HTTP Access Logging

HTTP access logs help you monitor your application's usage with information such as the persons who access it, how many hits it received, what the errors are, etc. This information is useful for troubleshooting errors. WSO2 Identity Server can enable access logs for the HTTP servlet transport. This servlet transport works on 9443/9763 ports, and it recieves admin/operation requests. Therefore, access logs for the servlet transport is useful for analysing operational/admin-level access details.

Configuring access logs for the HTTP servlet transport

In the Identity Server 5.9.0 only the access log pattern is configurable.

  1. Open the <IS_HOME>/repository/conf/deployment.toml file.

  2. Add the following configuration.

    pattern = "%h %l %u %t %r %s %b %{Referer}i %{User-Agent}i %T"

    The attributes that are used by default are explained below. See the descriptions of the Tomcat-supported Access Log Valve attributes.

    directory The path to the directory that will store the access log file. By default, this is location is set to ${carbon.home}/repository/logs in all WSO2 products.
    prefix The prefix added to the log file's name.
    suffix The suffix added to the log file's name. By default, this is .log for all WSO2 products.

    The attribute defines the format for the log pattern, which consists of the information fields from the requests and responses that should be logged. The pattern format is created using the following attributes:

    • A standard value to represent a particular string. For example, "%h" represents the remote host name in the request. See the list of string replacement values supported by the Tomcat valve .

    • %{xxx}i is used to represent the header in the incoming request (xxx=header value).
    • %{xxx}o is used to represents the header in the outgoing request (xxx=header value).

    While you can use the above attributes to define a custom pattern, the standard patterns shown below can be used.

  3. Restart the server. According to the configurations, a log file named http_access.{DATE}.log is created by default inside the <IS_HOME>/repository/logs directory. The log is rotated on a daily basis.

Customizing access logs by pattern

Given below are a few sample configurations for customizing the pattern attribute:

Example 1: Logging request headers

The configuration is as follows:

pattern = "%{Content-Type}i %{Accept}i %{Accept-Encoding}i"

This sample configuration logs the Content-type, Accept and Accept-encoding headers of every request coming to the server. For example, in the following example, we use the RequestInfoExample to send the HTTP request:

GET http://<IP>:<PORT>/example/servlets/servlet/RequestInfoExample?abc=xyz

The following log entry is recorded in the http_access.{DATE}.log file.

text/plain; charset=utf-8        */*        gzip,deflate,sdch

Example 2: Logging response headers

The configuration is as follows:

pattern = "%{Content-Type}o %{Content-Length}o %{Date}o %{Server}o"

The a bove configuration sample logs the Content-type , Content-Length, Date, and Server headers of every response coming from the server as follows:

text/html;charset=ISO-8859-1       662       Tue, 09 Jul 2013 11:21:50 GMT        WSO2 Carbon

Example 3: Logging other variable values

The configuration is as follows:

pattern = "%r %q %h"

The above sample configuration logs the first line of the request (method and request URI), query string (prepended with a '?' if it exists), and a remote hostname (or IP) of every request coming to the server as follows:

“GET http://<IP>:<PORT>//example/servlets/servlet/RequestInfoExample?abc=xyz HTTP/1.1”      ?abc=xyz

Example 4: Logging URL encoded parameters

You cannot use the AccessLogValve to log URL encoded parameters. However, you can use the ExtendedAccessLogValve attribute for this purpose. In this example only two values (namely, className, and pattern ) are modified from the previous configuration. Hence this will be added as a new valve.

The configuration is as follows:

className = "org.apache.catalina.valves.ExtendedAccessLogValve"
pattern="x-P(param1) x-P(param2)"

Send the POST request together with the URL encoded values such as param1 = value1 and param2 = value2 as follows:

POST http://<IP>:<PORT>/example/servlets/servlet/RequestInfoExample

The above sample configuration logs the following:

'value1'     'value2'