看来我们的apache httpd某处可能存在（不断增长的）内存问题。
快速图片：http://screencast.com/t/NGAzarD87O
请注意，它在原始（物理）服务器上运行了一段时间。现在在新VM（具有更多内存和CPU）上，它会运行但在mem / swap中慢慢消失，直到系统挂起。
如果我重新启动httpd，mem会跳回来（如果我们抓住它）。
httpd.x86_64 2.2.3-76.el5_9 installed
PHP 5.1.6 (cli) (built: Jun 22 2012 06:20:25)
MySQL Server version: 5.0.95
我不认为它可以是运行/ etc的任何脚本，因为它们在物理机器上运行了好几年。我们试图在新机器上匹配所有配置（http，php等），但无法弄清楚为什么httpd会不断增长。
$ ps -ylC httpd --sort:rss
S UID PID PPID C PRI NI RSS SZ WCHAN TTY TIME CMD
S 0 13814 1 0 78 0 29208 68382 - ? 00:00:00 httpd
S 48 20854 13814 0 76 0 34876 70930 semtim ? 00:00:00 httpd
S 48 20853 13814 0 75 0 36592 71387 semtim ? 00:00:00 httpd
S 48 13822 13814 0 75 0 36780 71430 semtim ? 00:00:00 httpd
S 48 20696 13814 0 75 0 37092 71520 semtim ? 00:00:00 httpd
S 48 13821 13814 0 75 0 37184 71529 semtim ? 00:00:01 httpd
S 48 13820 13814 0 75 0 37220 71527 - ? 00:00:01 httpd
S 48 13824 13814 0 75 0 37236 71513 semtim ? 00:00:01 httpd
S 48 13818 13814 0 75 0 37636 71547 semtim ? 00:00:01 httpd
S 48 13819 13814 0 75 0 37636 71617 semtim ? 00:00:01 httpd
S 48 13823 13814 0 75 0 37888 71689 semtim ? 00:00:01 httpd
S 48 13825 13814 0 75 0 37900 71676 semtim ? 00:00:01 httpd
更新：在写出这个问题时（可能是10-15分钟）我重申了上述内容，RSS全部都在~51072而不是上面的~37000
的运行 Private + Shared = RAM used Program
.... SNIPPED OUT ....
208.0 MiB + 25.5 MiB = 233.5 MiB httpd (12)
---------------------------------
477.1 MiB
PHP mem设置：
max_execution_time = 30
max_input_time = 60
memory_limit = 152M
模块：
$ apachectl -M
httpd: Could not reliably determine the server's fully qualified domain name, using 192.168.1.2 for ServerName
Loaded Modules:
core_module (static)
mpm_prefork_module (static)
http_module (static)
so_module (static)
auth_basic_module (shared)
auth_digest_module (shared)
authn_file_module (shared)
authn_alias_module (shared)
authn_anon_module (shared)
authn_dbm_module (shared)
authn_default_module (shared)
authz_host_module (shared)
authz_user_module (shared)
authz_owner_module (shared)
authz_groupfile_module (shared)
authz_dbm_module (shared)
authz_default_module (shared)
ldap_module (shared)
authnz_ldap_module (shared)
include_module (shared)
log_config_module (shared)
logio_module (shared)
env_module (shared)
ext_filter_module (shared)
mime_magic_module (shared)
expires_module (shared)
deflate_module (shared)
headers_module (shared)
usertrack_module (shared)
setenvif_module (shared)
mime_module (shared)
dav_module (shared)
status_module (shared)
autoindex_module (shared)
info_module (shared)
dav_fs_module (shared)
vhost_alias_module (shared)
negotiation_module (shared)
dir_module (shared)
actions_module (shared)
speling_module (shared)
userdir_module (shared)
alias_module (shared)
rewrite_module (shared)
proxy_module (shared)
proxy_balancer_module (shared)
proxy_ftp_module (shared)
proxy_http_module (shared)
proxy_connect_module (shared)
cache_module (shared)
suexec_module (shared)
disk_cache_module (shared)
file_cache_module (shared)
mem_cache_module (shared)
cgi_module (shared)
version_module (shared)
perl_module (shared)
php5_module (shared)
proxy_ajp_module (shared)
python_module (shared)
ssl_module (shared)
Syntax OK
httpd.conf设置：
IfModule prefork.c> ignore format on these tags
StartServers 8
MinSpareServers 5
MaxSpareServers 20
ServerLimit 256
MaxClients 256
MaxRequestsPerChild 4000
# worker MPM
StartServers 2
MaxClients 150
MinSpareThreads 25
MaxSpareThreads 75
ThreadsPerChild 25
MaxRequestsPerChild 0
使用https://code.google.com/p/check-httpd-limits/wiki/Documentation上的程序我已经获得：
Check Apache Httpd MPM Config Limits (Version 2.4)
by Jean-Sebastien Morisset - http://surniaulula.com/
Httpd Binary
- CONFIG : /etc/httpd/conf/httpd.conf
- EXE : /usr/sbin/httpd
- MPM : prefork
- ROOT : /etc/httpd
- VERSION : 2.2
Httpd Processes
- PID 10860 (httpd) : 106.93 MB / 3.95 MB shared
- PID 13814 (httpd) : 28.52 MB / 6.36 MB shared [excluded from averages]
- PID 13818 (httpd) : 180.28 MB / 4.29 MB shared
- PID 13819 (httpd) : 182.67 MB / 4.04 MB shared
- PID 13820 (httpd) : 182.45 MB / 4.08 MB shared
- PID 13821 (httpd) : 185.53 MB / 4.04 MB shared
- PID 13822 (httpd) : 176.12 MB / 4.36 MB shared
- PID 13823 (httpd) : 180.05 MB / 4.04 MB shared
- PID 13824 (httpd) : 182.21 MB / 4.05 MB shared
- PID 13825 (httpd) : 179.36 MB / 4.04 MB shared
- PID 20696 (httpd) : 180.10 MB / 4.04 MB shared
- PID 20853 (httpd) : 180.39 MB / 4.03 MB shared
- PID 20854 (httpd) : 180.79 MB / 4.04 MB shared
- PID 21003 (httpd) : 159.77 MB / 4.05 MB shared
- HttpdRealAvg : 166.09 MB [excludes shared]
- HttpdSharedAvg : 4.05 MB
- HttpdRealTot : 2225.76 MB [excludes shared]
- HttpdRunning : 14
Httpd Config
- StartServers : 8
- ServerLimit : 256
- MinSpareServers : 5
- MaxSpareServers : 20
- MaxRequestsPerChild : 4000
- MaxClients : 256
Server Memory
- Cached : 671.46 MB
- MemFree : 547.88 MB
- MemTotal : 3819.89 MB
- SwapFree : 5951.89 MB
- SwapTotal : 5951.99 MB
Calculations Summary
- OtherProcsMem : 370.74 MB (MemTotal - Cached - MemFree - HttpdRealTot - HttpdSharedAvg)
- FreeMemNoHttpd : 3449.15 MB (MemFree + Cached + HttpdRealTot + HttpdSharedAvg)
- MaxLimitHttpdMem : 42523.09 MB (HttpdRealAvg * MaxClients + HttpdSharedAvg)
- AllProcsTotalMem : 42893.83 MB (OtherProcsMem + MaxLimitHttpdMem)
Maximum Values for MemTotal (3819.89 MB)
StartServers 8 # (no change) Default is 5
ServerLimit 21 # (256 -> 21) MaxClients
MinSpareServers 5 # (no change) Default is 5
MaxSpareServers 20 # (no change) Default is 10
MaxRequestsPerChild 4000 # (no change) Default is 10000
MaxClients 21 # (256 -> 21) (MemFree + Cached + HttpdRealTot + HttpdSharedAvg) / HttpdRealAvg
Result
ERROR: AllProcsTotalMem (42893.83 MB) exceeds MemTotal (3819.89 MB) and free swap (5951.89 MB) by 33122.05 MB.
答案 0 :(得分：1)
Apache可能会占用太多内存。虽然没有通用的“答案”，但有一个故障排除列表：
答案 1 :(得分：1)
有时分配太多内存会产生内存问题。除非有特定的理由将152M分配给PHP，否则这很高。将其降至32M或64M。如果特定脚本需要更多，则仅为该脚本启用它。
接下来，检查您的数据库分配。当存在其他应该完成的项目时（例如查询调优），内存通常是人们分配以使某些内容运行得更快的第一件事。
基本上，过多的分配会为I / O创建信息备份。我知道，听起来倒退了。我有类似的问题，而且资源分配过多。将资源删除到默认值，看看这是否会改变内存使用情况。从那里调整以找到最佳设置。