What is the jvm.log?
Nexus Repository 3.1.0 and greater creates a log file at <data_dir>/log/jvm.log.
This log file is a side effect of a java vm option -XX:+LogVMOutput and is present to capture stderr output which can't otherwise be captured into the application log at <data_dir>/log/nexus.log.
The primary use case is to capture thread dumps triggered by SIGQUIT signals ( kill -3 <pid> or kill -QUIT <pid> ).
The file is not rotated out as it grows in size or age, but in practice should not grow very large either.
At the start of the Java process, the entire contents of the file are replaced. To preserve any triggered thread dumps inside this file, make a copy of the jvm.log before the next restart of the Java process.
The jvm.log contains dependency_failed messages - should I be concerned?
No. These messages do not indicate a problem.
The messages represent where a previous assumption about a class has changed (due to dynamic linking) and the JIT compiler needs to recompile the class.