[
https://issues.apache.org/jira/browse/HBASE-9968?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Esteban Gutierrez resolved HBASE-9968.
--------------------------------------
Resolution: Won't Fix
We no longer have {{-ROOT-}}
> Cluster is non operative if the RS carrying -ROOT- is expiring after deleting
> -ROOT- region transition znode and before adding it to online regions.
> ----------------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: HBASE-9968
> URL: https://issues.apache.org/jira/browse/HBASE-9968
> Project: HBase
> Issue Type: Bug
> Components: Region Assignment
> Affects Versions: 0.94.11
> Reporter: rajeshbabu
> Assignee: rajeshbabu
>
> When we check whether the dead region is carrying root or meta, first we will
> check any transition znode for the region is there or not. In this case it
> got deleted. So from zookeeper we cannot find the region location.
> {code}
> try {
> data = ZKAssign.getData(master.getZooKeeper(), hri.getEncodedName());
> } catch (KeeperException e) {
> master.abort("Unexpected ZK exception reading unassigned node for
> region="
> + hri.getEncodedName(), e);
> }
> {code}
> Now we will check from the AssignmentManager whether its in online regions or
> not
> {code}
> ServerName addressFromAM = getRegionServerOfRegion(hri);
> boolean matchAM = (addressFromAM != null &&
> addressFromAM.equals(serverName));
> LOG.debug("based on AM, current region=" + hri.getRegionNameAsString() +
> " is on server=" + (addressFromAM != null ? addressFromAM : "null") +
> " server being checked: " + serverName);
> {code}
> From AM we will get null because while adding region to online regions we
> will check whether the RS is in onlineservers or not and if not we will not
> add the region to online regions.
> {code}
> if (isServerOnline(sn)) {
> this.regions.put(regionInfo, sn);
> addToServers(sn, regionInfo);
> this.regions.notifyAll();
> } else {
> LOG.info("The server is not in online servers, ServerName=" +
> sn.getServerName() + ", region=" + regionInfo.getEncodedName());
> }
> {code}
> Even though the dead regionserver carrying ROOT region, its returning false.
> After that ROOT region never assigned.
> Here are the logs
> {code}
> 2013-11-11 18:04:14,730 INFO
> org.apache.hadoop.hbase.catalog.RootLocationEditor: Unsetting ROOT region
> location in ZooKeeper
> 2013-11-11 18:04:14,775 DEBUG
> org.apache.hadoop.hbase.master.AssignmentManager: No previous transition plan
> was found (or we are ignoring an existing plan) for -ROOT-,,0.70236052 so
> generated a random one; hri=-ROOT-,,0.70236052, src=,
> dest=HOST-10-18-40-69,60020,1384173244404; 1 (online=1, available=1)
> available servers
> 2013-11-11 18:04:14,809 DEBUG
> org.apache.hadoop.hbase.master.AssignmentManager: Assigning region
> -ROOT-,,0.70236052 to HOST-10-18-40-69,60020,1384173244404
> 2013-11-11 18:04:18,375 DEBUG
> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation:
> Looked up root region location,
> connection=org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation@12133926;
> serverName=HOST-10-18-40-69,60020,1384173244404
> 2013-11-11 18:04:26,213 DEBUG
> org.apache.hadoop.hbase.master.AssignmentManager: Handling
> transition=RS_ZK_REGION_OPENED, server=HOST-10-18-40-69,60020,1384173244404,
> region=70236052/-ROOT-
> 2013-11-11 18:04:26,213 INFO
> org.apache.hadoop.hbase.master.handler.OpenedRegionHandler: Handling OPENED
> event for -ROOT-,,0.70236052 from HOST-10-18-40-69,60020,1384173244404;
> deleting unassigned node
> 2013-11-11 18:04:31,553 DEBUG
> org.apache.hadoop.hbase.master.AssignmentManager: based on AM, current
> region=-ROOT-,,0.70236052 is on server=null server being checked:
> HOST-10-18-40-69,60020,1384173244404
> 2013-11-11 18:04:31,561 DEBUG org.apache.hadoop.hbase.master.ServerManager:
> Added=HOST-10-18-40-69,60020,1384173244404 to dead servers, submitted
> shutdown handler to be executed, root=false, meta=false
> {code}
> {code}
> 2013-11-11 18:04:32,323 DEBUG
> org.apache.hadoop.hbase.master.AssignmentManager: The znode of region
> -ROOT-,,0.70236052 has been deleted.
> 2013-11-11 18:04:32,323 INFO
> org.apache.hadoop.hbase.master.AssignmentManager: The server is not in online
> servers, ServerName=HOST-10-18-40-69,60020,1384173244404, region=70236052
> 2013-11-11 18:04:32,323 INFO
> org.apache.hadoop.hbase.master.AssignmentManager: The master has opened the
> region -ROOT-,,0.70236052 that was online on
> HOST-10-18-40-69,60020,1384173244404
> {code}
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
