15.2. Logs

The key process logs are as follows... (replace <user> with the user that started the service, and <hostname> for the machine name)

NameNode: $HADOOP_HOME/logs/hadoop-<user>-namenode-<hostname>.log

DataNode: $HADOOP_HOME/logs/hadoop-<user>-datanode-<hostname>.log

JobTracker: $HADOOP_HOME/logs/hadoop-<user>-jobtracker-<hostname>.log

TaskTracker: $HADOOP_HOME/logs/hadoop-<user>-jobtracker-<hostname>.log

HMaster: $HBASE_HOME/logs/hbase-<user>-master-<hostname>.log

RegionServer: $HBASE_HOME/logs/hbase-<user>-regionserver-<hostname>.log

ZooKeeper: TODO

15.2.1. Log Locations

For stand-alone deployments the logs are obviously going to be on a single machine, however this is a development configuration only. Production deployments need to run on a cluster.

15.2.1.1. NameNode

The NameNode log is on the NameNode server. The HBase Master is typically run on the NameNode server, and well as ZooKeeper.

For smaller clusters the JobTracker is typically run on the NameNode server as well.

15.2.1.2. DataNode

Each DataNode server will have a DataNode log for HDFS, as well as a RegionServer log for HBase.

Additionally, each DataNode server will also have a TaskTracker log for MapReduce task execution.