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From Alaa Zubaidi <alaa.zuba...@pdf.com>
Subject Re: 0.7 memory usage problem
Date Fri, 24 Sep 2010 22:03:01 GMT
  Nothing is working, after disabling swap entirely, the heap is not 
exhausted but Cassandra crashed with out of memory error.
I even slowed down the reading and writing, tried access mode=standard 
nothing is working.
am I using Cassandra wrong or is it Windows?

Any help is appreciated?
Alaa

On 9/21/2010 6:56 PM, Jonathan Ellis wrote:
> Disabling swap entirely is usually the easiest fix, yes.
>
> On Mon, Sep 20, 2010 at 8:10 PM, Alaa Zubaidi<alaa.zubaidi@pdf.com>  wrote:
>>   Thanks Peter,
>> I decreased the heap size, it did not help, however, it delayed the problem.
>> I noticed that its swapping, so, do you think that I should set windows to
>> Not to swap?
>>
>> Do you think its related to this issue?
>> https://issues.apache.org/jira/browse/CASSANDRA-1014
>>
>> Thanks,
>> Alaa
>>
>> On 9/18/2010 7:04 AM, Peter Schuller wrote:
>>>> I see a spike in heap memory usage on Node 2 where it goes from around 1G
>>>> to
>>>> 6GB (max) in less than an hour, and then goes our of memory.
>>>> There are some errors in the log file that are reported by other people,
>>>> but
>>>> I don't think that these errors are the reason, because it use to happen
>>>> even before I have seen them.
>>>>
>>>> Can someone help me understand whats going on??
>>> Only partially:
>>>
>>> 54 seconds ParNew GC:s are wild and crazy:
>>>
>>>     INFO [GC inspection] 2010-09-17 14:53:59,403 GCInspector.java (line
>>> 129) GC for ParNew: 54095 ms, 53297952 reclaimed leaving 4712568360
>>> used; max is 6563430400
>>>
>>> Is the machine swapping?
>>>
>>> I noticed there is hinted hand-off activity going on. Maybe that is a
>>> result of nodes dropping in and out due to swapping. In any case, you
>>> definitely don't want to have the machine swapping to death. I'm not
>>> sure what the best way is to avoid this on Windows, other than
>>> decreasing heap size.
>>>
>>> The repeated exceptions in your log aren't normal as far as I know. I
>>> don't remember, but IIRC the UTF-8 encoding issues can be caused by
>>> changing partitioner after inserting data (but I'm not sure).
>>>
>>> With respect to memory use, you don't seem to be inserting so much
>>> data for bloom filters and sstable index samples to be a problem.
>>> Memtable flushing could cause problems if they're happening too slowly
>>> (maybe plausible with swapping) - except that the stage statistics
>>> don't indicate there are lots of memtables in memory waiting to be
>>> flushed, so that shouldn't be it.
>>>
>>> Hinted handoff maybe, but I don't remember whether hinted handoff has
>>> the potential to accumulate data in RAM (no time to check now).
>>>
>>> Regardless, I'd recommend fixing any swapping issues you have before
>>> trying to draw conclusions about performance. And you don't want those
>>> exceptions in your logs.
>>>
>> --
>> Alaa Zubaidi
>> PDF Solutions, Inc.
>> 333 West San Carlos Street, Suite 700
>> San Jose, CA 95110  USA
>> Tel: 408-283-5639 (or 408-280-7900 x5639)
>> fax: 408-938-6479
>> email: alaa.zubaidi@pdf.com
>>
>>
>>
>
>

-- 
Alaa Zubaidi
PDF Solutions, Inc.
333 West San Carlos Street, Suite 700
San Jose, CA 95110  USA
Tel: 408-283-5639 (or 408-280-7900 x5639)
fax: 408-938-6479
email: alaa.zubaidi@pdf.com


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