Elasticsearch Logging

When you first start Liferay DXP, an embedded Elasticsearch server starts so that search works out of the box. The embedded search engine is not suitable for production, but is useful for testing and development.

In Fix Pack 3 and CE GA2, the Liferay log was slimmed down by removing INFO level Elasticsearch logs for the embedded Elasticsearch. WARN and ERROR logs are still displayed. If you miss hearing from Elasticsearch during startup, you can enable the INFO log level for the embedded Elasticsearch server.

Note: These instructions show you how to adjust the embedded Elasticsearch server’s logs. Logging for Liferay DXP’s search functionality is configurable via the Log Levels screen at Control Panel → Configuration → Server Administration → Log Levels tool. Narrow down the list to include only the search classes and packages by searching for com.liferay.portal.search.

To adjust logging for a remote Elasticsearch server, see Elastic’s documentation.

Here’s an example log message that is displayed by default:

2018-09-13 16:49:24.442 WARN  [Elasticsearch initialization thread][EmbeddedElasticsearchConnection:315]

Manage the log levels for the EmbeddedElasticsearchConnection in Server Administration.

Here’s an example Elasticsearch log message that isn’t displayed by default:

[2018-09-05T17:25:30,107][WARN ][o.e.d.i.m.MapperService  ] [unmapped_type:string] should be replaced with [unmapped_type:keyword]

To adjust logging for the o.e.d.i.m.MapperService and other Elasticsearch classes,

1. Create a config folder in Liferay Home/data/elasticsearch6/.

2. Create a log4j2.properties file in the new folder.

3. To enable INFO level logging, populate the log4j2.properties file with these contents:

   appender.console.layout.pattern=[%d{ISO8601}][%-5p][%-25c{1.}] %marker%m%n
   appender.console.layout.type=PatternLayout
   appender.console.name=console
   appender.console.type=Console
   logger.action.level=info
   logger.action.name=org.elasticsearch.action
   rootLogger.appenderRef.console.ref=console
   rootLogger.level=info
   status=error
   

   Read the Elasticsearch logging documentation for more information.

4. Restart the Liferay DXP server or just the embedded Elasticsearch.

5. To restart just the embedded Elasticsearch server, create a file called

   com.liferay.portal.bundle.blacklist.internal.BundleBlacklistConfiguration.config 
   

   in Liferay Home/osgi/configs directory and populate it with

   blacklistBundleSymbolicNames="com.liferay.portal.search.elasticsearch6.impl"
   

6. Save the .config file and the bundle is stopped. Once you see the [STOPPED] message in the logs, restart the bundle by commenting the line out and re-saving the file:

   #blacklistBundleSymbolicNames="com.liferay.portal.search.elasticsearch6.impl"
   

Once this is accomplished, the embedded Elasticsearch server displays Elasticsearch logs at the INFO level and above.

Two common Elasticsearch logs can be configured further: the Slow Log and the JVM’s Garbage Collection log.

Configuring Slow Log

Read about Elasticsearch’s Slow Log here.

Configure the Slow Log for the embedded Elasticsearch server in the Elasticsearch 6 entry in System Settings. Add these settings to the Additional Index Configurations property:

index.indexing.slowlog.threshold.index.debug: 2s
index.indexing.slowlog.threshold.index.info: 5s
index.indexing.slowlog.threshold.index.trace: 500ms
index.indexing.slowlog.threshold.index.warn: 10s

index.search.slowlog.threshold.fetch.debug: 500ms
index.search.slowlog.threshold.fetch.info: 800ms
index.search.slowlog.threshold.fetch.trace: 200ms
index.search.slowlog.threshold.fetch.warn: 1s

index.search.slowlog.threshold.query.debug: 2s
index.search.slowlog.threshold.query.info: 5s
index.search.slowlog.threshold.query.trace: 500ms
index.search.slowlog.threshold.query.warn: 10s

These are example values. Adjust as needed.

Configuring JVM Garbage Collection Logging

As with the Slow Log configuration, Elasticsearch’s JVM Garbage Collection logging is adjustable in the Elasticsearch 6 entry in System Settings. Add these settings to the Additional Configurations property:

monitor.jvm.gc.enabled: true
monitor.jvm.gc.overhead.debug: 40
monitor.jvm.gc.overhead.info: 70
monitor.jvm.gc.overhead.warn: 90

These are example values. Adjust as needed.