+ Post New Thread
Results 1 to 15 of 15
*nix Thread, Ubuntu Server slows to halt when multiple users log in. in Technical; We are soon (hopefully!) launching a wordpress based intranet site that is hosted on one of our local servers. The ...
  1. #1

    Join Date
    Aug 2007
    Posts
    818
    Thank Post
    101
    Thanked 65 Times in 47 Posts
    Rep Power
    26

    Ubuntu Server slows to halt when multiple users log in.

    We are soon (hopefully!) launching a wordpress based intranet site that is hosted on one of our local servers.

    The server is a HP Proliant DL380, 4GB Ram with 3 x 72GB SCSI Drives, these are in RAID5 formatted with one simple volume.
    It was setup with Ubuntu and currently using port:80

    It works perfectly when one user is accessing the site but when 5 or more users access the first default page it grinds to a halt.

    Can anyone please point in the direction that we should try and follow to find out what could be causing this?
    Is the server maybe not upto spec? We plan to have 60+ users logging in at once.

    Thanks in advance
    Last edited by burgemaster; 11th July 2011 at 03:37 PM.

  2. #2
    morganw's Avatar
    Join Date
    Apr 2009
    Location
    Cambridge
    Posts
    816
    Thank Post
    46
    Thanked 132 Times in 126 Posts
    Rep Power
    40
    Run top and iotop and see which processes are causing the problem. If the server looks okay then check you have a proxy exception so that you are accessing it over the LAN not through your internet connection.

  3. #3


    Join Date
    Jan 2006
    Posts
    8,202
    Thank Post
    442
    Thanked 1,032 Times in 812 Posts
    Rep Power
    339
    The server should easily cope with that load.
    I'm not sure what the current state of php accelerators is with ubuntu (IIRC newer versions of php have an accelerator by default?), but after checking out morganw's advice I would look into php accelerators and php configs. some tweaks here (i've not used)
    13 Great WordPress Speed Tips & Tricks for MAX Performance - Noupe Design Blog

  4. #4

    Join Date
    Apr 2008
    Posts
    5
    Thank Post
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    Quote Originally Posted by morganw View Post
    Run top and iotop and see which processes are causing the problem. If the server looks okay then check you have a proxy exception so that you are accessing it over the LAN not through your internet connection.
    Hi

    Have run top, here is the output when simulating 20 users

    wcess. org.uk/Capture1 . JPG

    Remove space etc as it's my first post.

  5. #5
    morganw's Avatar
    Join Date
    Apr 2009
    Location
    Cambridge
    Posts
    816
    Thank Post
    46
    Thanked 132 Times in 126 Posts
    Rep Power
    40
    Are those spiked values or is the CPU constantly being used like that? It looks like a problem with Apache. Is this server just based on choosing a LAMP installation from tasksel or have you set everything up separately?

  6. #6

    Join Date
    Apr 2008
    Posts
    5
    Thank Post
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    Spiked, as soon as I set the simulation going it creaps up and stays at that level untill I stop it. If I run it for a while I get the following:

    [Mon Jul 11 15:38:15 2011] [error] child process 1785 still did not exit, sending a SIGKILL
    [Mon Jul 11 15:38:15 2011] [error] child process 1786 still did not exit, sending a SIGKILL
    [Mon Jul 11 15:38:15 2011] [error] child process 1787 still did not exit, sending a SIGKILL
    [Mon Jul 11 15:38:15 2011] [error] child process 1788 still did not exit, sending a SIGKILL
    [Mon Jul 11 15:38:15 2011] [error] child process 1789 still did not exit, sending a SIGKILL
    [Mon Jul 11 15:38:16 2011] [notice] caught SIGTERM, shutting down

    This is a default LAMP install - the only thing I have done is enable mod_rewrite

    Can post anything you want that may help?

  7. #7

    Join Date
    Apr 2008
    Posts
    5
    Thank Post
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    Interestingly - this is idle...

    Code:
    Tasks: 241 total,   1 running, 240 sleeping,   0 stopped,   0 zombie
    Cpu(s):  0.1%us,  0.1%sy,  0.0%ni, 99.8%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
    Mem:   3990672k total,  3941460k used,    49212k free,    15588k buffers
    Swap:  5804028k total,  2970388k used,  2833640k free,   145636k cached
    is that not saying the memory is totaly in use even when idle?

  8. #8
    morganw's Avatar
    Join Date
    Apr 2009
    Location
    Cambridge
    Posts
    816
    Thank Post
    46
    Thanked 132 Times in 126 Posts
    Rep Power
    40
    Which version of Ubuntu Server are you using?

  9. #9

    Join Date
    Apr 2008
    Posts
    5
    Thank Post
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    Latest, Natty. Original install was 10.10 then I upgraded it the other day. Its the command line server edition

  10. #10
    morganw's Avatar
    Join Date
    Apr 2009
    Location
    Cambridge
    Posts
    816
    Thank Post
    46
    Thanked 132 Times in 126 Posts
    Rep Power
    40
    I would reinstall a clean LAMP server into a VM and see if you get the same issues. There is a bug report for similiar issues but that is from a while ago. If the VM doens't work then I would suspect that there is something up with the Wordpress install that is causing problems, if you snapshot the VM before you install Wordpress you could also test install similar system like Joomla or Moodle and see if you are getting the same problem. I've not used Wordpress before but it might be worth checking permissions on correct on the install, you could chmod 777 the entire install just for testing purposes and see what happens.

  11. #11

    Join Date
    Apr 2008
    Posts
    5
    Thank Post
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    I have done a fresh wordpress install on a new database. This is what I have got a result of:


    top - 10:45:49 up 20:29, 3 users, load average: 13.04, 7.88, 3.62
    Tasks: 109 total, 11 running, 98 sleeping, 0 stopped, 0 zombie
    Cpu(s): 91.0%us, 4.5%sy, 0.0%ni, 3.7%id, 0.0%wa, 0.0%hi, 0.8%si, 0.0%st
    Mem: 3990672k total, 1048072k used, 2942600k free, 14100k buffers
    Swap: 5804028k total, 34040k used, 5769988k free, 125204k cached


    It now seems to be using less memory, but the same CPU

  12. #12

    dhicks's Avatar
    Join Date
    Aug 2005
    Location
    Knightsbridge
    Posts
    5,655
    Thank Post
    1,259
    Thanked 782 Times in 679 Posts
    Rep Power
    236
    Quote Originally Posted by mattian View Post
    [Mon Jul 11 15:38:15 2011] [error] child process 1785 still did not exit, sending a SIGKILL
    [Mon Jul 11 15:38:15 2011] [error] child process 1786 still did not exit, sending a SIGKILL
    [Mon Jul 11 15:38:15 2011] [error] child process 1787 still did not exit, sending a SIGKILL
    [Mon Jul 11 15:38:15 2011] [error] child process 1788 still did not exit, sending a SIGKILL
    [Mon Jul 11 15:38:15 2011] [error] child process 1789 still did not exit, sending a SIGKILL
    [Mon Jul 11 15:38:16 2011] [notice] caught SIGTERM, shutting down
    Apache pre-branches handler processes, ready to pass off the work for each request. You can set how many processes it pre-branches - I think the default could well be 5. It looks like all your handler processes are busy, which maybe implies a long-running or infinite loop in some bit of code that gets called when you visit the default page - probably a bit of PHP code somewhere.

  13. #13
    morganw's Avatar
    Join Date
    Apr 2009
    Location
    Cambridge
    Posts
    816
    Thank Post
    46
    Thanked 132 Times in 126 Posts
    Rep Power
    40
    Wordpress recently (couple of months back) had malicious code inserted into their plug-ins, is this a brand new Wordpress install or are you moving it from somewhere else?

  14. #14
    jamesfed's Avatar
    Join Date
    Sep 2009
    Location
    Reading
    Posts
    2,208
    Thank Post
    137
    Thanked 345 Times in 291 Posts
    Rep Power
    87
    Not that its a solution to your problem (not even a work around) but have you considered getting an install of Windows Server on your DL380 and run WordPress off of IIS?
    All our sites here are hosted on IIS7.5 (a few internal WordPress installs and HAP+) and it works a real treat.

    Not that I'm looking to bring up a discussion about this but it could be the easy way out if you have a lic spare...
    Last edited by jamesfed; 12th July 2011 at 07:06 PM.

  15. #15

    localzuk's Avatar
    Join Date
    Dec 2006
    Location
    Minehead
    Posts
    17,885
    Thank Post
    518
    Thanked 2,489 Times in 1,930 Posts
    Blog Entries
    24
    Rep Power
    839
    My first thought would be this - don't use a non LTS release of Ubuntu to run a server - there's no need, and it is more work than you want to do maintaining it. Instead, use the latest LTS release and go from there. They are more stable, tested more and supported for longer.

    However, in this case, with massive number of Apache processes being spawned for so little load, I'd be thinking something is wrong with Wordpress. Can I ask what you are using to simulate your load? Also, do you have anything like custom themes or plugins installed in Wordpress? (I'm thinking not as you mention a fresh install).

    Finally, how are you installing it? Custom site definitions or straight into the default /var/www/ location?

SHARE:
+ Post New Thread

Similar Threads

  1. Replies: 0
    Last Post: 8th July 2010, 02:36 PM
  2. Replies: 4
    Last Post: 19th April 2010, 11:11 AM
  3. Replies: 5
    Last Post: 4th December 2009, 11:50 PM
  4. Replies: 2
    Last Post: 18th November 2009, 09:36 PM
  5. Replies: 8
    Last Post: 12th February 2009, 03:54 PM

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •