You could set the blocking store files setting higher (we have it at
17 here), but looking at the log I see it was blocking for 90secs only
to flush a 1MB file. Why was that flush requested? Global memstore
size reached? The log from a few lines before should tell

J-D

On Mon, Sep 27, 2010 at 1:18 PM, Jack Levin <[email protected]> wrote:
> I see it:  http://pastebin.com/tgQHBSLj
>
> Interesting situation indeed.  Any thoughts on how to avoid it?  Have
> compaction running more aggressively?
>
> -Jack
>
> On Mon, Sep 27, 2010 at 1:00 PM, Jean-Daniel Cryans <[email protected]> 
> wrote:
>> Can you grep around the region server log files to see what was going
>> on with that region during the previous run? There's only 1 way I see
>> this happening, and it would require that your region server would be
>> serving thousands of regions and that this region was in queue to be
>> compacted behind all those thousands of regions, and in the mean time
>> the flush blocker of 90 seconds would timeout at least enough times so
>> that you would end up with all those store files (which according to
>> my quick calculation, would mean that it took about 23 hours before
>> the region server was able to compact that region which is something
>> I've never seen, and it would have killed your region server with
>> OOME). Do you see this message often?
>>
>>       LOG.info("Waited " + (System.currentTimeMillis() - fqe.createTime) +
>>          "ms on a compaction to clean up 'too many store files'; waited " +
>>          "long enough... proceeding with flush of " +
>>          region.getRegionNameAsString());
>>
>> Thx,
>>
>> J-D
>>
>> On Mon, Sep 27, 2010 at 12:54 PM, Jack Levin <[email protected]> wrote:
>>> Strange: this is what I have:
>>>
>>>  <property>
>>>    <name>hbase.hstore.blockingStoreFiles</name>
>>>    <value>7</value>
>>>    <description>
>>>    If more than this number of StoreFiles in any one Store
>>>    (one StoreFile is written per flush of MemStore) then updates are
>>>    blocked for this HRegion until a compaction is completed, or
>>>    until hbase.hstore.blockingWaitTime has been exceeded.
>>>    </description>
>>>  </property>
>>>
>>> I wonder how it got there, I've deleted the files.
>>>
>>> -jack
>>>
>>>
>>> On Mon, Sep 27, 2010 at 12:42 PM, Jean-Daniel Cryans
>>> <[email protected]> wrote:
>>>> I'd say it's the:
>>>>
>>>> 2010-09-27 12:16:15,291 INFO
>>>> org.apache.hadoop.hbase.regionserver.Store: Started compaction of 943
>>>> file(s) in att of
>>>> img833,dsc03711s.jpg,1285493435306.da57612ee69d7baaefe84
>>>> eeb0e49f240.  into
>>>> hdfs://namenode-rd.imageshack.us:9000/hbase/img833/da57612ee69d7baaefe84eeb0e49f240/.tmp,
>>>> sequenceid=618626242
>>>>
>>>> That killed you. I wonder how it was able to get there since the
>>>> Memstore blocks flushing if the upper threshold for compactions was
>>>> reached (default is 7, did you set it to 1000 by any chance?).
>>>>
>>>> J-D
>>>>
>>>> On Mon, Sep 27, 2010 at 12:29 PM, Jack Levin <[email protected]> wrote:
>>>>> Strange situation, cold start the cluster, and one of the servers just
>>>>> started getting more and more consuming of RAM, you can see it form
>>>>> the screenshot I am attaching.  Here is the log:
>>>>> http://pastebin.com/MDPJzLQJ
>>>>>
>>>>> There seem to be nothing happen, and then it just runs out of Memory,
>>>>> and of course shuts down.
>>>>>
>>>>> Here is GC log before the crash:  http://pastebin.com/GwdC3nhx
>>>>>
>>>>> Strange , that other region servers stay up and consuming little
>>>>> memory (or rather stay stable.).
>>>>>
>>>>> Any ideas?
>>>>>
>>>>> -Jack
>>>>>
>>>>
>>>
>>
>

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