[jira] [Commented] (HBASE-20670) NPE in HMaster#isInMaintenanceMode

["Andrew Purtell (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HBASE-20670?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16498626#comment-16498626 ] 

Andrew Purtell commented on HBASE-20670:
----------------------------------------

Moving initialization of ZK trackers up ahead of the filesystem opens a can of worms, no go there. Probably will just throw a PleaseHoldException from HMaster.isInMaintenanceMode. So, some minor adjustments to MasterServices will be needed where in a couple of places we will now have checked exceptions. It is a Private annotated interface so no problem. 

> NPE in HMaster#isInMaintenanceMode
> ----------------------------------
>
>                 Key: HBASE-20670
>                 URL: https://issues.apache.org/jira/browse/HBASE-20670
>             Project: HBase
>          Issue Type: Bug
>    Affects Versions: 1.3.2
>            Reporter: Andrew Purtell
>            Assignee: Andrew Purtell
>            Priority: Minor
>             Fix For: 1.5.0, 1.3.3, 1.4.5
>
>
> {noformat}
> Problem accessing /master-status. Reason: INTERNAL_SERVER_ERROR
> Caused by: java.lang.NullPointerException
> at org.apache.hadoop.hbase.master.HMaster.isInMaintenanceMode(HMaster.java:2559)
> {noformat}
> The ZK trackers, including the maintenance mode tracker, are initialized only after we try to bring up the filesystem. If HDFS is in safe mode and the master is waiting on that, when an access to the master status page comes in we trip over this problem. There might be other issues after we fix this, but NPE Is always a bug, so let's address it. One option is to connect the ZK based components with ZK before attempting to bring up the filesystem. Let me try that first. If that doesn't work we could at least throw an IOE.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)