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https://issues.apache.org/jira/browse/HBASE-21751?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16749607#comment-16749607
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Allan Yang commented on HBASE-21751:
------------------------------------
{quote}
But if you do not use multi WAL, this will not cause a very big problem?
{quote}
We don not use multi WAL. Yes, no region on the RS before can cause this, but
in our case, it's the meta wal, so the RS don't host the meta region before
{quote}
And we will retry a lot of times when rolling a WAL, so for your production,
the first thing is that why we still fail after so many retries? The actual
problem is on HDFS?
{quote}
Yes, it is HDFS causing this, it is because of disk full this time, but we have
seen some other glitches in HDFS can cause roll log fail. Actually, the disk
full problem is soon auto recovered after hfiles in archive dir deleted. But
due to this issue, the meta region can not online forever.
> WAL creation fails during region open may cause region assign forever fail
> --------------------------------------------------------------------------
>
> Key: HBASE-21751
> URL: https://issues.apache.org/jira/browse/HBASE-21751
> Project: HBase
> Issue Type: Bug
> Affects Versions: 2.1.2, 2.0.4
> Reporter: Allan Yang
> Assignee: Allan Yang
> Priority: Major
> Fix For: 2.2.0, 2.1.3, 2.0.5
>
> Attachments: HBASE-21751.patch, HBASE-21751v2.patch
>
>
> During the first region opens on the RS, WALFactory will create a WAL file,
> but if the wal creation fails, in some cases, HDFS will leave a empty file in
> the dir(e.g. disk full, file is created succesfully but block allocation
> fails). We have a check in AbstractFSWAL that if WAL belong to the same
> factory exists, then a error will be throw. Thus, the region can never be
> open on this RS later.
> {code:java}
> 2019-01-17 02:15:53,320 ERROR [RS_OPEN_META-regionserver/server003:16020-0]
> handler.OpenRegionHandler(301): Failed open of region=hbase:meta,,1.1588230740
> java.io.IOException: Target WAL already exists within directory
> hdfs://cluster/hbase/WALs/server003.hbase.hostname.com,16020,1545269815888
> at
> org.apache.hadoop.hbase.regionserver.wal.AbstractFSWAL.<init>(AbstractFSWAL.java:382)
> at
> org.apache.hadoop.hbase.regionserver.wal.AsyncFSWAL.<init>(AsyncFSWAL.java:210)
> at
> org.apache.hadoop.hbase.wal.AsyncFSWALProvider.createWAL(AsyncFSWALProvider.java:72)
> at
> org.apache.hadoop.hbase.wal.AsyncFSWALProvider.createWAL(AsyncFSWALProvider.java:47)
> at
> org.apache.hadoop.hbase.wal.AbstractFSWALProvider.getWAL(AbstractFSWALProvider.java:138)
> at
> org.apache.hadoop.hbase.wal.AbstractFSWALProvider.getWAL(AbstractFSWALProvider.java:57)
> at org.apache.hadoop.hbase.wal.WALFactory.getWAL(WALFactory.java:264)
> at
> org.apache.hadoop.hbase.regionserver.HRegionServer.getWAL(HRegionServer.java:2085)
> at
> org.apache.hadoop.hbase.regionserver.handler.OpenRegionHandler.openRegion(OpenRegionHandler.java:284)
> at
> org.apache.hadoop.hbase.regionserver.handler.OpenRegionHandler.process(OpenRegionHandler.java:108)
> at
> org.apache.hadoop.hbase.executor.EventHandler.run(EventHandler.java:104)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1147)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:622)
> at java.lang.Thread.run(Thread.java:834)
> {code}
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