The web application [] appears to have started a thread named [Abandoned connection cleanup thread] com.mysql.jdbc.AbandonedConnectionCleanupThread
See this answer. It seems that MySQL driver should be in {$TOMCAT]/lib shared between applications. Check that you are not including it with each application. At least it worked for me and I have been able to remove the warning.
If you are using Maven mark the dependency as provided.
UPDATE:
root cause is that Tomcat have problems to garbage collect the driver because it is registered in a singleton common to several applications. Closing one application does not allow Tomcat to release the driver. See this answer.
For me i stop mysql (service mysql start) and then i stop tomcat (./shutdown.sh) in bin folder and the problem was fixed.
This works for me.
Issue was with elastic search in my case.
Send a DELETE request from postman to below endpoint and restart your application .
http://localhost:9200/*