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Zookeeper >> mail # dev >> Something about performance of Zookeeper


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Qian Ye 2011-03-08, 16:08
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Qian Ye 2011-03-08, 16:16
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Flavio Junqueira 2011-03-08, 16:29
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Qian Ye 2011-03-09, 02:44
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Eugene Koontz 2011-03-09, 07:24
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Flavio Junqueira 2011-03-09, 09:28
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lei he 2011-03-09, 13:00
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Benjamin Reed 2011-03-09, 17:22
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lei he 2011-03-10, 02:31
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lei he 2011-03-21, 05:35
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Flavio Junqueira 2011-03-21, 10:50
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Qian Ye 2011-03-21, 12:14
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Re: Something about performance of Zookeeper
Qian, I'm not sure where you're getting 20% performance degradation  
from, but I think multiple people on this list have observed severe  
performance degradation due to logging. I don't have numbers at this  
time to share with you, though. Perhaps Lei He can share some more  
numbers to help you understand the exact effect.

-Flavio

On Mar 21, 2011, at 1:14 PM, Qian Ye wrote:

> really? maybe that's the reason for my bad performance results too.  
> However, how could logging makes so huge effect to the performance.  
> I mean, usually it only leads to about 20% performance loss when you  
> adding more log in the program. This phenomenon is beyond my  
> understanding. Could any one give me some explanation?
>
> thanks
>
> 2011/3/21 Flavio Junqueira <[EMAIL PROTECTED]>
> Ah, right! Good catch.
>
> -Flavio
>
> On Mar 21, 2011, at 6:35 AM, lei he wrote:
>
>> Sorry for the report, I made a mistake. When I turn off the debug  
>> level log
>> in zookeeper servers, the performance is like you described.
>> Thanks for you guys.
>> 在 2011年3月10日 上午10:31���lei he <[EMAIL PROTECTED]>写道:
>>
>>> thanks for reply. I use scp to check my ethernet again, the  
>>> transmission
>>> rate is about 60MB/s. I send about 100000 requests in each  
>>> process(60
>>> processes in 2 clients), and it costs about 550 seconds to finish  
>>> all the
>>> requests. And I am sure that all the processes had been spread  
>>> around all
>>> the servers.
>>>
>>> Thanks
>>> Lei, He
>>>
>>> 在 2011年3月9日 上午9:22��Benjamin Reed <[EMAIL PROTECTED]>写
>>> 道:
>>>
>>> are you using 1 gbs ethernet or 100 mbs? those numbers seem to  
>>> correspond
>>>> to
>>>> 100 mbs. you may want to do a simple bandwidth test just to make  
>>>> sure.
>>>>
>>>> how long are you running the test for?
>>>>
>>>> also, you might check that the clients are being spread around  
>>>> the zk
>>>> servers. using the 4 letter works or phunts zktop.
>>>>
>>>> ben
>>>>
>>>> 2011/3/9 lei he <[EMAIL PROTECTED]>
>>>>
>>>>> Hi Flavio and Qian, I did some tests in my environment, too. And  
>>>>> it
>>>> seems
>>>>> it is not as good as it supposed to be. I used async
>>>> interface(zoo_aget),
>>>>> send about 10000 requests to3  servers at the same time. But it  
>>>>> turn out
>>>> to
>>>>> be on the same level with Qian's test. Is there anything I  
>>>>> should pay
>>>>> attentio to?
>>>>>
>>>>> thanks a lot
>>>>> He, Lei
>>>>>
>>>>> 2011/3/9 Flavio Junqueira <[EMAIL PROTECTED]>
>>>>>
>>>>>> How many outstanding requests do you have at a time, Qian? Only  
>>>>>> one? If
>>>>>> so, you should instead have multiple outstanding. That is, you  
>>>>>> don't
>>>> wait
>>>>>> for the callback to issue a new request.
>>>>>>
>>>>>> -Flavio
>>>>>>
>>>>>> On Mar 9, 2011, at 3:44 AM, Qian Ye wrote:
>>>>>>
>>>>>> Hi Flavio, asynchronous calls doesn't perform better, here is  
>>>>>> some
>>>> results
>>>>>> we've got,
>>>>>>
>>>>>> § 1 client server,1 process per client server,connect 1  
>>>>>> zookeeper
>>>>>> server,all reads:cpu:14%~15%,qps:3833,latency:
>>>>>> 0.000261
>>>>>> § 1 client server,1 process per client server,connect all 3  
>>>>>> zookeeper
>>>>>> server,all reads:cpu:14%~15%,qps:3832,latency:
>>>>>> 0.000261
>>>>>> § 1 client server,10 process per client server,connect all  
>>>>>> 3 zookeeper
>>>>>> server,all reads,cpu:13%~20%,qps���14000-
>>>>>> >12000,latency:0.000469
>>>>>> *§ 1 client server,30 process per client server,connect all  
>>>>>> 3 zookeeper
>>>>>> server,all reads,cpu:15%~20%,qps���14000-
>>>>>> >10000,,latency:
>>>>>> § 2 client server,30 process per client server,connect all  
>>>>>> 3 zookeeper
>>>>>> server,all reads,cpu:15%~20%,qps���about  
>>>>>> 11000,latency:*
>>>>>>
>>>>>> It seems that the asynchronous calls perform even worse than the
>>>>>> synchronous calls.
>>>>>>
>>>>>>
>>>>>> On Wed, Mar 9, 2011 at 12:29 AM, Flavio Junqueira <[EMAIL PROTECTED]
>>>>> wrote:
>>>>>>
>>>>>>> Hi Qian, If I understand your description correctly, you are  
>>>>>>> using
>>
flavio
junqueira

research scientist

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Qian Ye 2011-03-09, 15:36