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From Riccardo Ferrari <ferra...@gmail.com>
Subject Re: Is my cluster normal?
Date Fri, 08 Jul 2016 00:24:26 GMT
Hi Yuan,

You machine instance is 4 vcpus that is 4 threads (not cores!!!), aside
from any Cassandra specific discussion a system load of 10 on a 4 threads
machine is way too much in my opinion. If that is the running average
system load I would look deeper into system details. Is that IO wait? Is
that CPU Stolen? Is that a Cassandra only instance or are there other
processes pushing the load?
What does your "nodetool tpstats" say? Hoe many dropped messages do you
have?

Best,

On Fri, Jul 8, 2016 at 12:34 AM, Yuan Fang <yuan@kryptoncloud.com> wrote:

> Thanks Ben! For the post, it seems they got a little better but similar
> result than i did. Good to know it.
> I am not sure if a little fine tuning of heap memory will help or not.
>
>
> On Thu, Jul 7, 2016 at 2:58 PM, Ben Slater <ben.slater@instaclustr.com>
> wrote:
>
>> Hi Yuan,
>>
>> You might find this blog post a useful comparison:
>>
>> https://www.instaclustr.com/blog/2016/01/07/multi-data-center-apache-spark-and-apache-cassandra-benchmark/
>>
>> Although the focus is on Spark and Cassandra and multi-DC there are also
>> some single DC benchmarks of m4.xl clusters plus some discussion of how we
>> went about benchmarking.
>>
>> Cheers
>> Ben
>>
>>
>> On Fri, 8 Jul 2016 at 07:52 Yuan Fang <yuan@kryptoncloud.com> wrote:
>>
>>> Yes, here is my stress test result:
>>> Results:
>>> op rate                   : 12200 [WRITE:12200]
>>> partition rate            : 12200 [WRITE:12200]
>>> row rate                  : 12200 [WRITE:12200]
>>> latency mean              : 16.4 [WRITE:16.4]
>>> latency median            : 7.1 [WRITE:7.1]
>>> latency 95th percentile   : 38.1 [WRITE:38.1]
>>> latency 99th percentile   : 204.3 [WRITE:204.3]
>>> latency 99.9th percentile : 465.9 [WRITE:465.9]
>>> latency max               : 1408.4 [WRITE:1408.4]
>>> Total partitions          : 1000000 [WRITE:1000000]
>>> Total errors              : 0 [WRITE:0]
>>> total gc count            : 0
>>> total gc mb               : 0
>>> total gc time (s)         : 0
>>> avg gc time(ms)           : NaN
>>> stdev gc time(ms)         : 0
>>> Total operation time      : 00:01:21
>>> END
>>>
>>> On Thu, Jul 7, 2016 at 2:49 PM, Ryan Svihla <rs@foundev.pro> wrote:
>>>
>>>> Lots of variables you're leaving out.
>>>>
>>>> Depends on write size, if you're using logged batch or not, what
>>>> consistency level, what RF, if the writes come in bursts, etc, etc.
>>>> However, that's all sort of moot for determining "normal" really you need
a
>>>> baseline as all those variables end up mattering a huge amount.
>>>>
>>>> I would suggest using Cassandra stress as a baseline and go from there
>>>> depending on what those numbers say (just pick the defaults).
>>>>
>>>> Sent from my iPhone
>>>>
>>>> On Jul 7, 2016, at 4:39 PM, Yuan Fang <yuan@kryptoncloud.com> wrote:
>>>>
>>>> yes, it is about 8k writes per node.
>>>>
>>>>
>>>>
>>>> On Thu, Jul 7, 2016 at 2:18 PM, daemeon reiydelle <daemeonr@gmail.com>
>>>> wrote:
>>>>
>>>>> Are you saying 7k writes per node? or 30k writes per node?
>>>>>
>>>>>
>>>>> *.......*
>>>>>
>>>>>
>>>>>
>>>>> *Daemeon C.M. ReiydelleUSA (+1) 415.501.0198
>>>>> <%28%2B1%29%20415.501.0198>London (+44) (0) 20 8144 9872
>>>>> <%28%2B44%29%20%280%29%2020%208144%209872>*
>>>>>
>>>>> On Thu, Jul 7, 2016 at 2:05 PM, Yuan Fang <yuan@kryptoncloud.com>
>>>>> wrote:
>>>>>
>>>>>> writes 30k/second is the main thing.
>>>>>>
>>>>>>
>>>>>> On Thu, Jul 7, 2016 at 1:51 PM, daemeon reiydelle <daemeonr@gmail.com
>>>>>> > wrote:
>>>>>>
>>>>>>> Assuming you meant 100k, that likely for something with 16mb
of
>>>>>>> storage (probably way small) where the data is more that 64k
hence will not
>>>>>>> fit into the row cache.
>>>>>>>
>>>>>>>
>>>>>>> *.......*
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> *Daemeon C.M. ReiydelleUSA (+1) 415.501.0198
>>>>>>> <%28%2B1%29%20415.501.0198>London (+44) (0) 20 8144 9872
>>>>>>> <%28%2B44%29%20%280%29%2020%208144%209872>*
>>>>>>>
>>>>>>> On Thu, Jul 7, 2016 at 1:25 PM, Yuan Fang <yuan@kryptoncloud.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> I have a cluster of 4 m4.xlarge nodes(4 cpus and 16 gb memory
and
>>>>>>>> 600GB ssd EBS).
>>>>>>>> I can reach a cluster wide write requests of 30k/second and
read
>>>>>>>> request about 100/second. The cluster OS load constantly
above 10. Are
>>>>>>>> those normal?
>>>>>>>>
>>>>>>>> Thanks!
>>>>>>>>
>>>>>>>>
>>>>>>>> Best,
>>>>>>>>
>>>>>>>> Yuan
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>> --
>> ————————
>> Ben Slater
>> Chief Product Officer
>> Instaclustr: Cassandra + Spark - Managed | Consulting | Support
>> +61 437 929 798
>>
>
>

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