-Re: 0 tasktrackers in jobtracker but all datanodes present
madhu phatak 2012-04-02, 06:38
1. Stop the job tracker and task trackers. - bin/stop-mapred.sh
2. Disable namenode safemode - bin/hadoop dfsadmin -safemode leave
3. Start the job tracker and tasktrackers again - bin/start-mapred.sh
On Fri, Jan 13, 2012 at 5:20 AM, Ravi Prakash <[EMAIL PROTECTED]> wrote:
> Courtesy Kihwal and Bobby
> Have you tried increasing the max heap size with -Xmx? and make sure that
> you have swap enabled.
> On Wed, Jan 11, 2012 at 6:59 PM, Gaurav Bagga <[EMAIL PROTECTED]> wrote:
> > Hi
> > hadoop-0.19
> > I have a working hadoop cluster which has been running perfectly for
> > months.
> > But today after restarting the cluster, at jobtracker UI its showing
> > INITIALIZING for a long time and is staying on the same state.
> > The nodes in jobtracker are zero whereas all the nodes are present on the
> > dfs.
> > It says Safe mode is on.
> > grep'ed on slaves and I see the tasktrackers running.
> > In namenode logs i get the following error
> > 2012-01-11 16:50:57,195 WARN ipc.Server - Out of Memory in server select
> > java.lang.OutOfMemoryError: Java heap space
> > at java.nio.HeapByteBuffer.<init>(HeapByteBuffer.java:39)
> > at java.nio.ByteBuffer.allocate(ByteBuffer.java:312)
> > at
> > org.apache.hadoop.ipc.Server$Connection.readAndProcess(Server.java:804)
> > at org.apache.hadoop.ipc.Server$Listener.doRead(Server.java:400)
> > at org.apache.hadoop.ipc.Server$Listener.run(Server.java:309)
> > Not sure why the cluster is not coming up
> > -G