[CASSANDRA-13212] Remove hard dependency on Logback

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Workaround
• Component/s: Legacy/Core
• Severity: Normal
• Assignee: Unassigned
• Reporter: Michael Calderero
• Created: 11/Feb/17 20:38
• Updated: 04/Apr/21 11:41
• Resolved: 12/Feb/17 23:02

Description

Hi,

Our application is using Log4J2, SpringBoot and cassandraunit. We just upgraded to use cassandra-all version 3.0.10 (to approximately match the DataStax version wer're using) and excluded the logback-classic and logback-core dependencies from this dependency.

However when I try to run an embedded Cassandra unit test, it always fails with the following error:

Exception (java.lang.NoClassDefFoundError) encountered during startup: ch/qos/logback/core/Context
java.lang.NoClassDefFoundError: ch/qos/logback/core/Context
at org.apache.cassandra.service.StorageService.initServer(StorageService.java:604)
at org.apache.cassandra.service.StorageService.initServer(StorageService.java:558)
at org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:346)
at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:568)
at org.cassandraunit.utils.EmbeddedCassandraServerHelper$1.run(EmbeddedCassandraServerHelper.java:133)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: ch.qos.logback.core.Context
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 8 more

I looked at the source code of StorageService and it seems like it is invoking Logback-specific classes directly, instead of SLF4J ones. This code seems to have been introduced by CASSANDRA-5883.

I currently don't see a logback-to-slf4j bridge so seems it seems our options are to not use Cassandra (which is not possible) or to try to create a dummy bridge to route logback calls to slf4j (which then goes to Log4j2).

Any particular reason why the Logback classes are invoked directly instead through SLF4J?

Issue Links

• is related to: CASSANDRA-15606 Support Logback and log4j2