hadoop-common-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "dhruba borthakur (JIRA)" <j...@apache.org>
Subject [jira] Updated: (HADOOP-1501) Block reports from all datanodes arrive at the namenode within a small band of time
Date Wed, 20 Jun 2007 17:58:26 GMT

     [ https://issues.apache.org/jira/browse/HADOOP-1501?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel

dhruba borthakur updated HADOOP-1501:

    Assignee: dhruba borthakur
      Status: Patch Available  (was: Open)

Thanks for the review. I have not yet changed the 90-100% variablity of the periodicity of
the block reports. I would like to keep that variability because it provides us with another
randomization factor so that all block reports do not arrive at the namenode at around the
same time. 

> Block reports from all datanodes arrive at the namenode within a small band of time
> -----------------------------------------------------------------------------------
>                 Key: HADOOP-1501
>                 URL: https://issues.apache.org/jira/browse/HADOOP-1501
>             Project: Hadoop
>          Issue Type: Bug
>          Components: dfs
>            Reporter: dhruba borthakur
>            Assignee: dhruba borthakur
>         Attachments: randomBlockReportInterval.patch
> I have a 2000 node cluster and the block report interval is set to 1 hour. Most block
report arrive within a few minutes of one another. For example, I have seen block reports
from all 2000 nodes arrive within 5 minutes of one another. This causes CPU overload on the
namenode, causing dropped calls in Call queue.
> My proposal is to make the datanode send a block report as soon as the datanode starts.
Then, it waits for a random time between 0 to 1 hour (the configured value) before sending
the nect block report. From then on, block reports from that datanode are sent once every
1 hour (the configured value).

This message is automatically generated by JIRA.
You can reply to this email to add a comment to the issue online.

View raw message