To enable http level request/response logs in Application Server (AS), we can use the Access_Log_Valve which is provided in Tomcat 7. For more information, please go to http://tomcat.apache.org/tomcat-7.0-doc/config/valve.html#Access_Log_Valve.
To enable logging, you have to put the following XML element under /Server/Service/Engine/Host/ in {WSO2AS_HOME}/repository/conf/tomcat/catalina-server.xml and restart the AS server.
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The pattern parameter is used to specify which parts of the request/response needs to be logged. In the above sample, xxx stands for the header name we need to log. Here %{xxx}i stands for request headers and %{xxx}o stands for response headers.
Example 1: Logging request headers
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<Valve className="org.apache.catalina.valves.AccessLogValve"
directory="${carbon.home}/repository/logs"
prefix="localhost_access_log_test."
suffix=".log"
pattern="%{Content-Type}i %{Accept}i %{Accept-Encoding}i"
resolveHosts="false"/> |
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When we send the following http request:
GET http://<IP>:<PORT>/example/servlets/servlet/RequestInfoExample?abc=xyz
we can see the following log entry in the localhost_access_log_sample.{DATE}.log file.
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text/plain; charset=utf-8 */* gzip,deflate,sdch |
Example 2: Logging response headers
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<Valve className="org.apache.catalina.valves.AccessLogValve"
directory="${carbon.home}/repository/logs"
prefix="localhost_access_log_test."
suffix=".log"
pattern="%{Content-Type}o %{Content-Length}o %{Date}o %{Server}o"
resolveHosts="false"/> |
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text/html;charset=ISO-8859-1 662 Tue, 09 Jul 2013 11:21:50 GMT WSO2 Carbon |
Example 3: Logging other variable values
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<Valve className="org.apache.catalina.valves.AccessLogValve"
directory="${carbon.home}/repository/logs"
prefix="localhost_access_log_test."
suffix=".log"
pattern="%r %q %h"
resolveHosts="false"/> |
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“GET /example/servlets/servlet/RequestInfoExample?abc=xyz HTTP/1.1” ?abc=xyz 10.100.0.67 |
Example 4: Logging URL encoded parameters
You can not use the ‘Access Log Valve’ to log URL encoded parameters. But, you can use ‘Extended Access Log Valve’ for this. Here only 2 parts (className and pattern) are modified from the previous configuration.
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Now, when we send following POST request with URL encoded values param1=value1 and param2=value2,
POST http://<IP>:<PORT>/example/servlets/servlet/RequestInfoExample
The above configuration will log the following.
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