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From Brahma Reddy Battula <brahmareddy.batt...@huawei.com>
Subject RE: How to know when datanode are marked dead by namenode
Date Sat, 28 Mar 2015 11:42:20 GMT
HI

The NameNode updates this detail after 10.30 minutes by default. You can see the dead and
live datanodes at that time.

It computes this heartbeatExpireInterval time by the following formula

  heartbeatExpireInterval = 2 * heartbeatRecheckInterval +
      10 * 1000* heartbeatInterval

where heartbeatRecheckInterval is defined by the configuration dfs.namenode.heartbeat.recheck-interval
which is 5 minutes by default and heartbeatInterval by dfs.heartbeat.interval which is 3 seconds
by default.

Hence
heartbeatExpireInterval = 10.30 minutes


SO If you want keep more time, you can configure dfs.namenode.heartbeat.recheck-interval based
one your requirement..



Thanks & Regards

Brahma Reddy Battula




________________________________
From: Himawan Mahardianto [mahardianto@ugm.ac.id]
Sent: Saturday, March 28, 2015 4:42 PM
To: user@hadoop.apache.org
Subject: How to know when datanode are marked dead by namenode

Hi guys I'm newbie here, do you know how to time calculation when datanode are marked dead
by namenode, what parameters on HDFS-SITE.xml should I look for to calculate it, and how can
I reduce dead time from default 10 minutes to 5 minutes or increase it to 20 minutes?
Thank's before

best regards
Himawan Mahardianto

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