Logging

Access logging

Main article: access-log

An access log receives output describing each request received by the server. It is commonly used in conjunction with analysis tools to determine statistics and patterns of use for a website.

Examples

<access-log path="logs/access.log"
            format='%h %l %u %t "%r" %s %b "%{Referer}i" "%{User-Agent}i"'
            rollover-period="1W"/>

stdout-log and stderr-log

Main article: stdout-log

Main article: stderr-log

The stdout-log and stderr-log directives capture and redirect the output of System.out and System.err.

Examples

resin.conf configuration to capture System.out and System.err output to log files.

<resin xmlns="http://caucho.com/ns/resin"
       xmlns:resin="http://caucho.com/ns/resin/core">

  <stdout-log path='/var/log/foo/stdout.log'
              rollover-period='1W'/>
  <stderr-log path='/var/log/foo/stderr.log'
              rollover-period='1W'/>
 
  ...

log

Main article: log

Java programs (including Resin) can use the logging facilities included in the JDK. Log messages have a name and and a level.

Logging can be used to enable Resin logging names and to enable application specific logging that utilizes the JDK logging facilities.

Examples

resin.conf configuration to capture finer logging and display it on the console, useful during development:

<resin xmlns="http://caucho.com/ns/resin"
       xmlns:resin="http://caucho.com/ns/resin/core">
  ...
  <log name="" level="finer" path="stdout:"/>
  ...
</resin>

resin.conf configuration to capture finer request and response related logging from Resin, and all logging from the com.hogwarts application under development:

<resin xmlns="http://caucho.com/ns/resin"
       xmlns:resin="http://caucho.com/ns/resin/core">
 
  <log path='stdout:' timestamp='[%H:%M:%S.%s] '>
    <logger name="com.caucho.server.port.TcpConnection" level="fine"/>
    <logger name="com.caucho.server.http.HttpRequest" level="fine"/>
    <logger name="com.caucho.server.connection.AbstractHttpResponse" level="fine"/>
 
    <logger name="com.hogwarts" level="all"/>
  </log>
 
  ...
  
</resin>

Archiving

All log directives support archiving, when the log reaches a certain size or age a rollover occurs and the existing log is saved away while a new log is started.

path-format and archive-format are two mutually exclusive methods for archiving logs. Rollover determines the frequency at which the archive files are created.

path-format

path-format specifies the name of a file. The name contains date format escape sequences that are replaced with the current date and time. When the rollover occurs, a new file is started with the appropriate date and time. Thus path-format results in archive files that are named with the date and time of the first entry in the log.

...
<host id="www.foo.com">
   <access-log path-format="/var/www/log/%Y/%m/%d.access.log"
               rollover-period="1D"/>
   ... 
</host>
...

archive-format and path

Log messages are written to the file specified by path. When a rollover occurs the contents of the file are copied to the archive-path. The archive-path contains date format escape sequences that are replaced with the current date and time. Thus archive-format results in log files that are named with the date and time of the last entry in the log.

archive-format can use a *.gz or *.zip extension to indicate that the archived log should be compressed.

<access-log path="log/access.log"
            archive-path="/var/www/log/access.log.%Y%m%d.gz"
            rollover-period="1D"/>

Rollover

The fequency of the rollover is is specified with rollover-period or rollover-size.

rollover-period is a time based specification of a period in days (15D), weeks (2W), months (1M), or hours (1h). When the specified time period has elapsed the rollover occurs.

rollover-size is a size based specification of a size in bytes (50000), kb (128kb), or megabytes (10mb). When the log reaches the specified size the rollover occurs.

Disabling rollover

To completely disable rollovers, set the rollover-size to such a high number that it will never occur:

 <stdout-log path="log/stdout.log" rollover-size="1024mb"/>