Comparison of working models in httpd

Advantages and disadvantages of prefork, worker, and event in httpd working mode:

Http service requires a connection between the client and the server. httpd has three working modes: prefork worker event

Advantage: stable services when resources are sufficient

Worker: this is to improve the previous Working Model and let a process multiple responses.

Event: This model allows a process to generate multiple threads, so that each thread can process client requests, and each thread can process multiple threads.

Run the httpd-l command to view the currently loaded MPM module.

[Root @ s ~] # Httpd-l

Compiled in modules:

Core. c

Prefork. c

Http_core.c

Mod_so.c

Differences between http 2.2 and 2.4

Httpd2.2 you can modify the configuration file to change the modules used by the current server.

Http2.4: static module dynamic module

If MPM is compiled into a static module, you must modify the MPM by re-Compiling and installing httpd.

[Root @ s yum. repos. d] # ps uax | grep httpd

Root 2918 0.0 0.3 119088 1616 pts/2 S + vi httpd

Root 2997 0.0 0.5 183720 2720? Ss/usr/sbin/httpd

Root 3001 0.0 0.1 103252 824 pts/1 S + grep httpd

Remove comments from the/etc/sysconfig/httpd line.

HTTPD =/usr/sbin/httpd. worker

[Root @ s yum. repos. d] # ps aux | grep http

Root 2918 0.0 0.3 119088 1616 pts/2 S + vi httpd

Root 3029 0.0 0.8 186560 4164? Ss/usr/sbin/httpd. worker

Apache 3034 0.0 0.6 596356 3340? Sl/usr/sbin/httpd. worker

Apache 3035 0.1 0.6 596356 3336? Sl/usr/sbin/httpd. worker

Apache 3036 0.1 0.6 596356 3340? Sl/usr/sbin/httpd. worker

Root 3150 0.0 0.1 103252 828 pts/1 S + grep http

<IfModule prefork. c> If the prefork. c Module exists, the parameter defined in the label is valid.

StartServers 8: Number of worker processes enabled by default, excluding the master Process

MinSpareServers 5: Minimum number of idle Processes;

MaxSpareServers 20 Max number of idle processes;

ServerLimit 256 maximum number of active processes;

MaxClients 256 maximum number of concurrent requests, maximum number of requests processed by a process

MaxRequestsPerChild 4000 maximum number of requests that each sub-process can provide during its lifecycle

</IfModule>

<IfModule worker. c>

The number of sub-processes started when the StartServers 4 service is enabled;

MaxClients 300 maximum number of concurrent requests;

MinSpareThreads 25 min Number of Idle threads;

MaxSpareThreads 75 max Number of idle processes;

ThreadsPerChild 25: The number of threads in each sub-process;

MaxRequestsPerChild 0: Maximum number of requests that each sub-process can provide during the lifecycle. 0 indicates that the number of requests is not limited.

</IfModule>

Event parameter in httpd 2.4

<IfModule mpm_event_module>

Default StartServices process count

MinSpareThreads minimum number of idle Processes

MaxSpareThreads maximum number of idle Processes

ThreadsPerChild: the number of threads that each sub-process can generate.

MaxReqestWorkers maximum number of threads

The maximum number of connections of MaxConnectionPerchild sub-processes. When the set value is reached, APACHE ends the current sub-process.

Conclusion: parameters must be set for security and efficiency, and can be tested on your own to achieve satisfactory configuration.

CentOS 6.5 compile and install httpd-2.4.7