PENDING session is removed and added endlessly -- garbage allocation and high
CPU usage problem
------------------------------------------------------------------------------------------------
Key: DIRMINA-709
URL: https://issues.apache.org/jira/browse/DIRMINA-709
Project: MINA
Issue Type: Bug
Components: Core
Affects Versions: 2.0.0-M4
Environment: Debian Linux, kernel 2.6.24
Reporter: Victor N
(This problem was discussed in mail lists, I will copy it here).
Seems I have found a bug with IoSession - I can see that a "PREPARING" session
is not removed correctly from queue.
When some session is in PREPARING state, it is removed from "removingSessions"
queue but right after that it is added to this queue again! So this session is
added to the queue and removed from it until forever.
As a result, this give us significant garbage allocation, so CPU spends most of
time in garbage collector (I can see this is JConsole).
I see comments there in AbstractPollingIoProcessor class:
private int remove() {
...
case PREPARING:
// Retry later if session is not yet fully initialized.
// (In case that Session.close() is called before
addSession() is processed)
scheduleRemove(session);
return removedSessions;
...
}
I have added logging to this code, and I can see that the SAME session is
removed and added again and again.
Can somebody explain this logic please? Why don't we remove the PENDING
session? Or maybe is there a workaround for this.
Sorry, I can not provide a test for this issue, but it is reproduced almost
every day at out production servers under some load. Maybe, you can reproduce
it by adding a delay in addSession() and then closing the session during this
delay.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
