azagrebin commented on a change in pull request #11073: [FLINK-15672][build] Migrate to log4j2 URL: https://github.com/apache/flink/pull/11073#discussion_r382001667
########## File path: docs/monitoring/logging.md ########## @@ -38,6 +38,23 @@ Flink ships with the following default properties files: - `log4j-yarn-session.properties`: Used by the Flink command line client when starting a YARN session (`yarn-session.sh`) - `log4j.properties`: JobManager/Taskmanager logs (both standalone and YARN) +### Compatibility with Log4j1 + +Flink ships with the [Log4j API bridge](https://logging.apache.org/log4j/log4j-2.2/log4j-1.2-api/index.html), allowing existing applications that work against Log4j1 classes to continue working. + +If you have custom Log4j1 properties files or code that relies on Log4j1, please check out the official Log4j [compatibility](https://logging.apache.org/log4j/2.x/manual/compatibility.html) and [migration](https://logging.apache.org/log4j/2.x/manual/migration.html) guides. + +## Configuring Log4j1 + +To use Flink with Log4j1 you must ensure that: +- `org.apache.logging.log4j:log4j-slf4j-impl` and `org.apache.logging.log4j:log4j-1.2-api` are not on the classpath, +- `org.slf4j:slf4j-log4j12`and `log4j:log4j` are on the classpath. + +In the IDE this means to replacing such dependencies defined in your pom, and possible adding exclusions on dependencies that transitively depend on them. + +For Flink distributions this means to replace the respective jars in the `lib` directory, and +replacing all log4j properties files in the `conf` directory with Log4j1-compliant versions. + Review comment: Maybe also a note that native log4j2 deps should stay in /lib for ES ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
