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• Is my hard drive about to fail?

  - by Cody Harlow

  I hear some squeaking noises sometimes when I use my computer so I ran smartctl. This is the results: === START OF READ SMART DATA SECTION === SMART Self-test log structure revision number 1 Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error # 1 Short offline Completed: read failure 90% 5953 37922655 # 2 Extended offline Completed: read failure 90% 5953 37922655 # 3 Short offline Completed: read failure 90% 5953 37922655 # 4 Short offline Completed without error 00% 429 - # 5 Extended offline Aborted by host 90% 429 - # 6 Short offline Completed without error 00% 429 - # 7 Short offline Completed without error 00% 429 - Is this a bad sign?

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• 11g ???:Active Data Guard

  - by JaneZhang(???)

  ?Oracle 11g??,????(physical Standby)???redo???,???????,???mount??11g??,???redo???,????????read-only??,????Active Data Guard ???Active Data Guard,?????????????????,??????????????   Active Data Guard???????????,??,????????????,????????,????redo??,????????????,??????????? Oracle Active Data Guard ?Oracle Database Enterprise Edition?????,??????????????   ????Active Data Guard, ??????? read-only ????,???? ALTER DATABASE RECOVER MANAGED STANDBY DATABASE????????????:??????COMPATIBLE ????????11.0.0?  ???????Active Data Guard,???V$DATABASE????"READ ONLY WITH APPLY':      SQL> SELECT open_mode FROM V$DATABASE;      OPEN_MODE      --------------------      READ ONLY WITH APPLY   ????????????,???????real-time apply:   SQL>ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE; ?????????read-only????????:    • Issue SELECT statements, including queries that require multiple sorts that leverage TEMP segments    • Use ALTER SESSION and ALTER SYSTEM statements    • Use SET ROLE    • Call stored procedures    • Use database links (dblinks) to write to remote databases    • Use stored procedures to call remote procedures via dblinks    • Use SET TRANSACTION READ ONLY for transaction level read consistency    • Issue complex queries (such as grouping SET queries and WITH CLAUSE queries) ??????????read-only????????:    • Any DMLs (excluding simple SELECT statements) or DDLs    • Query accessing local sequences    • DMLs to local temporary tables    ?????Active Data Guard ??: • ????????????????? • ???Oracle Real Application Clusters (Oracle RAC) ,?????? • RAC???RAC??    Oracle Data Guard ?????,,????????:    * ?????????????????:     http://docs.oracle.com/cd/B28359_01/server.111/b28294/create_ps.htm   * ???Oracle Real Application Clusters (Oracle RAC) ,??????:     http://www.oracle.com/technetwork/database/features/availability/maa-wp-10g-racprimarysingleinstance-131970.pdf   * RAC ???RAC ??:     http://www.oracle.com/technetwork/database/features/availability/maa-wp-10g-racprimaryracphysicalsta-131940.pdf  ??Active Data Guard???????,?????:    http://www.oracle.com/technetwork/database/features/availability/maa-wp-11gr1-activedataguard-1-128199.pdf     ??Oracle Maximum Availability Architecture Best Practices?????,???:   http://www.oracle.com/goto/maa

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• Disk performance below expectations

  - by paulH

  this is a follow-up to a previous question that I asked (Two servers with inconsistent disk speed). I have a PowerEdge R510 server with a PERC H700 integrated RAID controller (call this Server B) that was built using eight disks with 3Gb/s bandwidth that I was comparing with an almost identical server (call this Server A) that was built using four disks with 6Gb/s bandwidth. Server A had much better I/O rates than Server B. Once I discovered the difference with the disks, I had Server A rebuilt with faster 6Gbps disks. Unfortunately this resulted in no increase in the performance of the disks. Expecting that there must be some other configuration difference between the servers, we took the 6Gbps disks out of Server A and put them in Server B. This also resulted in no increase in the performance of the disks. We now have two identical servers built, with the exception that one is built with six 6Gbps disks and the other with eight 3Gbps disks, and the I/O rates of the disks is pretty much identical. This suggests that there is some bottleneck other than the disks, but I cannot understand how Server B originally had better I/O that has subsequently been 'lost'. Comparative I/O information below, as measured by SQLIO. The same parameters were used for each test. It's not the actual numbers that are significant but rather the variations between systems. In each case D: is a 2 disk RAID 1 volume, and E: is a 4 disk RAID 10 volume (apart from the original Server A, where E: was a 2 disk RAID 0 volume). Server A (original setup with 6Gpbs disks) D: Read (MB/s) 63 MB/s D: Write (MB/s) 170 MB/s E: Read (MB/s) 68 MB/s E: Write (MB/s) 320 MB/s Server B (original setup with 3Gpbs disks) D: Read (MB/s) 52 MB/s D: Write (MB/s) 88 MB/s E: Read (MB/s) 112 MB/s E: Write (MB/s) 130 MB/s Server A (new setup with 3Gpbs disks) D: Read (MB/s) 55 MB/s D: Write (MB/s) 85 MB/s E: Read (MB/s) 67 MB/s E: Write (MB/s) 180 MB/s Server B (new setup with 6Gpbs disks) D: Read (MB/s) 61 MB/s D: Write (MB/s) 95 MB/s E: Read (MB/s) 69 MB/s E: Write (MB/s) 180 MB/s Can anybody suggest any ideas what is going on here? The drives in use are as follows: Dell Seagate F617N ST3300657SS 300GB 15K RPM SAS Dell Hitachi HUS156030VLS600 300GB 3.5 inch 15000rpm 6GB SAS Hitachi Hus153030vls300 300GB Server SAS Dell ST3146855SS Seagate 3.5 inch 146GB 15K SAS

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• What is some good lossless video codec for recording gameplay?

  - by Don Salva

  I'm an avid gamer and I like to record my gameplay. Usually I've been using Fraps to do it, however I'm thinking of switching to Dxtory as it allows to write on multiple HDDs at once. Say I have 3 HDDs with the following write speeds: HDD1 with 50 mb/s, HDD2 with 22 mb/s and HDD3 with 45 mb/s. Combined write speed would be: 117 mb/s. Dxtory allows you to utilize all 3 HDD's at once while recording your gameplay. Using this formula: RGB24 YUV24: Width x Height x 3 x fps = bitrate (byte/sec) YUV420: Width x Height x 3 / 2 x fps = bitrate (byte/sec) YUV410: Width x Height x 9 / 8 x fps = bitrate (byte/sec) And recording in YUV420 colorspace at 1920x1080 with 30 fps I'd need about 95 mb/s write speed. Dxtory is good because it allows me to play with constant 60 fps while recording in 30 fps. Fraps does not (even though they say it does), once you start recording with Fraps, the game's fps drops. So I'm looking for a codec that doesn't need a very high write speed (bitrate) yet records in good (lossless) quality. Dxtory comes with its own codec, the Dxtory codec. Which allows me some experimentation. Fraps has it's own codec which I can use in Dxtory to expirement around. I also came across http://lags.leetcode.net/codec.html . Are there more lossless codecs out there (besides Fraps' and Dxtory's) which are good for what I want to do? Edit: To clarify, yes, I'm aware a lossless codec always has "good" quality. But that's not what I'm looking for. Let me take the Fraps codec and Dxtory codec to clarify what I'm looking for. When I record with the Dxtory codec in RGB colorspace at 1920x1080 with targeted 30 fps, I can play the game at 60 fps, BUT I'm recording with 10-15 fps, that's because RGB with Dxtory needs much, much more write speed than my hdd can handle. When recording with Dxtory codec in YUV410 colorspace at 1920x1080 with targeted 30 fps, I can play at 60 fps and record at 30 fps, again, that's because YUV410 in Dxtory's codec takes much, much less write speed than RGB When recording with Fraps codec in ??? (I dunno the color space Fraps records in, I guess YUV420), I can play with 60 fps and record with 30 fps. What I'm looking for is a lossless codec that can record in YUV420 (or even RGB??) which does not exceed a write speed (or bitrate if you will) of 100 mb/s in 1920x1080 or in other words, which will allow me to record in constant 30fps. Obviously the best solution would be to buy an SDD, but that's not what I'm after.

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• vsftpd: ECONNREFUSED with "allow_writeable_chroot=YES"

  - by heinob

  When setting up vsftpd I am trapped. When I leave the ftpuser's home directory without write permission I can login and all is fine despite the fact, that I cannot write (of course). When I add write permission I get something like cannot change to directory with write permissions if user is chrooted Then I added allow_writeable_chroot=YES to vsftpd.conf. But now I get ECONNREFUSED - Connection refused by server I am lost. What am I doing wrong?

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• How to diagnose failing 6Gbps SATA connection?

  - by whitequark

  I have a Samsung RC530 notebook and OCZ Vertex-3 6Gbps SATA SSD working in AHCI mode. # dmesg | grep DMI SAMSUNG ELECTRONICS CO., LTD. RC530/RC730/RC530/RC730, BIOS 03WD.M008.20110927.PSA 09/27/2011 # lspci -nn 00:1f.2 SATA controller [0106]: Intel Corporation 6 Series/C200 Series Chipset Family 6 port SATA AHCI Controller [8086:1c03] (rev 04) # sdparm -a /dev/sda /dev/sda: ATA OCZ-VERTEX3 2.15 At the boot, the following messages are present in dmesg (I am running Debian wheezy @ Linux 3.2.8): # dmesg | grep -iE '(ata|ahci)' [ 5.179783] ahci 0000:00:1f.2: version 3.0 [ 5.179802] ahci 0000:00:1f.2: PCI INT B -> GSI 19 (level, low) -> IRQ 19 [ 5.179864] ahci 0000:00:1f.2: irq 42 for MSI/MSI-X [ 5.195424] ahci 0000:00:1f.2: AHCI 0001.0300 32 slots 6 ports 6 Gbps 0x5 impl SATA mode [ 5.195429] ahci 0000:00:1f.2: flags: 64bit ncq sntf pm led clo pio slum part ems apst [ 5.195436] ahci 0000:00:1f.2: setting latency timer to 64 [ 5.204035] scsi0 : ahci [ 5.204301] scsi1 : ahci [ 5.204447] scsi2 : ahci [ 5.204592] scsi3 : ahci [ 5.204682] scsi4 : ahci [ 5.204799] scsi5 : ahci [ 5.204917] ata1: SATA max UDMA/133 abar m2048@0xf7c06000 port 0xf7c06100 irq 42 [ 5.204920] ata2: DUMMY [ 5.204923] ata3: SATA max UDMA/133 abar m2048@0xf7c06000 port 0xf7c06200 irq 42 [ 5.204924] ata4: DUMMY [ 5.204926] ata5: DUMMY [ 5.204927] ata6: DUMMY [ 5.523039] ata3: SATA link up 1.5 Gbps (SStatus 113 SControl 300) [ 5.525911] ata3.00: ATAPI: TSSTcorp CDDVDW SN-208BB, SC00, max UDMA/100 [ 5.531006] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300) [ 5.533703] ata3.00: configured for UDMA/100 [ 5.542790] ata1.00: ATA-8: OCZ-VERTEX3, 2.15, max UDMA/133 [ 5.542800] ata1.00: 117231408 sectors, multi 16: LBA48 NCQ (depth 31/32), AA [ 5.552751] ata1.00: configured for UDMA/133 [ 5.553050] scsi 0:0:0:0: Direct-Access ATA OCZ-VERTEX3 2.15 PQ: 0 ANSI: 5 [ 5.559621] scsi 2:0:0:0: CD-ROM TSSTcorp CDDVDW SN-208BB SC00 PQ: 0 ANSI: 5 [ 5.564059] sd 0:0:0:0: [sda] 117231408 512-byte logical blocks: (60.0 GB/55.8 GiB) [ 5.564127] sd 0:0:0:0: [sda] Write Protect is off [ 5.564131] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00 [ 5.564158] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 5.564582] sda: sda1 [ 5.564810] sd 0:0:0:0: [sda] Attached SCSI disk [ 5.572006] sr0: scsi3-mmc drive: 16x/24x writer dvd-ram cd/rw xa/form2 cdda tray [ 5.572010] cdrom: Uniform CD-ROM driver Revision: 3.20 [ 5.572189] sr 2:0:0:0: Attached scsi CD-ROM sr0 [ 6.717181] ata1.00: exception Emask 0x50 SAct 0x1 SErr 0x280900 action 0x6 frozen [ 6.717238] ata1.00: irq_stat 0x08000000, interface fatal error [ 6.717291] ata1: SError: { UnrecovData HostInt 10B8B BadCRC } [ 6.717342] ata1.00: failed command: READ FPDMA QUEUED [ 6.717395] ata1.00: cmd 60/50:00:20:39:58/00:00:00:00:00/40 tag 0 ncq 40960 in [ 6.717396] res 40/00:00:20:39:58/00:00:00:00:00/40 Emask 0x50 (ATA bus error) [ 6.717503] ata1.00: status: { DRDY } [ 6.717553] ata1: hard resetting link [ 7.033417] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300) [ 7.055234] ata1.00: configured for UDMA/133 [ 7.055262] ata1: EH complete [ 7.147280] ata1.00: exception Emask 0x10 SAct 0xf8 SErr 0x280100 action 0x6 frozen [ 7.147340] ata1.00: irq_stat 0x08000000, interface fatal error [ 7.147393] ata1: SError: { UnrecovData 10B8B BadCRC } [ 7.147460] ata1.00: failed command: READ FPDMA QUEUED [ 7.147529] ata1.00: cmd 60/08:18:88:17:41/00:00:02:00:00/40 tag 3 ncq 4096 in [ 7.147531] res 40/00:38:50:99:64/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.147691] ata1.00: status: { DRDY } [ 7.147754] ata1.00: failed command: READ FPDMA QUEUED [ 7.147821] ata1.00: cmd 60/00:20:f8:42:4c/01:00:02:00:00/40 tag 4 ncq 131072 in [ 7.147822] res 40/00:38:50:99:64/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.147977] ata1.00: status: { DRDY } [ 7.148036] ata1.00: failed command: READ FPDMA QUEUED [ 7.148100] ata1.00: cmd 60/50:28:f8:43:4c/00:00:02:00:00/40 tag 5 ncq 40960 in [ 7.148101] res 40/00:38:50:99:64/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.148255] ata1.00: status: { DRDY } [ 7.148315] ata1.00: failed command: READ FPDMA QUEUED [ 7.148379] ata1.00: cmd 60/00:30:50:98:64/01:00:02:00:00/40 tag 6 ncq 131072 in [ 7.148380] res 40/00:38:50:99:64/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.148534] ata1.00: status: { DRDY } [ 7.148593] ata1.00: failed command: READ FPDMA QUEUED [ 7.148657] ata1.00: cmd 60/00:38:50:99:64/01:00:02:00:00/40 tag 7 ncq 131072 in [ 7.148658] res 40/00:38:50:99:64/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.148813] ata1.00: status: { DRDY } [ 7.148875] ata1: hard resetting link [ 7.464842] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300) [ 7.486794] ata1.00: configured for UDMA/133 [ 7.486822] ata1: EH complete [ 7.546395] ata1.00: exception Emask 0x10 SAct 0x2f SErr 0x280100 action 0x6 frozen [ 7.546470] ata1.00: irq_stat 0x08000000, interface fatal error [ 7.546531] ata1: SError: { UnrecovData 10B8B BadCRC } [ 7.546588] ata1.00: failed command: READ FPDMA QUEUED [ 7.546648] ata1.00: cmd 60/00:00:e0:4b:61/01:00:02:00:00/40 tag 0 ncq 131072 in [ 7.546649] res 40/00:28:e0:4c:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.546794] ata1.00: status: { DRDY } [ 7.546847] ata1.00: failed command: READ FPDMA QUEUED [ 7.546906] ata1.00: cmd 60/00:08:90:2f:48/01:00:02:00:00/40 tag 1 ncq 131072 in [ 7.546907] res 40/00:28:e0:4c:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.547053] ata1.00: status: { DRDY } [ 7.547106] ata1.00: failed command: READ FPDMA QUEUED [ 7.547165] ata1.00: cmd 60/00:10:90:30:48/01:00:02:00:00/40 tag 2 ncq 131072 in [ 7.547166] res 40/00:28:e0:4c:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.547310] ata1.00: status: { DRDY } [ 7.547363] ata1.00: failed command: READ FPDMA QUEUED [ 7.547422] ata1.00: cmd 60/00:18:50:c7:64/01:00:02:00:00/40 tag 3 ncq 131072 in [ 7.547423] res 40/00:28:e0:4c:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.547568] ata1.00: status: { DRDY } [ 7.547621] ata1.00: failed command: READ FPDMA QUEUED [ 7.547681] ata1.00: cmd 60/00:28:e0:4c:61/01:00:02:00:00/40 tag 5 ncq 131072 in [ 7.547682] res 40/00:28:e0:4c:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.547825] ata1.00: status: { DRDY } [ 7.547882] ata1: hard resetting link [ 7.864408] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300) [ 7.886351] ata1.00: configured for UDMA/133 [ 7.886375] ata1: EH complete [ 7.890012] ata1: limiting SATA link speed to 3.0 Gbps [ 7.890016] ata1.00: exception Emask 0x10 SAct 0x7 SErr 0x280100 action 0x6 frozen [ 7.890093] ata1.00: irq_stat 0x08000000, interface fatal error [ 7.890152] ata1: SError: { UnrecovData 10B8B BadCRC } [ 7.890210] ata1.00: failed command: READ FPDMA QUEUED [ 7.890272] ata1.00: cmd 60/00:00:90:33:48/01:00:02:00:00/40 tag 0 ncq 131072 in [ 7.890273] res 40/00:10:e0:4f:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.890418] ata1.00: status: { DRDY } [ 7.890472] ata1.00: failed command: READ FPDMA QUEUED [ 7.890530] ata1.00: cmd 60/00:08:90:34:48/01:00:02:00:00/40 tag 1 ncq 131072 in [ 7.890531] res 40/00:10:e0:4f:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.890672] ata1.00: status: { DRDY } [ 7.890724] ata1.00: failed command: READ FPDMA QUEUED [ 7.890781] ata1.00: cmd 60/78:10:e0:4f:61/00:00:02:00:00/40 tag 2 ncq 61440 in [ 7.890782] res 40/00:10:e0:4f:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.890925] ata1.00: status: { DRDY } [ 7.890981] ata1: hard resetting link [ 8.208021] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 320) [ 8.230100] ata1.00: configured for UDMA/133 [ 8.230124] ata1: EH complete Looks like the SATA interface tries to use 6Gbps link, then fails miserably and Linux fallbacks to 3Gbps. This is somewhat fine for me, as the system boots successfully each time and works under high load (cd linux-3.2.8; make -j16). I've also ran memtest86+ and it did not find any errors. What concerns me more is that Grub sometimes takes a long time to load the images and/or fails to load itself completely. The error is consistent and is probablistic: that is, each time I boot I have a certain chance to fail. Actually, I have a slight suspiction on the cause of the failure. Look at the cabling: What kind of engineer does it this way? Nah. Even 1Gbps Ethernet hardly tolerates cables bent over a small angle, and there you have 6Gbps SATA. How cound I determine and fix the cause of errors and/or switch the link to 3Gbps mode permanently?

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• e2fsck extremely slow, although enough memory exists

  - by kaefert

  I've got this external USB-Disk: kaefert@blechmobil:~$ lsusb -s 2:3 Bus 002 Device 003: ID 0bc2:3320 Seagate RSS LLC As can be seen in this dmesg output, there is some problem that prevents that disk from beeing mounted: kaefert@blechmobil:~$ dmesg ... [ 113.084079] usb 2-1: new high-speed USB device number 3 using ehci_hcd [ 113.217783] usb 2-1: New USB device found, idVendor=0bc2, idProduct=3320 [ 113.217787] usb 2-1: New USB device strings: Mfr=2, Product=3, SerialNumber=1 [ 113.217790] usb 2-1: Product: Expansion Desk [ 113.217792] usb 2-1: Manufacturer: Seagate [ 113.217794] usb 2-1: SerialNumber: NA4J4N6K [ 113.435404] usbcore: registered new interface driver uas [ 113.455315] Initializing USB Mass Storage driver... [ 113.468051] scsi5 : usb-storage 2-1:1.0 [ 113.468180] usbcore: registered new interface driver usb-storage [ 113.468182] USB Mass Storage support registered. [ 114.473105] scsi 5:0:0:0: Direct-Access Seagate Expansion Desk 070B PQ: 0 ANSI: 6 [ 114.474342] sd 5:0:0:0: [sdb] 732566645 4096-byte logical blocks: (3.00 TB/2.72 TiB) [ 114.475089] sd 5:0:0:0: [sdb] Write Protect is off [ 114.475092] sd 5:0:0:0: [sdb] Mode Sense: 43 00 00 00 [ 114.475959] sd 5:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 114.477093] sd 5:0:0:0: [sdb] 732566645 4096-byte logical blocks: (3.00 TB/2.72 TiB) [ 114.501649] sdb: sdb1 [ 114.502717] sd 5:0:0:0: [sdb] 732566645 4096-byte logical blocks: (3.00 TB/2.72 TiB) [ 114.504354] sd 5:0:0:0: [sdb] Attached SCSI disk [ 116.804408] EXT4-fs (sdb1): ext4_check_descriptors: Checksum for group 3976 failed (47397!=61519) [ 116.804413] EXT4-fs (sdb1): group descriptors corrupted! ... So I went and fired up my favorite partition manager - gparted, and told it to verify and repair the partition sdb1. This made gparted call e2fsck (version 1.42.4 (12-Jun-2012)) e2fsck -f -y -v /dev/sdb1 Although gparted called e2fsck with the "-v" option, sadly it doesn't show me the output of my e2fsck process (bugreport https://bugzilla.gnome.org/show_bug.cgi?id=467925 ) I started this whole thing on Sunday (2012-11-04_2200) evening, so about 48 hours ago, this is what htop says about it now (2012-11-06-1900): PID USER PRI NI VIRT RES SHR S CPU% MEM% TIME+ Command 3704 root 39 19 1560M 1166M 768 R 98.0 19.5 42h56:43 e2fsck -f -y -v /dev/sdb1 Now I found a few posts on the internet that discuss e2fsck running slow, for example: http://gparted-forum.surf4.info/viewtopic.php?id=13613 where they write that its a good idea to see if the disk is just that slow because maybe its damaged, and I think these outputs tell me that this is not the case in my case: kaefert@blechmobil:~$ sudo hdparm -tT /dev/sdb /dev/sdb: Timing cached reads: 3562 MB in 2.00 seconds = 1783.29 MB/sec Timing buffered disk reads: 82 MB in 3.01 seconds = 27.26 MB/sec kaefert@blechmobil:~$ sudo hdparm /dev/sdb /dev/sdb: multcount = 0 (off) readonly = 0 (off) readahead = 256 (on) geometry = 364801/255/63, sectors = 5860533160, start = 0 However, although I can read quickly from that disk, this disk speed doesn't seem to be used by e2fsck, considering tools like gkrellm or iotop or this: kaefert@blechmobil:~$ iostat -x Linux 3.2.0-2-amd64 (blechmobil) 2012-11-06 _x86_64_ (2 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 14,24 47,81 14,63 0,95 0,00 22,37 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sda 0,59 8,29 2,42 5,14 43,17 160,17 53,75 0,30 39,80 8,72 54,42 3,95 2,99 sdb 137,54 5,48 9,23 0,20 587,07 22,73 129,35 0,07 7,70 7,51 16,18 2,17 2,04 Now I researched a little bit on how to find out what e2fsck is doing with all that processor time, and I found the tool strace, which gives me this: kaefert@blechmobil:~$ sudo strace -p3704 lseek(4, 41026998272, SEEK_SET) = 41026998272 write(4, "\212\354K[_\361\3nl\212\245\352\255jR\303\354\312Yv\334p\253r\217\265\3567\325\257\3766"..., 4096) = 4096 lseek(4, 48404766720, SEEK_SET) = 48404766720 read(4, "\7t\260\366\346\337\304\210\33\267j\35\377'\31f\372\252\ffU\317.y\211\360\36\240c\30`\34"..., 4096) = 4096 lseek(4, 41027002368, SEEK_SET) = 41027002368 write(4, "\232]7Ws\321\352\t\1@[+5\263\334\276{\343zZx\352\21\316`1\271[\202\350R`"..., 4096) = 4096 lseek(4, 48404770816, SEEK_SET) = 48404770816 read(4, "\17\362r\230\327\25\346//\210H\v\311\3237\323K\304\306\361a\223\311\324\272?\213\tq \370\24"..., 4096) = 4096 lseek(4, 41027006464, SEEK_SET) = 41027006464 write(4, "\367yy>x\216?=\324Z\305\351\376&\25\244\210\271\22\306}\276\237\370(\214\205G\262\360\257#"..., 4096) = 4096 lseek(4, 48404774912, SEEK_SET) = 48404774912 read(4, "\365\25\0\21|T\0\21}3t_\272\373\222k\r\177\303\1\201\261\221$\261B\232\3142\21U\316"..., 4096) = 4096 ^CProcess 3704 detached around 16 of these lines every second, so 4 read and 4 write operations every second, which I don't consider to be a lot.. And finally, my question: Will this process ever finish? If those numbers from fseek (48404774912) represent bytes, that would be something like 45 gigabytes, with this beeing a 3 terrabyte disk, which would give me 134 days to go, if the speed stays constant, and e2fsck scans the disk like this completly and only once. Do you have some advice for me? I have most of the data on that disk elsewhere, but I've put a lot of hours into sorting and merging it to this disk, so I would prefer to getting this disk up and running again, without formatting it anew. I don't think that the hardware is damaged since the disk is only a few months and since I can't see any I/O errors in the dmesg output. UPDATE: I just looked at the strace output again (2012-11-06_2300), now it looks like this: lseek(4, 1419860611072, SEEK_SET) = 1419860611072 read(4, "3#\f\2447\335\0\22A\355\374\276j\204'\207|\217V|\23\245[\7VP\251\242\276\207\317:"..., 4096) = 4096 lseek(4, 43018145792, SEEK_SET) = 43018145792 write(4, "]\206\231\342Y\204-2I\362\242\344\6R\205\361\324\177\265\317C\334V\324\260\334\275t=\10F."..., 4096) = 4096 lseek(4, 1419860615168, SEEK_SET) = 1419860615168 read(4, "\262\305\314Y\367\37x\326\245\226\226\320N\333$s\34\204\311\222\7\315\236\336\300TK\337\264\236\211n"..., 4096) = 4096 lseek(4, 43018149888, SEEK_SET) = 43018149888 write(4, "\271\224m\311\224\25!I\376\16;\377\0\223H\25Yd\201Y\342\r\203\271\24eG<\202{\373V"..., 4096) = 4096 lseek(4, 1419860619264, SEEK_SET) = 1419860619264 read(4, ";d\360\177\n\346\253\210\222|\250\352T\335M\33\260\320\261\7g\222P\344H?t\240\20\2548\310"..., 4096) = 4096 lseek(4, 43018153984, SEEK_SET) = 43018153984 write(4, "\360\252j\317\310\251G\227\335{\214`\341\267\31Y\202\360\v\374\307oq\3063\217Z\223\313\36D\211"..., 4096) = 4096 So the numbers in the lseek lines before the reads, like 1419860619264 are already a lot bigger, standing for 1.29 terabytes if those numbers are bytes, so it doesn't seem to be a linear progress on a big scale, maybe there are only some areas that need work, that have big gaps in between them. UPDATE2: Okey, big disappointment, the numbers are back to very small again (2012-11-07_0720) lseek(4, 52174548992, SEEK_SET) = 52174548992 read(4, "\374\312\22\\\325\215\213\23\0357U\222\246\370v^f(\312|f\212\362\343\375\373\342\4\204mU6"..., 4096) = 4096 lseek(4, 46603526144, SEEK_SET) = 46603526144 write(4, "\370\261\223\227\23?\4\4\217\264\320_Am\246CQ\313^\203U\253\274\204\277\2564n\227\177\267\343"..., 4096) = 4096 so either e2fsck goes over the data multiple times, or it just hops back and forth multiple times. Or my assumption that those numbers are bytes is wrong. UPDATE3: Since it's mentioned here http://forums.fedoraforum.org/showthread.php?t=282125&page=2 that you can testisk while e2fsck is running, i tried that, though not with a lot of success. When asking testdisk to display the data of my partition, this is what I get: TestDisk 6.13, Data Recovery Utility, November 2011 Christophe GRENIER <[email protected]> http://www.cgsecurity.org 1 P Linux 0 4 5 45600 40 8 732566272 Can't open filesystem. Filesystem seems damaged. And this is what strace currently gives me (2012-11-07_1030) lseek(4, 212460343296, SEEK_SET) = 212460343296 read(4, "\315Mb\265v\377Gn \24\f\205EHh\2349~\330\273\203\3375\206\10\r3=W\210\372\352"..., 4096) = 4096 lseek(4, 47347830784, SEEK_SET) = 47347830784 write(4, "]\204\223\300I\357\4\26\33+\243\312G\230\250\371*m2U\t_\215\265J \252\342Pm\360D"..., 4096) = 4096 (times are in CET)

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• SSD performance

  - by Tom

  I recently upgraded to a Kingston Hyper-X 120GB SSD, when I run Crystaldiskmark my scores look really slow, my MB (gigabyte 775) does not have an option for ACHI in the BIOS, I'm wondering if that's an issue. The scores were: Seq read -233 write-176.8 512K-224 write-175.8 4K-25 write-80 4K-23 write-102 This drive is rated for over 500, Any help or input would be greatly appreciated..

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• Proper set up shared folders for users

  - by user221486

  First I would like to say thanks for helping, and I have huge problem with proper set up permission for shared folders. I have Windows 7 x64 ent. - name: backupfb - added to domain with shared folder on drive e: (e:\backup) 50 clients/laptops with TSM Tivoli fastback for workstations who save files on shared folder And I need to configure proper permission for my shared folders that only owner of folder can access to their folders. Folder structure is: e:\backup <- shared as a "backup" folder \\backupfb\backup\ e:\backup\BackupAdmin <-- directory is used by the Tivoli Storage Manager FastBack for Workstations client to download revisions and configurations. Nodes require read-only access to these directories e:\backup\RealTimeBackup <-- enable client accounts to create directories that are only accessible by the account that created them. As a result, the directory that contains data for a node is not created until that node connects to the server. So permission should look like that (take from instructions): Inheritable permissions from object`s parents are DISABLE Permission entries: \\backupfb\backup\BackupAdmin Allow Users Read, Execute This folder, subfolders, and files Traverse Folder / Execute Allow List Folder / Read Data Allow Read Attributes Allow Read Extended Attributes Allow Delete subfolders and files Allow Delete Allow Read Permission’s Allow Allow Administrators Full Control This folder, subfolders, and files Both folders have enabled option "apply these permissions to objects and/or containers within this container only" Here everything works fine \\backupfb\backup\RealTimeBackup <<-- Allow Administrators Full Control This folder, subfolders, and files Allow CREATOR OWNER Full Control This folder, subfolders, and files (from domain) Allow Users Special This folder only Traverse Folder / Execute Allow List Folder / Read Data Allow Read Attributes Allow Read Extended Attributes Allow Create Files / Write Data Allow Create Folders / Append Data Allow Delete subfolders and files Allow Read Permission’s Allow Allow OWNER RIGHTS* Full Control This folder, subfolders, and files Here I have huge problem with CREATOR OWNER Im able to set FULL CONTROL but I can only apply "Subfolders and files only". When I change props. to "This folder, subfolders and files" and save its change to "Subfolders and files only" So I try use icacls to set up permissions @echo off takeown /F E:\backup\ /R /A for /D %%i IN (E:\backup\RealTimeBackup*) DO icacls E:\backup\RealTimeBackup\%%~nxi /grant:r cloud\%%~nxi:F /T /C pause but after that user are able to create just one folder in \backupfb\backup\RealTimeBackup\userfolder but problem is with subfolders In log i have: FBW5022E Unable to access the specified file Explanation: The file specified is unable to be accessed. Possibly spelled incorrectly, or bad path, or permissions. User response: Ensure the user has the proper permissions for the file and directories involved andthat the file and directory exist Any idea ?? pls help ;-) thanks

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• Ruby SerialPorts Gem

  - by Seth Archer

  Using Ruby SerialPorts Gem to interact with hardware. When I write a byte array to the hardware using a program called "Serial Port Monitor" the hardware responds correctly. However, when I write the same byte array using ruby it doesn't work unless I do a read request just before the write request. This device doesn't respond correctly with this sp = SerialPort.new(args) sp.write [200.chr, 30.chr, 6.chr, 5.chr, 1.chr, 2.chr, 0.chr, 244.chr] But it does if I add a read request before the write. Like this sp SerialPort.new(args) sp.read sp.write [200.chr, 30.chr, 6.chr, 5.chr, 1.chr, 2.chr, 0.chr, 244.chr] This works, but I'm at a loss as to why. I should also add that the first snippet does work occasionally maybe 1/10 of the time.

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• C# SerialPort - Problems mixing ports with different baud rates.

  - by GrandAdmiral

  Greetings, I have two devices that I would like to connect over a serial interface, but they have incompatible connections. To get around this problem, I connected them both to my PC and I'm working on a C# program that will route traffic on COM port X to COM port Y and vice versa. The program connects to two COM ports. In the data received event handler, I read in incoming data and write it to the other COM port. To do this, I have the following code: private void HandleDataReceived(SerialPort inPort, SerialPort outPort) { byte[] data = new byte[1]; while (inPort.BytesToRead > 0) { // Read the data data[0] = (byte)inPort.ReadByte(); // Write the data if (outPort.IsOpen) { outPort.Write(data, 0, 1); } } } That code worked fine as long as the outgoing COM port operated at a higher baud rate than the incoming COM port. If the incoming COM port was faster than the outgoing COM port, I started missing data. I had to correct the code like this: private void HandleDataReceived(SerialPort inPort, SerialPort outPort) { byte[] data = new byte[1]; while (inPort.BytesToRead > 0) { // Read the data data[0] = (byte)inPort.ReadByte(); // Write the data if (outPort.IsOpen) { outPort.Write(data, 0, 1); while (outPort.BytesToWrite > 0); //<-- Change to fix problem } } } I don't understand why I need that fix. I'm new to C# (this is my first program), so I'm wondering if there is something I am missing. The SerialPort defaults to a 2048 byte write buffer and my commands are less than ten bytes. The write buffer should have the ability to buffer the data until it can be written to a slower COM port. In summary, I'm receiving data on COM X and writing the data to COM Y. COM X is connected at a faster baud rate than COM Y. Why doesn't the buffering in the write buffer handle this difference? Why does it seem that I need to wait for the write buffer to drain to avoid losing data? Thanks!

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• ASP Web Service Not Working

  - by BlitzPackage

  Good people, Hello. Our webservice is not working. We should be receiving information via an HTTP POST. However, nothing is working. Below are the code files. Let me know what you think. Thanks in advance for any help or information you can provide. (By the way, some information (e.g. class names, connection strings, etc...) has been removed or changed in order to hide any sensitive information. Imports System.Web.Mail Imports System.Data Imports System.Data.SqlClient Imports System.IO Partial Class hbcertification Inherits System.Web.UI.Page Public strBody As String = "" Public sqlInsertStr As String = "" Public errStr As String = "" Public txn_id, first_name, last_name, address_street, address_city, address_state, address_zip, address_country, address_phone, payer_email, Price, key, invoice, payment_date, mc_fee, buyer_ip As String Dim myConn As New SqlConnection(ConfigurationSettings.AppSettings("ConnectionInfo")) '******************************************************************************************* Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load strBody += "Test email sent.Customer name: " & Request("first_name") & " " & Request("last_name") strBody += "Reg Key: " & Request("key") & "Transaction ID: " & Request("txn_id") & "Tran Type: " & Request("txn_type") updateFile(Server.MapPath("log.txt"), strBody) txn_id = Request("txn_id") first_name = Request("first_name") last_name = Request("last_name") address_street = Request("address_street") address_city = Request("address_city") address_state = Request("address_state") address_zip = Request("address_zip") address_country = Request("address_country") address_phone = Request("address_phone") payer_email = Request("payer_email") Price = Request("Price") key = Request("key") invoice = Request("invoice") payment_date = Request("payment_date") mc_fee = Request("mc_fee") buyer_ip = Request("buyer_ip") If Request("first_name") "" And Request("last_name") "" Then SendMail("[email protected]", "[email protected]", strBody, "Software Order Notification", "[email protected]") Else Response.Write("Email not sent. Name missing.") End If Dim sItem As String Response.Write("") If Request.Form("dosubmit") = "1" Then Response.Write("FORM VALS:") For Each sItem In Request.Form Response.Write("" & sItem & " - [" & Request.Form(sItem) & "]") Next sqlInsertStr += "insert into aspnet_MorrisCustomerInfo (TransactionID,FirstName,LastName,AddressStreet,AddressCity,AddressState,AddressZip,AddressCountry,AddressPhone,PayerEmail,Price,AuthenticationCode,InvoiceID,PurchaseDate,PaypalFee,PurchaseIPAddress) values ('" & SQLSafe(txn_id) & "','" & SQLSafe(first_name) & "','" & SQLSafe(last_name) & "','" & SQLSafe(address_street) & "','" & SQLSafe(address_city) & "','" & SQLSafe(address_state) & "','" & SQLSafe(address_zip) & "','" & SQLSafe(address_country) & "','" & SQLSafe(address_phone) & "','" & SQLSafe(payer_email) & "','" & SQLSafe(Price) & "','" & SQLSafe(key) & "','" & SQLSafe(invoice) & "','" & SQLSafe(payment_date) & "','" & SQLSafe(mc_fee) & "','" & SQLSafe(buyer_ip) & "')" runMyQuery(sqlInsertStr, False) End If Response.Write("sqlInsertStr is: " & sqlInsertStr) Response.Write("") End Sub '******************************************************************************************* Sub SendMail(ByVal strEmailAddress, ByVal strEmailAddress_cc, ByVal Email_Body, ByVal Email_Subject, ByVal Email_From) If Request.ServerVariables("server_name") "localhost" Then Try Dim resumeEmail As New MailMessage resumeEmail.To = strEmailAddress resumeEmail.Cc = strEmailAddress_cc resumeEmail.From = Email_From resumeEmail.Subject = Email_Subject resumeEmail.Priority = MailPriority.High 'resumeEmail.BodyFormat = MailFormat.Html resumeEmail.BodyFormat = MailFormat.Html resumeEmail.Body = Email_Body 'System.Web.Mail.SmtpMail.SmtpServer = "morris.com" System.Web.Mail.SmtpMail.SmtpServer = "relay-hosting.secureserver.net" System.Web.Mail.SmtpMail.Send(resumeEmail) Response.Write("Email sent.") Catch exc As Exception Response.Write("MAIL ERROR OCCURRED" & exc.ToString() & "From: " & Email_From) End Try Else Response.Write("TEST RESPONSE" & strBody & "") End If End Sub End Function End Class Process Data Asp.Net Configuration option in Visual Studio. A full list of settings and comments can be found in machine.config.comments usually located in \Windows\Microsoft.Net\Framework\v2.x\Config -- section enables configuration of the security authentication mode used by ASP.NET to identify an incoming user. -- section enables configuration of what to do if/when an unhandled error occurs during the execution of a request. Specifically, it enables developers to configure html error pages to be displayed in place of a error stack trace. --

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• Parsing complex string using regex

  - by wojtek_z

  My regex skills are not very good and recently a new data element has thrown my parser into a loop Take the following string "+USER=Bob Smith-GROUP=Admin+FUNCTION=Read/FUNCTION=Write" Previously I had the following for my regex : [+\\-/] Which would turn the result into USER=Bob Smith GROUP=Admin FUNCTION=Read FUNCTION=Write FUNCTION=Read But now I have values with dashes in them which is causing bad output New string looks like "+USER=Bob Smith-GROUP=Admin+FUNCTION=Read/FUNCTION=Write/FUNCTION=Read-Write" Which gives me the following result , and breaks the key = value structure. USER=Bob Smith GROUP=Admin FUNCTION=Read FUNCTION=Write FUNCTION=Read Write Can someone help me formulate a valid regex for handling this or point me to some key / value examples. Basically I need to be able to handle + - / signs in order to get combinations.

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• Is there any way that an export-to-Excel function can be scalable?

  - by MusiGenesis

  Summary: ASP.Net website with a couple hundred users. Data is exported to Excel files which can be relatively large (~5 MB). In the pilot phase (just a few users), we are already seeing occasional errors on the server in the exporting method. Here's the stack trace: System.Web.HttpUnhandledException: Exception of type 'System.Web.HttpUnhandledException' was thrown. --- System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown. at System.IO.MemoryStream.set_Capacity(Int32 value) at System.IO.MemoryStream.EnsureCapacity(Int32 value) at System.IO.MemoryStream.Write(Byte[] buffer, Int32 offset, Int32 count) at MS.Internal.IO.Packaging.TrackingMemoryStream.Write(Byte[] buffer, Int32 offset, Int32 count) at MS.Internal.IO.Packaging.SparseMemoryStream.WriteAndCollapseBlocks(Byte[ ] buffer, Int32 offset, Int32 count) at MS.Internal.IO.Packaging.SparseMemoryStream.Write(Byte[] buffer, Int32 offset, Int32 count) at MS.Internal.IO.Packaging.CompressEmulationStream.Write(Byte[] buffer, Int32 offset, Int32 count) at MS.Internal.IO.Packaging.CompressStream.Write(Byte[] buffer, Int32 offset, Int32 count) at MS.Internal.IO.Zip.ProgressiveCrcCalculatingStream.Write(Byte[] buffer, Int32 offset, Int32 count) at MS.Internal.IO.Zip.ZipIOModeEnforcingStream.Write(Byte[] buffer, Int32 offset, Int32 count) at System.IO.StreamWriter.Flush(Boolean flushStream, Boolean flushEncoder) at System.IO.StreamWriter.Write(String value) at System.Xml.XmlTextEncoder.Write(String text) at System.Xml.XmlTextWriter.WriteString(String text) at System.Xml.XmlText.WriteTo(XmlWriter w) at System.Xml.XmlAttribute.WriteContentTo(XmlWriter w) at System.Xml.XmlAttribute.WriteTo(XmlWriter w) at System.Xml.XmlElement.WriteTo(XmlWriter w) at System.Xml.XmlElement.WriteContentTo(XmlWriter w) at System.Xml.XmlElement.WriteTo(XmlWriter w) at System.Xml.XmlElement.WriteContentTo(XmlWriter w) at System.Xml.XmlElement.WriteTo(XmlWriter w) at System.Xml.XmlElement.WriteContentTo(XmlWriter w) at System.Xml.XmlElement.WriteTo(XmlWriter w) at System.Xml.XmlDocument.WriteContentTo(XmlWriter xw) at System.Xml.XmlDocument.WriteTo(XmlWriter w) at System.Xml.XmlDocument.Save(Stream outStream) at OfficeOpenXml.ExcelWorksheet.Save() in C:\temp\XXXXXXXXXX\ExcelPackage\ExcelWorksheet.cs:line 605 at OfficeOpenXml.ExcelWorkbook.Save() in C:\temp\XXXXXXXXXX\ExcelPackage\ExcelWorkbook.cs:line 439 at OfficeOpenXml.ExcelPackage.Save() in C:\temp\XXXXXXXXXX\ExcelPackage\ExcelPackage.cs:line 348 at Framework.Exporting.Business.ExcelExport.BuildReport(HttpContext context) at WebUserControl.BtnXLS_Click(Object sender, EventArgs e) in C:\TEMP\XXXXXXXXXX\XXXXXXXXXX\OneList\UserControls\TicketReportExporter. ascx.cs:line 108 at System.Web.UI.WebControls.Button.OnClick(EventArgs e) at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.Rai sePostBackEvent(String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace --- at System.Web.UI.Page.HandleError(Exception e) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest() at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) at System.Web.UI.Page.ProcessRequest(HttpContext context) at ASP.XXXXXXXXXXX_aspx.ProcessRequest(HttpContext context) in c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\XXXX\cdf32a52\d1a5eabd\App_Web_enxdwlks.1.cs:line 0 at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpAppli cation.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) Even aside from this particular problem, in general exporting to Excel requires the instantiation of huge Excel objects on the server for each request, which I've always assumed to mean disqualifies Excel for "serious" work on a highly-loaded server. Is there any general way to export to Excel in a "light-weight" manner? Would simply streaming the data into a CSV file work for this?

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• Exporting info from PS script to csv

  - by George

  Hi, This is a powershell/AD/Exchange question.... I'm running a script against a number of Users to check some of their attributes however I'm having trouble getting this to output to CSV. The script runs well and does exactly what I need it to do, the output on screen is fine, I'm just having trouble getting it to directly export to csv. The input is a comma seperated txt file of usernames (eg "username1,username2,username3") I've experimented with creating custom ps objects, adding to them and then exporting those but its not working.... Any suggestions gratefully received.. Thanks George $array = Get-Content $InputPath #split the comma delimited string into an array $arrayb = $array.Split(","); foreach ($User in $arrayb) { #find group memebership Write-Host "AD group membership for $User" Get-QADMemberOf $User #Get Mailbox Info Write-Host "Mailbox info for $User" Get-Mailbox $User | select ServerName, Database, EmailAddresses, PrimarySmtpAddress, WindowsEmailAddress #get profile details Write-Host "Home drive info for $User" Get-QADUser $User| select HomeDirectory,HomeDrive #add space between users Write-Host "" Write-Host "******************************************************" } Write-Host "End Script"

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• How to embed a progressbar into a HTML form?

  - by Noah Brainey

  I have this code below and want it to show the progress of a form submission of a file upload. I want it to work on my website visit it through this IP (24.148.156.217). So if you saw the website I want the progress bar to be displayed when the user fills in the information and then hits the submit button. Then the progress bar displays with the time until it's finished. <style> <!-- .hide { position:absolute; visibility:hidden; } .show { position:absolute; visibility:visible; } --> </style> <SCRIPT LANGUAGE="JavaScript"> //Progress Bar script- by Todd King ([email protected]) //Modified by JavaScript Kit for NS6, ability to specify duration //Visit JavaScript Kit (http://javascriptkit.com) for script var duration=3 // Specify duration of progress bar in seconds var _progressWidth = 50; // Display width of progress bar. var _progressBar = "|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||" var _progressEnd = 5; var _progressAt = 0; // Create and display the progress dialog. // end: The number of steps to completion function ProgressCreate(end) { // Initialize state variables _progressEnd = end; _progressAt = 0; // Move layer to center of window to show if (document.all) { // Internet Explorer progress.className = 'show'; progress.style.left = (document.body.clientWidth/2) - (progress.offsetWidth/2); progress.style.top = document.body.scrollTop+(document.body.clientHeight/2) - (progress.offsetHeight/2); } else if (document.layers) { // Netscape document.progress.visibility = true; document.progress.left = (window.innerWidth/2) - 100+"px"; document.progress.top = pageYOffset+(window.innerHeight/2) - 40+"px"; } else if (document.getElementById) { // Netscape 6+ document.getElementById("progress").className = 'show'; document.getElementById("progress").style.left = (window.innerWidth/2)- 100+"px"; document.getElementById("progress").style.top = pageYOffset+(window.innerHeight/2) - 40+"px"; } ProgressUpdate(); // Initialize bar } // Hide the progress layer function ProgressDestroy() { // Move off screen to hide if (document.all) { // Internet Explorer progress.className = 'hide'; } else if (document.layers) { // Netscape document.progress.visibility = false; } else if (document.getElementById) { // Netscape 6+ document.getElementById("progress").className = 'hide'; } } // Increment the progress dialog one step function ProgressStepIt() { _progressAt++; if(_progressAt > _progressEnd) _progressAt = _progressAt % _progressEnd; ProgressUpdate(); } // Update the progress dialog with the current state function ProgressUpdate() { var n = (_progressWidth / _progressEnd) * _progressAt; if (document.all) { // Internet Explorer var bar = dialog.bar; } else if (document.layers) { // Netscape var bar = document.layers["progress"].document.forms["dialog"].bar; n = n * 0.55; // characters are larger } else if (document.getElementById){ var bar=document.getElementById("bar") } var temp = _progressBar.substring(0, n); bar.value = temp; } // Demonstrate a use of the progress dialog. function Demo() { ProgressCreate(10); window.setTimeout("Click()", 100); } function Click() { if(_progressAt >= _progressEnd) { ProgressDestroy(); return; } ProgressStepIt(); window.setTimeout("Click()", (duration-1)*1000/10); } function CallJS(jsStr) { //v2.0 return eval(jsStr) } </script> <SCRIPT LANGUAGE="JavaScript"> // Create layer for progress dialog document.write("<span id=\"progress\" class=\"hide\">"); document.write("<FORM name=dialog id=dialog>"); document.write("<TABLE border=2 bgcolor=\"#FFFFCC\">"); document.write("<TR><TD ALIGN=\"center\">"); document.write("Progress<BR>"); document.write("<input type=text name=\"bar\" id=\"bar\" size=\"" + _progressWidth/2 + "\""); if(document.all||document.getElementById) // Microsoft, NS6 document.write(" bar.style=\"color:navy;\">"); else // Netscape document.write(">"); document.write("</TD></TR>"); document.write("</TABLE>"); document.write("</FORM>"); document.write("</span>"); ProgressDestroy(); // Hides </script> <form name="form1" method="post"> <center> <input type="button" name="Demo" value="Display progress" onClick="CallJS('Demo()')"> </center> </form> <a href="javascript:CallJS('Demo()')">Text link example</a>

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• Java Compiler Creation Help..Please

  - by Brian

  I need some help with my code here...What we are trying to do is make a compiler that will read a file containing Machine Code and converting it to 100 lines of 4 bits example: this code is the machine code being converting to opcode and operands. I need some help please.. thanks 799 798 198 499 1008 1108 899 909 898 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Everything compiles but when I go and run my Test.java I get the following OutPut: Exception in thread "main" java.util.NoSuchElementException: No line found at java.util.Scanner.nextLine(Scanner.java:1516) at Compiler.FirstPass(Compiler.java:22) at Compiler.compile(Compiler.java:11) at Test.main(Test.java:5) Here is my class Compiler: import java.io.*; import java.io.DataOutputStream; import java.util.NoSuchElementException; import java.util.Scanner; class Compiler{ private int lc = 0; private int dc = 99; public void compile(String filename) { SymbolList symbolTable = FirstPass(filename); SecondPass(symbolTable, filename); } public SymbolList FirstPass(String filename) { File file = new File(filename); SymbolList temp = new SymbolList(); int dc = 99; int lc = 0; try{ Scanner scan = new Scanner(file); String line = scan.nextLine(); String[] linearray = line.split(" "); while(line!=null){ if(!linearray[0].equals("REM")){ if(!this.isInstruction(linearray[0])){ linearray[0]=removeColon(linearray[0]); if(this.isInstruction(linearray[1])){ temp.add(new Symbol(linearray[0], lc, null)); lc++; } else { temp.add(new Symbol(linearray[0], dc, Integer.valueOf((linearr\ ay[2])))); dc--; } } else { if(!linearray[0].equals("REM")) lc++; } } try{ line = scan.nextLine(); } catch(NoSuchElementException e){ line=null; break; } linearray = line.split(" "); } } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } return temp; } public String makeFilename(String filename) { return filename + ".ex"; } public String removeColon(String str) { if(str.charAt(str.length()-1) == ':'){ return str.substring(0, str.length()-1); } else { return str; } } public void SecondPass(SymbolList symbolTable, String filename){ try { int dc = 99; //Open file for reading File file = new File(filename); Scanner scan = new Scanner(file); //Make filename of new executable file String newfile = makeFilename(filename); //Open Output Stream for writing new file. FileOutputStream os = new FileOutputStream(filename); DataOutputStream dos = new DataOutputStream(os); //Read First line. Split line by Spaces into linearray. String line = scan.nextLine(); String[] linearray = line.split(" "); while(scan.hasNextLine()){ if(!linearray[0].equals("REM")){ int inst=0, opcode, loc; if(isInstruction(linearray[0])){ opcode = getOpcode(linearray[0]); loc = symbolTable.searchName(linearray[1]).getMemloc(); inst = (opcode*100)+loc; } else if(!isInstruction(linearray[0])){ if(isInstruction(linearray[1])){ opcode = getOpcode(linearray[1]); if(linearray[1].equals("STOP")) inst=0000; else { loc = symbolTable.searchName(linearray[2]).getMemloc(); inst = (opcode*100)+loc; } } if(linearray[1].equals("DC")) dc--; } System.out.println(inst); dos.writeInt(inst); linearray = line.split(" "); } if(scan.hasNextLine()) { line = scan.nextLine(); } } scan.close(); for(int i = lc; i <= dc; i++) { dos.writeInt(0); } for(int i = dc+1; i<100; i++){ dos.writeInt(symbolTable.searchLocation(i).getValue()); if(i!=99) dos.writeInt(0); } dos.close(); os.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } public int getOpcode(String inst){ int toreturn = -1; if(isInstruction(inst)){ if(inst.equals("STOP")) toreturn=0; if(inst.equals("LD")) toreturn=1; if(inst.equals("STO")) toreturn=2; if(inst.equals("ADD")) toreturn=3; if(inst.equals("SUB")) toreturn=4; if(inst.equals("MPY")) toreturn=5; if(inst.equals("DIV")) toreturn=6; if(inst.equals("IN")) toreturn=7; if(inst.equals("OUT")) toreturn=8; if(inst.equals("B")) toreturn=9; if(inst.equals("BGTR")) toreturn=10; if(inst.equals("BZ")) toreturn=11; return toreturn; } else { return -1; } } public boolean isInstruction(String totest){ boolean toreturn = false; String[] labels = {"IN", "LD", "SUB", "BGTR", "BZ", "OUT", "B", "STO", "STOP", "AD\ D", "MTY", "DIV"}; for(int i = 0; i < 12; i++){ if(totest.equals(labels[i])) toreturn = true; } return toreturn; } } And here is my class Computer: import java.io.*; import java.util.NoSuchElementException; import java.util.Scanner; class Computer{ private Cpu cpu; private Input in; private OutPut out; private Memory mem; public Computer() throws IOException { Memory mem = new Memory(100); Input in = new Input(); OutPut out = new OutPut(); Cpu cpu = new Cpu(); System.out.println(in.getInt()); } public void run() throws IOException { cpu.reset(); cpu.setMDR(mem.read(cpu.getMAR())); cpu.fetch2(); while (!cpu.stop()) { cpu.decode(); if (cpu.OutFlag()) OutPut.display(mem.read(cpu.getMAR())); if (cpu.InFlag()) mem.write(cpu.getMDR(),in.getInt()); if (cpu.StoreFlag()) { mem.write(cpu.getMAR(),in.getInt()); cpu.getMDR(); } else { cpu.setMDR(mem.read(cpu.getMAR())); cpu.execute(); cpu.fetch(); cpu.setMDR(mem.read(cpu.getMAR())); cpu.fetch2(); } } } public void load() { mem.loadMemory(); } } Here is my Memory class: import java.io.*; import java.util.NoSuchElementException; import java.util.Scanner; class Memory{ private MemEl[] memArray; private int size; private int[] mem; public Memory(int s) {size = s; memArray = new MemEl[s]; for(int i = 0; i < s; i++) memArray[i] = new MemEl(); } public void write (int loc,int val) {if (loc >=0 && loc < size) memArray[loc].write(val); else System.out.println("Index Not in Domain"); } public int read (int loc) {return memArray[loc].read(); } public void dump() { for(int i = 0; i < size; i++) if(i%1 == 0) System.out.println(memArray[i].read()); else System.out.print(memArray[i].read()); } public void writeTo(int location, int value) { mem[location] = value; } public int readFrom(int location) { return mem[location]; } public int size() { return mem.length; } public void loadMemory() { this.write(0, 799); this.write(1, 798); this.write(2, 198); this.write(3, 499); this.write(4, 1008); this.write(5, 1108); this.write(6, 899); this.write(7, 909); this.write(8, 898); this.write(9, 0000); } public void loadFromFile(String filename){ try { FileReader fr = new FileReader(filename); BufferedReader br = new BufferedReader(fr); String read=null; int towrite=0; int l=0; do{ try{ read=br.readLine(); towrite = Integer.parseInt(read); }catch(Exception e){ } this.write(l, towrite); l++; }while(l<100); }catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } Here is my Test class: public class Test{ public static void main(String[] args) throws java.io.IOException { Compiler compiler = new Compiler(); compiler.compile("program.txt"); } }

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• asp.net Web server control with child controls, event not firing

  - by bleeeah

  I have a simple web control (TaskList) that can have children (Task) which inherit from LinkButton, that can be added declaratively or programatically. This works ok, but I can't get the onclick event of a Task to be fired in my code behind. The code .. [ToolboxData("<{0}:TaskList runat=\"server\"> </{0}:TaskList>")] [ParseChildren(true)] [PersistChildren(false)] public class TaskList : System.Web.UI.Control { //[DefaultProperty("Text")] public TaskList() {} private List<Task> _taskList = new List<Task>(); private string _taskHeading = ""; public string Heading { get { return this._taskHeading; } set { this._taskHeading = value; } } [NotifyParentProperty(true)] [PersistenceMode(PersistenceMode.InnerProperty)] [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)] public List<Task> Tasks { get { return this._taskList; } set { this._taskList = value; } } protected override void CreateChildControls() { foreach (Task task in this._taskList) this.Controls.Add(task); base.CreateChildControls(); } protected override void Render(HtmlTextWriter writer) { writer.Write("<h2>" + this._taskHeading + "</h2>"); writer.Write("<div class='tasks_container'>"); writer.Write("<div class='tasks_list'>"); writer.Write("<ul>"); foreach (Task task in this._taskList) { writer.Write("<li>"); task.RenderControl(writer); writer.Write("</li>"); } writer.Write("</ul>"); writer.Write("</div>"); writer.Write("</div>"); } } public class Task : LinkButton { private string _key = ""; public string Key { get { return this._key; } set { this._key = value; } } } Markup: <rf:TaskList runat="server" ID="tskList" Heading="Tasks"> <Tasks> <rf:Task Key="ba" ID="L1" Text="Helllo" OnClick="task1_Click" runat="server" /> </Tasks> </rf:TaskList> The Onclick event task1_Click never fires when clicked (although a postback occurs).

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• How do I catch the exception in windows application in c#?

  - by user291169

  Where should we catch exception • In Layer Boundary (UI-BLL & BLL-DAL) • In that methods where there is no interaction between Layers only some business logic present How do I write exception in Save/Delete where some DML statement executing? • What should I write in DAL end? • What should I write in BLL end? • What should I write in UI end? In Get/Load method How do we handle exception • What should I write in BLL end? • What should I write in UI end? Should I catch System exception?

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• C#: Searching through arrays

  - by Jonathan Oberhaus

  I have a dvd app that stores dvds and blu-rays, I want to search the arrays by director. Below is the code for the inventory class I have seen many different ways to do this. There seems to be some debate as the best/most efficient way to accomplish this, any suggestions? Blockquote namespace MovieInventoryApplication { class Inventory { public Bluray[] BlurayMovies; public DVD[] DVDMovies; private int blurayCount; private int dvdCount; public Inventory() { BlurayMovies = new Bluray[5]; DVDMovies = new DVD[5]; blurayCount = 0; dvdCount = 0; } public void AddBluray() { String strTitle; int intReleaseYear; int intRunningTimeMinutes; String strDirector; int intPrice; int intRegionCode; try { Console.Write("Enter a title: "); strTitle = Console.ReadLine(); Console.Write("Enter a release year: "); intReleaseYear = Convert.ToInt32(Console.ReadLine()); Console.Write("Enter the running time in minutes: "); intRunningTimeMinutes = Convert.ToInt32(Console.ReadLine()); Console.Write("Enter the directors name: "); strDirector = Console.ReadLine(); Console.Write("Enter a rental price: "); intPrice = Convert.ToInt32(Console.ReadLine()); BlurayMovies[blurayCount] = new Bluray(strTitle, intReleaseYear, intRunningTimeMinutes, strDirector, intPrice); blurayCount++; Console.Write("Enter the DVD region code: "); intRegionCode = Convert.ToInt32(Console.ReadLine()); DVDMovies[dvdCount] = new DVD(strTitle, intReleaseYear, intRunningTimeMinutes, strDirector, intPrice, intRegionCode); dvdCount++; } catch (FormatException FormatException) { Console.WriteLine(FormatException.Message); Console.WriteLine("Please enter a number in this field."); } } public void AddDVD() { String strTitle; int intReleaseYear; int intRunningTimeMinutes; String strDirector; int intPrice; int intRegionCode; try { Console.Write("Enter a title: "); strTitle = Console.ReadLine(); Console.Write("Enter a release year: "); intReleaseYear = Convert.ToInt32(Console.ReadLine()); Console.Write("Enter the running time in minutes: "); intRunningTimeMinutes = Convert.ToInt32(Console.ReadLine()); Console.Write("Enter the directors name: "); strDirector = Console.ReadLine(); Console.Write("Enter a rental price: "); intPrice = Convert.ToInt32(Console.ReadLine()); Console.Write("Enter the region code: "); intRegionCode = Convert.ToInt32(Console.ReadLine()); DVDMovies[dvdCount] = new DVD(strTitle, intReleaseYear, intRunningTimeMinutes, strDirector, intPrice, intRegionCode); dvdCount++; } catch (FormatException FormatException) { Console.WriteLine(FormatException.Message); Console.WriteLine("Please enter a number in this field."); } } public void ListAllBluray() { int position = 0; while (BlurayMovies[position] != null) { Console.WriteLine(position + " " + BlurayMovies[position].strTitle); position++; } } public void ListAllDVD() { int position = 0; while (DVDMovies[position] != null) { //position + 1 + " " + Console.WriteLine(position + " " + DVDMovies[position].strTitle); position++; } } public void BlurayInfo(int position) { Console.WriteLine("Title: {0}", DVDMovies[position].strTitle); Console.WriteLine("Release Year: {0}", DVDMovies[position].intReleaseYear); Console.WriteLine("Running Time (Minutes): {0}", DVDMovies[position].intRunningTimeMinutes); Console.WriteLine("Director: {0}", DVDMovies[position].strDirector); Console.WriteLine("Price: {0}", DVDMovies[position].intPrice); } public void DVDInfo(int position) { Console.WriteLine("Title: {0}", DVDMovies[position].strTitle); Console.WriteLine("Release Year: {0}", DVDMovies[position].intReleaseYear); Console.WriteLine("Running Time (Minutes): {0}", DVDMovies[position].intRunningTimeMinutes); Console.WriteLine("Director: {0}", DVDMovies[position].strDirector); Console.WriteLine("Price: {0}", DVDMovies[position].intPrice); Console.WriteLine("Region Code: {0}", DVDMovies[position].intRegionCode); } } }

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• SQL SERVER – Repair a SQL Server Database Using a Transaction Log Explorer

  - by Pinal Dave

  In this blog, I’ll show how to use ApexSQL Log, a SQL Server transaction log viewer. You can download it for free, install, and play along. But first, let’s describe some disaster recovery scenarios where it’s useful. About SQL Server disaster recovery Along with database development and administration, you must work on a good recovery plan. Disasters do happen and no one’s immune. What you can do is take all actions needed to be ready for a disaster and go through it with minimal data loss and downtime. Besides creating a recovery plan, it’s necessary to have a list of steps that will be executed when a disaster occurs and to test them before a disaster. This way, you’ll know that the plan is good and viable. Testing can also be used as training for all team members, so they can all understand and execute it when the time comes. It will show how much time is needed to have your servers fully functional again and how much data you can lose in a real-life situation. If these don’t meet recovery-time and recovery-point objectives, the plan needs to be improved. Keep in mind that all major changes in environment configuration, business strategy, and recovery objectives require a new recovery plan testing, as these changes most probably induce a recovery plan changing and tweaking. What is a good SQL Server disaster recovery plan? A good SQL Server disaster recovery strategy starts with planning SQL Server database backups. An efficient strategy is to create a full database backup periodically. Between two successive full database backups, you can create differential database backups. It is essential is to create transaction log backups regularly between full database backups. Keep in mind that transaction log backups can be created only on databases in the full recovery model. In other words, a simple, but efficient backup strategy would be a full database backup every night, a transaction log backup every hour, or every 15 minutes. The frequency depends on how much data you can afford to lose and how busy the database is. Another option, instead of creating a full database backup every night, is to create a full database backup once a week (e.g. on Friday at midnight) and differential database backup every night until next Friday when you will create a full database backup again. Once you create your SQL Server database backup strategy, schedule the backups. You can do that easily using SQL Server maintenance plans. Why are transaction logs important? Transaction log backups contain transactions executed on a SQL Server database. They provide enough information to undo and redo the transactions and roll back or forward the database to a point in time. In SQL Server disaster recovery situations, transaction logs enable to repair a SQL Server database and bring it to the state before the disaster. Be aware that even with regular backups, there will be some data missing. These are the transactions made between the last transaction log backup and the time of the disaster. In some situations, to repair your SQL Server database it’s not necessary to re-create the database from its last backup. The database might still be online and all you need to do is roll back several transactions, such as wrong update, insert, or delete. The restore to a point in time feature is available in SQL Server, but for large databases, it is very time-consuming, as SQL Server first restores a full database backup, and then restores transaction log backups, one after another, up to the recovery point. During that time, the database is unavailable. This is where a SQL Server transaction log viewer can help. For optimal recovery, besides having a database in the full recovery model, it’s important that you haven’t manually truncated the online transaction log. This ensures that all transactions made after the last transaction log backup are still in the online transaction log. All you have to do is read and replay them. How to read a SQL Server transaction log? SQL Server doesn’t provide an option to read transaction logs. There are several SQL Server commands and functions that read the content of a transaction log file (fn_dblog, fn_dump_dblog, and DBCC PAGE), but they are undocumented. They require T-SQL knowledge, return a large number of not easy to read and understand columns, sometimes in binary or hexadecimal format. Another challenge is reading UPDATE statements, as it’s necessary to match it to a value in the MDF file. When you finally read the transactions executed, you have to create a script for it. How to easily repair a SQL database? The easiest solution is to use a transaction log reader that will not only read the transactions in the transaction log files, but also automatically create scripts for the read transactions. In the following example, I will show how to use ApexSQL Log to repair a SQL database after a crash. If a database has crashed and both MDF and LDF files are lost, you have to rely on the full database backup and all subsequent transaction log backups. In another scenario, the MDF file is lost, but the LDF file is available. First, restore the last full database backup on SQL Server using SQL Server Management Studio. I’ll name it Restored_AW2014. Then, start ApexSQL Log It will automatically detect all local servers. If not, click the icon right to the Server drop-down list, or just type in the SQL Server instance name. Select the Windows or SQL Server authentication type and select the Restored_AW2014 database from the database drop-down list. When all options are set, click Next. ApexSQL Log will show the online transaction log file. Now, click Add and add all transaction log backups created after the full database backup I used to restore the database. In case you don’t have transaction log backups, but the LDF file hasn’t been lost during the SQL Server disaster, add it using Add.   To repair a SQL database to a point in time, ApexSQL Log needs to read and replay all the transactions in the transaction log backups (or the LDF file saved after the disaster). That’s why I selected the Whole transaction log option in the Filter setup. ApexSQL Log offers a range of various filters, which are useful when you need to read just specific transactions. You can filter transactions by the time of the transactions, operation type (e.g. to read only data inserts), table name, SQL Server login that made the transaction, etc. In this scenario, to repair a SQL database, I’ll check all filters and make sure that all transactions are included. In the Operations tab, select all schema operations (DDL). If you omit these, only the data changes will be read so if there were any schema changes, such as a new function created, or an existing table modified, they will be ignored and database will not be properly repaired. The data repair for modified tables will fail. In the Tables tab, I’ll make sure all tables are selected. I will uncheck the Show operations on dropped tables option, to reduce the number of transactions. Click Next. ApexSQL Log offers three options. Select Open results in grid, to get a user-friendly presentation of the transactions. As you can see, details are shown for every transaction, including the old and new values for updated columns, which are clearly highlighted. Now, select them all and then create a redo script by clicking the Create redo script icon in the menu.   For a large number of transactions and in a critical situation, when acting fast is a must, I recommend using the Export results to file option. It will save some time, as the transactions will be directly scripted into a redo file, without showing them in the grid first. Select Generate reconstruction (REDO) script , change the output path if you want, and click Finish. After the redo T-SQL script is created, ApexSQL Log shows the redo script summary: The third option will create a command line statement for a batch file that you can use to schedule execution, which is not really applicable when you repair a SQL database, but quite useful in daily auditing scenarios. To repair your SQL database, all you have to do is execute the generated redo script using an integrated developer environment tool such as SQL Server Management Studio or any other, against the restored database. You can find more information about how to read SQL Server transaction logs and repair a SQL database on ApexSQL Solution center. There are solutions for various situations when data needs to be recovered, restored, or transactions rolled back. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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• Beware Sneaky Reads with Unique Indexes

  - by Paul White NZ

  A few days ago, Sandra Mueller (twitter | blog) asked a question using twitter’s #sqlhelp hash tag: “Might SQL Server retrieve (out-of-row) LOB data from a table, even if the column isn’t referenced in the query?” Leaving aside trivial cases (like selecting a computed column that does reference the LOB data), one might be tempted to say that no, SQL Server does not read data you haven’t asked for.  In general, that’s quite correct; however there are cases where SQL Server might sneakily retrieve a LOB column… Example Table Here’s a T-SQL script to create that table and populate it with 1,000 rows: CREATE TABLE dbo.LOBtest ( pk INTEGER IDENTITY NOT NULL, some_value INTEGER NULL, lob_data VARCHAR(MAX) NULL, another_column CHAR(5) NULL, CONSTRAINT [PK dbo.LOBtest pk] PRIMARY KEY CLUSTERED (pk ASC) ); GO DECLARE @Data VARCHAR(MAX); SET @Data = REPLICATE(CONVERT(VARCHAR(MAX), 'x'), 65540);   WITH Numbers (n) AS ( SELECT ROW_NUMBER() OVER (ORDER BY (SELECT 0)) FROM master.sys.columns C1, master.sys.columns C2 ) INSERT LOBtest WITH (TABLOCKX) ( some_value, lob_data ) SELECT TOP (1000) N.n, @Data FROM Numbers N WHERE N.n <= 1000; Test 1: A Simple Update Let’s run a query to subtract one from every value in the some_value column: UPDATE dbo.LOBtest WITH (TABLOCKX) SET some_value = some_value - 1; As you might expect, modifying this integer column in 1,000 rows doesn’t take very long, or use many resources.  The STATITICS IO and TIME output shows a total of 9 logical reads, and 25ms elapsed time.  The query plan is also very simple: Looking at the Clustered Index Scan, we can see that SQL Server only retrieves the pk and some_value columns during the scan: The pk column is needed by the Clustered Index Update operator to uniquely identify the row that is being changed.  The some_value column is used by the Compute Scalar to calculate the new value.  (In case you are wondering what the Top operator is for, it is used to enforce SET ROWCOUNT). Test 2: Simple Update with an Index Now let’s create a nonclustered index keyed on the some_value column, with lob_data as an included column: CREATE NONCLUSTERED INDEX [IX dbo.LOBtest some_value (lob_data)] ON dbo.LOBtest (some_value) INCLUDE ( lob_data ) WITH ( FILLFACTOR = 100, MAXDOP = 1, SORT_IN_TEMPDB = ON ); This is not a useful index for our simple update query; imagine that someone else created it for a different purpose.  Let’s run our update query again: UPDATE dbo.LOBtest WITH (TABLOCKX) SET some_value = some_value - 1; We find that it now requires 4,014 logical reads and the elapsed query time has increased to around 100ms.  The extra logical reads (4 per row) are an expected consequence of maintaining the nonclustered index. The query plan is very similar to before (click to enlarge): The Clustered Index Update operator picks up the extra work of maintaining the nonclustered index. The new Compute Scalar operators detect whether the value in the some_value column has actually been changed by the update.  SQL Server may be able to skip maintaining the nonclustered index if the value hasn’t changed (see my previous post on non-updating updates for details).  Our simple query does change the value of some_data in every row, so this optimization doesn’t add any value in this specific case. The output list of columns from the Clustered Index Scan hasn’t changed from the one shown previously: SQL Server still just reads the pk and some_data columns.  Cool. Overall then, adding the nonclustered index hasn’t had any startling effects, and the LOB column data still isn’t being read from the table.  Let’s see what happens if we make the nonclustered index unique. Test 3: Simple Update with a Unique Index Here’s the script to create a new unique index, and drop the old one: CREATE UNIQUE NONCLUSTERED INDEX [UQ dbo.LOBtest some_value (lob_data)] ON dbo.LOBtest (some_value) INCLUDE ( lob_data ) WITH ( FILLFACTOR = 100, MAXDOP = 1, SORT_IN_TEMPDB = ON ); GO DROP INDEX [IX dbo.LOBtest some_value (lob_data)] ON dbo.LOBtest; Remember that SQL Server only enforces uniqueness on index keys (the some_data column).  The lob_data column is simply stored at the leaf-level of the non-clustered index.  With that in mind, we might expect this change to make very little difference.  Let’s see: UPDATE dbo.LOBtest WITH (TABLOCKX) SET some_value = some_value - 1; Whoa!  Now look at the elapsed time and logical reads: Scan count 1, logical reads 2016, physical reads 0, read-ahead reads 0, lob logical reads 36015, lob physical reads 0, lob read-ahead reads 15992.   CPU time = 172 ms, elapsed time = 16172 ms. Even with all the data and index pages in memory, the query took over 16 seconds to update just 1,000 rows, performing over 52,000 LOB logical reads (nearly 16,000 of those using read-ahead). Why on earth is SQL Server reading LOB data in a query that only updates a single integer column? The Query Plan The query plan for test 3 looks a bit more complex than before: In fact, the bottom level is exactly the same as we saw with the non-unique index.  The top level has heaps of new stuff though, which I’ll come to in a moment. You might be expecting to find that the Clustered Index Scan is now reading the lob_data column (for some reason).  After all, we need to explain where all the LOB logical reads are coming from.  Sadly, when we look at the properties of the Clustered Index Scan, we see exactly the same as before: SQL Server is still only reading the pk and some_value columns – so what’s doing the LOB reads? Updates that Sneakily Read Data We have to go as far as the Clustered Index Update operator before we see LOB data in the output list: [Expr1020] is a bit flag added by an earlier Compute Scalar.  It is set true if the some_value column has not been changed (part of the non-updating updates optimization I mentioned earlier). The Clustered Index Update operator adds two new columns: the lob_data column, and some_value_OLD.  The some_value_OLD column, as the name suggests, is the pre-update value of the some_value column.  At this point, the clustered index has already been updated with the new value, but we haven’t touched the nonclustered index yet. An interesting observation here is that the Clustered Index Update operator can read a column into the data flow as part of its update operation.  SQL Server could have read the LOB data as part of the initial Clustered Index Scan, but that would mean carrying the data through all the operations that occur prior to the Clustered Index Update.  The server knows it will have to go back to the clustered index row to update it, so it delays reading the LOB data until then.  Sneaky! Why the LOB Data Is Needed This is all very interesting (I hope), but why is SQL Server reading the LOB data?  For that matter, why does it need to pass the pre-update value of the some_value column out of the Clustered Index Update? The answer relates to the top row of the query plan for test 3.  I’ll reproduce it here for convenience: Notice that this is a wide (per-index) update plan.  SQL Server used a narrow (per-row) update plan in test 2, where the Clustered Index Update took care of maintaining the nonclustered index too.  I’ll talk more about this difference shortly. The Split/Sort/Collapse combination is an optimization, which aims to make per-index update plans more efficient.  It does this by breaking each update into a delete/insert pair, reordering the operations, removing any redundant operations, and finally applying the net effect of all the changes to the nonclustered index. Imagine we had a unique index which currently holds three rows with the values 1, 2, and 3.  If we run a query that adds 1 to each row value, we would end up with values 2, 3, and 4.  The net effect of all the changes is the same as if we simply deleted the value 1, and added a new value 4. By applying net changes, SQL Server can also avoid false unique-key violations.  If we tried to immediately update the value 1 to a 2, it would conflict with the existing value 2 (which would soon be updated to 3 of course) and the query would fail.  You might argue that SQL Server could avoid the uniqueness violation by starting with the highest value (3) and working down.  That’s fine, but it’s not possible to generalize this logic to work with every possible update query. SQL Server has to use a wide update plan if it sees any risk of false uniqueness violations.  It’s worth noting that the logic SQL Server uses to detect whether these violations are possible has definite limits.  As a result, you will often receive a wide update plan, even when you can see that no violations are possible. Another benefit of this optimization is that it includes a sort on the index key as part of its work.  Processing the index changes in index key order promotes sequential I/O against the nonclustered index. A side-effect of all this is that the net changes might include one or more inserts.  In order to insert a new row in the index, SQL Server obviously needs all the columns – the key column and the included LOB column.  This is the reason SQL Server reads the LOB data as part of the Clustered Index Update. In addition, the some_value_OLD column is required by the Split operator (it turns updates into delete/insert pairs).  In order to generate the correct index key delete operation, it needs the old key value. The irony is that in this case the Split/Sort/Collapse optimization is anything but.  Reading all that LOB data is extremely expensive, so it is sad that the current version of SQL Server has no way to avoid it. Finally, for completeness, I should mention that the Filter operator is there to filter out the non-updating updates. Beating the Set-Based Update with a Cursor One situation where SQL Server can see that false unique-key violations aren’t possible is where it can guarantee that only one row is being updated.  Armed with this knowledge, we can write a cursor (or the WHILE-loop equivalent) that updates one row at a time, and so avoids reading the LOB data: SET NOCOUNT ON; SET STATISTICS XML, IO, TIME OFF;   DECLARE @PK INTEGER, @StartTime DATETIME; SET @StartTime = GETUTCDATE();   DECLARE curUpdate CURSOR LOCAL FORWARD_ONLY KEYSET SCROLL_LOCKS FOR SELECT L.pk FROM LOBtest L ORDER BY L.pk ASC;   OPEN curUpdate;   WHILE (1 = 1) BEGIN FETCH NEXT FROM curUpdate INTO @PK;   IF @@FETCH_STATUS = -1 BREAK; IF @@FETCH_STATUS = -2 CONTINUE;   UPDATE dbo.LOBtest SET some_value = some_value - 1 WHERE CURRENT OF curUpdate; END;   CLOSE curUpdate; DEALLOCATE curUpdate;   SELECT DATEDIFF(MILLISECOND, @StartTime, GETUTCDATE()); That completes the update in 1280 milliseconds (remember test 3 took over 16 seconds!) I used the WHERE CURRENT OF syntax there and a KEYSET cursor, just for the fun of it.  One could just as well use a WHERE clause that specified the primary key value instead. Clustered Indexes A clustered index is the ultimate index with included columns: all non-key columns are included columns in a clustered index.  Let’s re-create the test table and data with an updatable primary key, and without any non-clustered indexes: IF OBJECT_ID(N'dbo.LOBtest', N'U') IS NOT NULL DROP TABLE dbo.LOBtest; GO CREATE TABLE dbo.LOBtest ( pk INTEGER NOT NULL, some_value INTEGER NULL, lob_data VARCHAR(MAX) NULL, another_column CHAR(5) NULL, CONSTRAINT [PK dbo.LOBtest pk] PRIMARY KEY CLUSTERED (pk ASC) ); GO DECLARE @Data VARCHAR(MAX); SET @Data = REPLICATE(CONVERT(VARCHAR(MAX), 'x'), 65540);   WITH Numbers (n) AS ( SELECT ROW_NUMBER() OVER (ORDER BY (SELECT 0)) FROM master.sys.columns C1, master.sys.columns C2 ) INSERT LOBtest WITH (TABLOCKX) ( pk, some_value, lob_data ) SELECT TOP (1000) N.n, N.n, @Data FROM Numbers N WHERE N.n <= 1000; Now here’s a query to modify the cluster keys: UPDATE dbo.LOBtest SET pk = pk + 1; The query plan is: As you can see, the Split/Sort/Collapse optimization is present, and we also gain an Eager Table Spool, for Halloween protection.  In addition, SQL Server now has no choice but to read the LOB data in the Clustered Index Scan: The performance is not great, as you might expect (even though there is no non-clustered index to maintain): Table 'LOBtest'. Scan count 1, logical reads 2011, physical reads 0, read-ahead reads 0, lob logical reads 36015, lob physical reads 0, lob read-ahead reads 15992.   Table 'Worktable'. Scan count 1, logical reads 2040, physical reads 0, read-ahead reads 0, lob logical reads 34000, lob physical reads 0, lob read-ahead reads 8000.   SQL Server Execution Times: CPU time = 483 ms, elapsed time = 17884 ms. Notice how the LOB data is read twice: once from the Clustered Index Scan, and again from the work table in tempdb used by the Eager Spool. If you try the same test with a non-unique clustered index (rather than a primary key), you’ll get a much more efficient plan that just passes the cluster key (including uniqueifier) around (no LOB data or other non-key columns): A unique non-clustered index (on a heap) works well too: Both those queries complete in a few tens of milliseconds, with no LOB reads, and just a few thousand logical reads.  (In fact the heap is rather more efficient). There are lots more fun combinations to try that I don’t have space for here. Final Thoughts The behaviour shown in this post is not limited to LOB data by any means.  If the conditions are met, any unique index that has included columns can produce similar behaviour – something to bear in mind when adding large INCLUDE columns to achieve covering queries, perhaps. Paul White Email: [email protected] Twitter: @PaulWhiteNZ

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• Ant telnet is hanging on a simple task

  - by Sagar

  <?xml version="1.0" ?> <project name="test" default="root"> <target name="telnet"> <telnet server="10.1.1.1"> <read>login:</read> <write>root</write> <read>password:</read> <write>${PASSWORD}</write> <read>#</read> <write>ls</write> <read>#</read> </telnet> </target> </project> That is the code I have in a build.xml file. When I run ant (version 1.8, in bash) (I have downloaded and copied over the jars for commons-net-2.0 and jakarta-oro-2.0.8 already), this is the output I get: Buildfile: /home/sagar/build.xml telnet: and then it just sits there. When I do a "who" on my server, I can see "System" waiting on login. But there is no progress after this. I can telnet into the server using normal telnet means (putty, bash, etc). I even tried the full telnet command instead of read/write: <telnet server="10.1.1.1" userid="root" password="root"> Any help is much appreciated! Note: JRE 1.5, Ant 1.8, commons-net version 2.0, jakarta version 2.0.8

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• Unit testing best practices for a unit testing newbie

  - by wilhil

  In recent years, I have only written small components for people in larger projects or small tools. I have never written a unit test and it always seems like learning how to write them and actually making one takes a lot longer than simply firing up the program and testing for real. I am just about to start a fairly large scale project that could take a few months to complete and whilst I will try to test elements as I write them (like always), I am wondering if unit testing could save me time. I was just wondering if anyone could give good advice: Should I be looking at unit testing at the start of the project and possibly adopt a TDD approach. Should I just write tests as I go along, after each section is complete. Should I complete the project and then write unit tests at the end.

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• Cannot mount Android phone in Ubuntu and sync with Banshee

  - by Brett Alton

  I can't get my LG Optimus One to sync with Banshee. I read somewhere that the root needs to have an empty file called '.is_audio_player'. I did that and it still doesn't mount. I ran dmesg however and it appears that the card is unmounting before I even have a change to run Banshee. [ 7250.321359] usb 1-1.4: new high speed USB device using ehci_hcd and address 10 [ 7250.444795] scsi12 : usb-storage 1-1.4:1.0 [ 7251.567946] scsi 12:0:0:0: Direct-Access Multiple Card Reader 1.00 PQ: 0 ANSI: 0 [ 7251.568839] sd 12:0:0:0: Attached scsi generic sg3 type 0 [ 7252.232433] sd 12:0:0:0: [sdc] 15564800 512-byte logical blocks: (7.96 GB/7.42 GiB) [ 7252.233299] sd 12:0:0:0: [sdc] Write Protect is off [ 7252.233306] sd 12:0:0:0: [sdc] Mode Sense: 03 00 00 00 [ 7252.233309] sd 12:0:0:0: [sdc] Assuming drive cache: write through [ 7252.235658] sd 12:0:0:0: [sdc] Assuming drive cache: write through [ 7252.235666] sdc: sdc1 [ 7252.239132] sd 12:0:0:0: [sdc] Assuming drive cache: write through [ 7252.239140] sd 12:0:0:0: [sdc] Attached SCSI removable disk [ 7272.573437] usb 1-1.4: USB disconnect, address 10 Suggestions?

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