Why is the process of restarting the Tomcat 9.0.0.M22 web application server hanging?

Question

IntelliJ IDEA

Hello.
I work in Intellig IDEA 2017.1.4 and windows 10, JVM jdk1.8.0_131.
I am developing a WEB application on Apache Tomcat 9.0.0.M22.
After making enough changes, I need to restart the server, I run a restart and the process freezes.
For example, below is the log

30-Jun-2017 21:51:54.220 INFO [main] org.apache.coyote.AbstractProtocol.pause Pausing ProtocolHandler ["ajp-nio-50680"]
30-Jun-2017 21:51:54.295 INFO [main] org.apache.catalina.core.StandardService.stopInternal Stopping service [Catalina]
30-Jun-2017 21:51:54.308 WARNING [main] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesJdbc The web application [ROOT] registered the JDBC driver [oracle.jdbc.OracleDriver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
30-Jun-2017 21:51:54.309 WARNING [main] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [ROOT] appears to have started a thread named [oracle.jdbc.driver.BlockSource.ThreadedCachingBlockSource.BlockReleaser] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
java.lang.Object.wait(Native Method)
oracle.jdbc.driver.BlockSource$ThreadedCachingBlockSource$BlockReleaser.run(BlockSource.java:327)
30-Jun-2017 21:51:54.318 INFO [main] org.apache.coyote.AbstractProtocol.stop Stopping ProtocolHandler ["http-nio-8000"]
30-Jun-2017 21:51:54.319 INFO [main] org.apache.coyote.AbstractProtocol.stop Stopping ProtocolHandler ["ajp-nio-50680"]
30-Jun-2017 21:51:54.320 INFO [main] org.apache.coyote.AbstractProtocol.destroy Destroying ProtocolHandler ["http-nio-8000"]
30-Jun-2017 21:51:54.321 INFO [main] org.apache.coyote.AbstractProtocol.destroy Destroying ProtocolHandler ["ajp-nio-50680"]

Realizing that you can wait forever, I open the list of OS processes in it, I find java with the utilization of more than 1 Gb of memory, I kill it and after the restart process is completed successfully.
What could be the problem and how to solve it?
ps just in case started a topic on the JetBrains community

Answer 1

the new version 2017.2 also reproduces the same problem, finally had to abandon Apache Tomcat 9.0.0.M22 in favor of Apache Tomcat 8.5.16