optimizing apache/mysql on Linode 1024
I have a linode1024, Apache with one site only.
The site can not take 10 to 15 requests at a time, I have around 5K page views daily but expecting 50K soon, the server runs out of memory very quickly. I need help finding the problem in the following configuration.
ps. I have W3Totalcache in-place configured with page caching and MAXCDN.
For apache2.conf I have the following settings
<ifmodule mpm_prefork_module="">StartServers 2
MinSpareServers 6
MaxSpareServers 12
MaxClients 48
MaxRequestsPerChild 6000</ifmodule>
Httpd.conf is blank
For MySQL, my.cnf has the following values:
key_buffer = 16M
max_allowed_packet = 16M
thread_stack = 192K
thread_cache_size = 8
myisam-recover = BACKUP
#max_connections = 100
#table_cache = 64
#thread_concurrency = 10
#
# * Query Cache Configuration
#
query_cache_limit = 1M
query_cache_size = 16M
Any tips will be appreciated, I thought a VPS with 1GB memory should easily handle more connections, just can't find the problem, thanks
10 Replies
I do believe there's some issues with the default modphp from apache and mpmworker, but if you use PHP-FPM/FastCGI with pools it shouldn't be a problem, AFAIK.
And yes, if you ditch modphp and move to php-fpm, you can also ditch mpm-prefork and set the world on fire accordingly. I handle about 120,000 hits/day on vBulletin with a 1 GB VPS, Apache, and PHP-FPM with room to spare (I could resize down to 512 MB…), which replaces a previous VPS with 4 GB, Apache, and modphp, which occasionally slammed itself into the turf…
@hoopycat:
Your KeepaliveTimeout should be in the single digits, perhaps 2 or 3 seconds instead of the extra-long default. That's the #1 eater of otherwise-idle connections.
And yes, if you ditch modphp and move to php-fpm, you can also ditch mpm-prefork and set the world on fire accordingly. I handle about 120,000 hits/day on vBulletin with a 1 GB VPS, Apache, and PHP-FPM with room to spare (I could resize down to 512 MB…), which replaces a previous VPS with 4 GB, Apache, and modphp, which occasionally slammed itself into the turf…
Thanks for the tips, decreasing the KeepAlive Timeout has helped a lot.
I was not able to switch to php-fpm as it turned out to be a complicated thing ( the site went down and I had to revert to an old backup! )
I'm interested to know about your Apache configurations, will it be possible to mention what other settings you have in there, the default file I have is way too long and I believe that's one of the issues. here is the whole file I have:
ServerRoot "/etc/apache2"
LockFile /var/lock/apache2/accept.lock
PidFile ${APACHE_PID_FILE}
Timeout 300
KeepAlive On
MaxKeepAliveRequests 100
KeepAliveTimeout 8
<ifmodule mpm_prefork_module="">StartServers 2
MinSpareServers 6
MaxSpareServers 12
MaxClients 48
MaxRequestsPerChild 6000</ifmodule>
<ifmodule mpm_worker_module="">StartServers 2
MinSpareThreads 25
MaxSpareThreads 75
ThreadLimit 64
ThreadsPerChild 25
MaxClients 150
MaxRequestsPerChild 0</ifmodule>
<ifmodule mpm_event_module="">StartServers 2
MaxClients 150
MinSpareThreads 25
MaxSpareThreads 75
ThreadLimit 64
ThreadsPerChild 25
MaxRequestsPerChild 0</ifmodule>
User ${APACHE_RUN_USER}
Group ${APACHE_RUN_GROUP}
AccessFileName .htaccess
<files ~="" "^\.ht"="">Order allow,deny
Deny from all
Satisfy all</files>
DefaultType text/plain
HostnameLookups Off
ErrorLog /var/log/apache2/error.log
LogLevel warn
Include /etc/apache2/mods-enabled/*.load
Include /etc/apache2/mods-enabled/*.conf
Include /etc/apache2/httpd.conf
Include /etc/apache2/ports.conf
LogFormat "%v:%p %h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" vhost_combined
LogFormat "%h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" combined
LogFormat "%h %l %u %t \"%r\" %>s %O" common
LogFormat "%{Referer}i -> %U" referer
LogFormat "%{User-agent}i" agent
Include /etc/apache2/conf.d/
Include /etc/apache2/sites-enabled/
Thanks
ServerRoot "/etc/apache2"
LockFile /var/lock/apache2/accept.lock
PidFile /var/run/apache2.pid
Timeout 300
KeepAlive On
MaxKeepAliveRequests 100
KeepAliveTimeout 5
<ifmodule mpm_worker_module="">StartServers 4
MaxClients 1024
MinSpareThreads 64
MaxSpareThreads 192
ThreadsPerChild 64
MaxRequestsPerChild 0</ifmodule>
User www-data
Group www-data
AccessFileName .htaccess
<files ~="" "^\.ht"="">Order allow,deny
Deny from all</files>
DefaultType text/plain
HostnameLookups Off
ErrorLog /var/log/apache2/error.log
LogLevel warn
Include /etc/apache2/mods-enabled/*.load
Include /etc/apache2/mods-enabled/*.conf
Include /etc/apache2/ports.conf
LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
LogFormat "%h %l %u %t \"%r\" %>s %b" common
LogFormat "%{Referer}i -> %U" referer
LogFormat "%{User-agent}i" agent
ServerRoot "/etc/apache2"
LockFile /var/lock/apache2/accept.lock
PidFile /var/run/apache2.pid
Timeout 300
KeepAlive On
MaxKeepAliveRequests 100
KeepAliveTimeout 5
<ifmodule mpm_worker_module="">StartServers 4
MaxClients 1024
MinSpareThreads 64
MaxSpareThreads 192
ThreadsPerChild 64
MaxRequestsPerChild 0</ifmodule>
User www-data
Group www-data
AccessFileName .htaccess
<files ~="" "^\.ht"="">Order allow,deny
Deny from all</files>
DefaultType text/plain
HostnameLookups Off
ErrorLog /var/log/apache2/error.log
LogLevel warn
Include /etc/apache2/mods-enabled/*.load
Include /etc/apache2/mods-enabled/*.conf
Include /etc/apache2/ports.conf
LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
LogFormat "%h %l %u %t \"%r\" %>s %b" common
LogFormat "%{Referer}i -> %U" referer
LogFormat "%{User-agent}i" agent
LogFormat "%{X-Real-IP}i %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" host=%{Host}i proxy=%{X-Urmom-Proxy}i time=%T pid=%P remotehost=%h remoteport=%{remote}p" proxied
CustomLog ${APACHE_LOG_DIR}/other_vhosts_access.log vhost_combined
ServerTokens Prod
ServerSignature On
TraceEnable On
<virtualhost *:80="">ServerName example.com
ServerAlias www.example.com dev.example.com
DocumentRoot /home/www/example.com/current/htdocs
RewriteEngine On
SetEnvIf ^X-Forwarded-Protocol$ "^ssl$" HTTPS=on
<ifmodule rpaf_module="">RPAFenable On
RPAFsethostname On
RPAFproxy_ips 192.0.2.1 192.0.2.2 127.0.0.1</ifmodule>
<directory home="" www="" example.com="" current="" htdocs="">Options FollowSymLinks
AllowOverride All
Order allow,deny
Allow from all</directory>
<directory>Options FollowSymLinks
AllowOverride None</directory>
<location server-status="">SetHandler server-status
Order Deny,Allow
Deny from all
Allow from 127.0.0.1</location>
<location example_fpm_status="">Order Deny,Allow
Deny from all
Allow from 127.0.0.1</location>
Alias /php5.fcgi /home/www/example.com/current/htdocs/../php5.fcgi
FastCGIExternalServer /home/www/example.com/current/htdocs/../php5.fcgi -flush -host 127.0.0.1:5301
AddType application/x-httpd-fastphp5 .php
Action application/x-httpd-fastphp5 /php5.fcgi
LogLevel info
ErrorLog /var/log/apache2/example-error.log
CustomLog /var/log/apache2/example-access.log proxied
RewriteEngine On
RewriteLog /var/log/apache2/example-rewrite.log
RewriteLogLevel 1</virtualhost>
Again, though, this assumes mpm-worker, which assumes that I am not using mod_php.
The only thing I would really add beyond what's been already mentioned is to trim down your list of loaded modules to just what you need. The more modules you have loaded, the more memory each child process uses. I trimmed the default Fedora-installed module list by about half (and could probably trim a few more if I bothered to dig a bit deeper into what's actually being used). If you're not doing server side includes, WebDAV, or other fancier things, there's no point having all that loaded into memory. It's more secure, too, since that's less potentially exploitable code running that an attacker might try to access.
Here's a few relevant bits from my config file since you asked for them:
Timeout 60
KeepAlive On
MaxKeepAliveRequests 200
KeepAliveTimeout 5
<ifmodule prefork.c="">StartServers 5
MinSpareServers 5
MaxSpareServers 20
ServerLimit 75
MaxClients 75
MaxRequestsPerChild 1000</ifmodule>
I also use moddeflate and modexpires to cut down heavily on unnecessary traffic. As for improving your MySQL overhead, a PHP opcode/variable cache will help immensely. (I personally use XCache
It seems like I have a problem with the wordpress plugins and theme.
I tried keeping prefork and using the same settings as mentioned by jtdarlington, the site become unstable and most of the times it doesn't get a response from the server, So i had to revert back to my original settings keeping my original settings:
Timeout 300
KeepAlive On
MaxKeepAliveRequests 200
KeepAliveTimeout 5
<ifmodule mpm_prefork_module="">StartServers 2
MinSpareServers 6
MaxSpareServers 12
MaxClients 48
MaxRequestsPerChild 6000</ifmodule>
I also tested Nginx with phpfpm and phpapc on a new linode 1GB, as per the following link:
Still no luck once I loaded my plugins and theme.
My challenge is still to find a more effective setup keeping the same website, I still need to try replacing prefork and mod_php with worker and fpm as hoopycat suggested, I'm trying to figure out how to do that.
I will post results here once I reach optimal settings here when done. Thanks for your time.
@isamj:
Thanks all.
It seems like I have a problem with the wordpress plugins and theme.
I tried keeping prefork and using the same settings as mentioned by jtdarlington, the site become unstable and most of the times it doesn't get a response from the server, So i had to revert back to my original settings keeping my original settings:
Timeout 300 KeepAlive On MaxKeepAliveRequests 200 KeepAliveTimeout 5 <ifmodule mpm_prefork_module="">StartServers 2 MinSpareServers 6 MaxSpareServers 12 MaxClients 48 MaxRequestsPerChild 6000</ifmodule>I also tested Nginx with phpfpm and phpapc on a new linode 1GB, as per the following link:
http://www.ewanleith.com/blog/900/10-mi … -15-server">http://www.ewanleith.com/blog/900/10-million-hits-a-day-with-wordpress-using-a-15-server Still no luck once I loaded my plugins and theme.
My challenge is still to find a more effective setup keeping the same website, I still need to try replacing prefork and mod_php with worker and fpm as hoopycat suggested, I'm trying to figure out how to do that.
I will post results here once I reach optimal settings here when done. Thanks for your time.
You say it's a forum theme, does that mean the site works fine with the default Wordpress theme? What do the logs say? Load/memory-usage? Maybe there's simply something wrong with the theme, rather than apache/PHP.
MaxKeepAliveRequests 100
KeepAliveTimeout 2
<ifmodule mpm_prefork_module="">StartServers 2
MinSpareServers 6
MaxSpareServers 8
MaxClients 48
MaxRequestsPerChild 500</ifmodule>
Then monitor you memory usage with top command, with "netstat -ln |grep 80" monitor your connection.
If your connection always great then 6, you can add the value of MaxSpareServers.
If never use swap, then you can add the value of MaxRequestsPerChild.