Apache的多根进程 [英] Multiple apache root processes
问题描述
今天我注意到，实现从我们的Web服务器请求时，事情相当缓慢。
我开始寻找到它，我已经找到了属于root的Apache进程的负载。
I noticed today that when making requests from our web server, things were rather slow. I started looking into it and I've found a load of root owned apache processes.
我不知道肯定这实际上是什么导致东西是缓慢的，但尽管如此，它看起来并不好。
I don't know for sure that this is actually what's causing things to be slow, but none the less, it doesn't look good.
问题是，我不知道该怎么在这里做什么？
我如何找出为什么有那么多根进程？
可能有的建议一组测试？我试过stracing他们几个，他们似乎在做什么，但strace的输出是超越我。
problem is, I don't know what to do from here? How do I find out why there are so many root processes? Could some recommend a set of tests? I've tried stracing a few of them, and they appear to be doing something, but the output of strace is beyond me.
root 30918 1.8 1.3 84284 52296 ? Ss 14:11 0:01 /usr/sbin/apache2 -k restart
root 30919 0.0 1.1 84420 45612 ? S 14:11 0:00 /usr/sbin/apache2 -k restart
root 30920 0.0 1.1 84420 45604 ? S 14:11 0:00 /usr/sbin/apache2 -k restart
root 30921 0.0 1.1 84420 45612 ? S 14:11 0:00 /usr/sbin/apache2 -k restart
root 30922 0.1 1.1 84420 45612 ? S 14:11 0:00 /usr/sbin/apache2 -k restart
root 30923 0.0 1.1 84420 45612 ? S 14:11 0:00 /usr/sbin/apache2 -k restart
www-data 30926 6.6 1.5 104964 61336 ? S 14:12 0:03 /usr/sbin/apache2 -k restart
root 30930 0.1 1.1 84420 45616 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
root 30933 0.0 1.1 84420 45616 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
root 30935 0.0 1.1 84420 45616 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
root 30936 0.0 1.1 84420 45616 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
root 30937 0.0 1.1 84420 45616 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
root 30938 0.0 1.1 84420 45616 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
root 30961 0.0 1.1 84420 45612 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
root 30989 0.0 1.1 84420 45612 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
root 30990 0.0 1.1 84420 45612 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
root 31011 0.1 1.1 84420 45612 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
root 31013 0.1 1.1 84420 45612 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
root 31014 0.0 1.1 84420 45612 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
www-data 31175 2.5 1.5 104168 60524 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
www-data 31189 2.3 1.4 102360 58920 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
www-data 31190 1.5 1.4 101904 58356 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
www-data 31191 0.3 1.1 84556 46760 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
www-data 31192 1.4 1.4 101916 58384 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
www-data 31193 1.5 1.4 101916 58376 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
root 31240 0.1 1.1 84420 45612 ? S 14:12 0:00 /usr/sbin/apache2 -k restart
这是从strace的输出从工艺中的一个的例子。
This is an example of the output from strace from one of the processes.
--- SIGCHLD (Child exited) @ 0 (0) ---
read(6, 0xff87f6ef, 1) = -1 EAGAIN (Resource temporarily unavailable)
getuid32() = 0
close(17) = 0
gettimeofday({1354109303, 670988}, NULL) = 0
semop(5668864, {{0, -1, SEM_UNDO}}, 1) = 0
accept(4, {sa_family=AF_INET, sin_port=htons(48107), sin_addr=inet_addr("192.168.16.12")}, [16]) = 17
fcntl64(17, F_GETFD) = 0
fcntl64(17, F_SETFD, FD_CLOEXEC) = 0
semop(5668864, {{0, 1, SEM_UNDO}}, 1) = 0
clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0xf74a2768) = 1949
waitpid(1949, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0) = 1949
--- SIGCHLD (Child exited) @ 0 (0) ---
read(6, 0xff87f6ef, 1) = -1 EAGAIN (Resource temporarily unavailable)
getuid32() = 0
close(17) = 0
gettimeofday({1354109305, 724358}, NULL) = 0
semop(5668864, {{0, -1, SEM_UNDO}}, 1) = 0
accept(4, {sa_family=AF_INET, sin_port=htons(48132), sin_addr=inet_addr("192.168.16.12")}, [16]) = 17
fcntl64(17, F_GETFD) = 0
fcntl64(17, F_SETFD, FD_CLOEXEC) = 0
semop(5668864, {{0, 1, SEM_UNDO}}, 1) = 0
clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0xf74a2768) = 1974
waitpid(1974, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0) = 1974
--- SIGCHLD (Child exited) @ 0 (0) ---
启用MODS-
我已经停用所有的模块除了像权威性，ENV，siteenv和别名必不可少的人并启动服务器。在这种情况下，我仍然得到6根Apache的进程并拥有Apache进程1 www数据。
I've disabled all of the modules in mods-enabled except for essential ones like auth, env, siteenv and alias and started the server. In this case I still get 6 root apache processes and 1 www-data owned apache process.
我确信所有的模块都up2date的。
I've made sure all the modules are up2date.
有没有明显的错误，在日志中。
There are no obvious errors in the logs.
配置如下;
ServerRoot "/etc/apache2"
LockFile /var/lock/apache2/accept.lock
PidFile ${APACHE_PID_FILE}
Timeout 300
KeepAlive On
MaxKeepAliveRequests 100
KeepAliveTimeout 15
<IfModule mpm_worker_module>
StartServers 2
MaxClients 150
MinSpareThreads 25
MaxSpareThreads 75
ThreadsPerChild 25
MaxRequestsPerChild 0
</IfModule>
User ${APACHE_RUN_USER}
Group ${APACHE_RUN_GROUP}
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/httpd.conf
Include /etc/apache2/ports.conf
LogFormat "%v:%p %h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" vhost_combined
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
CustomLog /var/log/apache2/other_vhosts_access.log vhost_combined
Include /etc/apache2/conf.d/
Include /etc/apache2/sites-enabled/
该模块编译如下：
编译模块：
core.c
mod_log_config.c
mod_logio.c
itk.c
http_core.c
mod_so.c
The compiled in modules are: Compiled in modules: core.c mod_log_config.c mod_logio.c itk.c http_core.c mod_so.c
所以我现在只运行mpm_worker配置。
So I'm only running the mpm_worker config now.
DEBUG UPDATER
When I restart apache, and ps, I get something like this;
root 26921 0.5 1.3 80008 52452 ? Ss 21:27 0:02 /usr/sbin/apache2 -k start
root 27114 0.0 1.1 80144 44804 ? S 21:34 0:00 /usr/sbin/apache2 -k start
root 27115 0.0 1.1 80144 44820 ? S 21:34 0:00 /usr/sbin/apache2 -k start
root 27116 0.0 1.1 80144 44804 ? S 21:34 0:00 /usr/sbin/apache2 -k start
root 27117 0.0 1.1 80144 44804 ? S 21:34 0:00 /usr/sbin/apache2 -k start
root 27119 0.0 1.1 80144 44804 ? S 21:34 0:00 /usr/sbin/apache2 -k start
如果我把LogLevel的调试和重新启动，然后我看到mod_proxy的这些消息
If I put LogLevel to debug and restart, then I see these messages from mod_proxy
[Thu Nov 29 21:34:01 2012] [info] Server built: Sep 9 2012 21:17:36
[Thu Nov 29 21:34:01 2012] [debug] itk.c(1100): AcceptMutex: sysvsem (default: sysvsem)
[Thu Nov 29 21:34:01 2012] [debug] proxy_util.c(1818): proxy: grabbed scoreboard slot 0 in child 27115 for worker proxy:reverse
[Thu Nov 29 21:34:01 2012] [debug] proxy_util.c(1818): proxy: grabbed scoreboard slot 0 in child 27114 for worker proxy:reverse
[Thu Nov 29 21:34:01 2012] [debug] proxy_util.c(1934): proxy: initialized single connection worker 0 in child 27115 for (*)
[Thu Nov 29 21:34:01 2012] [debug] proxy_util.c(1837): proxy: worker proxy:reverse already initialized
[Thu Nov 29 21:34:01 2012] [debug] proxy_util.c(1934): proxy: initialized single connection worker 0 in child 27114 for (*)
[Thu Nov 29 21:34:01 2012] [debug] proxy_util.c(1818): proxy: grabbed scoreboard slot 0 in child 27117 for worker proxy:reverse
[Thu Nov 29 21:34:01 2012] [debug] proxy_util.c(1837): proxy: worker proxy:reverse already initialized
[Thu Nov 29 21:34:01 2012] [debug] proxy_util.c(1934): proxy: initialized single connection worker 0 in child 27117 for (*)
[Thu Nov 29 21:34:01 2012] [debug] proxy_util.c(1818): proxy: grabbed scoreboard slot 0 in child 27119 for worker proxy:reverse
[Thu Nov 29 21:34:01 2012] [debug] proxy_util.c(1837): proxy: worker proxy:reverse already initialized
[Thu Nov 29 21:34:01 2012] [debug] proxy_util.c(1934): proxy: initialized single connection worker 0 in child 27119 for (*)
[Thu Nov 29 21:34:01 2012] [debug] proxy_util.c(1818): proxy: grabbed scoreboard slot 0 in child 27116 for worker proxy:reverse
[Thu Nov 29 21:34:01 2012] [debug] proxy_util.c(1837): proxy: worker proxy:reverse already initialized
[Thu Nov 29 21:34:01 2012] [debug] proxy_util.c(1934): proxy: initialized single connection worker 0 in child 27116 for (*)
[Thu Nov 29 21:36:20 2012] [notice] SIGHUP received. Attempting to restart
注意的PID匹配。不过，如果我禁用mod_proxy的，那么这些消息消失，但我仍然获得首发相同数量的根进程，所以我相信这是一种症状而不是原因。
Notice the pids match. However, if I disable mod_proxy, then these message disappear, but I still get the same number of root processes starting, so I believe this is a symptom not a cause.
推荐答案
这是Apache绝对正常的。每个进程一次处理一个请求。因此，如果只有一个进程（称为工人），那么这将是非常缓慢的，如果有大量的用户。
This is absolutely normal for Apache. Each process processes one request at a time. So if there was only one process (it is called worker) then it would be really slow if there are lots of users.
我看到的问题是，这些不应该是root拥有的进程。根据您的平台上它应该有它自己的用户。像Debian的用户是www数据。那么只有一个进程会通过根和剩下的就由该用户所拥有拥有。
The issue I see is that these should not be root owned processes. Depending on your platform it should have it's own user. Like in Debian user would be www-data. Then only one process would be owned by root and rest would be owned by that user.
然而速度是由几个因素来定义。
However speed is defined by several factors - hardware, web server, and web application.
请确保您的硬件上正在运行符合要求（足够的内存和CPU）
Make sure that hardware you are running on fits requirements (enough ram and CPU)
在较差的硬件功能，或者增加，如果它是超级好的情况下许多工人。
Lower number of workers in case of poor hardware capabilities or increase if it is super good.
确保Web应用程序（如果有一个，而且往往是PHP应用程序）不是性能的瓶颈。
Make sure that web application (if there's is one, and often it is php app) is not a bottleneck for performance.
PS：对不起格式不佳，clamsily从手机类型。
PS: sorry for poor formatting, typed clamsily from phone.
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