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  • What Device/System to use as a "router on a stick"

    - by Jeff Leyser
    I need to create several distinct VLANs, and provide a way for traffic to move between them. A "router on a stick" approach seems ideal: Internet | Router with Trunking Capability ("router on a stick") * * Trunk between router and switch * Switch with Trunking Capability | | | | | | | | | | | LAN 2 | LAN 4 | | 10.0.2.0/24 | 10.0.4.0/24 | | | | LAN 1 LAN 3 LAN 5 10.0.1.0/24 10.0.3.0/24 10.0.5.0/24 We have trunk-capable Layer-2 switches. The question is what to use as the router on a stick. My choices seem to be: 1) Use an existing Cisco 5505 ASA firewall. It appears the ASA can do the routing, but it's a 100Mbps device, and so seems sub-optimal at best 2) Buy a router. This seems overkill. 3) Buy a Layer-3 switch. Also seems overkill. 4) Use an existing Linux Box as a router 5) Use a new Linux box as a router' 6) Something I'm not thinking of I think either (4) or (5) is my best option, but I'm not sure how to choose between them. I expect the amount of traffic that has to cross the VLANs to be somewhat small, but bursty. How much load does routing add to a CentOS machine?

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  • Why database partitioning didn't work? Extract from thedailywtf.com

    - by questzen
    Original link. http://thedailywtf.com/Articles/The-Certified-DBA.aspx. Article summary: The DBA suggests an approach involving rigorous partitioning, 10 partitions per disk (3 actual disks and 3 raid). The stats show that the performance is non-optimal. Then the DBA suggests an alternative of 1 partition per disk (with more added disks). This also fails. The sys-admin then sets up a single disk, single partition and saves the day. The size of disks was not mentioned but given today,s typical disk sizes (of the order of 100 GB), the partitions ; would be huge, it surprises me that a single disk with all partitions outperformed. Initially I suspect that the data was segregated and hence faster reads. But how come the performance didn't degrade as time went by with all the inserts and updates happening? Saw this on reddit, but the explanation was by far spindle/platter centered. There was no mention in the article about this. Is there any other reason? I can only guess that the tables were using a incorrect hash distribution causing non-uniform allocation across disks (wrong partitioning); this would increase fetch times. Any thoughts?

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  • Backup data from RAID 1 disk out of its server

    - by Doomsday
    I'm facing with a pretty easy problem in my opinion. I've extracted a working disk from a RAID1 and I'm looking to copy only data (FS and RAID configuration doesn't matter) into another location (another FS). My problem is I'm not able to mount properly this disk into another linux. I've first looked the partition table : # fdisk -l /dev/sdc Disk /dev/sdc: 640.1 GB, 640135028736 bytes 255 heads, 63 sectors/track, 77825 cylinders, total 1250263728 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/sdc1 63 1249535699 624767818+ fd Linux raid autodetect /dev/sdc2 1249535700 1250017649 240975 fd Linux raid autodetect /dev/sdc3 1250017650 1250258624 120487+ 82 Linux swap / Solaris I've understood I should use dmraid tools. Once installed : # cat /proc/mdstat Personalities : md0 : inactive sdc1[1](S) 624767744 blocks unused devices: <none> And some other informations : # mdadm --examine /dev/sdc1 /dev/sdc1: Magic : a92b4efc Version : 0.90.00 UUID : 8f292f54:7e5aef72:7e5ab5fd:b348fd05 Creation Time : Mon Jun 2 03:39:41 2008 Raid Level : raid1 Used Dev Size : 624767744 (595.82 GiB 639.76 GB) Array Size : 624767744 (595.82 GiB 639.76 GB) Raid Devices : 2 Total Devices : 2 Preferred Minor : 0 Update Time : Tue Feb 7 22:34:59 2012 State : clean Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 Checksum : a505b324 - correct Events : 15148 Number Major Minor RaidDevice State this 1 8 1 1 active sync /dev/sda1 0 0 8 17 0 active sync /dev/sdb1 1 1 8 1 1 active sync /dev/sda1 From here, I've tried to mount but I'm not comfortable with dmtools and how it's working. # mount /dev/sdc1 /mnt/sdc1 mount: unknown filesystem type 'linux_raid_member' # mount /dev/md0 /mnt/sdc1 mount: /dev/md0: can't read superblock I've seen some options to alter RAID array with mdadm but I only want to copy data on its filesystem before wiping them... Anyone has a clue ?

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  • 85 Hz on old/new driver looks the same like 75 Hz on previous one?

    - by jon
    I have old philips 107T5 CRT and Nvidia graphics card. I used old Nvidia driver (but it wasn't 'legacy' one when I installed it) for few years but recently I decided to install other Linux distribution. I used 75 Hz refresh rate and 1024x768 resolution on my previous distribution. After I installed the new distribution I had to install a Nvidia driver so I downloaded one from the Nvidia site (this time only legacy supported my card so I downloaded legacy and installed it). It wasn't automatically updating xorg.conf but I had my previous xorg.conf copy and I used it. When I run X I could only choose 85 and 75 Hz, 85 was checked as default. And now what shocks me: that default 85 Hz looks identically like 75 Hz on previous driver looked (at least to me). I tried 75 Hz out of curiosity and it's too bright, hurts, etc. But on the previous driver 75 Hz wasn't hurting my eyes. Why is it different? It's the same number after all, so it should always give the same results, right? That's my first question. Second question: Is 85 Hz OK for that monitor model? Would it break it? I tried to find the optimal refresh rate for this model but couldn't find it.

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  • Debian Wheezy (testing) df reported volume size

    - by TheRoadrunner
    I am a bit confused about the /dev/sda* references since I installed Wheezy instead of Squeeze on a testing box. fdisk -l returns: Disk /dev/sda: 250.1 GB, 250059350016 bytes 255 heads, 63 sectors/track, 30401 cylinders, total 488397168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000e9623 Device Boot Start End Blocks Id System /dev/sda1 * 2048 480278527 240138240 83 Linux /dev/sda2 480280574 488396799 4058113 5 Extended /dev/sda5 480280576 488396799 4058112 82 Linux swap / Solaris This seems correct. But df -h /dev/sda (and /dev/sda1 and /dev/sda2 and /dev/sda5) returns: Filesystem Size Used Avail Use% Mounted on udev 10M 0 10M 0% /dev The same happens with every entry under /dev/disk/by-id and /dev/disk/by-path. Only one of two entries under /dev/disk/by-uuid returns the correct volume size: df -h /dev/disk/by-uuid/cacdbad6-7e6b-4e80-84ba-e3c77ef48796 Filesystem Size Used Avail Use% Mounted on /dev/disk/by-uuid/cacdbad6-7e6b-4e80-84ba-e3c77ef48796 229G 22G 196G 11% / Contents of /etc/fstab: # /etc/fstab: static file system information. # # Use 'blkid' to print the universally unique identifier for a # device; this may be used with UUID= as a more robust way to name devices # that works even if disks are added and removed. See fstab(5). # # <file system> <mount point> <type> <options> <dump> <pass> # / was on /dev/sda1 during installation UUID=cacdbad6-7e6b-4e80-84ba-e3c77ef48796 / ext4 errors=remount-ro 0 1 # swap was on /dev/sda5 during installation UUID=45840d13-ee36-4e77-8e73-16cbdff25eb1 none swap sw 0 0 /dev/sr0 /media/cdrom0 udf,iso9660 user,noauto 0 0 /dev/fd0 /media/floppy0 auto rw,user,noauto 0 0 It seems all other references than the uuid points to the swap partition. Is this because Wheezy is in testing, and should it be reported as an error?

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  • At what point does the performance gap between GPU & CPU become so great that the CPU is holding back a system?

    - by Matthew Galloway
    I know that generally speaking for gaming performance the GPU is the primary factor which holds back performance, with everything else such as RAM/motherboard/PSU/CPU being secondary in importance to the graphics card. But at some point the other components ARE going to be significant in holding back the whole system! For instance nobody would be silly enough to play modern games with 512MB RAM and the very latest graphics cards (such as an HD7970) as I bet the performance increase over such a system with only 512MB but a mid range card would be non-existent! Thus it would be a "waste" for such a person to buy any high end graphics card without resolving first the system's other problems. The same point applies to other components, such as if it only had a Pentium II a current high end graphics card would be wasted on it! So my core question is how do you determine at what point for your system is spending on extra GPU power be completely "wasted"? (also, a slightly more nuanced question is trying work out at what point might the extra graphics power not be "wasted" but would be "sub optimal" value for money, when the expenditure should then be split around graphics card and other components. As obviously a gamer shouldn't always just spend on upgrading the graphics card! But needs to balance it out)

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  • Unable to resize ec2 ebs root volume

    - by nathanjosiah
    I have followed many of the tutorials that pretty much all say the same thing which is basically: Stop the instance Detach the volume Create a snapshot of the volume Create a bigger volume from the snapshot Attach the new volume to the instance Start the instance back up Run resize2fs /dev/xxx However, step 7 is where the problems start happening. In any case running resize2fs always tells me that it is already xxxxx blocks big and does nothing, even with -f passed. So I start to continue with tutorials which all basically say the same thing and that is: Delete all partitons Recreate them back to what they were except with the bigger sizes Reboot the instance and run resize2fs (I have tried these steps both from the live instance and by attaching the volume to another instance and running the commands there) The main problem is that the instance won't start back up again and the system error log provided in the AWS console doesn't provide any errors. (it does however stop at the grub bootloader which to me indicates that it doesn't like the partitions(yes, the boot flag was toggled on the partition with no affect)) The other thing that happens regardless of what changes I make to the partitions is that the instance that the volume is attached to says that the partition has an invalid magic number and the super-block is corrupt. However, if I make no changes and reattach the volume, the instance runs without a problem. Can anybody shed some light on what I could be doing wrong? Edit On my new volume of 20GB with the 6GB image,df -h says: Filesystem Size Used Avail Use% Mounted on /dev/xvde1 5.8G 877M 4.7G 16% / tmpfs 836M 0 836M 0% /dev/shm And fdisk -l /dev/xvde says: Disk /dev/xvde: 21.5 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x7d833f39 Device Boot Start End Blocks Id System /dev/xvde1 1 766 6144000 83 Linux Partition 1 does not end on cylinder boundary. /dev/xvde2 766 784 146432 82 Linux swap / Solaris Partition 2 does not end on cylinder boundary. Also, sudo resize2fs /dev/xvde1 says: resize2fs 1.41.12 (17-May-2010) The filesystem is already 1536000 blocks long. Nothing to do!

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  • Extending partition on linux gparted but not more space in the vm

    - by Asken
    I have a vm test installation of a linux running a build server. Unfortunately I just pressed ok when adding the disk and ended up with an 8gb drive to play with. Well into the test the builds are consuming more and more space, of course. The vm drive was resized to 21gb and using gparted I expanded the drive partitions and that all worked fine but when I go back into the console and do df there's still only 8gb available. How can I claim the other 13gb I added? fdisk -l Disk /dev/sda: 21.0 GB, 20971520000 bytes 255 heads, 63 sectors/track, 2549 cylinders, total 40960000 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0006d284 Device Boot Start End Blocks Id System /dev/sda1 * 2048 499711 248832 83 Linux /dev/sda2 501758 40959999 20229121 5 Extended /dev/sda5 501760 40959999 20229120 8e Linux LVM vgdisplay --- Volume group --- VG Name ct System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 4 VG Access read/write VG Status resizable MAX LV 0 Cur LV 2 Open LV 2 Max PV 0 Cur PV 1 Act PV 1 VG Size 19.29 GiB PE Size 4.00 MiB Total PE 4938 Alloc PE / Size 1977 / 7.72 GiB Free PE / Size 2961 / 11.57 GiB VG UUID MwiMAz-52e1-iGVf-eL4f-P5lq-FvRA-L73Sl3 lvdisplay --- Logical volume --- LV Name /dev/ct/root VG Name ct LV UUID Rfk9fh-kqdM-q7t5-ml6i-EjE8-nMtU-usBF0m LV Write Access read/write LV Status available # open 1 LV Size 5.73 GiB Current LE 1466 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 252:0 --- Logical volume --- LV Name /dev/ct/swap_1 VG Name ct LV UUID BLFaa6-1f5T-4MM0-5goV-1aur-nzl9-sNLXIs LV Write Access read/write LV Status available # open 2 LV Size 2.00 GiB Current LE 511 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 252:1

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  • Separate Certificate by Subdomain (With multiple IPs)

    - by Brian
    Note: Yes, I realize this problem is easier to solve by just using 1 multi-domain or wildcard certificate. I wish to have an ASP.NET site running on IIS with 2 SSL domains sharing 1 web application but using separate certificates. Assuming I have 2 certificates, this can be solved on IIS7 as follows: Web Application1: Binding 1: http, 80, IP Address *, Host Name * Binding 2: https, 443, IPADDRESS1, using CERTDOMAIN1 (DOMAIN1 resolves to IPADDRESS1) Binding 3: https, 443, IPADDRESS2, using CERTDOMAIN2 (DOMAIN2 resolves to IPADDRESS2) That is to say, 2 certificates and 2 ip addresses, but both mapped to the same web application. In IIS6, the closest I have been able to come to this configuration is: Web Application1: Binding 1: http, 80, IPADDRESS1 Binding 2: https, 443, IPADDRESS1, using CERTDOMAIN1 (DOMAIN1 resolves to IPADDRESS1) Web Application2: Binding 1: http, 80, IPADDRESS2 Binding 2: https, 443, IPADDRESS2, using CERTDOMAIN2 (DOMAIN2 resolves to IPADDRESS2) That is to say, 2 certificates and 2 IP addresses, 2 web applications, both mapped to the same file location. The IIS6 solution is not optimal. Even if sharing an application pool, there are still costs associated with running the same site as two applications. Is upgrading from IIS6 to IIS7 a legitimate way to resolve this problem? Is there an IIS6 way to map 2 IP addresses within the same web application to different certificates?

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  • Fixing damaged partition table

    - by dr4cul4
    This is continuation of Recover Extended Partition , but this time I have different problem related partition table it self. I managed to restore partition that I needed and backed up files that were crucial to me (at least those that I had space to store somewhere) OK now get to the problem. My partition table is corrupted, booting RIP Linux I can mount it in truecrypt (and other ones that recovered), but that's basically it. When I launch GParted I have unallocated drive. GParted Dev info: Device Information Model: ATA ST2000DL003-9VT1 Size: 1.82TiB Path: /dev/sda Partition table: unrecognized Heads: 255 Sectors/track: 63 Cylinders: 243201 Total Sectors: 3907029168 Sector size: 512 When I check information on unallocated space I get: File system: unallocated Size: 1.82TiB First sector: 0 Last sector: 3907029167 Total sectors: 3907029168 Warning: Can't have a partition outside the disk! Now the output of testdisc (Analyze): TestDisk 6.13, Data Recovery Utility, November 2011 Christophe GRENIER <[email protected]> http://www.cgsecurity.org Disk /dev/sda - 2000 GB / 1863 GiB - CHS 243201 255 63 Current partition structure: Partition Start End Size in sectors > 1 P Linux 13132 242 39 16353 233 8 51744768 2 E extended LBA 16807 223 1 243201 254 63 3637021626 No partition is bootable 5 L Linux 16807 223 57 20430 39 25 58191872 X extended 20430 70 1 243201 78 13 3578816632 Invalid NTFS or EXFAT boot 6 L HPFS - NTFS 20430 71 58 243201 78 13 3578816512 6 LNext Now fdisk: # fdisk -l /dev/sda Disk /dev/sda: 2000.4 GB, 2000398934016 bytes 255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00039cd0 Device Boot Start End Blocks Id System /dev/sda1 210980864 262725631 25872384 83 Linux /dev/sda2 270018504 3907040129 1818510813 f W95 Ext'd (LBA) /dev/sda5 270018560 328210431 29095936 83 Linux /dev/sda6 328212480 3907028991 1789408256 7 HPFS/NTFS/exFAT Now I would like to fix that to arrange partitions correctly, but I have no idea which tool is capable of fixing that (tried, a few, some of them offered fixing, but it was to risky at the moment - still backing up data).

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  • Strategy for Incremental Datasource fetchings in Excel

    - by user1352530
    I am in an scenario with a table that is refresh by a third app every week. I need to keep accumulating all data in Excel, using an ODBC connection to the database. I am wondering Approach 1: Is there a way to force Excel to append results for every update (this update would be triggered according to a parameter that indicates week)? I tried to define the table for which the connection loads using a dynamic reference but once is anchored first time, table position is never redefined Approach 2: Use an ETL to accumulate all weekly results into a staging table and then connect Excel to it in real time. But, I would need a mechanism for caching old data, as I cannot grow exponentially the time Excel opens. Imagine after 10 years, Excel would need to update at opening 10 years fo data before showing it. Is there a way to store already fetched data and increment it at real time (when book is opened) by selecting new data (with a query/filter of something) Thanks EDIT: Maybe it's better to ask it that way: What is the optimal strategy for a table that keeps growing and needs to be read in real time by Excel? I just don't want to fetch absolutely all data after some months...

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  • Configuring two nearby WLANs: should I use the same ssid?

    - by Rory
    I'm configuring a home network for basic internet use (ie don't really need connectivity between workstations on the network). My brick walls mean a single wireless router doesn't provide good coverage throughout the house, so I have purchased two powerline adapters and now have the incoming modem/wireless router at one end of the house plugged into a powerline adapter, and at the other end of the house the other powerline adapter plugged into another wireless router. Currently the two wireless networks have different ssids. (The powerline adapters only do power-Ethernet; they're not wireless access points themselves.) This works well, except when I move between rooms and would ideally like my devices (iPad, phones, laptops) to switch from the weak to the strong signal. Sometimes there's enough signal that they hold on to the weak connects instead of switching to the strong one. Should I name the two networks the same ssid, and if so what is the actual effect? Do the signals get confused, is the bandwidth affected, will this help my devices seamlessly move from one to the other, or is the ssid just a cosmetic thing that actually doesn't have any impact on this situation? Are there any other settings that I should configure to make my setup optimal?

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  • Matched or unmatched drives for RAID arrays?

    - by Will
    Looking around there is conflciting information on this, with some strongly suggesting one or the other. From my understanding the issue with matched drives is that the wear on both drives is more or less the same, so the potential for the second drive failing with or very soon after the first is pretty high. People also claim matched drives give substianatally higher performance however assuming the unmatched drives are more or less the same (eg 2, 1 TB STATA II 7200rpm drives with 32MB cache), would the minor differences between say a Seagate and a Western Digital one (say one has a 128MB/s read rate, and the other a 150MB/s read rate, as well as I guess various other minor differences) actually cause any notable performance loss, ie potentialy worse than two matched 128MB/s drives, or does RAID not really care and give you essentially an optimal solution (eg upto 278MB/s total read speed for RAID 0 and 1) and similar for other RAID with more "unmatched" drives (5 and 1+0 come to mind as possibilities)? Also I couldnt find much info on how this is different on different RAID setups, eg RAID 0 or RAID 1, software or hardware RAID, etc. I'm assuming such things have an effect, and thats it's not all the same for RAID in general?

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  • erratic response times with Apache 2.0.52 on redhat 4.

    - by Kevin
    Under load, we've noticed response times from Apache vary greatly for the same 7k image. It can range anywhere from .01 seconds to 25 seconds or greater. Unfortunately, due to corporate policy constraints we are pretty much stuck on Apache 2.0.52. I'm at best an Apache novice so I'm in over my head with this problem. My focus recently has turned to our choice of MPM modules. We use the worker model on a dual core hyper threaded blade. It doesn't appear that swapping is an issue, and I don't see any signs of a hardware problem. I've read that worker is optimal on hardware with many CPU's where prefork it more suitable for our specific hardware profile. I can see conceptually how choosing the wrong MPM could result in this erratic behavior, but I'm not confident that it's the root cause here. Has anyone else seen this type of range in your response times for simple static content? What else should I be looking into here?

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  • Boot stuck at blinking cursor before GRUB - only works via BIOS boot menu

    - by delta1
    I have a new box running Debian Squeeze. Grub is installed on /dev/sda, but when booting up I just get a blinking cursor, before the Grub menu. I can only boot to grub successfully when I choose boot options (during post) and select that specific drive! I have made sure the correct drive is set to boot first in the BIOS. So Grub works, but the system won't boot to that drive automatically? Any ideas on what could cause this? Drives sda/b/c are all 2TB (sda runs the system with b/c as raid device md0) with the following partitions: $ cat /proc/partitions major minor #blocks name 8 0 1953514584 sda 8 1 977 sda1 8 2 9765625 sda2 8 3 6445313 sda3 8 4 1937302627 sda4 8 32 1953514584 sdc 8 16 1953514584 sdb 9 0 1953513424 md0 but # fdisk -l /dev/sda gives WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn't support GPT. Use GNU Parted. Disk /dev/sda: 2000.4 GB, 2000398934016 bytes 255 heads, 63 sectors/track, 243201 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/sda1 1 243202 1953514583+ ee GPT Any insight into this strange behaviour would be greatly appreciated.

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  • Mysql InnoDB and quickly applying large updates

    - by Tim
    Basically my problem is that I have a large table of about 17,000,000 products that I need to apply a bunch of updates to really quickly. The table has 30 columns with the id set as int(10) AUTO_INCREMENT. I have another table which all of the updates for this table are stored in, these updates have to be pre-calculated as they take a couple of days to calculate. This table is in the format of [ product_id int(10), update_value int(10) ]. The strategy I'm taking to issue these 17 million updates quickly is to load all of these updates into memory in a ruby script and group them in a hash of arrays so that each update_value is a key and each array is a list of sorted product_id's. { 150: => [1,2,3,4,5,6], 160: => [7,8,9,10] } Updates are then issued in the format of UPDATE product SET update_value = 150 WHERE product_id IN (1,2,3,4,5,6); UPDATE product SET update_value = 160 WHERE product_id IN (7,8,9,10); I'm pretty sure I'm doing this correctly in the sense that issuing the updates on sorted batches of product_id's should be the optimal way to do it with mysql / innodb. I'm hitting a weird issue though where when I was testing with updating ~13 million records, this only took around 45 minutes. Now I'm testing with more data, ~17 million records and the updates are taking closer to 120 minutes. I would have expected some sort of speed decrease here but not to the degree that I'm seeing. Any advice on how I can speed this up or what could be slowing me down with this larger record set? As far as server specs go they're pretty good, heaps of memory / cpu, the whole DB should fit into memory with plenty of room to grow.

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  • Matched or unmatched drives for RAID arrays?

    - by Will
    Looking around there is conflciting information on this, with some strongly suggesting one or the other. From my understanding the issue with matched drives is that the wear on both drives is more or less the same, so the potential for the second drive failing with or very soon after the first is pretty high. People also claim matched drives give substianatally higher performance however assuming the unmatched drives are more or less the same (eg 2, 1 TB STATA II 7200rpm drives with 32MB cache), would the minor differences between say a Seagate and a Western Digital one (say one has a 128MB/s read rate, and the other a 150MB/s read rate, as well as I guess various other minor differences) actually cause any notable performance loss, ie potentialy worse than two matched 128MB/s drives, or does RAID not really care and give you essentially an optimal solution (eg upto 278MB/s total read speed for RAID 0 and 1) and similar for other RAID with more "unmatched" drives (5 and 1+0 come to mind as possibilities)? Also I couldnt find much info on how this is different on different RAID setups, eg RAID 0 or RAID 1, software or hardware RAID, etc. I'm assuming such things have an effect, and thats it's not all the same for RAID in general?

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  • Map Subdomains to Folders Owned/Run by Other Apache/PHP/Cpanel Users

    - by kristofferR
    I run a small service for Norwegian customers where they get automatically installed and configured Wordpress blogs on their own domains ready immediately after payment is finished. It's quite similar to Page.ly and WPEngine, just aimed at Norwegian customers with Norwegian Wordpress, support, billing etc. The backend is WHM/CPanel (Apache, PHP, mySQL), with a script running immediately after payment that installs and configures Wordpress and sends the customer an email with their username and password. Newly registered domains takes some time to propagate though, so for a day or two my customers unfortunately have to use a temporary URL before I can switch them over to their own domains. Right now my system uses mod_userdir ("serverIP/~cpanelusername"). However, it's not an optimal solution. It looks unprofessional, is confusing, and is quite problematic for both my customers and me. I'd rather prefer the temporary URL for their blogs to be "theirdomainwithoutextension.host.no", with "host.no" being a domain I own and served from the same server as the customer sites. I can easily modify the script to create the subdomains on my "host.no"-domain, but how can I seamlessly map the subdomains to folders owned/ran on/by different CPanel/Apache/PHP users?

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  • Trouble Starting MySL Community Server on Windows 7

    - by CodeAngel
    I have installed Netbeans 7 on my Windows 7. In addition, the MySQL Community Server 5.6.12 is installed with the MSI installer on thesame 7 PC. The MySQL server is integrated with the Netbeans IDE. However , it is not possible to start or stop the MySQL server from the command prompt or the Netbeans IDE. I am only able to start or stop the server from the Windows 7 services tool. Also , it is difficult running SQL queries from the Netbeans IDE even though it shows there is connection with the MySQL server. I have added the my.ini file to the installed directory of the MySQL server , that is : C:\Program Files\MySQL\MySQL Server 5.6 below is the my.ini file : # For advice on how to change settings please see # http://dev.mysql.com/doc/refman/5.6/en/server-configuration-defaults.html # *** DO NOT EDIT THIS FILE. It's a template which will be copied to the # *** default location during install, and will be replaced if you # *** upgrade to a newer version of MySQL. [mysqld] # Remove leading # and set to the amount of RAM for the most important data # cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%. # innodb_buffer_pool_size = 128M # Remove leading # to turn on a very important data integrity option: logging # changes to the binary log between backups. # log_bin # These are commonly set, remove the # and set as required. # basedir = ..... # datadir = ..... port = 3306 # server_id = ..... # Remove leading # to set options mainly useful for reporting servers. # The server defaults are faster for transactions and fast SELECTs. # Adjust sizes as needed, experiment to find the optimal values. # join_buffer_size = 128M # sort_buffer_size = 2M # read_rnd_buffer_size = 2M sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES Any suggestion is welcomed.

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  • SQL SERVER – Disable Clustered Index and Data Insert

    - by pinaldave
    Earlier today I received following email. “Dear Pinal, [Removed unrelated content] We looked at your script and found out that in your script of disabling indexes, you have only included non-clustered index during the bulk insert and missed to disabled all the clustered index. Our DBA[name removed] has changed your script a bit and included all the clustered indexes. Since our application is not working. When DBA [name removed] tried to enable clustered indexes again he is facing error incorrect syntax error. We are in deep problem [word replaced] [Removed Identity of organization and few unrelated stuff ]“ I have replied to my client and helped them fixed the problem. What really came to my attention is the concept of disabling clustered index. Let us try to learn a lesson from this experience. In this case, there was no need to disable clustered index at all. I had done necessary work when I was called in to work on tuning project. I had removed unused indexes, created few optimal indexes and wrote a script to disable few selected high cost indexes when bulk insert (and similar) operations are performed. There was another script which rebuild all the indexes as well. The solution worked till they included clustered index in disabling the script. Clustered indexes are in fact original table (or heap) physically ordered (any more things – not scope of this article) according to one or more keys(columns). When clustered index is disabled data rows of the disabled clustered index cannot be accessed. This means there will be no insert possible. When non clustered indexes are disabled all the data related to physically deleted but the definition of the index is kept in the system. Due to the same reason even reorganization of the index is not possible till the clustered index (which was disabled) is rebuild. Now let us come to the second part of the question, regarding receiving the error when clustered index is ‘enabled’. This is very common question I receive on the blog. (The following statement is written keeping the syntax of T-SQL in mind) Clustered indexes can be disabled but can not be enabled, they have to rebuild. It is intuitive to think that something which we have ‘disabled’ can be ‘enabled’ but the syntax for the same is ‘rebuild’. This issue has been explained here: SQL SERVER – How to Enable Index – How to Disable Index – Incorrect syntax near ‘ENABLE’. Let us go over this example where inserting the data is not possible when clustered index is disabled. USE AdventureWorks GO -- Create Table CREATE TABLE [dbo].[TableName]( [ID] [int] NOT NULL, [FirstCol] [varchar](50) NULL, CONSTRAINT [PK_TableName] PRIMARY KEY CLUSTERED ([ID] ASC) ) GO -- Create Nonclustered Index CREATE UNIQUE NONCLUSTERED INDEX [IX_NonClustered_TableName] ON [dbo].[TableName] ([FirstCol] ASC) GO -- Populate Table INSERT INTO [dbo].[TableName] SELECT 1, 'First' UNION ALL SELECT 2, 'Second' UNION ALL SELECT 3, 'Third' GO -- Disable Nonclustered Index ALTER INDEX [IX_NonClustered_TableName] ON [dbo].[TableName] DISABLE GO -- Insert Data should work fine INSERT INTO [dbo].[TableName] SELECT 4, 'Fourth' UNION ALL SELECT 5, 'Fifth' GO -- Disable Clustered Index ALTER INDEX [PK_TableName] ON [dbo].[TableName] DISABLE GO -- Insert Data will fail INSERT INTO [dbo].[TableName] SELECT 6, 'Sixth' UNION ALL SELECT 7, 'Seventh' GO /* Error: Msg 8655, Level 16, State 1, Line 1 The query processor is unable to produce a plan because the index 'PK_TableName' on table or view 'TableName' is disabled. */ -- Reorganizing Index will also throw an error ALTER INDEX [PK_TableName] ON [dbo].[TableName] REORGANIZE GO /* Error: Msg 1973, Level 16, State 1, Line 1 Cannot perform the specified operation on disabled index 'PK_TableName' on table 'dbo.TableName'. */ -- Rebuliding should work fine ALTER INDEX [PK_TableName] ON [dbo].[TableName] REBUILD GO -- Insert Data should work fine INSERT INTO [dbo].[TableName] SELECT 6, 'Sixth' UNION ALL SELECT 7, 'Seventh' GO -- Clean Up DROP TABLE [dbo].[TableName] GO I hope this example is clear enough. There were few additional posts I had written years ago, I am listing them here. SQL SERVER – Enable and Disable Index Non Clustered Indexes Using T-SQL SQL SERVER – Enabling Clustered and Non-Clustered Indexes – Interesting Fact Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Constraint and Keys, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – What is Spatial Database? – Developing with SQL Server Spatial and Deep Dive into Spati

    - by pinaldave
    What is Spatial Database? A spatial database is a database that is optimized to store and query data related to objects in space, including points, lines and polygons. While typical databases can understand various numeric and character types of data, additional functionality needs to be added for databases to process spatial data types. (Source: Wikipedia) Today I will be talking about the same subject at Microsoft TechEd India. If you want to learn about how to spatial aspect of data and how to integrate them with SQL Server this is the perfect session for you. Spatial is very special concept of SQL Server and I really like how it is implemented in SQL Server. In general Performance Tuning and Query Optimization is something I always have enjoyed in my professional life. Index are my best friends and many time, by implementing and many time by removing I have improved the performance of the system. In this session, I will be talking about Index along with Spatial Data. As Spatial Database is very interesting concept, I will cover super short but very interesting 10 quick slides about this subject. I will make sure in very first 20 mins, you will understand following topics Introduction to Spatial Database One line definition Understanding Spatial Indexing Index Internals Query/Performance Tuning Query Hinting/Cost Analysis Spatial Index Catalog Views Performance Troubleshooting Finding Optimal Index using Spatial Index SP Common Errors Index Maintenance This slides decks will be followed by around 30 mins demo which will have story of geometry, geography, index internals and performance tuning. If you are interested in learning how GIS works and how SQL Server out of the box supports this wonderful tools, you will really like how the story is told. I am sure all people who attend the event will know how the Bangalore is positioned on the map of India. I will take example of Bangalore and Hyderabad and demonstrate how index can improve the performance. Well there are lots of story to tell in the session, and I will be opening this session with the beautiful script of Botticelli’s Birth of Venus created by Michael J. Swart. I will also demonstrate few real life scenario where I will be talking about Spatial Database and its usage. Do not miss this session. At the end of session there will be book awarded to best participant. My session details: Session 3: Developing with SQL Server Spatial and Deep Dive into Spatial Indexing Date: April 14, 2010 Time: 5:00pm-6:00pm Microsoft SQL Server 2008 delivers new spatial data types that enable you to consume, use, and extend location-based data through spatial-enabled applications. Attend this session to learn how to use spatial functionality in next version of SQL Server to build and optimize spatial queries. This session outlines the new geography data type to store geodetic spatial data and perform operations on it, use the new geometry data type to store planar spatial data and perform operations on it, take advantage of new spatial indexes for high performance queries, use the new spatial results tab to quickly and easily view spatial query results directly from within Management Studio, extend spatial data capabilities by building or integrating location-enabled applications through support for spatial standards and specifications and much more. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Index, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, T SQL, Technology Tagged: Spatial Database

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  • Convert YouTube Videos to MP3 with YouTube Downloader

    - by DigitalGeekery
    Are you looking for a way to take the music videos you watch on YouTube and convert them to MP3? Today we take a look at an easy way to convert those YouTube videos to MP3 for free with YouTube Downloader. The YouTube Downloader functions in two steps. First, it downloads the video from YouTube in MP4 format, and then allows you to convert that MP4 file to MP3. Note: It also supports conversion conversion to some other formats such as AVI video, MOV, iPhone, PSP, 3GP, and WMV.   Installation and usage Download and Install YouTube Downloader. (See download link below) Open the YouTube Downloader by clicking on the desktop icon. Find a YouTube video you’d like to convert to MP3 and copy the URL. Paste the URL into the “Enter video URL” text box in YouTube Downloader. When you hover your mouse over the text box, the text box will auto-fill with the URL from your clipboard. Select the “Download video from YouTube” radio button and click “Ok.” Choose a folder to location to download your YouTube video and click “Save.” The video is downloaded in MP4 format. Now wait while the video is downloaded to your hard drive.   Select the “Convert video (previously downloaded) from file” radio button. Click the (…) button to the right of the “Select video file” text box to browse for and select the MP4 file you just downloaded. Then select “MPEG Audio Layer (MP3) from the “Convert to” drop down list. Select “OK” to begin the conversion. Choose the conversion quality by moving the slider to the right or left. The options are: Low (96kbps bite rate), Medium (128kbps bit rate), Optimal (192kbps bit rate), and High 256kbps bit rate). Here you can select the output volume as well. Click “OK” when finished. If there is a portion of the beginning or end of the video that you wish to cut out of the MP3, select the “Cut video” check box and choose a Start and End time. Click “OK” when finished. Note: The start and end time represent the audio portion of the MP3 you wish to keep. All portions before and after these times will be cut.   The conversion process will begin and should only take a few moments. Times will vary depending on the size of the video you’re converting. Conversion was successful! The MP3 you converted will be in the same directory you downloaded the video to. Now you’re ready to listen to your MP3 or import it to your Zune, iTunes, or music library. You may also want to delete the MP4 files after the conversion if you will no longer need them. Conclusion YouTube Downloader features a very simple interface that’s user friendly and easy to use. It comes in handy when you watch videos that look horrible, but the sound quality is good. Or if you just need to hear the audio of something posted and don’t need the video. It also allows you to download from Google Video, MySpace, and others. Download YouTube Downloader Similar Articles Productive Geek Tips Download YouTube Videos with Cheetah YouTube DownloaderWatch YouTube Videos in Cinema Style in FirefoxStop YouTube Videos from Automatically Playing in FirefoxRemove Unsuitable Comments from YouTubeImprove YouTube Video Viewing in Google Chrome TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 PCmover Professional Windows Media Player 12: Tweak Video & Sound with Playback Enhancements Own a cell phone, or does a cell phone own you? Make your Joomla & Drupal Sites Mobile with OSMOBI Integrate Twitter and Delicious and Make Life Easier Design Your Web Pages Using the Golden Ratio Worldwide Growth of the Internet

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  • Framework 4 Features: Support for Timed Jobs

    - by Anthony Shorten
    One of the new features of the Oracle Utilities Application Framework V4 is the ability for the batch framework to support Timed Batch. Traditionally batch is associated with set processing in the background in a fixed time frame. For example, billing customers. Over the last few versions their has been functionality required by the products required a more monitoring style batch process. The monitor is a batch process that looks for specific business events based upon record status or other pieces of data. For example, the framework contains a fact monitor (F1-FCTRN) that can be configured to look for specific status's or other conditions. The batch process then uses the instructions on the object to determine what to do. To support monitor style processing, you need to run the process regularly a number of times a day (for example, every ten minutes). Traditional batch could support this but it was not as optimal as expected (if you are a site using the old Workflow subsystem, you understand what I mean). The Batch framework was extended to add additional facilities to support times (and continuous batch which is another new feature for another blog entry). The new facilities include: The batch control now defines the job as Timed or Not Timed. Non-Timed batch are traditional batch jobs. The timer interval (the interval between executions) can be specified The timer can be made active or inactive. Only active timers are executed. Setting the Timer Active to inactive will stop the job at the next time interval. Setting the Timer Active to Active will start the execution of the timed job. You can specify the credentials, language to view the messages and an email address to send the a summary of the execution to. The email address is optional and requires an email server to be specified in the relevant feature configuration. You can specify the thread limits and commit intervals to be sued for the multiple executions. Once a timer job is defined it will be executed automatically by the Business Application Server process if the DEFAULT threadpool is active. This threadpool can be started using the online batch daemon (for non-production) or externally using the threadpoolworker utility. At that time any batch process with the Timer Active set to Active and Batch Control Type of Timed will begin executing. As Timed jobs are executed automatically then they do not appear in any external schedule or are managed by an external scheduler (except via the DEFAULT threadpool itself of course). Now, if the job has no work to do as the timer interval is being reached then that instance of the job is stopped and the next instance started at the timer interval. If there is still work to complete when the interval interval is reached, the instance will continue processing till the work is complete, then the instance will be stopped and the next instance scheduled for the next timer interval. One of the key ways of optimizing this processing is to set the timer interval correctly for the expected workload. This is an interesting new feature of the batch framework and we anticipate it will come in handy for specific business situations with the monitor processes.

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  • MongoDB usage best practices

    - by andresv
    The project I'm working on uses MongoDB for some stuff so I'm creating some documents to help developers speedup the learning curve and also avoid mistakes and help them write clean & reliable code. This is my first version of it, so I'm pretty sure I will be adding more stuff to it, so stay tuned! C# Official driver notes The 10gen official MongoDB driver should always be referenced in projects by using NUGET. Do not manually download and reference assemblies in any project. C# driver quickstart guide: http://www.mongodb.org/display/DOCS/CSharp+Driver+Quickstart Reference links C# Language Center: http://www.mongodb.org/display/DOCS/CSharp+Language+Center MongoDB Server Documentation: http://www.mongodb.org/display/DOCS/Home MongoDB Server Downloads: http://www.mongodb.org/downloads MongoDB client drivers download: http://www.mongodb.org/display/DOCS/Drivers MongoDB Community content: http://www.mongodb.org/display/DOCS/CSharp+Community+Projects Tutorials Tutorial MongoDB con ASP.NET MVC - Ejemplo Práctico (Spanish):http://geeks.ms/blogs/gperez/archive/2011/12/02/tutorial-mongodb-con-asp-net-mvc-ejemplo-pr-225-ctico.aspx MongoDB and C#:http://www.codeproject.com/Articles/87757/MongoDB-and-C C# driver LINQ tutorial:http://www.mongodb.org/display/DOCS/CSharp+Driver+LINQ+Tutorial C# driver reference: http://www.mongodb.org/display/DOCS/CSharp+Driver+Tutorial Safe Mode Connection The C# driver supports two connection modes: safe and unsafe. Safe connection mode (only applies to methods that modify data in a database like Inserts, Deletes and Updates. While the current driver defaults to unsafe mode (safeMode == false) it's recommended to always enable safe mode, and force unsafe mode on specific things we know aren't critical. When safe mode is enabled, the driver internal code calls the MongoDB "getLastError" function to ensure the last operation is completed before returning control the the caller. For more information on using safe mode and their implicancies on performance and data reliability see: http://www.mongodb.org/display/DOCS/getLastError+Command If safe mode is not enabled, all data modification calls to the database are executed asynchronously (fire & forget) without waiting for the result of the operation. This mode could be useful for creating / updating non-critical data like performance counters, usage logging and so on. It's important to know that not using safe mode implies that data loss can occur without any notification to the caller. As with any wait operation, enabling safe mode also implies dealing with timeouts. For more information about C# driver safe mode configuration see: http://www.mongodb.org/display/DOCS/CSharp+getLastError+and+SafeMode The safe mode configuration can be specified at different levels: Connection string: mongodb://hostname/?safe=true Database: when obtaining a database instance using the server.GetDatabase(name, safeMode) method Collection: when obtaining a collection instance using the database.GetCollection(name, safeMode) method Operation: for example, when executing the collection.Insert(document, safeMode) method Some useful SafeMode article: http://stackoverflow.com/questions/4604868/mongodb-c-sharp-safemode-official-driver Exception Handling The driver ensures that an exception will be thrown in case of something going wrong, in case of using safe mode (as said above, when not using safe mode no exception will be thrown no matter what the outcome of the operation is). As explained here https://groups.google.com/forum/?fromgroups#!topic/mongodb-user/mS6jIq5FUiM there is no need to check for any returned value from a driver method inserting data. With updates the situation is similar to any other relational database: if an update command doesn't affect any records, the call will suceed anyway (no exception thrown) and you manually have to check for something like "records affected". For MongoDB, an Update operation will return an instance of the "SafeModeResult" class, and you can verify the "DocumentsAffected" property to ensure the intended document was indeed updated. Note: Please remember that an Update method might return a null instance instead of an "SafeModeResult" instance when safe mode is not enabled. Useful Community Articles Comments about how MongoDB works and how that might affect your application: http://ethangunderson.com/blog/two-reasons-to-not-use-mongodb/ FourSquare using MongoDB had serious scalability problems: http://mashable.com/2010/10/07/mongodb-foursquare/ Is MongoDB a replacement for Memcached? http://www.quora.com/Is-MongoDB-a-good-replacement-for-Memcached/answer/Rick-Branson MongoDB Introduction, shell, when not to use, maintenance, upgrade, backups, memory, sharding, etc: http://www.markus-gattol.name/ws/mongodb.html MongoDB Collection level locking support: https://jira.mongodb.org/browse/SERVER-1240 MongoDB performance tips: http://www.quora.com/MongoDB/What-are-some-best-practices-for-optimal-performance-of-MongoDB-particularly-for-queries-that-involve-multiple-documents Lessons learned migrating from SQL Server to MongoDB: http://www.wireclub.com/development/TqnkQwQ8CxUYTVT90/read MongoDB replication performance: http://benshepheard.blogspot.com.ar/2011/01/mongodb-replication-performance.html

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  • SQL SERVER – MSQL_XP – Wait Type – Day 20 of 28

    - by pinaldave
    In this blog post, I am going to discuss something from my field experience. While consultation, I have seen various wait typed, but one of my customers who has been using SQL Server for all his operations had an interesting issue with a particular wait type. Our customer had more than 100+ SQL Server instances running and the whole server had MSSQL_XP wait type as the most number of wait types. While running sp_who2 and other diagnosis queries, I could not immediately figure out what the issue was because the query with that kind of wait type was nowhere to be found. After a day of research, I was relieved that the solution was very easy to figure out. Let us continue discussing this wait type. From Book On-Line: ?MSQL_XP occurs when a task is waiting for an extended stored procedure to end. SQL Server uses this wait state to detect potential MARS application deadlocks. The wait stops when the extended stored procedure call ends. MSQL_XP Explanation: This wait type is created because of the extended stored procedure. Extended Stored Procedures are executed within SQL Server; however, SQL Server has no control over them. Unless you know what the code for the extended stored procedure is and what it is doing, it is impossible to understand why this wait type is coming up. Reducing MSQL_XP wait: As discussed, it is hard to understand the Extended Stored Procedure if the code for it is not available. In the scenario described at the beginning of this post, our client was using third-party backup tool. The third-party backup tool was using Extended Stored Procedure. After we learned that this wait type was coming from the extended stored procedure of the backup tool they were using, we contacted the tech team of its vendor. The vendor admitted that the code was not optimal at some places, and within that day they had provided the patch. Once the updated version was installed, the issue on this wait type disappeared. As viewed in the wait statistics of all the 100+ SQL Server, there was no more MSSQL_XP wait type found. In simpler terms, you must first identify which Extended Stored Procedure is creating the wait type of MSSQL_XP and see if you can get in touch with the creator of the SP so you can help them optimize the code. If you have encountered this MSSQL_XP wait type, I encourage all of you to write how you managed it. Please do not mention the name of the vendor in your comment as I will not approve it. The focus of this blog post is to understand the wait types; not talk about others. Read all the post in the Wait Types and Queue series. Note: The information presented here is from my experience and there is no way that I claim it to be accurate. I suggest reading Book OnLine for further clarification. All the discussion of Wait Stats in this blog is generic and varies from system to system. It is recommended that you test this on a development server before implementing it to a production server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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