Caucho maker of Resin Server | Application Server (Java EE Certified) and Web Server

Resin Documentation

log

Resin can perform access logging, specify where JDK logging interface messages go, and redirect the stderr and stdout for your applications.

<log-handler>
Log format string

<log-handler>

child of <resin>,<server>,<host-default>,<host>,<web-app-default>,<web-app>

Configure a log handler for the JDK java.util.logging.* API. java.util.logging has two steps: configure a set of log handlers, and configure the levels for each logger. The <log-handler> creates a destination for logs, sets a minimum logging level for the handler, and attaches the handler to a logging name.

In addition to configuring custom handlers, <log-handler> has the most common configuration build-in: logging to a rotating file. Most of the configuration attributes are used for the rotating file and are shared with the other logging configuration.

<log-handler> Attributes
ATTRIBUTE	DESCRIPTION	DEFAULT
archive-format	the format for the archive filename when a rollover occurs, see Rollovers.	see below
class	configures a custom Handler class
format	An EL expression string to format the current output line.
formatter	Configures a custom java.util.logging.Formatter to format the output.
level	The log level for the handler. Typically, the handler's level will be finer than the logger's level	info
mbean-name	an mbean name.	no mbean name, no mbean registration
name	A hierarchical name, typically aligned with the Java packaging names. The handler will be registered with the Logger with the matching name.	match all names
path	Output path for the log messages, see "Log Paths"	required
path-format	Selects a format for generating path names. The syntax is the same as for archive-format	optional
timestamp	a timestamp format string to use at the beginning of each log line.	"[%Y/%m/%d %H:%M:%S.%s] "
rollover-count	maximum number of rollover files before the oldest ones get overwritten. See Rollovers.	none
rollover-cron	cron-style specification on rollover times.	none
rollover-period	how often to rollover the log. Specify in days (15D), weeks (2W), months (1M), or hours (1h). See Rollovers.	none
rollover-size	maximum size of the file before a rollover occurs, in bytes (50000), kb (128kb), or megabytes (10mb). See Rollovers.	1mb

<log-handler> schema

element log-handler {
  archive-format?
  & class?
  & filter?
  & format?
  & formatter?
  & level?
  & mbean-name?
  & name
  & path?
  & path-format?
  & rollover-count?
  & rollover-period?
  & rollover-size?
  & timestamp?
  & use-parent-handlers?
}

The following example is a standard log handler writing to a rollover file. Because the handler's level is "all", the <logger> configuration will set the actual logging level.

Example: logging to a rollover file

<web-app xmlns="http://caucho.com/ns/resin">

  <log-handler name="" level="all"
       timestamp="[%Y/%m/%d %H:%M:%S.%s] {%{thread}} "/>

  <logger name="com.caucho" level="info"/>

</web-app>

Log format string

The format for log tags is used to specify a format string for each log message. format recognizes EL-expressions. The EL variable log is a com.caucho.log.ELFormatter.ELFormatterLogRecord object.

log format string


<log name='' level='all' path='stderr:' timestamp="[%H:%M:%S.%s]"
     format=" ${log.level} ${log.loggerName} ${log.message}"/>

log EL variable 'log' is a LogRecord
ACCESSOR	VALUE
${log.level}	The level of the log record
${log.name}	The source loggers name
${log.shortName}	A shorter version of the source loggers name, "Foo" instead of "com.hogwarts.Foo"
${log.message}	The message, with no formatting or localization
${log.millis}	event time in milliseconds since 1970
${log.sourceClassName}	Get the name of the class that issued the logging request (may not be available at runtime)
${log.sourceMethodName}	Get the name of the method that issued the logging request (may not be available at runtime)
${log.threadID}	Get an int identifier of the thread where the logging request originated
${log.thrown}	Get any `java.lang.Throwable` associated with the logging request

You can also use the Environment EL variables in your format string:

log format string using an Environment EL variable.

<host ...>

  <web-app>
    <log name='' level='all' path='log/debug.log' timestamp="[%H:%M:%S.%s]"
         format=" [${app.contextPath}] ${log.message}"/>

    ...
  </web-app>

  ...

</host>

[14:55:10.189] [/foo] `null' returning JNDI java:
       model for EnvironmentClassLoader[web-app:http://localhost:8080/foo]
[14:55:10.189] [/foo] JNDI lookup `java:comp/env/caucho/auth'
       exception javax.naming.NameNotFoundException: java:comp/env/caucho/auth
[14:55:10.199] [/foo] Application[http://localhost:8080/foo] starting

The fmt.sprintf() function can space pad the values and make the results look a little nicer:

fmt.sprintf() in log format string

<log name='' level='all' path='stderr:' timestamp="[%H:%M:%S.%s]"
     format=" ${fmt.sprintf('%-7s %45s %s',log.level,log.loggerName,log.message)}"/>

[14:28:08.137] INFO com.caucho.vfs.QJniServerSocket Loaded Socket JNI library.
[14:28:08.137] INFO com.caucho.server.port.Port http listening to *:8080
[14:28:08.137] INFO com.caucho.server.resin.ServletServer ServletServer[] starting
[14:28:08.307] INFO com.caucho.server.port.Port hmux listening to localhost:6802
[14:28:08.437] INFO com.caucho.server.host.Host Host[] starting

fmt.sprintf() and fmt.timestamp() can be used to produce CSV files:

CSV log files

<log name='' level='all' path='log/debug.csv' timestamp=""
     format="${fmt.sprintf('%vs,%d,%d,%vs,%vs',fmt.timestamp('%Y-%m-%d %H:%M:%S.%s'), 
               log.threadID, log.level.intLevel(), log.loggerName, log.message)}"/>

"2003-11-17 14:46:14.529",10,800,"com.caucho.vfs.QJniServerSocket",
            "Loaded Socket JNI library."
"2003-11-17 14:46:14.549",10,800,"com.caucho.server.port.Port",
            "http listening to *:8080"
"2003-11-17 14:46:14.549",10,800,"com.caucho.server.resin.ServletServer",
            "ServletServer[] starting"
"2003-11-17 14:46:14.719",10,800,"com.caucho.server.port.Port",
            "hmux listening to localhost:6802"
"2003-11-17 14:46:14.850",10,800,"com.caucho.server.host.Host",
            "Host[] starting"
"2003-11-17 14:46:15.100",10,800,"com.caucho.server.webapp.Application",
            "Application[http://localhost:8080/freelistbm] starting"

Copyright © 1998-2015 Caucho Technology, Inc. All rights reserved. Resin ^® is a registered trademark. Quercus^tm, and Hessian^tm are trademarks of Caucho Technology.

Cloud-optimized Resin Server is a Java EE certified Java Application Server, and Web Server, and Distributed Cache Server (Memcached).
Leading companies worldwide with demand for reliability and high performance web applications including SalesForce.com, CNET, DZone and many more are powered by Resin.

home company docs
app server