A valid shutdown command was received via the shutdown port

[JasonXiao]

Our server has stop responding this morning. I have found this error message at catalina.2016-06-16.log. Could you please give me some suggestions about why this issue happened?

Code: Select all

Jun 16, 2016 7:57:46 AM org.apache.catalina.core.StandardServer await
INFO: A valid shutdown command was received via the shutdown port. Stopping the Server instance.
Jun 16, 2016 7:57:46 AM org.apache.coyote.AbstractProtocol pause
INFO: Pausing ProtocolHandler ["http-apr-3030"]
Jun 16, 2016 7:57:46 AM org.apache.coyote.AbstractProtocol pause
INFO: Pausing ProtocolHandler ["ajp-apr-8009"]
Jun 16, 2016 7:57:46 AM org.apache.catalina.core.StandardService stopInternal
INFO: Stopping service Catalina
Jun 16, 2016 7:58:52 AM org.apache.catalina.session.StandardManager stopInternal
SEVERE: Exception unloading sessions to persistent storage
java.lang.StackOverflowError
	at java.io.ObjectOutputStream$BlockDataOutputStream.writeUTF(Unknown Source)
	at java.io.ObjectOutputStream.writeUTF(Unknown Source)
	at java.io.ObjectStreamClass.writeNonProxy(Unknown Source)
	at java.io.ObjectOutputStream.writeClassDescriptor(Unknown Source)
	at java.io.ObjectOutputStream.writeNonProxyDesc(Unknown Source)
	at java.io.ObjectOutputStream.writeClassDesc(Unknown Source)
	at java.io.ObjectOutputStream.writeNonProxyDesc(Unknown Source)
	at java.io.ObjectOutputStream.writeClassDesc(Unknown Source)
	at java.io.ObjectOutputStream.writeNonProxyDesc(Unknown Source)
	at java.io.ObjectOutputStream.writeClassDesc(Unknown Source)
	at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source)
	at java.io.ObjectOutputStream.writeObject0(Unknown Source)
	at java.io.ObjectOutputStream.writeObject(Unknown Source)

...

[Jon]

So far as I am aware, this message means that someone or something shut down the server e.g. by running one of the stop scripts in the UfsServer directory or invoking the Tomcat shutdown script in UfsServer/tomcat/bin.