Peter Minearo created AMQ-5262:
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Summary: ActiveMQ hangs on shutdown when JMS Bridge is created
Key: AMQ-5262
URL: https://issues.apache.org/jira/browse/AMQ-5262
Project: ActiveMQ
Issue Type: Bug
Components: Broker
Affects Versions: 5.10.0, 5.9.1, 5.9.0
Reporter: Peter Minearo
Priority: Minor
We are having a problem with ActiveMQ hanging on shutdown. Here is the
scenario, we have a stand alone application that runs an embedded ActiveMQ
which creates a JMS Queue Bridge via Spring configs. When we call shutdown, the
TCPTransport that connects the JMS Queue Bridge does not shutdown, it hangs on
java.net.SocketInputStream.socketRead0().
java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:129)
at
org.apache.activemq.transport.tcp.TcpBufferedInputStream.fill(TcpBufferedInputStream.java:50)
at
org.apache.activemq.transport.tcp.TcpTransport$2.fill(TcpTransport.java:604)
at
org.apache.activemq.transport.tcp.TcpBufferedInputStream.read(TcpBufferedInputStream.java:58)
at
org.apache.activemq.transport.tcp.TcpTransport$2.read(TcpTransport.java:589)
at java.io.DataInputStream.readInt(DataInputStream.java:370)
at
org.apache.activemq.openwire.OpenWireFormat.unmarshal(OpenWireFormat.java:275)
at
org.apache.activemq.transport.tcp.TcpTransport.readCommand(TcpTransport.java:221)
at
org.apache.activemq.transport.tcp.TcpTransport.doRun(TcpTransport.java:213)
at
org.apache.activemq.transport.tcp.TcpTransport.run(TcpTransport.java:196)
at java.lang.Thread.run(Thread.java:662)
Digging around on the forums and the issue tracker, the work around seems to
add a parameter to the URI (Ex - tcp://localhost:60606?daemon=true).
According to this StackOverflow posting
(http://stackoverflow.com/questions/2213340/what-is-daemon-thread-in-java)
which quotes from Java Concurrency in Practice
* When a new thread is created it inherits the daemon status of its parent.
* Normal thread and daemon threads differ in what happens when they exit. When
the JVM halts any remaining daemon threads are abandoned: **finally blocks are
not executed**, stacks are not unwound - JVM just exits. Due to this reason
daemon threads should be used sparingly and it is dangerous to use them for
tasks that might perform any sort of I/O.
So, making the Socket that connects the JMS Queue Bridge a Daemon thread, seems
to be the wrong solution.
I was trying to debug the initialization of ActiveMQ, and noticed the
org.apache.activemq.network.jms.JmsConnector class has a stop() method on it.
I believe this class creates the connection for the JMS Bridge, right? If so,
the stop method does not seem to shutdown the connection properly.
public void stop() throws Exception {
if (started.compareAndSet(true, false)) {
ThreadPoolUtils.shutdown(connectionSerivce);
connectionSerivce = null;
for (DestinationBridge bridge : inboundBridges) {
bridge.stop();
}
for (DestinationBridge bridge : outboundBridges) {
bridge.stop();
}
LOG.info("JMS Connector {} stopped", getName());
}
}
The question I have is why is the stop() method relying on the
ThreadPoolUtils.shutdown(connectionSerivce) and NOT calling close() on the
Connections first? For example:
public void stop() throws Exception {
if (started.compareAndSet(true, false)) {
foreignConnection.get().close();
localConnection.get().close();
ThreadPoolUtils.shutdown(connectionSerivce);
connectionSerivce = null;
for (DestinationBridge bridge : inboundBridges) {
bridge.stop();
}
for (DestinationBridge bridge : outboundBridges) {
bridge.stop();
}
LOG.info("JMS Connector {} stopped", getName());
}
}
It was a little difficult to follow the code, so I may be missing something.
BUT shouldn't the connections close first? Or am I looking in the wrong place.
I have created a small project that creates this scenario.
https://github.com/pminearo/activemq-shutdown-bug.git
This was done with ActiveMQ 5.9. Though, since this bug has been around for
quite some time, it most likely is still in 5.10, 5.11, and 6.0.
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