[
https://issues.apache.org/jira/browse/QPID-6819?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14998585#comment-14998585
]
Lorenz Quack edited comment on QPID-6819 at 11/10/15 1:54 PM:
--------------------------------------------------------------
I think there is something wrong here.
Yesterday I had a test failure that seems related to this change:
{noformat}
2015-11-09 23:30:38,623 ERROR [IO-pool-Port-amqp-6]
o.a.q.t.u.InternalBrokerHolder Uncaught exception from thread
IO-pool-Port-amqp-6
java.lang.NullPointerException: null
at
org.apache.qpid.server.transport.SelectorThread$SelectionTask$1.run(SelectorThread.java:191)
~[qpid-broker-core-6.0.0-SNAPSHOT.jar:6.0.0-SNAPSHOT]
at
org.apache.qpid.server.transport.SelectorThread.run(SelectorThread.java:448)
~[qpid-broker-core-6.0.0-SNAPSHOT.jar:6.0.0-SNAPSHOT]
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
~[na:1.8.0_60]
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
~[na:1.8.0_60]
at java.lang.Thread.run(Thread.java:745) ~[na:1.8.0_60]
{noformat}
The line numbers are a little off because I had added some debug lines.
The null pointer happened on the line
{{transport.acceptSocketChannel(channel);}} (I believe currently that should be
line 189 on trunk).
It is hard to see how this could null pointer but I think there is a race with
{{unregisterConnection()}}.
In the unlucky case
* {{processSelectionKeys()}} enters {{if(key.isAcceptable())}} on line 166.
* before line 168 is executed {{unregisterConnection()}} calls
{{connection.getSocketChannel().register(connection.getSelectionTask().getSelector(),
0);}} (line 480) setting the attachment to {{null}}
* when {{processSelectionKeys()}} continues it will null pointer.
One other more general point about the SelectionThread/Task code. I think the
intent would be clearer if instead of calling register repeatedly to set the
interest we would call interestOps(ops) on the key.
was (Author: lorenz.quack):
I think there is something wrong here.
Yesterday I had a test failure that seems related to this change:
{noformat}
2015-11-09 23:30:38,623 ERROR [IO-pool-Port-amqp-6]
o.a.q.t.u.InternalBrokerHolder Uncaught exception from thread
IO-pool-Port-amqp-6
java.lang.NullPointerException: null
at
org.apache.qpid.server.transport.SelectorThread$SelectionTask$1.run(SelectorThread.java:191)
~[qpid-broker-core-6.0.0-SNAPSHOT.jar:6.0.0-SNAPSHOT]
at
org.apache.qpid.server.transport.SelectorThread.run(SelectorThread.java:448)
~[qpid-broker-core-6.0.0-SNAPSHOT.jar:6.0.0-SNAPSHOT]
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
~[na:1.8.0_60]
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
~[na:1.8.0_60]
at java.lang.Thread.run(Thread.java:745) ~[na:1.8.0_60]
{noformat}
The line numbers are a little off because I had added some debug lines.
The null pointer happened on the line
{{transport.acceptSocketChannel(channel);}} (I believe currently that should be
line 189 on trunk).
It is hard to see how this could null pointer but I think there is a race with
{{unregisterConnection()}}.
In the unlucky case
* {{processSelectionKeys()}} enters {{if(key.isAcceptable())}} on line 166.
* before line 168 is executed {{unregisterConnection()}} calls
{{connection.getSocketChannel().register(connection.getSelectionTask().getSelector(),
0);}} (line 480) setting the attachment to {{null}}
* when {{processSelectionKeys()}} continues it will null pointer.
> Schedule socket accepts on the thread pool
> ------------------------------------------
>
> Key: QPID-6819
> URL: https://issues.apache.org/jira/browse/QPID-6819
> Project: Qpid
> Issue Type: Improvement
> Components: Java Broker
> Reporter: Keith Wall
> Assignee: Keith Wall
> Fix For: qpid-java-6.0
>
> Attachments:
> 0001-QPID-6819-Java-Broker-Schedule-socket-accepts-on-the.patch
>
>
> Testing with very large numbers of connections shows that accepting socket
> connections in the same thread as the selector can be a bottleneck. Change
> the algorithm to schedule the accept of new socket connections as a task,
> deregistering {{OP_ACCEPT}} from the selector, whilst the task is in progress.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
