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https://issues.apache.org/jira/browse/HBASE-8276?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13623453#comment-13623453
]
Nicolas Liochon commented on HBASE-8276:
----------------------------------------
I think (I m'not sure but it seems better) we should put here the release notes
of HBASE-6738.
{noformat}
+ ServerName curWorker = null;
+ if (!Strings.isNullOrEmpty(task.cur_worker_name)) {
+ try {
+ curWorker = ServerName.parseServerName(task.cur_worker_name);
+ } catch (IllegalArgumentException ie) {
+ LOG.warn("Got invalid server name:" + task.cur_worker_name);
+ }
+ }
+ final boolean alive =
+ (master.getServerManager() != null && curWorker != null) ?
master.getServerManager()
+ .isServerOnline(curWorker) : true;
{noformat}
You're doing more work than on 0.95 here (on 0.95 we don't parse
task.cur_worker_name and we expect it to be non null/non empty).
Does it mean that 0.95 has a bug?
If I'm not wrong, if it can't be parsed or it's null it will be marked as live
hence not submitted before the timeout. I don't have any opinion on this (I
guess we're in a bad shape anyway), but we we log our intend explicitly
+ } catch (IllegalArgumentException ie) {
+ LOG.error("Got invalid server name:" + task.cur_worker_name + " -
task " + taskId + " won't be resubmitted before timeout");
+ }
+ } else {
+ LOG.error("Got empty/null server name:" + task.cur_worker_name + " -
task " + taskId + " won't be resubmitted before timeout");
+ }
In anycase, the code should be commented to say if the check is for protecting
us from a development bugs or of if it's something that can be expected in some
conditions in production.
As well, we should not rely on the timeout imho (imho, the original distributed
split should have relied only on the ZK timeout: my initial patch kept itto be
compatible with the existing design while adding this, but I would personnaly
recommend a timeout of 15 minutes or no timeout at all).
> Backport hbase-6738 to 0.94 "Too aggressive task resubmission from the
> distributed log manager"
> -----------------------------------------------------------------------------------------------
>
> Key: HBASE-8276
> URL: https://issues.apache.org/jira/browse/HBASE-8276
> Project: HBase
> Issue Type: Bug
> Reporter: Jeffrey Zhong
> Assignee: Jeffrey Zhong
> Attachments: hbase-8276.patch
>
>
> In recent tests, we found situations that when some data nodes are down and
> file operations are slow depending on underlying hdfs timeout(normally 30
> secs and socket connection timeout maybe around 1 min). While split log task
> heart beat time out is only 25 secs, a split log task will be preempted by
> SplitLogManager and assign to someone else after the 25 secs. On a small
> cluster, you'll see the same task is keeping bounced back & force for a
> while. I pasted a snippet of related logs below. You can search "preempted
> from" to see a task is preempted.
> {code}
> 2013-04-01 21:22:08,599 INFO
> org.apache.hadoop.hbase.regionserver.wal.HLogSplitter: Splitting hlog:
> hdfs://ip-10-137-16-140.ec2.internal:8020/apps/hbase/data/.logs/ip-10-137-20-188.ec2.internal,60020,1364849530779-splitting/ip-10-137-20-188.ec2.internal%2C60020%2C1364849530779.1364865506159,
> length=127639653
> 2013-04-01 21:22:08,599 INFO org.apache.hadoop.hbase.util.FSHDFSUtils:
> Recovering file
> hdfs://ip-10-137-16-140.ec2.internal:8020/apps/hbase/data/.logs/ip-10-137-20-188.ec2.internal,60020,1364849530779-splitting/ip-10-137-20-188.ec2.internal%2C60020%2C1364849530779.1364865506159
> 2013-04-01 21:22:09,603 INFO org.apache.hadoop.hbase.util.FSHDFSUtils:
> Finished lease recover attempt for
> hdfs://ip-10-137-16-140.ec2.internal:8020/apps/hbase/data/.logs/ip-10-137-20-188.ec2.internal,60020,1364849530779-splitting/ip-10-137-20-188.ec2.internal%2C60020%2C1364849530779.1364865506159
> 2013-04-01 21:22:09,629 WARN
> org.apache.hadoop.hbase.regionserver.wal.HLogSplitter: Found existing old
> edits file. It could be the result of a previous failed split attempt.
> Deleting
> hdfs://ip-10-137-16-140.ec2.internal:8020/apps/hbase/data/IntegrationTestLoadAndVerify/73387f8d327a45bacf069bd631d70b3b/recovered.edits/0000000000003703447.temp,
> length=0
> 2013-04-01 21:22:09,629 WARN
> org.apache.hadoop.hbase.regionserver.wal.HLogSplitter: Found existing old
> edits file. It could be the result of a previous failed split attempt.
> Deleting
> hdfs://ip-10-137-16-140.ec2.internal:8020/apps/hbase/data/IntegrationTestLoadAndVerify/b749cbceaaf037c97f70cc2a6f48f2b8/recovered.edits/0000000000003703446.temp,
> length=0
> 2013-04-01 21:22:09,630 WARN
> org.apache.hadoop.hbase.regionserver.wal.HLogSplitter: Found existing old
> edits file. It could be the result of a previous failed split attempt.
> Deleting
> hdfs://ip-10-137-16-140.ec2.internal:8020/apps/hbase/data/IntegrationTestLoadAndVerify/c26b9d4a042d42c1194a8c2f389d33c8/recovered.edits/0000000000003703448.temp,
> length=0
> 2013-04-01 21:22:09,666 WARN
> org.apache.hadoop.hbase.regionserver.wal.HLogSplitter: Found existing old
> edits file. It could be the result of a previous failed split attempt.
> Deleting
> hdfs://ip-10-137-16-140.ec2.internal:8020/apps/hbase/data/IntegrationTestLoadAndVerify/adabdb40ccd52140f09f953ff41fd829/recovered.edits/0000000000003703451.temp,
> length=0
> 2013-04-01 21:22:09,722 WARN
> org.apache.hadoop.hbase.regionserver.wal.HLogSplitter: Found existing old
> edits file. It could be the result of a previous failed split attempt.
> Deleting
> hdfs://ip-10-137-16-140.ec2.internal:8020/apps/hbase/data/IntegrationTestLoadAndVerify/19f463fe74f4365e7df3e5fdb13aecad/recovered.edits/0000000000003703468.temp,
> length=0
> 2013-04-01 21:22:09,734 WARN
> org.apache.hadoop.hbase.regionserver.wal.HLogSplitter: Found existing old
> edits file. It could be the result of a previous failed split attempt.
> Deleting
> hdfs://ip-10-137-16-140.ec2.internal:8020/apps/hbase/data/IntegrationTestLoadAndVerify/b3e759a3fc9c4e83064961cc3cd4a911/recovered.edits/0000000000003703459.temp,
> length=0
> 2013-04-01 21:22:09,770 WARN
> org.apache.hadoop.hbase.regionserver.wal.HLogSplitter: Found existing old
> edits file. It could be the result of a previous failed split attempt.
> Deleting
> hdfs://ip-10-137-16-140.ec2.internal:8020/apps/hbase/data/IntegrationTestLoadAndVerify/6f078553be50897a986734ae043a5889/recovered.edits/0000000000003703454.temp,
> length=0
> 2013-04-01 21:22:34,985 INFO
> org.apache.hadoop.hbase.regionserver.SplitLogWorker: task
> /hbase/splitlog/hdfs%3A%2F%2Fip-10-137-16-140.ec2.internal%3A8020%2Fapps%2Fhbase%2Fdata%2F.logs%2Fip-10-137-20-188.ec2.internal%2C60020%2C1364849530779-splitting%2Fip-10-137-20-188.ec2.internal%252C60020%252C1364849530779.1364865506159
> preempted from ip-10-151-29-196.ec2.internal,60020,1364849530671, current
> task state and owner=unassigned
> ip-10-137-16-140.ec2.internal,60000,1364849528428
> {code}
> The exact same issue is fixed by hbase-6738 in trunk so here comes the
> backport.
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