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From Carlos Alvarez <cbalva...@gmail.com>
Subject Re: Cassandra thrift question
Date Mon, 24 May 2010 21:09:38 GMT
I have the same issue in my cluster: 0,5% of requests are extremely
slow because the time it takes to read the data from the socket.

However in my case it is not related to the load. Actually the
percentage of anomalies drop as the load increases.

On the other hand the nio is actually slow than blocking io when you
have enough resources to handle all connections (which is my situation
in the server).

I tend to blame the client and my unoptimized client connection scheme
( c# client) which opens a lot of sockets and doenst pool at all.

I am currently pinpointing this issue. I will let you know if find something.


Carlos.e


On 5/22/10, Даниел Симеонов <dsimeonov@gmail.com> wrote:
> Hi Jonathan,
>   This sounds a little bit strange, I would expect that NIO server sockets
> to be more scalable than regular socket, well I don't have much experience
> with tcp programming. What was the scenario you used? The problem I observe
> is that most of the requests to Cassandra are quite performant (lets say
> miliseconds) yet some requests (~ 0.2 % of all requests) are slow ~2-5
> seconds. Profiling Cassandra showed that thrift socket read operations
> contributed for most of the time spent.
> Best regards, Daniel.
>
> 2010/5/22 Jonathan Ellis <jbellis@gmail.com>
>
>> Because when we tested it, it was slower.
>>
>> 2010/5/21 Даниел Симеонов <dsimeonov@gmail.com>:
>>  > Hi,
>> >    I have a question about the thrift protocol used to connect to
>> Cassandra,
>> > I saw in class CassandraDaemon that TServerSocket is being used,
>> > why TNonblockingServerSocket is not being used? Thank you very much!
>> > Best regards, Daniel.
>>
>>
>>
>> --
>>  Jonathan Ellis
>> Project Chair, Apache Cassandra
>> co-founder of Riptano, the source for professional Cassandra support
>> http://riptano.com
>>
>

-- 
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Tal vez hubo un error en la grafía. O en la articulación del Sacro Nombre.

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