cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Michal August├Żn <augustyn.mic...@gmail.com>
Subject Re: Network latency on Cassandra 0.7 (TFramedTransport)
Date Sat, 18 Sep 2010 20:30:45 GMT
Thank you very much. This solves my issue.

Augi

2010/9/17 Michael Greene <michael.greene@gmail.com>

> This is the correct cause.  Reproducing your test gives 38-45ms in each of
> 10 runs.  If you run a profiler against it, you can see that the time is
> entirely spent blocking on receive in TStreamTransport.Read.
>
> Your test can be modified with the following line:
> coreTransport.TcpClient.NoDelay = true;
>
> After disabling Nagle's each test runs in < 1ms.
>
> Michael
>
> On Fri, Sep 17, 2010 at 9:57 AM, Peter Schuller <
> peter.schuller@infidyne.com> wrote:
>
>> > The latency is about 200 ms on every request when I'm connected to
>> another
>>
>> My first thought here was that maybe you're seeing the effects of
>> nagle[1] + delayed acks on the other side. On Unix, normally something
>> like a thrift client would set TCP_NODELAY on its socket to avoid the
>> problem. I'm not sure whether or not this is a reasonable hypothesis
>> with C# + Thrift on Windows. Sorry, I don't know what the easy fix is
>> either but perhaps it might help dig further.
>>
>> [1] http://en.wikipedia.org/wiki/Nagle's_algorithm
>>
>> --
>> / Peter Schuller
>>
>
>

Mime
View raw message