tomcat access日志

每次看access log都会记不住pattern里的各个标识代表的什么意思，记录下，备忘！

tomcat的access log是由实现了org.apache.catalina.AccessLog接口的Valve完成的，（Valve是tomcat配置文件server.xml中的一个标签元素）

下面来简单介绍下tomcat的Access Log Valve

简介

标签属性

访问日志Valve支持一下属性配置

属性	原文描述	瞎比翻译
className	Java class name of the implementation to use. This MUST be set to org.apache.catalina.valves.AccessLogValve to use the default access log valve.	指定需要的
directory	Absolute or relative pathname of a directory in which log files created by this valve will be placed. If a relative path is specified, it is interpreted as relative to $CATALINA_BASE. If no directory attribute is specified, the default value is "logs" (relative to $CATALINA_BASE).	日志文件存放路径（ $CATALINA_BASE的相对路径）
prefix	The prefix added to the start of each log file's name. If not specified, the default value is "access_log.".	日志文件统一前缀
suffix	The suffix added to the end of each log file's name. If not specified, the default value is "" (a zero-length string), meaning that no suffix will be added.	日志文件统一后缀
fileDateFormat	Allows a customized timestamp in the access log file name. The file is rotated whenever the formatted timestamp changes. The default value is yyyy-MM-dd. If you wish to rotate every hour, then set this value to yyyy-MM-dd.HH. The date format will always be localized using the locale en_US.	日志文件名上的时间格式
rotatable	Flag to determine if log rotation should occur. If set to false, then this file is never rotated and fileDateFormat is ignored. Default value: true	是否分隔日志文件
renameOnRotate	By default for a rotatable log the active access log file name will contain the current timestamp in fileDateFormat. During rotation the file is closed and a new file with the next timestamp in the name is created and used. When setting renameOnRotate to true, the timestamp is no longer part of the active log file name. Only during rotation the file is closed and then renamed to include the timestamp. This is similar to the behavior of most log frameworks when doing time based rotation. Default value: false	当前写入的日志文件不带时间标识
pattern	A formatting layout identifying the various information fields from the request and response to be logged, or the word common or combined to select a standard format. See below for more information on configuring this attribute.
encoding	Character set used to write the log file. An empty string means to use the system default character set. Default value: use the system default character set.	编码
locale	The locale used to format timestamps in the access log lines. Any timestamps configured using an explicit SimpleDateFormat pattern (%{xxx}t) are formatted in this locale. By default the default locale of the Java process is used. Switching the locale after the AccessLogValve is initialized is not supported. Any timestamps using the common log format (CLF) are always formatted in the locale en_US.
requestAttributesEnabled	Set to true to check for the existence of request attributes (typically set by the RemoteIpValve and similar) that should be used to override the values returned by the request for remote address, remote host, server port and protocol. If the attributes are not set, or this attribute is set to false then the values from the request will be used. If not set, the default value of false will be used.
conditionIf	Turns on conditional logging. If set, requests will be logged only if ServletRequest.getAttribute() is not null. For example, if this value is set to important, then a particular request will only be logged if ServletRequest.getAttribute("important") != null. The use of Filters is an easy way to set/unset the attribute in the ServletRequest on many different requests.
conditionUnless	Turns on conditional logging. If set, requests will be logged only if ServletRequest.getAttribute() is null. For example, if this value is set to junk, then a particular request will only be logged if ServletRequest.getAttribute("junk") == null. The use of Filters is an easy way to set/unset the attribute in the ServletRequest on many different requests.
condition	The same as conditionUnless. This attribute is provided for backwards compatibility.
buffered	Flag to determine if logging will be buffered. If set to false, then access logging will be written after each request. Default value: true
resolveHosts	This attribute is no longer supported. Use the connector attribute enableLookups instead. If you have enableLookups on the connector set to true and want to ignore it, use %a instead of %h in the value of pattern.

pattern属性

当前请求的request和response中的属性输出

标签	原文解析	瞎比翻译
%a	Remote IP address	远程ip地址
%A	Local IP address	本地ip地址
%b	Bytes sent, excluding HTTP headers, or '-' if zero	不包含http头部的发送字节数
%B	Bytes sent, excluding HTTP headers	包含http头部的发送字节数
%h	Remote host name (or IP address if enableLookups for the connector is false)	远程主机名（如果标签enableLookups=false，就是ip地址了）
%H	Request protocol	使用的协议
%l	Remote logical username from identd (always returns '-')	总是返回‘-’，有毛用啊
%m	Request method (GET, POST, etc.)	请求方法
%p	Local port on which this request was received. See also %{xxx}p below.	接受这次请求的本地端口号
%q	Query string (prepended with a '?' if it exists)	url后面的查询字符串
%r	First line of the request (method and request URI)	http请求的第一行？
%s	HTTP status code of the response	http响应的状态码
%S	User session ID	会话id
%t	Date and time, in Common Log Format	请求访问时间
%u	Remote user that was authenticated (if any), else '-'	？
%U	Requested URL path	请求的路径
%v	Local server name	本地服务名
%D	Time taken to process the request, in millis	毫秒单位的请求耗时
%T	Time taken to process the request, in seconds	秒单位的请求耗时
%F	Time taken to commit the response, in millis	毫秒单位的提交响应结果的耗时
%I	Current request thread name (can compare later with stacktraces)	当前请求的线程名称

请求头部、响应头部、cookies、session及特殊时间戳的信息输出

标识	原文解析	瞎比翻译
%{xxx}i	write value of incoming header with name xxx	请求头部属性
%{xxx}o	write value of outgoing header with name xxx	响应头部属性
%{xxx}c	write value of cookie with name xxx	cookie信息
%{xxx}r	write value of ServletRequest attribute with name xxx	request？和上面的一样功能？
%{xxx}s	write value of HttpSession attribute with name xxx	会话信息
%{xxx}p	write local (server) port (xxx==local) or remote (client) port (xxx=remote)	端口
%{xxx}t	write timestamp at the end of the request formatted using the enhanced SimpleDateFormat pattern xxx	时间戳

参考

http://tomcat.apache.org/tomcat-7.0-doc/config/valve.html