修改Apache的超时设置，解决长连接请求超时问题

某日，组内后台开发找到我，问我们的WEB服务器超时设置是多少。他反馈的问题是，有一个VLAN切换任务cgi接口经常返回504网关超时错误，要我分析解决下。

我问了一下，得知这个请求遇到网络设备对象较多的时候，需要小半个小时才能完成，也就是要用到长连接才行。

老规矩，从开发那拿到接口地址，得到接入层服务器IP，是一台Haproxy代理，看了一下Haproxy的超时设置：

# 设置成功连接到一台服务器的最长等待时间，默认单位是毫秒，新版本的haproxy使用timeout connect替代，该参数向后兼容 contimeout 3600 # 设置连接客户端发送数据时的成功连接最长等待时间，默认单位是毫秒，新版本haproxy使用timeout client替代。该参数向后兼容 clitimeout 3600 # 设置服务器端回应客户度数据发送的最长等待时间，默认单位是毫秒，新版本haproxy使用timeout server替代。该参数向后兼容 srvtimeout 3600

各种1小时超时，所以排除Haproxy的影响，继续往下看。

Haproxy 代理的是2台Apache，也就是部署了cgi接口的服务器。第一时间查看了 httpd.conf 和 httpd-vhost.conf 中的配置，居然没找到超时设置。

于是，搜索了下相关教程，发现原来藏在了 httpd-default.conf 当中：

# # This configuration file reflects default settings for Apache HTTP Server. # # You may change these, but chances are that you may not need to. # # # Timeout: The number of seconds before receives and sends time out. # Timeout 300 # # KeepAlive: Whether or not to allow persistent connections (more than # one request per connection). Set to “Off” to deactivate. # KeepAlive On # # MaxKeepAliveRequests: The maximum number of requests to allow # during a persistent connection. Set to 0 to allow an unlimited amount. # We recommend you leave this number high, for maximum performance. # MaxKeepAliveRequests 100 # # KeepAliveTimeout: Number of seconds to wAIt for the next request from the # same client on the same connection. # KeepAliveTimeout 5 # # UseCanonicalName: Determines how Apache constructs self-referencing # URLs and the SERVER_NAME and SERVER_PORT variables. # When set “Off”, Apache will use the Hostname and Port supplied # by the client. When set “On”, Apache will use the value of the # ServerName directive. # UseCanonicalName Off # # AccessFileName: The name of the file to look for in each directory # for additional configuration directives. See also the AllowOverride # directive. # AccessFileName .htaccess # # ServerTokens # This directive configures what you return as the Server HTTP response # Header. The default is Full which sends information about the OS-Type # and compiled in modules. # Set to one of: Full | OS | Minor | Minimal | Major | Prod # where Full conveys the most information, and Prod the least. # ServerTokens Full # # Optionally add a line containing the server version and virtual host # name to server-generated pages (internal error documents, FTP directory # listings, mod_status and mod_info output etc., but not CGI generated # documents or custom error documents). # Set to “EMail” to also include a mailto: link to the ServerAdmin. # Set to one of: On | Off | EMail # ServerSignature On # # HostnameLookups: Log the names of clients or just their IP addresses # e.g., www.apache.org (on) or 204.62.129.132 (off). # The default is off because itd be overall better for the net if people # had to knowingly turn this feature on, since enabling it means that # each client request will result in AT LEAST one lookup request to the # nameserver. # HostnameLookups Off

看了下，这些是Apache的默认配置，Apache也没有include到httpd.conf当中。因此，编辑 httpd.conf，找到如下参数：

#Include conf/extra/httpd-default.conf

去掉注释，保存文件。然后再编辑 /usr/local/apache2/conf/extra/httpd-default.conf 文件，将Timeout的值修改为符合生产环境要求的1800秒，最后执行Apache平滑重启命令即可：

/usr/local/apache2/bin/apachectl -k graceful 或者 /usr/local/apache2/bin/httpd -k graceful

Ps：我之前一直以为只有Nginx有一个平滑reload命令，后面才知道Apache、Haproxy都支持平滑重启名称，这个非常棒！

重载之后，就不会出现504网关超时设置了。