The following are the places that index information about Hadoop/HBase and other project exceptions, and where we can search for information about Hadoop/HBase errors:
#hbase on irc.freenode.net
A mailing list of HBase at http://hbase.apache.org/mail-lists.html
Now, let's see the frequent errors and solutions for these:
For troubleshooting, a log is an excellent place to look into. Now, let's see the default log locations of various daemon processes:
NameNode:
<hadoop home path>/logs/hadoop-<user>-namenode-<hostname>.log
DataNode:
<hadoop home path>/logs/hadoop-<user>-datanode-<hostname>.log
JobTracker:
<hadoop home path>/logs/hadoop-<user>-jobtracker-<hostname>.log
TaskTracker:
<hadoop home path>/logs/hadoop-<user>-tasktracker-<hostname>.log
HMaster:
<hadoop home path>/logs/hbase-<user>-master-<hostname>.log...