Tuning for CPU usage

Discussion in 'Install/Configuration' started by alex, Jun 13, 2006.

  1. alex

    alex Well-Known Member

    We are running into a definite CPU bottleneck, the IO and memory seem to be holding up fine. Are there any specific settings that can be tweaked to improve this?
  2. mistwang

    mistwang LiteSpeed Staff

    lshttpd should consumes little CPU cycles, the rest should be taken by PHP processes. So, you need to focus on PHP tuning, like using opcode caching if it has not been used yet. Also, try finding vBulltin add-on modules which can improve performance.
    Worst case, add more hardware. :) Our load balancer will be ready soon.
  3. ts77

    ts77 Well-Known Member

    just curious:
    where will the load-balancer kick in? separate software in front of a couple of lsws servers or simply included in them?
  4. xing

    xing LiteSpeed Staff

    alex, based on your last php.ini configuration, you should think about using op-code caching like mistwang suggested. For php 4 code, I would highly recommend eacclerator.co.uk. Note when installing, make sure you disable "code optimization", only enable the caching part of eAcc.

    Opcode caching can drastically improve php's cpu usage.

    Another sure thing is also to upgrade to the latest vBulletin build.
  5. mistwang

    mistwang LiteSpeed Staff


    The load balancer is a standalone server in front of a web server farm.
  6. alex

    alex Well-Known Member

    Eaccelerator worked...oh my god did it work
  7. ts77

    ts77 Well-Known Member

    alex, any measures of that?
  8. alex

    alex Well-Known Member

    Prior to installing eaccelerator last night top was showing 100 (where they were set to give a "server too busy" message). This was happening at about 2200 simultaneous users.
    Today we made it to 2450 users, I never saw load go over 40 and most of the time it was around 20-30
  9. Xorlev

    Xorlev Well-Known Member

    I recommend APC over Eaccelerator, but eh, if it works. Even so with such concurrency it'd be recommended to upgrade to a more powerful server. I'd recommend an Opteron, as they're rather leading the server market in price/performance ratio.

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