Attempted a regular Tomcat JVM restart to address "http status 503 - pegarules server not available" issue.

But JVM is not coming up even after multiple restart attempts.

In the Logs post load instance filter step JVM waiting for nearly 6 hours without any action later failing to restart  with below errors.

Log File:

2020-05-20 17:21:17,667 [       *SERVERNAME*] [  STANDARD] [                    ] [                    ] (   internal.mgmt.PREnvironment) ERROR   - com.pega.pegarules.pub.PRRuntimeException: caught exception during autocommit check

2020-05-20 17:21:17,706 [       *SERVERNAME*] [  STANDARD] [                    ] [                    ] (      etier.impl.EngineStartup) ERROR   - PegaRULES initialization failed. Server: *SERVERNAME*
com.pega.pegarules.pub.context.InitializationFailedError: PRNodeImpl init failed
    at com.pega.pegarules.session.internal.mgmt.PREnvironment.getThreadAndInitialize(PREnvironment.java:388)
    at com.pega.pegarules.session.internal.PRSessionProviderImpl.getThreadAndInitialize(PRSessionProviderImpl.java:1976)
    at com.pega.pegarules.session.internal.engineinterface.etier.impl.EngineStartup.initEngine(EngineStartup.java:664)
    at com.pega.pegarules.session.internal.engineinterface.etier.impl.EngineImpl._initEngine_privact(EngineImpl.java:165)
    at com.pega.pegarules.session.internal.engineinterface.etier.impl.EngineImpl.doStartup(EngineImpl.java:138)
    at com.pega.pegarules.web.servlet.WebAppLifeCycleListener._contextInitialized_privact(WebAppLifeCycleListener.java:311)
    at com.pega.pegarules.web.servlet.WebAppLifeCycleListener.contextInitialized(WebAppLifeCycleListener.java:218)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.pega.pegarules.internal.bootstrap.PRBootstrap.invokeMethod(PRBootstrap.java:367)
    at com.pega.pegarules.internal.bootstrap.PRBootstrap.invokeMethodPropagatingThrowable(PRBootstrap.java:408)
    at com.pega.pegarules.boot.internal.extbridge.AppServerBridgeToPega.invokeMethodPropagatingThrowable(AppServerBridgeToPega.java:223)
    at com.pega.pegarules.boot.internal.extbridge.AppServerBridgeToPega.invokeMethod(AppServerBridgeToPega.java:272)
    at com.pega.pegarules.internal.web.servlet.WebAppLifeCycleListenerBoot.contextInitialized(WebAppLifeCycleListenerBoot.java:83)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4994)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5492)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:649)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1245)
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1895)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: com.pega.pegarules.pub.PRRuntimeException: caught exception during autocommit check
    at com.pega.pegarules.data.internal.access.ConnectionManagerImpl.returnConnection(ConnectionManagerImpl.java:2228)
    at com.pega.pegarules.data.internal.access.ThreadConnectionStoreImpl.returnConnection(ThreadConnectionStoreImpl.java:504)
    at com.pega.pegarules.data.internal.access.DatabaseImpl.callStoredProc(DatabaseImpl.java:10179)
    at com.pega.pegarules.data.internal.access.DatabaseImpl.setDataNodeState(DatabaseImpl.java:7850)
    at com.pega.pegarules.session.internal.mgmt.PRNodeImpl.initializeSystem(PRNodeImpl.java:899)
    at com.pega.pegarules.session.internal.mgmt.PREnvironment.getThreadAndInitialize(PREnvironment.java:373)
    ... 28 more
Caused by: java.sql.SQLException: Connection has already been closed.
    at org.apache.tomcat.jdbc.pool.ProxyConnection.invoke(ProxyConnection.java:117)
    at org.apache.tomcat.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:109)
    at org.apache.tomcat.jdbc.pool.DisposableConnectionFacade.invoke(DisposableConnectionFacade.java:80)
    at com.sun.proxy.$Proxy5.getAutoCommit(Unknown Source)
    at com.pega.pegarules.data.internal.access.DatabaseConnectionImpl.getAutoCommit(DatabaseConnectionImpl.java:806)
    at com.pega.pegarules.data.internal.access.ConnectionManagerImpl.returnConnection(ConnectionManagerImpl.java:2221)
    ... 33 more
2020-05-20 17:21:17,708 [       *SERVERNAME*] [  STANDARD] [                    ] [                    ] (      etier.impl.EngineStartup) INFO    - PegaRULES initialization failed. Server:  *SERVERNAME*
2020-05-20 17:21:17,861 [       *SERVERNAME*] [  STANDARD] [                    ] [                    ] (ervlet.WebAppLifeCycleListener) ERROR   - Enterprise tier failed to initialize properly, PegaRULES not available
2020-05-20 17:21:17,882 [       *SERVERNAME*] [  STANDARD] [                    ] [                    ] (ervlet.WebAppLifeCycleListener) INFO    - Web Tier initialization is complete.