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https://issues.apache.org/jira/browse/HBASE-14735?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15015330#comment-15015330
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Anoop Sam John commented on HBASE-14735:
----------------------------------------
{code|
public synchronized boolean requestSplit(final Region r) {
239 // don't split regions that are blocking
240 if (shouldSplitRegion() && ((HRegion)r).getCompactPriority() >=
Store.PRIORITY_USER) {
{code}
Here what we says in the comment looks reasonable no? And the patch changes
that
And what was the blocking files count in ur cluster?
See this code
{code}
public int getStoreCompactionPriority() {
int priority = blockingFileCount - storefiles.size();
return (priority == HStore.PRIORITY_USER) ? priority + 1 : priority;
}
{code}
When the current store files count is equal to blockingFilesCount, we will get
a priority = 0 only which looks to be wrong
See this
{code}
// degenerate case: blocked regions require recursive enqueues
536 if (store.getCompactPriority() <= 0) {
537 requestSystemCompaction(region, store, "Recursive enqueue");
538 } else {
539 // see if the compaction has caused us to exceed max region
size
540 requestSplit(region);
541 }
{code}
Comment says for blocked regions we will need recursive enque but check is
doing priority <=0 !!!
What is wrong overall?
> Region may grow too big and can not be split
> --------------------------------------------
>
> Key: HBASE-14735
> URL: https://issues.apache.org/jira/browse/HBASE-14735
> Project: HBase
> Issue Type: Bug
> Components: Compaction, regionserver
> Affects Versions: 1.1.2, 0.98.15
> Reporter: Shuaifeng Zhou
> Assignee: Shuaifeng Zhou
> Attachments: 14735-0.98.patch, 14735-branch-1.1.patch,
> 14735-branch-1.2.patch, 14735-branch-1.2.patch, 14735-master (2).patch,
> 14735-master.patch, 14735-master.patch
>
>
> When a compaction completed, may there are also many storefiles in the store,
> and CompactPriority < 0, then compactSplitThread will do a "Recursive
> enqueue" compaction request instead of request a split:
> {code:title=CompactSplitThread.java|borderStyle=solid}
> if (completed) {
> // degenerate case: blocked regions require recursive enqueues
> if (store.getCompactPriority() <= 0) {
> requestSystemCompaction(region, store, "Recursive enqueue");
> } else {
> // see if the compaction has caused us to exceed max region size
> requestSplit(region);
> }
> {code}
> But in some situation, the "recursive enqueue" request may return null, and
> not build up a new compaction runner. For example, an other compaction of the
> same region is running, and compaction selection will exclude all files older
> than the newest files currently compacting, this may cause no enough files
> can be selected by the "recursive enqueue" request. When this happen, split
> will not be trigged. If the input load is high enough, compactions aways
> running on the region, and split will never be triggered.
> In our cluster, this situation happened, and a huge region more than 400GB
> and 100+ storefiles appeared. Version is 0.98.10, and the trank also have the
> problem.
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