CODEWITHSUNDEEP
hadoophbaseapache-zookeeper
Raj Kishore
Raj Kishore

Reputation: 1

hbase zookeeper client connect issue

I received the below error in zookeeper when I log in my cluster environment. I am using the default zookeeper which comes along with hbase.

HBase is able to connect to ZooKeeper but the connection closes immediately. 
This could be a sign that the server has too many connections (30 is the default)
Consider inspecting your ZK server logs for that error and then make sure you  
are reusing HBase Configuration as often as you can. See HTable's javadoc for
more information.

Upvotes: 0

Views: 1726

Answers (3)

Joarder Kamal
Joarder Kamal

Reputation: 1397

You can also take a look at the hbase.regionserver.handler.count

http://hbase.apache.org/configuration.html#recommended_configurations

Upvotes: 0

Tariq
Tariq

Reputation: 34184

It seems to be a file handle issue to me. HBase uses a lot of files all at the same time. The default ulimit -n -- i.e. user file limit -- of 1024 on most *nix systems is insufficient. Increasing the maximum number of file handles to a higher value say 10,000 or more might help. Please note that increasing the file handles for the user who is running the HBase process is an operating system configuration and not an HBase configuration.

If you are on Ubuntu you will need to make the following changes:

In the file /etc/security/limits.conf add the following line 

hadoop  -       nofile  32768

Replace hadoop with whatever user is running Hadoop and HBase. If you have separate users, you will need 2 entries, one for each user. In the same file set nproc hard and soft limits. For example:

hadoop soft/hard nproc 32000

In the file /etc/pam.d/common-session add as the last line in the file:

session required  pam_limits.so

Otherwise the changes in /etc/security/limits.conf won't be applied.

Don't forget to log out and back in again for the changes to take effect.

Reference : http://hbase.apache.org/book.html#basic.prerequisites

HTH

Upvotes: 1

Tejas Patil
Tejas Patil

Reputation: 6169

There can be many reasons.

  1. I would say, first try this.
  2. verify if /etc/hosts file is set correctly
  3. Check your hbase configuration. Have you configured hbase-env.sh to manage Zookeeper itself? Have you configured zookeeper quorums in hbase-site.xml?
  4. try copying the zoo.cfg in the hadoop conf directory (on classpath really) on the entire cluster. (Source)
  5. If that doesn't work out, go through your code and see if you are creating multiples HBaseConfiguration objects. The approach, as mentioned here, is to this is to create one single HBaseConfiguration object and then reuse it in all your code.

Upvotes: 0

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