hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Andrew Wang (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-7400) More reliable namenode health check to detect OS/HW issues
Date Sat, 15 Nov 2014 01:08:33 GMT

    [ https://issues.apache.org/jira/browse/HDFS-7400?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14213215#comment-14213215
] 

Andrew Wang commented on HDFS-7400:
-----------------------------------

So in {{monitorHealth}} we do a basic check just to see if the NN has free disk space. I'd
be okay extending this to other checks related to disk health.

Out of curiosity, did your failure condition result in a situation where {{df}} worked, but
the disk was otherwise non-functional? I guess with no SSH it's a little hard to check, but
I wonder what we could add to {{monitorHealth}} to detect this failure condition.

> More reliable namenode health check to detect OS/HW issues
> ----------------------------------------------------------
>
>                 Key: HDFS-7400
>                 URL: https://issues.apache.org/jira/browse/HDFS-7400
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>            Reporter: Ming Ma
>
> We had this scenario on an active NN machine.
> * Disk array controller firmware has a bug. So disks stop working.
> * ZKFC and NN still considered the node healthy; Communications between ZKFC and ZK as
well as ZKFC and NN are good.
> * The machine can be pinged.
> * The machine can't be sshed.
> So all clients and DNs can't use the NN. But ZKFC and NN still consider the node healthy.
> The question is how we can have ZKFC and NN detect such OS/HW specific issues quickly?
Some ideas we discussed briefly,
> * Have other machines help to make the decision whether the NN is actually healthy. Then
you have to figure out to make the decision accurate in the case of network issue, etc.
> * Run OS/HW health check script external to ZKFC/NN on the same machine. If it detects
disk or other issues, it can reboot the machine for example.
> * Run OS/HW health check script inside ZKFC/NN. For example NN's HAServiceProtocol#monitorHealth
can be modified to call such health check script.
> Thoughts?



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message