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Cannection to HBase / Zookeeper hangs.

Cannection to HBase / Zookeeper hangs.

New Contributor
Hello all

I have a MapReduce job connecting to HBase. I have tested it on Cloudera VM 5.0.0 (so psuedo-distributed mode). Now I try to run it on a CDH5 cluster deployed on Amazon EC2.
Following the advices found in Google, I updated the dependency in my JAR to match the one on the cluster: for HBase and 2.3.0-cdh5.0.2 for Hadoop. Also, I added hbase.zookeeper.quorum property to my HBaseConfiguration (it was not necessary in pseudo-distributed mode...):

Configuration mapReduceConfiguration = HBaseConfiguration.create();
mapReduceConfiguration.set("hbase.zookeeper.quorum", "domU-12-31-39-16-60-87.compute-1.internal");
mapReduceConfiguration.set("", "2181");
My job hangs after a successful (?) session establishment to Zookeeper. Stacktrace available here:

My HBase cluster consists of a master and 2 slaves. Zookeeper has one server, the same as HBase master. Some of these values are present in the logs, so a quick summary:
Master public
Master private DNS: domU-12-31-39-16-60-87.compute-1.internal
Slave01 public

Slave01 private DNS: ip-10-2-31-239.ec2.internal

Slave02 private DNS: ip-10-72-214-28.ec2.internal
Any ideas what might be set wrong?

Best regards,



Re: Cannection to HBase / Zookeeper hangs.

Master Guru
Right after the ZK connection is successfully established, the client would attempt to talk to the RegionServer hosting the META region. I suspect this is what it is getting failures at (and is silently retrying).

If you give it a while (say, 10m), or attempt a jstack on it, do you see any forms of exception or places where it is stuck trying to grab a connection to your RSes? That information may help you proceed with troubleshooting the issue.