[noPoll] noPoll : Query related to I/O mechanism, max concurrent connections.

[ayush jain]

Thanks Francis for your responses.

Would update you soon once am done with my POC with nopoll.

Regards,
_Ayush

On 12/26/13, Francis Brosnan Blazquez <francis en aspl.es> wrote:
>> Hello Francis,
>
> Hi there,
>
> Sorry for the delay, been busy ;-)
>
>> Thanks a lot for this info. I was also of the impression that noPoll
>> provides it internal select,poll and epoll I/O based on some switch.
>
> That's right..
>
>> But traversing the code I found out that only 'select' is implemented
>> as part of default. Does that mean we need to write our own waiting
>> mechanism in case we wish to use 'NOPOLL_IO_ENGINE_EPOLL' etc, and
>> also need to change e.g. 'nopoll_io_get_engine' as it didn't use
>> 'engine_type' currently.
>
> Ok, several things here.
>
> You could go and update noPoll to add support for epoll but, if you
> already have a I/O waiting mechanism or you are planning you have one,
> do not update noPoll and put your all efforts into your I/O waiting
> mechnism (using epoll).
>
> This way you'll have an independent I/O waiting mechanism that will play
> well with all next noPoll releases (because you are using its API).
>
> Once you have your own I/O waiting mechanism, you take a look at the
> following link to have each noPoll socket watched:
>
> http://www.aspl.es/nopoll/html/nopoll_core_library_manual.html#nopoll_manual_reading_content_from_connection
>
>> So my understanding is that in case we wish to use internal noPoll
>> I/O, we need to write wrappers and waiting mechanism (would need to
>> change library functions as well), and in case we need to integrate to
>> our existing I/O, we need to go as you have described.
>
> Ok, to this particular matter, you only have one waiting I/O in your
> app. It could be noPoll's or yours but not both at the same time (excuse
> me if I got it wrong from your words).
>
> Because that, I recommend you to have your own I/O waiting poll
> mechanism (plus all the features you may want to add it)...so you can
> use it to wait and watch noPoll sockets...plus the fact that it will
> allow you easy upgrades when noPoll releases come out.
>
>> When I tried to test concurrent connections using my client with
>> noPoll, I could not proceed more than 1050 connections (I guess the
>> limit due to default 'select' and my kernel limitation for the same).
>
> Ok, that's because you have to update FD_SETSIZE to a bigger value at
> compilation time....but I wouldn't go that way; epoll is your best bet
> (at least for linux ;-)
>
>> >>> 3) Let's say if we implement websocket server, Can we do the receive
>> >>> handling in 1 thread for all the (say max 200000 sockets) and
>> >>> continue
>> >>> with send operation using multiple threads. In that case do we need
>> >>> any callback to check if the connection is ready?
>> >>
>> >> Under previous links you'll find everything about this. In short: you
>> >> can watch noPoll sockets as regular sockets (in fact they are). Once
>> >> movement is detected, call appropriate functions to get data
>> >> received...
>> >>
>> >>> And also, would I
>> >>> need some locking before sending my data from any thread or its
>> >>> already taken care of in noPoll library?
>> >>
>> >> Ok, we've designed the library so it can work in threaded and
>> >> non-threaded scenarios. In this case you must provide the right
>> >> functions to let noPoll to create mutexes, destroy, lock and unlock
>> >> them... with this:
>> >>
>> >> http://www.aspl.es/nopoll/html/group__nopoll__support_ga7f2a26a896c1416b23933097a993a435.html#ga7f2a26a896c1416b23933097a993a435
>> >>
>> >> Then noPoll will use these at the right places...
>> >>
>> Nice! That's great. So we need to just initialize the global mutex,
>> and have to insert my lock/unlock etc API's inside those mutex
>> wrappers during 'nopoll_thread_handlers' and noPoll would take care of
>> appropriate locking and synchronization no matter which thread is
>> accessing the noPoll context at the same time. Please correct me if my
>> understanding is wrong here.
>
> That's right.
>
>> >> Let us to know your progress and any product using noPoll. We will be
>> >> glad to publish some references about it. BR
>> >>
>> :) Sure Francis. Would definitely update once we get a go ahead with
>> the websocket library.
>
> Great,
> Best Regards!
>
>> >>> Would really appreciate your responses on the same.
>> >>>
>> >>> Regards,
>> >>> _Ayush
>> >>> _______________________________________________
>> >>> noPoll mailing list
>> >>> noPoll en lists.aspl.es
>> >>> http://lists.aspl.es/cgi-bin/mailman/listinfo/nopoll
>> >>
>> >>
>> >>
>
> --
> Francis Brosnan Blázquez <francis.brosnan en aspl.es>
> ASPL
> 91 134 14 22 - 91 134 14 45 - 91 116 07 57
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