I have spent a week or two researching and setting up my server to run Apache with the Worker MPM and FCID. I am trying to optimize it to allow for the most concurrent connections possible. It has been a nightmare to find good info on the Worker MPM.
Server - VPS with 1GB RAM (With Apache off its only using about 150MB of RAM) I would like Apache to have a memory usage CAP of about 750MB - so that my server will never run out of RAM.
I have been running the server for about 2 years without any problems - but we have recently started streaming MP3`s and this requires more concurrent connections. The server has also had a few minor DDOS attacks - so I trimmed the settings down a ton to prevent the server from running out of memory - I also added some firewall rules to rate limit.
The set up I have now looks like its working well - but I am getting some Segmentation fault errors
[Sat Mar 23 03:19:50 2013] [notice] child pid 28351 exit signal Segmentation fault (11)
[Sat Mar 23 03:56:20 2013] [notice] child pid 29740 exit signal Segmentation fault (11)
*** glibc detected *** /usr/sbin/httpd.worker: malloc(): memory corruption: 0xb83abdd8 ***
And some Out of Memory Errors
Out of memory during array extend.
This is my current set up, I would really appreciate some advice.
Apache Settings:
Timeout 30
KeepAlive On
MaxKeepAliveRequests 100
KeepAliveTimeout 2
#####################
# Spawn 2 child processes, spawning 25 threads for each child process.
# So, a pool of 50 threads is left up and sleeping, ready to serve incoming requests.
# If more requests will come in, apache will spawn new child processes, each one spawning 25 threads,
# enlarging the thread pool until the total number of threads become 50. In that case, apache begin
# to cleanly drop processes, trying to reach 25 threads.
# New processes and its threads are spawned in case of a large spike of requests, until 200 parallel
# client requests are reached, then apache will no longer accept new incoming connections.
# When the load calm down, and requests come back under 200 parallel connections, apache will continue
# to accept connections. After 25, 000 requests served by a child, q. 1000 per thread, the process
# get closed by the father to ensure no memory leak is fired.
<IfModule worker.c>
ServerLimit 16
StartServers 2
MaxClients 400
MinSpareThreads 25
MaxSpareThreads 50
ThreadsPerChild 25
MaxRequestsPerChild 1000
ThreadLimit 64
ThreadStackSize 1048576
</IfModule>
#####################
And then some settings in fcgid.conf
FcgidMinProcessesPerClass 0
FcgidMaxProcessesPerClass 8
FcgidMaxProcesses 25
FcgidIdleTimeout 60
FcgidProcessLifeTime 120
FcgidIdleScanInterval 30
As requested my output for /etc/my.cnf
[mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock user=mysql #skip-innodb connect_timeout = 10 max_connections = 300 symbolic-links=0 innodb_file_per_table = 1 myisam_sort_buffer_size = 8M read_rnd_buffer_size = 512K net_buffer_length = 8K read_buffer_size = 256K sort_buffer_size = 512K table_cache = 32 max_allowed_packet = 1M key_buffer = 16k query_cache_type = 1 query-cache-size = 32M thread_cache_size = 16 net_buffer_length = 2K thread_stack = 256K wait_timeout = 300 slow_query_log #log-slow-queries=/var/log/mysql/slow-queries.log slow_query_log=/var/log/mysql/slow-queries.log long_query_time = 1 [mysqld_safe] log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid
And PHP memory_limit = 64M
