Please look at dfs.heartbeat.interval and dfs.namenode.heartbeat.recheck-interval
40 datanodes is not a large cluster IMHO and the Namenode is capable of managing 100 times more datanodes. ________________________________ From: Rita <rmorgan...@gmail.com> To: "<common-user@hadoop.apache.org>" <common-user@hadoop.apache.org> Sent: Sunday, October 6, 2013 9:49 AM Subject: datanode tuning I would like my 40 data nodes to aggressively report to namenode if they are alive or not therefore I think I need to change these params dfs.block.access.token.lifetime : Default is 600 seconds. Can I decrease this to 60? dfs.block.access.key.update.interval: Default is 600 seconds. Can I decrease this to 60? Also, what are some other turnings people do for datanodes in a relatively large cluster? -- --- Get your facts first, then you can distort them as you please.--
