@Araron you're right and i was wrong!

2011/10/20 Yang <teddyyyy123@gmail.com>
found it , https://issues.apache.org/jira/browse/CASSANDRA-3387

On Thu, Oct 20, 2011 at 1:37 PM, aaron morton <aaron@thelastpickle.com> wrote:
> It's unlikely that HH is the issue. (Disclaimer, am not familiar with HH in
> 1.0, i know it's changes a bit)
> Take a look at the TP Stats, what's happening ?
> Cheers
> -----------------
> Aaron Morton
> Freelance Developer
> @aaronmorton
> http://www.thelastpickle.com
> On 20/10/2011, at 10:10 AM, Jérémy SEVELLEC wrote:
>
> Ok.
> I think a degration could be normal because your cluster is in a degraded
> state when a node is down.
> With a replication_factor of 3 and with a 3 nodes cluster, each data you
> write is replicated on each node. As One node is down, when writing, it's
> impossible to send a replica on the down node and hints are send
> : http://www.datastax.com/docs/1.0/dml/about_writes#hinted-handoff-writes
> And it could be more expensive to achieve QUORUM when you read in that
> context.
> It may be one explanation. You can turn cassandra log into debug level to
> see what happen when when there is a down node.
> 2011/10/19 Yang <teddyyyy123@gmail.com>
>>
>> 3
>>
>> sorry forgot this important info
>>
>> On Oct 19, 2011 11:31 AM, "Jérémy SEVELLEC" <jsevellec@gmail.com> wrote:
>>>
>>> Hi, what is your replication_factor?
>>>
>>> 2011/10/19 Yang <teddyyyy123@gmail.com>
>>>>
>>>> I'm using a cassandra version compiled from 1.0.0  github HEAD.
>>>>
>>>> I have 3 nodes, A B and C,  on node A I run a client, which talks only
>>>> to B as the coordinator.
>>>>
>>>> the performance is pretty good, a QUORUM read+write  takes < 10ms.
>>>>
>>>> but then I shutdown C, quickly the performance starts to degrade, and
>>>> QUORUM read+write time steadily increase to about 300ms.
>>>>
>>>> if I shutdown A and keep C, I observe the same effect.
>>>>
>>>>
>>>> I understand that "2 out of 3" is going to give you faster response
>>>> than "2 out of 2", but  the difference should not be that dramatic as
>>>> 10ms vs 300ms.
>>>>
>>>> any possible reasons for this?(or how to debug this?)
>>>>
>>>> Thanks
>>>> Yang
>>>
>>>
>>>
>>> --
>>> Jérémy
>
>
>
> --
> Jérémy
>
>



--
Jérémy