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From Ted Yu <yuzhih...@gmail.com>
Subject Re: How to know when datanode are marked dead by namenode
Date Sun, 29 Mar 2015 01:13:59 GMT
Himawan:
Please see the following constants
in hadoop-hdfs-project//hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java
:

  public static final String  DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_KEY =
"dfs.namenode.heartbeat.recheck-interval";

  public static final int
DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_DEFAULT = 5*60*1000;

Cheers

On Sat, Mar 28, 2015 at 5:48 PM, Himawan Mahardianto <mahardianto@ugm.ac.id>
wrote:

> Thank you for your response and explanation, but I couldn't find "
> dfs.namenode.heartbeat.recheck-interval" parameter on
> http://hadoop.apache.org/docs/current/hadoop-project-dist/hadoop-hdfs/hdfs-default.xml
> that you told before, maybe any other formula with this version?
>
> On Sat, Mar 28, 2015 at 6:42 PM, Brahma Reddy Battula <
> brahmareddy.battula@huawei.com> wrote:
>
>>  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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