Low logging level preventing shutdown hook to run properly - mysql

Question

I am using the MariaDb4j library for my integration tests and it registers a shutdown hook, this way:
protected void cleanupOnExit() {
String threadName = "Shutdown Hook Deletion Thread for Temporary DB " + dataDir.toString();
final DB db = this;
Runtime.getRuntime().addShutdownHook(new Thread(threadName) {
#Override
public void run() {
// ManagedProcess DestroyOnShutdown ProcessDestroyer does
// something similar, but it shouldn't hurt to better be save
// than sorry and do it again ourselves here as well.
try {
// Shut up and don't log if it was already stop() before
if (mysqldProcess != null && mysqldProcess.isAlive()) {
logger.info("cleanupOnExit() ShutdownHook now stopping database");
db.stop();
}
} catch (ManagedProcessException e) {
logger.warn("cleanupOnExit() ShutdownHook: An error occurred while stopping the database", e);
}
if (dataDir.exists() && Util.isTemporaryDirectory(dataDir.getAbsolutePath())) {
logger.info("cleanupOnExit() ShutdownHook quietly deleting temporary DB data directory: " + dataDir);
FileUtils.deleteQuietly(dataDir);
}
if (baseDir.exists() && Util.isTemporaryDirectory(baseDir.getAbsolutePath())) {
logger.info("cleanupOnExit() ShutdownHook quietly deleting temporary DB base directory: " + baseDir);
FileUtils.deleteQuietly(baseDir);
}
}
});
}
This was working fine.
But then I added Logback and created a Console appender.
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<Pattern>${defaultPattern}</Pattern>
</encoder>
</appender>
<root level="DEBUG">
<appender-ref ref="STDOUT" />
</root>
If I set the Logging level to WARN or ERROR it is still working fine, but when I set it to INFO or lower then I get this exception:
Exception: java.lang.IllegalStateException thrown from the UncaughtExceptionHandler in thread "Shutdown Hook Deletion Thread for Temporary DB /var/folders/t5/lr8ytf257hb9_649cjp9hkn40000gn/T/MariaDB4j/data/3306"
"Shutdown Hook Deletion Thread for Temporary DB... " is the name of the thread registered in the first piece of code above.
The result is that I am left with a mysqld process running. And that prevents the tests to run again as MariaDB4j complains about it and won't start a new database.
Once I kill the mysqld process than I can run my tests again, but then same thing happens.
I assume this is a JVM problem. I don't see how the logging level can prevent a shutdown hook to work properly.
I use MariaDB4j in my integration tests. When I run them with IntelliJ or Eclipse it do not get this error. I only get it when I run them with gradle (as part of the build task).
What could be causing that and how to get around it?

Answer 1

I had similar problem. It was caused by Gradle issue which is described there.
It can be solved by downgrading Gradle to version 3.2 or upgrading to version 3.5.