APC 和子 pid XXXXX 退出信号 Segmentation fault

Question

首先，我在服务器上安装了 xCache，我在很多服务器上都安装了 xCache，但是在几天后，除了在 apache 错误日志中出现此错误的空白页面之外，您什么也没有：

 child pid XXXXX exit signal Segmentation fault

据我所知，这意味着某种内存损坏。

所以我从 php.ini 中删除了 xCache 并安装了 APC。但现在情况更糟。一小时或更短/更多后服务器变得无响应。我可以在我网站的服务器状态中清楚地看到 W 模式下有很多连接。而且他们没有任何共同点。其中一些来自 Joomla（第一页），一些来自 vBulletin（论坛），一些来自其他自定义代码。如果我让它更长时间，我将在 Apache 错误日志中出现此错误：

 Server reached MaxClients setting, consider raising the MaxClients setting

Apache 处于 mod_php 和 mod_ruid2 模式。

这是挂起时服务器状态的结果：

Server uptime: 52 minutes 57 seconds
Total accesses: 31025 - Total Traffic: 279.0 MB
CPU Usage: u418.14 s64.28 cu0 cs0 - 15.2% CPU load
9.77 requests/sec - 89.9 kB/second - 9.2 kB/request
398 requests currently being processed, 27 idle workers

WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WWWWWWWWWWWWWWWWWWWWWWWWW.......................................
WW___WW_WW_W_WWW__WWWW_W_.......................................
_W___W___WW_W_W_W_W______.......................................

这是 xCache 的错误日志（很多这些行）：

[Thu Mar 28 09:50:38 2013] [notice] child pid 1607 exit signal Aborted (6)
httpd: /usr/src/xcache-2.0.0/utils.c:589: xc_sandbox_error_cb: Assertion `sandbox != ((void *)0)' failed.
[Thu Mar 28 09:51:57 2013] [notice] child pid 1643 exit signal Aborted (6)
httpd: /usr/src/xcache-2.0.0/utils.c:589: xc_sandbox_error_cb: Assertion `sandbox != ((void *)0)' failed.
[Thu Mar 28 09:52:32 2013] [notice] child pid 1724 exit signal Aborted (6)
httpd: /usr/src/xcache-2.0.0/utils.c:589: xc_sandbox_error_cb: Assertion `sandbox != ((void *)0)' failed.
[Thu Mar 28 09:55:21 2013] [notice] child pid 1672 exit signal Aborted (6)
httpd: /usr/src/xcache-2.0.0/utils.c:589: xc_sandbox_error_cb: Assertion `sandbox != ((void *)0)' failed.
[Thu Mar 28 09:55:56 2013] [notice] child pid 1471 exit signal Aborted (6)
httpd: /usr/src/xcache-2.0.0/utils.c:589: xc_sandbox_error_cb: Assertion `sandbox != ((void *)0)' failed.
[Thu Mar 28 09:56:49 2013] [notice] child pid 1753 exit signal Aborted (6)
[Thu Mar 28 09:58:29 2013] [notice] child pid 1810 exit signal Segmentation fault (11)
[Thu Mar 28 09:58:29 2013] [notice] child pid 1877 exit signal Segmentation fault (11)
httpd: /usr/src/xcache-2.0.0/utils.c:589: xc_sandbox_error_cb: Assertion `sandbox != ((void *)0)' failed.
[Thu Mar 28 10:01:34 2013] [notice] child pid 1844 exit signal Segmentation fault (11)
[Thu Mar 28 10:01:34 2013] [notice] child pid 1913 exit signal Aborted (6)
[Thu Mar 28 10:01:34 2013] [notice] child pid 1941 exit signal Segmentation fault (11)
[Thu Mar 28 10:01:36 2013] [notice] child pid 2007 exit signal Segmentation fault (11)
[Thu Mar 28 10:01:37 2013] [notice] child pid 2035 exit signal Segmentation fault (11)
[Thu Mar 28 10:01:37 2013] [notice] child pid 2036 exit signal Segmentation fault (11)

达到最大客户端之前 APC 的错误日志（从一次重启到另一次重启）：

[Thu Mar 28 19:17:10 2013] [notice] Apache/2.2.24 (Unix) mod_ssl/2.2.24 OpenSSL/1.0.0-fips DAV/2 PHP/5.2.17 configured -- resuming normal operations
[Thu Mar 28 19:21:40 2013] [notice] child pid 1356 exit signal Segmentation fault (11)
[Thu Mar 28 19:22:41 2013] [notice] child pid 1520 exit signal Segmentation fault (11)
[Thu Mar 28 19:22:42 2013] [notice] child pid 1330 exit signal Segmentation fault (11)
[Thu Mar 28 19:22:42 2013] [notice] child pid 1518 exit signal Segmentation fault (11)
[Thu Mar 28 19:22:46 2013] [notice] child pid 1967 exit signal Segmentation fault (11)
[Thu Mar 28 19:22:46 2013] [notice] child pid 1968 exit signal Segmentation fault (11)
[Thu Mar 28 19:22:49 2013] [notice] child pid 1939 exit signal Segmentation fault (11)
[Thu Mar 28 19:22:50 2013] [notice] child pid 2034 exit signal Segmentation fault (11)
[Thu Mar 28 19:22:51 2013] [notice] child pid 2062 exit signal Segmentation fault (11)
[Thu Mar 28 19:22:57 2013] [notice] child pid 2091 exit signal Segmentation fault (11)
[Thu Mar 28 19:22:58 2013] [notice] child pid 2090 exit signal Segmentation fault (11)
[Thu Mar 28 19:25:34 2013] [notice] caught SIGTERM, shutting down
[Thu Mar 28 19:25:37 2013] [notice] SSL FIPS mode disabled
[Thu Mar 28 19:25:37 2013] [warn] RSA server certificate CommonName (CN) `localhost' does NOT match server name!?
[Thu Mar 28 19:25:37 2013] [warn] Init: Name-based SSL virtual hosts only work for clients with TLS server name indication support (RFC 4366)
[Thu Mar 28 19:25:37 2013] [notice] suEXEC mechanism enabled (wrapper: /usr/sbin/suexec)
[Thu Mar 28 19:25:38 2013] [notice] SSL FIPS mode disabled
[Thu Mar 28 19:25:38 2013] [warn] RSA server certificate CommonName (CN) `localhost' does NOT match server name!?
[Thu Mar 28 19:25:38 2013] [warn] Init: Name-based SSL virtual hosts only work for clients with TLS server name indication support (RFC 4366)
[Thu Mar 28 19:25:38 2013] [notice] Apache/2.2.24 (Unix) mod_ssl/2.2.24 OpenSSL/1.0.0-fips DAV/2 PHP/5.2.17 configured -- resuming normal operations

来自 PHP 信息的一点点：

System  Linux xxx.xxxxx.com 2.6.32-358.0.1.el6.x86_64 #1 SMP Wed Feb 27 06:06:45 UTC 2013 x86_64
Build Date  Mar 17 2013 12:55:14
Configure Command   './configure' '--with-apxs2' '--with-curl=/usr/local/lib' '--with-gd' '--with-ttf' '--with-gettext' '--with-jpeg-dir=/usr/local/lib' '--with-freetype-dir=/usr/local/lib' '--with-kerberos' '--with-openssl' '--with-mcrypt' '--with-mhash' '--with-mysql=/usr' '--with-mysqli=/usr/bin/mysql_config' '--with-pdo-mysql=/usr' '--with-pcre-regex=/usr/local' '--with-pear' '--with-png-dir=/usr/local/lib' '--with-xsl' '--with-zlib' '--with-zlib-dir=/usr/local/lib' '--with-iconv=/usr/local' '--enable-bcmath' '--enable-calendar' '--enable-exif' '--enable-ftp' '--enable-gd-native-ttf' '--enable-magic-quotes' '--enable-safe-mode' '--enable-soap' '--enable-sockets' '--enable-mbstring' '--enable-zip' '--enable-wddx'
Server API  Apache 2.0 Handler
Virtual Directory Support   enabled
Configuration File (php.ini) Path   /usr/local/lib
Loaded Configuration File   /usr/local/lib/php.ini
Scan this dir for additional .ini files     (none)
additional .ini files parsed    (none)
PHP API     20041225
PHP Extension   20060613
Zend Extension  220060519
Debug Build     no
Thread Safety   enabled
Zend Memory Manager     enabled
IPv6 Support    enabled
Registered PHP Streams  https, ftps, compress.zlib, php, file, data, http, ftp, zip
Registered Stream Socket Transports     tcp, udp, unix, udg, ssl, sslv3, sslv2, tls
Registered Stream Filters   zlib.*, convert.iconv.*, string.rot13, string.toupper, string.tolower, string.strip_tags, convert.*, consumed 

APC 设置：

enabled
Version     3.1.13
APC Debugging   Disabled
MMAP Support    Enabled
MMAP File Mask  no value
Locking type    pthread read/write Locks
Serialization Support   php
Revision    $Revision: 327136 $
Build Date  Mar 28 2013 12:40:18

php -v:

PHP 5.2.17 (cli) (built: Mar 17 2013 12:55:24) 
Copyright (c) 1997-2010 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2010 Zend Technologies

httpd -V:

Server version: Apache/2.2.24 (Unix)
Server built:   Mar 10 2013 09:18:00
Server's Module Magic Number: 20051115:31
Server loaded:  APR 1.4.6, APR-Util 1.4.1
Compiled using: APR 1.4.6, APR-Util 1.4.1
Architecture:   64-bit
Server MPM:     Worker
  threaded:     yes (fixed thread count)
    forked:     yes (variable process count)
Server compiled with....
 -D APACHE_MPM_DIR="server/mpm/worker"
 -D APR_HAS_SENDFILE
 -D APR_HAS_MMAP
 -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
 -D APR_USE_SYSVSEM_SERIALIZE
 -D APR_USE_PTHREAD_SERIALIZE
 -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
 -D APR_HAS_OTHER_CHILD
 -D AP_HAVE_RELIABLE_PIPED_LOGS
 -D DYNAMIC_MODULE_LIMIT=128
 -D HTTPD_ROOT="/etc/httpd"
 -D SUEXEC_BIN="/usr/sbin/suexec"
 -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
 -D DEFAULT_ERRORLOG="logs/error_log"
 -D AP_TYPES_CONFIG_FILE="conf/mime.types"
 -D SERVER_CONFIG_FILE="conf/httpd.conf"

任何的想法？！我会奖励50 :)

Answer 1

从您的服务器状态页面的外观来看，您正在尝试将 PHP 作为 mod_php 与线程化的 Apache MPM 一起运行。许多 PHP 扩展，可能包括 APC 和 Xcache，都不是线程安全的。因此，它们会在负载下频繁崩溃。

您需要将 Apache 切换到 prefork MPM，或者将 PHP 作为 CGI 或 FastCGI 运行。