Home | About | Sematext search-lucene.com search-hadoop.com
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB
 Search Hadoop and all its subprojects:

Switch to Plain View
HBase >> mail # user >> connection loss for /hbase


+
Geoff Hendrey 2011-06-04, 00:28
Copy link to this message
-
Re: connection loss for /hbase
Hi Geoff,

The default number of connections in ZK is 10 I believe. You don't need 32K for 100 mappers. But it would help to increase that.
Here's my answer for a related problem http://stackoverflow.com/questions/6153560/hbase-client-connectionloss-for-hbase-error/

I'm not sure how HBase managed ZK works, but I suspect there's a single instance (somebody correct me if I'm wrong).

There's a "zk dump" link on the HBase master web interface where you can see the status of all ZK connections to each node.
You should run a ZK cluster as well on the HBase nodes (3 or 5 nodes, make sure it's not an even number). Here's a set of puppet recipes for Hadoop, HBase, Zookeeper https://github.com/hstack/puppet as well if you want to automate the setup.

Cosmin

On Jun 4, 2011, at 3:28 AM, Geoff Hendrey wrote:

> Hi Folks -
>
>
>
> I am experiencing "ConnectionLoss for /hbase" when I run a mapreduce job
> with around 100 mappers and TableInputFormat. I am running a fully
> distributed cluster, letting hbase manage zookeeper. I am running HBase
> 90.1. Is the solution, per this jira,
> https://issues.apache.org/jira/browse/HBASE-3773 , to increase
> hbase.zookeeper.property.maxClientCnxns to 32k?
>
>
>
> This is the stack trace that I get.
>
>
>
> Caused by: org.apache.hadoop.hbase.ZooKeeperConnectionException:
> org.apache.hadoop.hbase.ZooKeeperConnectionException:
> org.apache.zookeeper.KeeperException$ConnectionLossException:
> KeeperErrorCode = ConnectionLoss for /hbase
>
>        at
> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementat
> ion.getZooKeeperWatcher(HConnectionManager.java:988)
>
>        at
> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementat
> ion.setupZookeeperTrackers(HConnectionManager.java:301)
>
>        at
> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementat
> ion.<init>(HConnectionManager.java:292)
>
>        at
> org.apache.hadoop.hbase.client.HConnectionManager.getConnection(HConnect
> ionManager.java:155)
>
>        at org.apache.hadoop.hbase.client.HTable.<init>(HTable.java:167)
>
>        at org.apache.hadoop.hbase.client.HTable.<init>(HTable.java:145)
>
>
>
>
>
> -geoff
>

+
Buttler, David 2011-06-06, 16:29
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB