Tony Zeng created LOGBACK-1406: ---------------------------------- Summary: Seems all threads blocked Key: LOGBACK-1406 URL: https://jira.qos.ch/browse/LOGBACK-1406 Project: logback Issue Type: Bug Components: logback-core Environment: Linux ubuntu-100 4.4.0-116-generic #140-Ubuntu SMP Mon Feb 12 21:23:04 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
java version "1.8.0_161" Java(TM) SE Runtime Environment (build 1.8.0_161-b12) Java HotSpot(TM) 64-Bit Server VM (build 25.161-b12, mixed mode) Reporter: Tony Zeng Assignee: Logback dev list Attachments: dump We are using `logback-core-1.1.11` as our logging framework, and recently we found sometimes our web application is blocked and no response. After thread dump, we found that most of web threads (and many, around 150) are waiting for a lock in `OutputStreamAppender` as following stacktrace show: {code:java} "qtp956480812-17384" #17384 prio=5 os_prio=0 tid=0x00007f667400e800 nid=0x43f3 waiting on condition [0x00007f652d4d0000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x00000000843211e8> (a java.util.concurrent.locks.ReentrantLock$NonfairSync) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175) at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836) at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:870) at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1199) at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:209) at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285) at ch.qos.logback.core.OutputStreamAppender.subAppend(OutputStreamAppender.java:210) at ch.qos.logback.core.OutputStreamAppender.append(OutputStreamAppender.java:100) at ch.qos.logback.core.UnsynchronizedAppenderBase.doAppend(UnsynchronizedAppenderBase.java:84) at ch.qos.logback.core.spi.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:51) at ch.qos.logback.classic.Logger.appendLoopOnAppenders(Logger.java:270) at ch.qos.logback.classic.Logger.callAppenders(Logger.java:257) at ch.qos.logback.classic.Logger.buildLoggingEventAndAppend(Logger.java:421) at ch.qos.logback.classic.Logger.filterAndLog_2(Logger.java:414) at ch.qos.logback.classic.Logger.info(Logger.java:587) at cn.superid.auth.utils.PermissionUtil.hasPermission(PermissionUtil.java:31) {code} And following is the only thread which has the lock {code:java} "qtp956480812-17230" #17230 prio=5 os_prio=0 tid=0x00007f65c0017800 nid=0x4359 runnable [0x00007f65e5fe9000] java.lang.Thread.State: RUNNABLE at java.io.FileOutputStream.writeBytes(Native Method) at java.io.FileOutputStream.write(FileOutputStream.java:326) at java.io.BufferedOutputStream.write(BufferedOutputStream.java:122) - locked <0x00000000830542d0> (a java.io.BufferedOutputStream) at java.io.PrintStream.write(PrintStream.java:480) - locked <0x00000000830542b0> (a java.io.PrintStream) at java.io.FilterOutputStream.write(FilterOutputStream.java:97) at ch.qos.logback.core.joran.spi.ConsoleTarget$1.write(ConsoleTarget.java:37) at ch.qos.logback.core.encoder.LayoutWrappingEncoder.doEncode(LayoutWrappingEncoder.java:131) at ch.qos.logback.core.OutputStreamAppender.writeOut(OutputStreamAppender.java:187) at ch.qos.logback.core.OutputStreamAppender.subAppend(OutputStreamAppender.java:212) at ch.qos.logback.core.OutputStreamAppender.append(OutputStreamAppender.java:100) at ch.qos.logback.core.UnsynchronizedAppenderBase.doAppend(UnsynchronizedAppenderBase.java:84) at ch.qos.logback.core.spi.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:51) at ch.qos.logback.classic.Logger.appendLoopOnAppenders(Logger.java:270) at ch.qos.logback.classic.Logger.callAppenders(Logger.java:257) at ch.qos.logback.classic.Logger.buildLoggingEventAndAppend(Logger.java:421) at ch.qos.logback.classic.Logger.filterAndLog_2(Logger.java:414) at ch.qos.logback.classic.Logger.info(Logger.java:587) {code} From the stacktrace, it seems no deadlock and application should not be blocked. But the actual phenomenon is no log, no response. So, what's the problem? If you need more info, let me know. Thanks. -- This message was sent by Atlassian JIRA (v7.3.1#73012) _______________________________________________ logback-dev mailing list logback-dev@qos.ch http://mailman.qos.ch/mailman/listinfo/logback-dev