com.smartgwt.client.docs

Interface ServerLogging

public interface ServerLogging

Server logging

Default logging

Smart GWT's server-side classes have extensive built-in diagnostics which are output via the Apache Log4j library (see below for other alternatives).

At startup, Smart GWT will automatically load the file log4j.isc.config.xml from the classpath and use it to configure Log4j. log4j.isc.config.xml is in Log4j's standard XML configuration format, and sets default log threshold levels for various subsystems to produce output that is generally appropriate for both development and production systems. Various Smart GWT documentation may encourage you to enable certain diagnostic logs using this file when troubleshooting specific problems.

There's a iscLog4jConfiguration JVM argument, which if explicitly set will be used instead of the default log4j.isc.config.xml configuration file. It should point to an alternative configuration file using the same Log4j's standard XML configuration format:

  -DiscLog4jConfiguration=log4j.custom.config.xml
  

Note if the iscLog4jConfiguration is present, but the configuration file could not be loaded, Smartclient will fallback to default log4j.isc.config.xml configuration.

Server Logs tab (Smart GWT Developer Console)

The Server Logs tab of the Smart GWT Developer Console provides the ability to view the most recent 500 log entries, and change log threshold levels dynamically at runtime.

Redirecting logging to other frameworks

Smart GWT server logging can alternatively use the Simple Logging Facade for Java (slf4j), which allows logs to be sent to a variety of different logging frameworks that support slf4j.

To send all logging to slf4j, the iscUseSlf4j VM argument must be set to true on the command line, like this:

  -DiscUseSlf4j=true
  

If slf4j is used and the underlying log system is still Log4j, Smart GWT will still configure Log4j using log4j.isc.config.xml as describe above unless you pass an additional command line argument to prevent this:

  -DiscUseLog4jConfig=false
  

If slf4j is used with any other logging system, Smart GWT will not attempt to apply configuration - see the SLF4J user manual for details on how to configure slf4j.

Note that the features of the "Server Logs" tab will not be available if using slf4j, even if Log4j is also used.

Configure custom log4j loggers

If log4j is used and custom loggers are configured in log4j.isc.config.xml file, use DataTools.getLoggerRespository() method to access them on server side, like this:

  DataTools.getLoggerRepository().getLogger(CustomClass.class.getName());
  

Special logging category: com.isomorphic.SLOW_SQL

Used to log slow SQL queries. SQL query is condidered "slow" if its execution time exceeds configured threshold, see the global sql.log.queriesSlowerThan server.properties SQL setting and more specific DataSource.logSlowSQL setting for more details.

Set category logging level to "DEBUG" to log all slow queries:

  <category name="com.isomorphic.SLOW_SQL">
     <priority value="DEBUG" />
  </category>
  

or enable logging for specific operation types:

  <category name="com.isomorphic.SLOW_SQL.fetch">
     <priority value="DEBUG" />
  </category>
  <category name="com.isomorphic.SLOW_SQL.update">
     <priority value="DEBUG" />
  </category>