Blocked threads waiting for logback SiftingAppender on WebLogic
I have one problem with performance in production because of, as I think, blocked threads . When I got thread dumps from production environment I was surprised that about 50% of thread are in status: *-- Blocked trying to get lock: ch/qos/logback/classic/sift/SiftingAppender@0x1111fe3e8[unlocked]* At the same time, as you can see, SiftingAppender is 'unlocked'. I have no idea why it's happened. If we deep into logback sources we will find there a synchronized method which is the 'thin' place I think: ch.qos.logback.core.AppenderBase.doAppend(E) public synchronized void doAppend(E eventObject) { // WARNING: The guard check MUST be the first statement in the // doAppend() method. // prevent re-entry. if (guard) { return; } ... } We use weblogic v.10.3.5.0 slf4j.version - 1.7.5 logback.version - 1.0.13 Has anybody ideas why it's happened and how to avoid this problem? It may be not logback's problem. I now trying to find resolution only.
Strange. Any idea what that [unlocked] really means? David On 6 Jun 2013, at 13:07, Артём Тарасов <arttaras@gmail.com> wrote:
I have one problem with performance in production because of, as I think, blocked threads .
When I got thread dumps from production environment I was surprised that about 50% of thread are in status:
-- Blocked trying to get lock: ch/qos/logback/classic/sift/SiftingAppender@0x1111fe3e8[unlocked]
At the same time, as you can see, SiftingAppender is 'unlocked'.
I have no idea why it's happened.
If we deep into logback sources we will find there a synchronized method which is the 'thin' place I think:
ch.qos.logback.core.AppenderBase.doAppend(E)
public synchronized void doAppend(E eventObject) { // WARNING: The guard check MUST be the first statement in the // doAppend() method.
// prevent re-entry. if (guard) { return; } ... }
We use weblogic v.10.3.5.0
slf4j.version - 1.7.5
logback.version - 1.0.13
Has anybody ideas why it's happened and how to avoid this problem?
It may be not logback's problem. I now trying to find resolution only. <logback.rar> <threadDumps.rar> _______________________________________________ Logback-user mailing list Logback-user@qos.ch http://mailman.qos.ch/mailman/listinfo/logback-user
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Артём Тарасов