HDFS' ZKFC service unable to start

Question

CDH4's ZooKeeper Failover Controller (ZKFC) has been installed.

Starting the ZKFC service:

[vagrant@localhost ~]$ sudo service hadoop-hdfs-zkfc start                      
Starting Hadoop zkfc:                                      [  OK  ]
starting zkfc, logging to /var/log/hadoop-hdfs/hadoop-hdfs-zkfc-localhost.localdomain.out

does not seem to work as the log file is empty:

sudo vim /var/log/hadoop-hdfs/hadoop-hdfs-zkfc-localhost.localdomain.log

Question

How to run HDFS' ZKFC?

Solution

Just installing the ZKFC and starting it is not sufficient. HDFS' NameNode (NN) needs to be installed, High Availability (HA) needs to be enabled for this NN to avoid HA is not enabled for this namenode. error and to avoid Missing required configuration 'ha.zookeeper.quorum' for ZooKeeper quorum issue ha.zookeeper.quorum needs to be configured in HDFS' core-site.xml

/etc/hadoop/conf/core-site.xml

 <property>
   <name>ha.zookeeper.quorum</name>
   <value>ip1:2181,ip2:2181,ip3:2181</value>
 </property> 

Cloudera documents this extensively in their High Availability Guide.

Comments

[Travis Campbell]

In addition, you also need to run the "hdfs zkfc –formatZK" so the right znodes are set up in zookeeper.