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From Igor <i...@4friends.od.ua>
Subject Re: Repair Process Taking too long
Date Sat, 14 Apr 2012 05:57:46 GMT
Hi!

What is the difference between 'repair' and '-pr repair'? Simple repair 
touch all token ranges (for all nodes) and -pr touch only range for 
which given node responsible?


On 04/12/2012 05:59 PM, Sylvain Lebresne wrote:
> On Thu, Apr 12, 2012 at 4:06 PM, Frank Ng<buzztemk@gmail.com>  wrote:
>> I also noticed that if I use the -pr option, the repair process went down
>> from 30 hours to 9 hours.  Is the -pr option safe to use if I want to run
>> repair processes in parallel on nodes that are not replication peers?
> There is pretty much two use case for repair:
> 1) to rebuild a node: if say a node has lost some data due to a hard
> drive corruption or the like and you want to to rebuild what's missing
> 2) the periodic repairs to avoid problem with deleted data coming back
> from the dead (basically:
> http://wiki.apache.org/cassandra/Operations#Frequency_of_nodetool_repair)
>
> In case 1) you want to run 'nodetool repair' (without -pr) against the
> node to rebuild.
> In case 2) (which I suspect is the case your talking now), you *want*
> to use 'nodetool repair -pr' on *every* node of the cluster. I.e.
> that's the most efficient way to do it. The only reason not to use -pr
> in this case would be that it's not available because you're using an
> old version of Cassandra. And yes, it's is safe to run with -pr in
> parallel on nodes that are not replication peers.
>
> --
> Sylvain
>
>
>> thanks
>>
>>
>> On Thu, Apr 12, 2012 at 12:06 AM, Frank Ng<berrytemk@gmail.com>  wrote:
>>> Thank you for confirming that the per node data size is most likely
>>> causing the long repair process.  I have tried a repair on smaller column
>>> families and it was significantly faster.
>>>
>>> On Wed, Apr 11, 2012 at 9:55 PM, aaron morton<aaron@thelastpickle.com>
>>> wrote:
>>>> If you have 1TB of data it will take a long time to repair. Every bit of
>>>> data has to be read and a hash generated. This is one of the reasons we
>>>> often suggest that around 300 to 400Gb per node is a good load in the
>>>> general case.
>>>>
>>>> Look at nodetool compactionstats .Is there a validation compaction
>>>> running ? If so it is still building the merkle  hash tree.
>>>>
>>>> Look at nodetool netstats . Is it streaming data ? If so all hash trees
>>>> have been calculated.
>>>>
>>>> Cheers
>>>>
>>>>
>>>> -----------------
>>>> Aaron Morton
>>>> Freelance Developer
>>>> @aaronmorton
>>>> http://www.thelastpickle.com
>>>>
>>>> On 12/04/2012, at 2:16 AM, Frank Ng wrote:
>>>>
>>>> Can you expand further on your issue? Were you using Random Patitioner?
>>>>
>>>> thanks
>>>>
>>>> On Tue, Apr 10, 2012 at 5:35 PM, David Leimbach<leimy2k@gmail.com>
>>>> wrote:
>>>>> I had this happen when I had really poorly generated tokens for the
>>>>> ring.  Cassandra seems to accept numbers that are too big.  You get hot
>>>>> spots when you think you should be balanced and repair never ends (I
think
>>>>> there is a 48 hour timeout).
>>>>>
>>>>>
>>>>> On Tuesday, April 10, 2012, Frank Ng wrote:
>>>>>> I am not using tier-sized compaction.
>>>>>>
>>>>>>
>>>>>> On Tue, Apr 10, 2012 at 12:56 PM, Jonathan Rhone<rhone@tinyco.com>
>>>>>> wrote:
>>>>>>> Data size, number of nodes, RF?
>>>>>>>
>>>>>>> Are you using size-tiered compaction on any of the column families
>>>>>>> that hold a lot of your data?
>>>>>>>
>>>>>>> Do your cassandra logs say you are streaming a lot of ranges?
>>>>>>> zgrep -E "(Performing streaming repair|out of sync)"
>>>>>>>
>>>>>>>
>>>>>>> On Tue, Apr 10, 2012 at 9:45 AM, Igor<igor@4friends.od.ua>
 wrote:
>>>>>>>> On 04/10/2012 07:16 PM, Frank Ng wrote:
>>>>>>>>
>>>>>>>> Short answer - yes.
>>>>>>>> But you are asking wrong question.
>>>>>>>>
>>>>>>>>
>>>>>>>> I think both processes are taking a while.  When it starts
up,
>>>>>>>> netstats and compactionstats show nothing.  Anyone out there
successfully
>>>>>>>> using ext3 and their repair processes are faster than this?
>>>>>>>>
>>>>>>>> On Tue, Apr 10, 2012 at 10:42 AM, Igor<igor@4friends.od.ua>
 wrote:
>>>>>>>>> Hi
>>>>>>>>>
>>>>>>>>> You can check with nodetool  which part of repair process
is slow -
>>>>>>>>> network streams or verify compactions. use nodetool netstats
or
>>>>>>>>> compactionstats.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On 04/10/2012 05:16 PM, Frank Ng wrote:
>>>>>>>>>> Hello,
>>>>>>>>>>
>>>>>>>>>> I am on Cassandra 1.0.7.  My repair processes are
taking over 30
>>>>>>>>>> hours to complete.  Is it normal for the repair process
to take this long?
>>>>>>>>>>   I wonder if it's because I am using the ext3 file
system.
>>>>>>>>>>
>>>>>>>>>> thanks
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Jonathan Rhone
>>>>>>> Software Engineer
>>>>>>>
>>>>>>> TinyCo
>>>>>>> 800 Market St., Fl 6
>>>>>>> San Francisco, CA 94102
>>>>>>> www.tinyco.com
>>>>>>>
>>>>


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