HBase Administration - HBase Essentials - page 137

To ix this issue, increase the process execution count for the user by adding the
following property in the /etc/security/limits.conf ile:
$ vi /etc/security/limits.conf
<username> soft nproc 35000
<username> hard nproc 35000
Also, add the following line to the /etc/pam.d/login ile:
$ vi /etc/pam.d/login
session required pam_limits.so
Once done, log out and log in again as the user and restart the Hadoop and HBase
clusters. The upper limit for iles can be veriied using the following command:
$ ulimit -u
ZooKeeper client connection error: ZooKeeper deines the maxClientCnxns property
that deines the number of concurrent connections any client might make to a
member of the ZooKeeper ensemble. This error usually occurs when running a
MapReduce job over an HBase cluster. In the HBase cluster, region server acts as a
ZooKeeper client, and if a region server's concurrent connection count exceeds the
limit deined by ZooKeeper, the following error occurs:
java.io.IOException: Connection reset by peer
To ix this error, add/update the following property in the ZooKeeper coniguration
ile ( zoo.cfg ) on every ZooKeeper quorum node:
$ vi $ZOOKEEPER_HOME/conf/zoo.cfg
maxClientCnxns=100
Restart the ZooKeeper to apply the changes.
Summary
In this chapter, we looked at the HBase cluster administration techniques. We
also discussed the different ways to monitor the HBase cluster starting from using
the HBase monitoring framework and JMX to third-party tools, such as Ganglia
and Nagios.
In the last section, we learned about the performance tuning areas that require
considerations to get the optimized performance based on the workloads. This
chapter also sheds some light on the HBase cluster trouble shooting.