What happens when HBase node fails?

Question

HBase is wonderful, but...

What will happen to the data when a node (explodes/burns down/gets stolen/Torn into pieces by mad IT on the loose)?

• Is the data lost?
• Can the cluster auto recover?
• Can I add new nodes without downtime?

Thanks guys, Maxim.

Answer 1

1. Because HBase uses HDFS as a data storage layer, your data is replicated on the other nodes (3 by default). And same rules apply as to normal HDFS usage.

2. What to you mean by auto recovery? The data after some time will eventually return to the state of replication level before crash.

3. Yes, you can. See this topic in FAQ: http://wiki.apache.org/hadoop/Hbase/FAQ#A21