[Hadoop-common-user] jobtracker.jsp reports "GC overhead limit exceeded"

Thanks, Alex.

Actually I enabled all level logs. But I didn't realize to check logs in .out files and only looked at .log file and didn't see any error msgs. now I opened the .out file and saw the following logged exception:

Exception in thread "IPC Server handler 5 on 50002" java.lang.OutOfMemoryError: Java heap space
at java.util.Arrays.copyOf(Arrays.java:2786)
at java.io.ByteArrayOutputStream.toByteArray(ByteArrayOutputStream.java:133)
at org.apache.hadoop.ipc.Server.setupResponse(Server.java:1087)
at org.apache.hadoop.ipc.Server.access$2400(Server.java:77)
at org.apache.hadoop.ipc.Server$Handler.run(Server.java:984)

Exception in thread "IPC Client (47) connection to servername/serverip:50001 from auser" java.lang.OutOfMemoryError: Java heap space
at java.nio.ByteBuffer.wrap(ByteBuffer.java:350)
at org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:128)
at java.io.FilterInputStream.read(FilterInputStream.java:116)
at org.apache.hadoop.ipc.Client$Connection$PingInputStream.read(Client.java:276)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:218)
at java.io.BufferedInputStream.read(BufferedInputStream.java:237)
at java.io.DataInputStream.readInt(DataInputStream.java:370)
at org.apache.hadoop.ipc.Client$Connection.receiveResponse(Client.java:501)
at org.apache.hadoop.ipc.Client$Connection.run(Client.java:446)

Exception in thread "LeaseChecker" java.lang.OutOfMemoryError: GC overhead limit exceeded
Exception in thread "IPC Server handler 4 on 50002" java.lang.OutOfMemoryError: Java heap space
Exception in thread "IPC Server handler 8 on 50002" java.lang.OutOfMemoryError: GC overhead limit exceeded
Exception in thread "IPC Server handler 9 on 50002" java.lang.OutOfMemoryError: GC overhead limit exceeded
Exception in thread "IPC Server handler 2 on 50002" java.lang.OutOfMemoryError: GC overhead limit exceeded
Exception in thread "IPC Server handler 6 on 50002" java.lang.OutOfMemoryError: GC overhead limit exceeded
Exception in thread "ResponseProcessor for block blk_-573819335330670501_1268378" java.lang.OutOfMemoryError: GC overhead limit exceeded
Exception in thread "IPC Server handler 7 on 50002" java.lang.OutOfMemoryError: Java heap space

50001 and 50002 used for dfs and jobtracker. But it's normal that IPC threads consume such big memory?

Thanks,

Michael

--- On Fri, 7/30/10, Alex Loddengaard wrote:

From: Alex Loddengaard <alex@cloudera.com>
Subject: Re: jobtracker.jsp reports "GC overhead limit exceeded"
To: common-user@hadoop.apache.org
Date: Friday, July 30, 2010, 2:19 PM

What does "ps" show you?  How much memory is being used by the jobtracker,
and how large is its heap (loop for HADOOP_HEAPSIZE in hadoop-env.sh)?  Also
consider turning on GC logging, which will find its way to the jobtracker
.out log in /var/log/hadoop:

<http://java.sun.com/developer/technicalArticles/Programming/GCPortal/>

Alex