[QPID-8491] Connection leak when using CPP qpid-proton client

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Not A Problem
• Affects Version/s: qpid-java-broker-8.0.2
• Fix Version/s: qpid-java-broker-8.0.3, qpid-java-broker-7.1.11
• Component/s: Broker-J
• Assignee: Unassigned
• Reporter: Daniil Kirilyuk
• Created: 14/Dec/20 12:10
• Updated: 28/Jan/21 12:26
• Resolved: 21/Dec/20 14:17

Description

Issue is similar to QPID-8477: when broker is configured to accept limited number of connections from certain client and client is not well behaved, there is a possibility to exceed configured connection limit.

Steps to reproduce

1. Configure broker to allow only 1 connection

 

3. Prepare certificates

 

4. Install Qpid::Proton 0.28.0

wget http://archive.apache.org/dist/qpid/proton/0.28.0/qpid-proton-0.28.0.tar.gz

gunzip qpid-proton-0.28.0.tar.gz

mkdir -p qpid-proton-0.28.0/build && pushd qpid-proton-0.28.0/build && cmake .. && make all && popd

5. Replace and edit example qpid-proton-0.28.0/cpp/examples/simple_recv.cpp with the one attached

6. Build again

cd qpid-proton-0.28.0/build

make

7. Start clients

./cpp/examples/simple_recv & ./cpp/examples/simple_recv

 8. Check connection count
curl http://admin_user:password@your_broker_host:http_administration_port/api/latest/querybroker/VirtualHost?select=connectionCount

Analysis:

Client outputs following error message:

Connection error
[0x1c4fac0]:unable to find an open available channel within limit of 0
[0x1c4fac0]:process error -2

In broker log following stacktrace is seen:

2020-12-09 11:03:32,252 WARN  [IO-/10.112.45.3:45094] (o.a.q.s.p.v.f.FrameHandler) - Unexpected exception handling frame
org.apache.qpid.server.util.ConnectionScopedRuntimeException: Unexpected state, client has sent frame in an illegal order.  Required state: OPENED, actual state: CLOSED
	at org.apache.qpid.server.protocol.v1_0.AMQPConnection_1_0Impl.assertState(AMQPConnection_1_0Impl.java:1768)
	at org.apache.qpid.server.protocol.v1_0.AMQPConnection_1_0Impl.receiveBegin(AMQPConnection_1_0Impl.java:701)
	at org.apache.qpid.server.protocol.v1_0.type.transport.Begin.invoke(Begin.java:230)
	at org.apache.qpid.server.protocol.v1_0.AMQPConnection_1_0Impl.received(AMQPConnection_1_0Impl.java:515)
	at org.apache.qpid.server.protocol.v1_0.AMQPConnection_1_0Impl.receive(AMQPConnection_1_0Impl.java:480)
	at org.apache.qpid.server.protocol.v1_0.framing.FrameHandler.parse(FrameHandler.java:224)
	at org.apache.qpid.server.protocol.v1_0.AMQPConnection_1_0Impl.onReceive(AMQPConnection_1_0Impl.java:1312)
	at org.apache.qpid.server.transport.AbstractAMQPConnection.lambda$received$2(AbstractAMQPConnection.java:576)
	at java.security.AccessController.doPrivileged(Native Method)
	at org.apache.qpid.server.transport.AbstractAMQPConnection.received(AbstractAMQPConnection.java:571)
	at org.apache.qpid.server.transport.MultiVersionProtocolEngine.received(MultiVersionProtocolEngine.java:135)
	at org.apache.qpid.server.transport.NonBlockingConnection.processAmqpData(NonBlockingConnection.java:611)
	at org.apache.qpid.server.transport.NonBlockingConnectionTLSDelegate.processData(NonBlockingConnectionTLSDelegate.java:141)
	at org.apache.qpid.server.transport.NonBlockingConnection.doRead(NonBlockingConnection.java:496)
	at org.apache.qpid.server.transport.NonBlockingConnection.doWork(NonBlockingConnection.java:270)
	at org.apache.qpid.server.transport.NetworkConnectionScheduler.processConnection(NetworkConnectionScheduler.java:134)
	at org.apache.qpid.server.transport.SelectorThread$ConnectionProcessor.processConnection(SelectorThread.java:575)
	at org.apache.qpid.server.transport.SelectorThread$SelectionTask.performSelect(SelectorThread.java:366)
	at org.apache.qpid.server.transport.SelectorThread$SelectionTask.run(SelectorThread.java:97)
	at org.apache.qpid.server.transport.SelectorThread.run(SelectorThread.java:533)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.qpid.server.bytebuffer.QpidByteBufferFactory.lambda$null$0(QpidByteBufferFactory.java:464)
	at java.lang.Thread.run(Thread.java:748)

 Error is triggered by following callback in qpid-proton cpp client:

void on_connection_open (proton::connection &c) {
 c.open_session();
 }

Broker receives session opening call AMQPConnection_1_0Impl.receiveBegin(). During the check whether connection is opened or not ( AMQPConnection_1_0Impl.assertState() ) an exception is thrown, which isn't handled and connection remains not closed.

 

Issue Links

• is caused by: QPID-8489 Connection thread looping