Thanks to all of you. Here's a quick summary of the answers I got:

performance problems in a LAMP system

The problem could be located in one or more components:

  1. hardware/os
  2. apache
  3. mysql
  4. the application itself

    the usual suspects are the application itself (bad SQL code, inefficient Perl code) and the database (badly laid out database tables on physical spindles)

    hardware/os
    check: CPU utilization, physical RAM/Swap utilization, network bandwidth and disk spindle utilization time.
    tools: vmstat, mpstat, top,...
    apache
    links: Apache Performance Tuning
    mysql
    tools: the mysql slow log, DBIx::Profile
    links: linuxmag article on mysql performance tuning
    the application itself
    tools: Devel::DProf, Apache::DProf

2001-12-13 Edit by Corion : Added missing <OL> tag

In reply to SUMMARY: performance of LAMP-system by bjelli
in thread performance of LAMP-system by bjelli

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