aggregate query like “Total Sales By Customer” is going to be inefficient if you use event sourcing but not CQRS. I don’t understand why that would be the case. I imagine in that case you’d simply have a method/property on the Customer object that calculated total sales for that customer by enumerating over the Orders collection. Then the application services layer would generate DTO’s off of the Customers collection that included say the CustomerID, CustomerName, TotalSales, or whatever the case may be. As long as you use a snapshotting implementation, I don’t see why that would be anymore inefficient in a DDD+Event Sourcing implementation than in a typical DDD implementation. Like I mentioned in my last post I still have some questions about query logic that haven’t been answered yet, but before I start asking those I want to make sure I have a strong grasp on what benefits CQRS provides.  My main concern with the query logic was that I know I could just toss it all into the query side, but I was concerned that I would be losing the benefits of using CQRS in the first place if I did that.  I want to elaborate more on this though with some example situations in an upcoming post.

    Read the article

  • OTN Architect Day Headed to Reston, VA - May 16

    - by Bob Rhubart
    In 2011 OTN Architect Day made stops in Chicago, Denver, Phoenix, Redwood Shores, and Toronto. The 2012 series begins with OTN Architect Day in Reston, VA on Wednesday May 16. Registration is now open for this free event, but don't get caught napping -- seating is limited, and the event is just 5 weeks away. The information below reflects the most recent updates to the event agenda, including the addition of Oracle ACE Director Kai Yu as the guest keynote speaker. Kai is Senior System Engineer / Architect at Dell, Inc., and has been very busy of late as a speaker at various industry and Oracle User Group events. I'm very happy Kai has agreed to make the trek from his hometown in Austin, TX to share his insight at the Architect Day event in Reston.  If you're in the area, put this one on your calendar. You won't be sorry.   Venue Sheraton Reston Hotel 11810 Sunrise Valley Drive Reston, VA 20191 Event Agenda 8:30 am - 9:00 am Registration and Continental Breakfast 9:00 am - 9:15 am Welcome and Opening Comments 9:15 am - 10:00 am Engineered Systems: Oracle's Vision for the Future | Ralf Dossman Oracle's Exadata and Exalogic are impressive products in their own right. But working in combination they deliver unparalleled transaction processing performance with up to a 30x increase over existing legacy systems, with the lowest cost of ownership over a 3 or 5 year basis than any other hardware. In this session you'll learn how to leverage Oracle's Engineered Systems within your enterprise to deliver record-breaking performance at the lowest TCO. 10:00 am - 10:30 am High Availability Infrastructure for Cloud Computing | Kai Yu Infrastructure high availability is extremely critical to Cloud Computing. In a Cloud system that hosts a large number of databases and applications with different SLAs, any unplanned outage can be devastating, and even a small planned downtime may be unacceptable. This presentation will discuss various technology solutions and the related best practices that system architects should consider in cloud infrastructure design to ensure high availability. 10:30 am - 10:45 am Break 10:45 am - 11:30 am Breakout Sessions: (pick one) Innovations in Grid Computing with Oracle Coherence | Bjorn Boe Learn how Coherence can increase the availability, scalability and performance of your existing applications with its advanced low-latency data-grid technologies. Also hear some interesting industry-specific use cases that customers had implemented and how Oracle is integrating Coherence into its Enterprise Java stack. Cloud Computing - Making IT Simple | Scott Mattoon The road to Cloud Computing is not without a few bumps. This session will help to smooth out your journey by tackling some of the potential complications. We'll examine whether standardization is a prerequisite for the Cloud. We'll look at why refactoring isn't just for application code. We'll check out deployable entities and their simplification via higher levels of abstraction. And we'll close out the session with a look at engineered systems and modular clouds. 11:30 pm - 12:15 pm Breakout Sessions: (pick one) Oracle Enterprise Manager | Joe Diemer Oracle Enterprise Manager (EM) provides complete lifecycle management for the cloud - from automated cloud setup to self-service delivery to cloud operations. In this session you'll learn how to take control of your cloud infrastructure with EM features including Consolidation Planning and Self-Service provisioning with Metering and Chargeback. Come hear how Oracle is expanding its management capabilities into the cloud! Rationalization and Defense in Depth - Two Steps Closer to the Clouds | Dave Chappelle Security represents one of the biggest concerns about cloud computing. In this session we'll get past the FUD with a real-world look at some key issues. We'll discuss the infrastructure necessary to support rationalization and security services, explore architecture for defense -in-depth, and deal frankly with the good, the bad, and the ugly in Cloud security. 12:15 pm - 1:15 pm Lunch 1:40 pm - 2:00 pm Panel Discussion - Q&A 2:00 pm - 2:45 pm Breakout Sessions: (pick one) 21st Century SOA | Peter Belknap Service Oriented Architecture has evolved from concept to reality in the last decade. The right methodology coupled with mature SOA technologies has helped customers demonstrate success in both innovation and ROI. In this session you will learn how Oracle SOA Suite's orchestration, virtualization, and governance capabilities provide the infrastructure to run mission critical business and system applications. And we'll take a special look at the convergence of SOA & BPM using Oracle's Unified technology stack. Track B: Oracle Cloud Reference Architecture | Anbu Krishnaswamy Cloud initiatives are beginning to dominate enterprise IT roadmaps. Successful adoption of Cloud and the subsequent governance challenges warrant a Cloud reference architecture that is applied consistently across the enterprise. This presentation gives an overview of Oracle's Cloud Reference Architecture, which is part of the Cloud Enterprise Technology Strategy (ETS). Concepts covered include common management layer capabilities, service models, resource pools, and use cases. 2:45 pm - 3:00 pm Break 3:00 pm - 4:00 pm Roundtable Discussions 4:00 pm - 4:15 pm Closing Comments & Readouts from Roundtable 4:15 pm - 5:00 pm Cocktail Reception / Networking Session schedule and content subject to change.

    Read the article

  • CLR via C# 3rd Edition is out

    - by Abhijeet Patel
    Time for some book news update. CLR via C#, 3rd Edition seems to have been out for a little while now. The book was released in early Feb this year, and needless to say my copy is on it’s way. I can barely wait to dig in and chew on the goodies that one of the best technical authors and software professionals I respect has in store. The 2nd edition of the book was an absolute treat and this edition promises to be no less. Here is a brief description of what’s new and updated from the 2nd edition. Part I – CLR Basics Chapter 1-The CLR’s Execution Model Added about discussion about C#’s /optimize and /debug switches and how they relate to each other. Chapter 2-Building, Packaging, Deploying, and Administering Applications and Types Improved discussion about Win32 manifest information and version resource information. Chapter 3-Shared Assemblies and Strongly Named Assemblies Added discussion of TypeForwardedToAttribute and TypeForwardedFromAttribute. Part II – Designing Types Chapter 4-Type Fundamentals No new topics. Chapter 5-Primitive, Reference, and Value Types Enhanced discussion of checked and unchecked code and added discussion of new BigInteger type. Also added discussion of C# 4.0’s dynamic primitive type. Chapter 6-Type and Member Basics No new topics. Chapter 7-Constants and Fields No new topics. Chapter 8-Methods Added discussion of extension methods and partial methods. Chapter 9-Parameters Added discussion of optional/named parameters and implicitly-typed local variables. Chapter 10-Properties Added discussion of automatically-implemented properties, properties and the Visual Studio debugger, object and collection initializers, anonymous types, the System.Tuple type and the ExpandoObject type. Chapter 11-Events Added discussion of events and thread-safety as well as showing a cool extension method to simplify the raising of an event. Chapter 12-Generics Added discussion of delegate and interface generic type argument variance. Chapter 13-Interfaces No new topics. Part III – Essential Types Chapter 14-Chars, Strings, and Working with Text No new topics. Chapter 15-Enums Added coverage of new Enum and Type methods to access enumerated type instances. Chapter 16-Arrays Added new section on initializing array elements. Chapter 17-Delegates Added discussion of using generic delegates to avoid defining new delegate types. Also added discussion of lambda expressions. Chapter 18-Attributes No new topics. Chapter 19-Nullable Value Types Added discussion on performance. Part IV – CLR Facilities Chapter 20-Exception Handling and State Management This chapter has been completely rewritten. It is now about exception handling and state management. It includes discussions of code contracts and constrained execution regions (CERs). It also includes a new section on trade-offs between writing productive code and reliable code. Chapter 21-Automatic Memory Management Added discussion of C#’s fixed state and how it works to pin objects in the heap. Rewrote the code for weak delegates so you can use them with any class that exposes an event (the class doesn’t have to support weak delegates itself). Added discussion on the new ConditionalWeakTable class, GC Collection modes, Full GC notifications, garbage collection modes and latency modes. I also include a new sample showing how your application can receive notifications whenever Generation 0 or 2 collections occur. Chapter 22-CLR Hosting and AppDomains Added discussion of side-by-side support allowing multiple CLRs to be loaded in a single process. Added section on the performance of using MarshalByRefObject-derived types. Substantially rewrote the section on cross-AppDomain communication. Added section on AppDomain Monitoring and first chance exception notifications. Updated the section on the AppDomainManager class. Chapter 23-Assembly Loading and Reflection Added section on how to deploy a single file with dependent assemblies embedded inside it. Added section comparing reflection invoke vs bind/invoke vs bind/create delegate/invoke vs C#’s dynamic type. Chapter 24-Runtime Serialization This is a whole new chapter that was not in the 2nd Edition. Part V – Threading Chapter 25-Threading Basics Whole new chapter motivating why Windows supports threads, thread overhead, CPU trends, NUMA Architectures, the relationship between CLR threads and Windows threads, the Thread class, reasons to use threads, thread scheduling and priorities, foreground thread vs background threads. Chapter 26-Performing Compute-Bound Asynchronous Operations Whole new chapter explaining the CLR’s thread pool. This chapter covers all the new .NET 4.0 constructs including cooperative cancelation, Tasks, the aralle class, parallel language integrated query, timers, how the thread pool manages its threads, cache lines and false sharing. Chapter 27-Performing I/O-Bound Asynchronous Operations Whole new chapter explaining how Windows performs synchronous and asynchronous I/O operations. Then, I go into the CLR’s Asynchronous Programming Model, my AsyncEnumerator class, the APM and exceptions, Applications and their threading models, implementing a service asynchronously, the APM and Compute-bound operations, APM considerations, I/O request priorities, converting the APM to a Task, the event-based Asynchronous Pattern, programming model soup. Chapter 28-Primitive Thread Synchronization Constructs Whole new chapter discusses class libraries and thread safety, primitive user-mode, kernel-mode constructs, and data alignment. Chapter 29-Hybrid Thread Synchronization Constructs Whole new chapter discussion various hybrid constructs such as ManualResetEventSlim, SemaphoreSlim, CountdownEvent, Barrier, ReaderWriterLock(Slim), OneManyResourceLock, Monitor, 3 ways to solve the double-check locking technique, .NET 4.0’s Lazy and LazyInitializer classes, the condition variable pattern, .NET 4.0’s concurrent collection classes, the ReaderWriterGate and SyncGate classes.

    Read the article

  • Do Not Optimize Without Measuring

    - by Alois Kraus
    Recently I had to do some performance work which included reading a lot of code. It is fascinating with what ideas people come up to solve a problem. Especially when there is no problem. When you look at other peoples code you will not be able to tell if it is well performing or not by reading it. You need to execute it with some sort of tracing or even better under a profiler. The first rule of the performance club is not to think and then to optimize but to measure, think and then optimize. The second rule is to do this do this in a loop to prevent slipping in bad things for too long into your code base. If you skip for some reason the measure step and optimize directly it is like changing the wave function in quantum mechanics. This has no observable effect in our world since it does represent only a probability distribution of all possible values. In quantum mechanics you need to let the wave function collapse to a single value. A collapsed wave function has therefore not many but one distinct value. This is what we physicists call a measurement. If you optimize your application without measuring it you are just changing the probability distribution of your potential performance values. Which performance your application actually has is still unknown. You only know that it will be within a specific range with a certain probability. As usual there are unlikely values within your distribution like a startup time of 20 minutes which should only happen once in 100 000 years. 100 000 years are a very short time when the first customer tries your heavily distributed networking application to run over a slow WIFI network… What is the point of this? Every programmer/architect has a mental performance model in his head. A model has always a set of explicit preconditions and a lot more implicit assumptions baked into it. When the model is good it will help you to think of good designs but it can also be the source of problems. In real world systems not all assumptions of your performance model (implicit or explicit) hold true any longer. The only way to connect your performance model and the real world is to measure it. In the WIFI example the model did assume a low latency high bandwidth LAN connection. If this assumption becomes wrong the system did have a drastic change in startup time. Lets look at a example. Lets assume we want to cache some expensive UI resource like fonts objects. For this undertaking we do create a Cache class with the UI themes we want to support. Since Fonts are expensive objects we do create it on demand the first time the theme is requested. A simple example of a Theme cache might look like this: using System; using System.Collections.Generic; using System.Drawing; struct Theme { public Color Color; public Font Font; } static class ThemeCache { static Dictionary<string, Theme> _Cache = new Dictionary<string, Theme> { {"Default", new Theme { Color = Color.AliceBlue }}, {"Theme12", new Theme { Color = Color.Aqua }}, }; public static Theme Get(string theme) { Theme cached = _Cache[theme]; if (cached.Font == null) { Console.WriteLine("Creating new font"); cached.Font = new Font("Arial", 8); } return cached; } } class Program { static void Main(string[] args) { Theme item = ThemeCache.Get("Theme12"); item = ThemeCache.Get("Theme12"); } } This cache does create font objects only once since on first retrieve of the Theme object the font is added to the Theme object. When we let the application run it should print “Creating new font” only once. Right? Wrong! The vigilant readers have spotted the issue already. The creator of this cache class wanted to get maximum performance. So he decided that the Theme object should be a value type (struct) to not put too much pressure on the garbage collector. The code Theme cached = _Cache[theme]; if (cached.Font == null) { Console.WriteLine("Creating new font"); cached.Font = new Font("Arial", 8); } does work with a copy of the value stored in the dictionary. This means we do mutate a copy of the Theme object and return it to our caller. But the original Theme object in the dictionary will have always null for the Font field! The solution is to change the declaration of struct Theme to class Theme or to update the theme object in the dictionary. Our cache as it is currently is actually a non caching cache. The funny thing was that I found out with a profiler by looking at which objects where finalized. I found way too many font objects to be finalized. After a bit debugging I found the allocation source for Font objects was this cache. Since this cache was there for years it means that the cache was never needed since I found no perf issue due to the creation of font objects. the cache was never profiled if it did bring any performance gain. to make the cache beneficial it needs to be accessed much more often. That was the story of the non caching cache. Next time I will write something something about measuring.

    Read the article

  • Retrieve Performance Data from SOA Infrastructure Database

    - by fip
    My earlier blog posting shows how to enable, retrieve and interpret BPEL engine performance statistics to aid performance troubleshooting. The strength of BPEL engine statistics at EM is its break down per request. But there are some limitations with the BPEL performance statistics mentioned in that blog posting: The statistics were stored in memory instead of being persisted. To avoid memory overflow, the data are stored to a buffer with limited size. When the statistic entries exceed the limitation, old data will be flushed out to give ways to new statistics. Therefore it can only keep the last X number of entries of data. The statistics 5 hour ago may not be there anymore. The BPEL engine performance statistics only includes latencies. It does not provide throughputs. Fortunately, Oracle SOA Suite runs with the SOA Infrastructure database and a lot of performance data are naturally persisted there. It is at a more coarse grain than the in-memory BPEL Statistics, but it does have its own strengths as it is persisted. Here I would like offer examples of some basic SQL queries you can run against the infrastructure database of Oracle SOA Suite 11G to acquire the performance statistics for a given period of time. You can run it immediately after you modify the date range to match your actual system. 1. Asynchronous/one-way messages incoming rates The following query will show number of messages sent to one-way/async BPEL processes during a given time period, organized by process names and states select composite_name composite, state, count(*) Count from dlv_message where receive_date >= to_timestamp('2012-10-24 21:00:00','YYYY-MM-DD HH24:MI:SS') and receive_date <= to_timestamp('2012-10-24 21:59:59','YYYY-MM-DD HH24:MI:SS') group by composite_name, state order by Count; 2. Throughput of BPEL process instances The following query shows the number of synchronous and asynchronous process instances created during a given time period. It list instances of all states, including the unfinished and faulted ones. The results will include all composites cross all SOA partitions select state, count(*) Count, composite_name composite, component_name,componenttype from cube_instance where creation_date >= to_timestamp('2012-10-24 21:00:00','YYYY-MM-DD HH24:MI:SS') and creation_date <= to_timestamp('2012-10-24 21:59:59','YYYY-MM-DD HH24:MI:SS') group by composite_name, component_name, componenttype order by count(*) desc; 3. Throughput and latencies of BPEL process instances This query is augmented on the previous one, providing more comprehensive information. It gives not only throughput but also the maximum, minimum and average elapse time BPEL process instances. select composite_name Composite, component_name Process, componenttype, state, count(*) Count, trunc(Max(extract(day from (modify_date-creation_date))*24*60*60 + extract(hour from (modify_date-creation_date))*60*60 + extract(minute from (modify_date-creation_date))*60 + extract(second from (modify_date-creation_date))),4) MaxTime, trunc(Min(extract(day from (modify_date-creation_date))*24*60*60 + extract(hour from (modify_date-creation_date))*60*60 + extract(minute from (modify_date-creation_date))*60 + extract(second from (modify_date-creation_date))),4) MinTime, trunc(AVG(extract(day from (modify_date-creation_date))*24*60*60 + extract(hour from (modify_date-creation_date))*60*60 + extract(minute from (modify_date-creation_date))*60 + extract(second from (modify_date-creation_date))),4) AvgTime from cube_instance where creation_date >= to_timestamp('2012-10-24 21:00:00','YYYY-MM-DD HH24:MI:SS') and creation_date <= to_timestamp('2012-10-24 21:59:59','YYYY-MM-DD HH24:MI:SS') group by composite_name, component_name, componenttype, state order by count(*) desc;   4. Combine all together Now let's combine all of these 3 queries together, and parameterize the start and end time stamps to make the script a bit more robust. The following script will prompt for the start and end time before querying against the database: accept startTime prompt 'Enter start time (YYYY-MM-DD HH24:MI:SS)' accept endTime prompt 'Enter end time (YYYY-MM-DD HH24:MI:SS)' Prompt "==== Rejected Messages ===="; REM 2012-10-24 21:00:00 REM 2012-10-24 21:59:59 select count(*), composite_dn from rejected_message where created_time >= to_timestamp('&&StartTime','YYYY-MM-DD HH24:MI:SS') and created_time <= to_timestamp('&&EndTime','YYYY-MM-DD HH24:MI:SS') group by composite_dn; Prompt " "; Prompt "==== Throughput of one-way/asynchronous messages ===="; select state, count(*) Count, composite_name composite from dlv_message where receive_date >= to_timestamp('&StartTime','YYYY-MM-DD HH24:MI:SS') and receive_date <= to_timestamp('&EndTime','YYYY-MM-DD HH24:MI:SS') group by composite_name, state order by Count; Prompt " "; Prompt "==== Throughput and latency of BPEL process instances ====" select state, count(*) Count, trunc(Max(extract(day from (modify_date-creation_date))*24*60*60 + extract(hour from (modify_date-creation_date))*60*60 + extract(minute from (modify_date-creation_date))*60 + extract(second from (modify_date-creation_date))),4) MaxTime, trunc(Min(extract(day from (modify_date-creation_date))*24*60*60 + extract(hour from (modify_date-creation_date))*60*60 + extract(minute from (modify_date-creation_date))*60 + extract(second from (modify_date-creation_date))),4) MinTime, trunc(AVG(extract(day from (modify_date-creation_date))*24*60*60 + extract(hour from (modify_date-creation_date))*60*60 + extract(minute from (modify_date-creation_date))*60 + extract(second from (modify_date-creation_date))),4) AvgTime, composite_name Composite, component_name Process, componenttype from cube_instance where creation_date >= to_timestamp('&StartTime','YYYY-MM-DD HH24:MI:SS') and creation_date <= to_timestamp('&EndTime','YYYY-MM-DD HH24:MI:SS') group by composite_name, component_name, componenttype, state order by count(*) desc;  

    Read the article

  • Searching for the Perfect Developer&rsquo;s Laptop.

    - by mbcrump
    I have been in the market for a new computer for several months. I set out with a budget of around $1200. I knew up front that the machine would be used for developing applications and maybe some light gaming. I kept switching between buying a laptop or a desktop but the laptop won because: With a Laptop, I can carry it everywhere and with a desktop I can’t. I searched for about 2 weeks and narrowed it down to a list of must-have’s : i7 Processor (I wasn’t going to settle for an i5 or AMD. I wanted a true Quad-core machine, not 2 dual-core fused together). 15.6” monitor SSD 128GB or Larger. – It’s almost 2011 and I don’t want an old standard HDD in this machine. 8GB of DDR3 Ram. – The more the better, right? 1GB Video Card (Prefer NVidia) – I might want to play games with this. HDMI Port – Almost a standard on new Machines. This would be used when I am on the road and want to stream Netflix to the HDTV in the Hotel room. Webcam Built-in – This would be to video chat with the wife and kids if I am on the road. 6-Cell Battery. – I’ve read that an i7 in a laptop really kills the battery. A 6-cell or 9-cell is even better. That is a pretty long list for a budget of around $1200. I searched around the internet and could not buy this machine prebuilt for under $1200. That was even with coupons and my company’s 10% Dell discount. The only way that I would get a machine like this was to buy a prebuilt and replace parts. I chose the  Lenovo Y560 on Newegg to start as my base. Below is a top-down picture of it.   Part 1: The Hardware The Specs for this machine: Color :  GrayOperating System : Windows 7 Home Premium 64-bitCPU Type : Intel Core i7-740QM(1.73GHz)Screen : 15.6" WXGAMemory Size : 4GB DDR3Hard Disk : 500GBOptical Drive : DVD±R/RWGraphics Card : ATI Mobility Radeon HD 5730Video Memory : 1GBCommunication : Gigabit LAN and WLANCard slot : 1 x Express Card/34Battery Life : Up to 3.5 hoursDimensions : 15.20" x 10.00" x 0.80" - 1.30"Weight : 5.95 lbs. This computer met most of the requirements above except that it didn’t come with an SSD or have 8GB of DDR3 Memory. So, I needed to start shopping except this time for an SSD. I asked around on twitter and other hardware forums and everyone pointed me to the Crucial C300 SSD. After checking prices of the drive, it was going to cost an extra $275 bucks and I was going from a spacious 500GB drive to 128GB. After watching some of the SSD videos on YouTube I started feeling better. Below is a pic of the Crucial C300 SSD. The second thing that I needed to upgrade was the RAM. It came with 4GB of DDR3 RAM, but it was slow. I decided to buy the Crucial 8GB (4GB x 2) Kit from Newegg. This RAM cost an extra $120 and had a CAS Latency of 7. In the end this machine delivered everything that I wanted and it cost around $1300. You are probably saying, well your budget was $1200. I have spare parts that I’m planning on selling on eBay or Anandtech.  =) If you are interested then shoot me an email and I will give you a great deal mbcrump[at]gmail[dot]com. 500GB Laptop 7200RPM HDD 4GB of DDR3 RAM (2GB x 2) faceVision HD 720p Camera – Unopened In the end my Windows Experience Rating of the SSD was 7.7 and the CPU 7.1. The max that you can get is a 7.9. Part 2: The Software I’m very lucky that I get a lot of software for free. When choosing a laptop, the OS really doesn’t matter because I would never keep the bloatware pre-installed or Windows 7 Home Premium on my main development machine. Matter of fact, as soon as I got the laptop, I immediately took out the old HDD without booting into it. After I got the SSD into the machine, I installed Windows 7 Ultimate 64-Bit. The BIOS was out of date, so I updated that to the latest version and started downloading drivers off of Lenovo’s site. I had to download the Wireless Networking Drivers to a USB-Key before I could get my machine on my wireless network. I also discovered that if the date on your computer is off then you cannot join the Windows 7 Homegroup until you fix it. I’m aware that most people like peeking into what programs other software developers use and I went ahead and listed my “essentials” of a fresh build. I am a big Silverlight guy, so naturally some of the software listed below is specific to Silverlight. You should also check out my master list of Tools and Utilities for the .NET Developer. See a killer app that I’m missing? Feel free to leave it in the comments below. My Software Essential List. CPU-Z Dropbox Everything Search Tool Expression Encoder Update Expression Studio 4 Ultimate Foxit Reader Google Chrome Infragistics NetAdvantage Ultimate Edition Keepass Microsoft Office Professional Plus 2010 Microsoft Security Essentials 2  Mindscape Silverlight Elements Notepad 2 (with shell extension) Precode Code Snippet Manager RealVNC Reflector ReSharper v5.1.1753.4 Silverlight 4 Toolkit Silverlight Spy Snagit 10 SyncFusion Reporting Controls for Silverlight Telerik Silverlight RadControls TweetDeck Virtual Clone Drive Visual Studio 2010 Feature Pack 2 Visual Studio 2010 Ultimate VS KB2403277 Update to get Feature Pack 2 to work. Windows 7 Ultimate 64-Bit Windows Live Essentials 2011 Windows Live Writer Backup. Windows Phone Development Tools That is pretty much it, I have a new laptop and am happy with the purchase. If you have any questions then feel free to leave a comment below.  Subscribe to my feed

    Read the article

< Previous Page | 38 39 40 41 42 43 44 45 46 47  | Next Page >