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From Filip Hanik - Dev Lists <>
Subject Re: WebSocket status
Date Thu, 01 Mar 2012 18:00:32 GMT
I see, MessageInbound has hard coded receive buffers. Got it


On 3/1/2012 10:13 AM, Filip Hanik - Dev Lists wrote:
> Mark, what buffer size are you referring to increase for the web socket tests to all
> Filip
> On 3/1/2012 9:42 AM, Mark Thomas wrote:
>> On 01/03/2012 15:03, Filip Hanik - Dev Lists wrote:
>>>> I have a draft patch [1] that seems to fix this. A similar change would
>>>> be required for the Comet part of Poller.processKey()
>>>> Thoughts and/or comments? Not knowing the NIO code very well, there
>>>> might be a better way to achieve the same result that I haven't seen.
>>>> Mark
>>>> [1]
>>> I took a look at the patch. IMHO it's not the right way to go.
>> That doesn't surprise me. You know the NIO code better than I do.
>>> You're adding in flags to compensate for the state machine in the selector.
>> Yep. On that topic, I couldn't find any decent information on the state
>> machine in the selector. Do you know of any? There was a fair amount of
>> guess work involved investigating this issue and a clearer picture of
>> the state machine would help develop a better patch.
>>> And by doing so, you will have the selector run more than it needs to
>> Yep.
>>> cause you have read interest turned on,
>> Yep.
>>> on sockets that you are already processing,
>> Yep. Agree with you completely up to this point.
>>> wasting CPU cycles.
>> This part I wasn't so sure of. There is a problem here that affects
>> WebSocket badly and Comet intermittently and fixing that problem may
>> well require the trade off of additional processing. I compared the NIO
>> blocking figures I have and the NIO non-blocking figures to see if there
>> was a noticeable performance difference.
>> The patch does impact performance. Typically it is<3% but for large
>> numbers of small packets it can be as high as ~15%. On this basis my
>> patch is clearly far from ideal. I look forward to seeing what insights
>> you have on how best to solve this for both WebSocket and Comet.
>> Interestingly, I don't recall anything that suggests that this problem
>> affects HTTP although it isn't impossible that there is a very slim
>> window somewhere where HTTP may be affected.
>> Mark
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