Return-Path: X-Original-To: apmail-hadoop-mapreduce-user-archive@minotaur.apache.org Delivered-To: apmail-hadoop-mapreduce-user-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 5D67FDF98 for ; Sat, 22 Dec 2012 10:20:03 +0000 (UTC) Received: (qmail 58084 invoked by uid 500); 22 Dec 2012 10:19:58 -0000 Delivered-To: apmail-hadoop-mapreduce-user-archive@hadoop.apache.org Received: (qmail 57684 invoked by uid 500); 22 Dec 2012 10:19:57 -0000 Mailing-List: contact user-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@hadoop.apache.org Delivered-To: mailing list user@hadoop.apache.org Delivered-To: moderator for user@hadoop.apache.org Received: (qmail 52073 invoked by uid 99); 22 Dec 2012 10:16:47 -0000 X-ASF-Spam-Status: No, hits=-0.7 required=5.0 tests=RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of tabatabaeised@gmail.com designates 209.85.220.43 as permitted sender) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:date:message-id:subject:from:to:content-type; bh=3JAGiz147pKv8/iho/G1N14iP6m7pmH2Kx6khJ4nPzo=; b=urti3kFfcXWjr/pXMTmMyq/Z1kMNho4TKDduVbzknuHU7lfmKXrCAF4LmJRW/+WseG 3Urr1eApJM2A79Ng1nA8NsfDLkKVZhMspGG1zBcIFc+Ymcf/QM/ug+madEyFieH+mD6Z 1Hp6XoUf3gK+m54Dbqqj7ATqIRsSollmDhEI0+xGGgot6ATBruP/YkX+7mQTAIVjxtcc rXeQNmpvw45vB81Bqq2i7R8VFE58GHDHidlc9fkwa7hjQFgEcMTS5W+3NCHLVNYxX+8K Xznz1YYQBAQnaQPLHF3M9d+6NYCnu9fUdoUCJYBiHiY3OPhBXXryB+d2kFYJicDkAU2W d65Q== MIME-Version: 1.0 Date: Sat, 22 Dec 2012 13:46:20 +0330 Message-ID: Subject: Child processes on datanodes/task trackers From: Sedighe Tabatabaei To: user@hadoop.apache.org Content-Type: text/plain; charset=ISO-8859-1 X-Virus-Checked: Checked by ClamAV on apache.org Hello I wanted to know why I see running Child processes on my datanodes even though there is no job running at that time. when i use jstack command,result is: Full thread dump Java HotSpot(TM) 64-Bit Server VM (17.1-b03 mixed mode): "Attach Listener" daemon prio=10 tid=0x00007f2a74002000 nid=0x1f3 waiting on condition [0x0000000000000000] java.lang.Thread.State: RUNNABLE "SIGTERM handler" daemon prio=10 tid=0x00007f2a74001000 nid=0x2fae waiting for monitor entry [0x00007f2a79891000] java.lang.Thread.State: BLOCKED (on object monitor) at java.lang.Shutdown.exit(Shutdown.java:168) - waiting to lock <0x00007f2a9ffa68d0> (a java.lang.Class for java.lang.Shutdown) at java.lang.Terminator$1.handle(Terminator.java:35) at sun.misc.Signal$1.run(Signal.java:195) at java.lang.Thread.run(Thread.java:662) "Thread-16" prio=10 tid=0x00007f2ae83d1000 nid=0x2f85 runnable [0x00007f2a9cb5a000] java.lang.Thread.State: RUNNABLE at java.lang.Throwable.fillInStackTrace(Native Method) - locked <0x00007f2ad36e4d50> (a java.util.ConcurrentModificationException) at java.lang.Throwable.(Throwable.java:181) at java.lang.Exception.(Exception.java:29) at java.lang.RuntimeException.(RuntimeException.java:32) at java.util.ConcurrentModificationException.(ConcurrentModificationException.java:57) at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793) at java.util.HashMap$KeyIterator.next(HashMap.java:828) at com.sun.media.jai.codec.TempFileCleanupThread.run(FileCacheSeekableStream.java:315) "DestroyJavaVM" prio=10 tid=0x00007f2ae8009800 nid=0x1113 in Object.wait() [0x00007f2aedb81000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x00007f2aa5248528> (a com.sun.media.jai.codec.TempFileCleanupThread) at java.lang.Thread.join(Thread.java:1186) - locked <0x00007f2aa5248528> (a com.sun.media.jai.codec.TempFileCleanupThread) at java.lang.Thread.join(Thread.java:1239) at java.lang.ApplicationShutdownHooks.runHooks(ApplicationShutdownHooks.java:79) at java.lang.ApplicationShutdownHooks$1.run(ApplicationShutdownHooks.java:24) at java.lang.Shutdown.runHooks(Shutdown.java:79) at java.lang.Shutdown.sequence(Shutdown.java:123) at java.lang.Shutdown.shutdown(Shutdown.java:190) - locked <0x00007f2a9ffa68d0> (a java.lang.Class for java.lang.Shutdown) "Java2D Disposer" daemon prio=10 tid=0x00007f2ae8415000 nid=0x1775 in Object.wait() [0x00007f2a7a16d000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x00007f2aa528a748> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:118) - locked <0x00007f2aa528a748> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:134) at sun.java2d.Disposer.run(Disposer.java:127) at java.lang.Thread.run(Thread.java:662) "Thread for syncLogs" daemon prio=10 tid=0x00007f2ae83bf000 nid=0x1208 waiting on condition [0x00007f2a9f2fa000] java.lang.Thread.State: TIMED_WAITING (sleeping) at java.lang.Thread.sleep(Native Method) at org.apache.hadoop.mapred.Child$2.run(Child.java:87) "Low Memory Detector" daemon prio=10 tid=0x00007f2ae8093000 nid=0x112f runnable [0x0000000000000000] java.lang.Thread.State: RUNNABLE "CompilerThread1" daemon prio=10 tid=0x00007f2ae8090800 nid=0x112d waiting on condition [0x0000000000000000] java.lang.Thread.State: RUNNABLE "CompilerThread0" daemon prio=10 tid=0x00007f2ae808d800 nid=0x112a waiting on condition [0x0000000000000000] java.lang.Thread.State: RUNNABLE "Signal Dispatcher" daemon prio=10 tid=0x00007f2ae808b800 nid=0x1129 runnable [0x0000000000000000] java.lang.Thread.State: RUNNABLE "Finalizer" daemon prio=10 tid=0x00007f2ae806d000 nid=0x1126 in Object.wait() [0x00007f2a9fafd000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x00007f2aa50c8bf0> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:118) - locked <0x00007f2aa50c8bf0> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:134) at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:159) "Reference Handler" daemon prio=10 tid=0x00007f2ae806b000 nid=0x1124 in Object.wait() [0x00007f2a9fbfe000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x00007f2aa50c8ba8> (a java.lang.ref.Reference$Lock) at java.lang.Object.wait(Object.java:485) at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:116) - locked <0x00007f2aa50c8ba8> (a java.lang.ref.Reference$Lock) "VM Thread" prio=10 tid=0x00007f2ae8066800 nid=0x1122 runnable "GC task thread#0 (ParallelGC)" prio=10 tid=0x00007f2ae801c800 nid=0x1114 runnable "GC task thread#1 (ParallelGC)" prio=10 tid=0x00007f2ae801e800 nid=0x1115 runnable "GC task thread#2 (ParallelGC)" prio=10 tid=0x00007f2ae8020000 nid=0x111c runnable "GC task thread#3 (ParallelGC)" prio=10 tid=0x00007f2ae8022000 nid=0x111f runnable "VM Periodic Task Thread" prio=10 tid=0x00007f2ae809d000 nid=0x1131 waiting on condition JNI global references: 1774 Thanks, Tabatabaei