Ambari Alert

[#1]

Issue:

Sometimes ambari might throw the above alert which puts you in some confusion how all 50 DN's can be active and stale.

Firstly, I suggest you to go through this article from HCC and understand how to identify stale datanodes

Resolution:

Increase the value of the property from 30000(default) to 60000 milli seconds or 180000 milli seconds

dfs.namenode.stale.datanode.interval=60000 or 180000