[zeromq-dev] Dealer socket pkts are not drained by I/O thread

[Osiris Pedroso]

Hi Siva,

What Stephane meant was to write some code that shows the issue you are
experiencing.

Yes, it's more work, but it would speed up wonders how fast you get a
solution for your issue.

Best regards,
Osiris

On Tue, Nov 16, 2021, 10:14 donthamsetty sivaprasad via zeromq-dev <
zeromq-dev at lists.zeromq.org> wrote:

>
> Stephane .
> Thanks for the response.
> To simplify the question ,
> If more than 8192(output_batch_size) bytes is lying in the dealer socket
> pipe , will the I/O thread get more than one notification to drain the
> pipe.?  My understanding  sender will not notify the I/O thread unless pipe
> is completely drained.
>
> Please correct me if i am wrong .
>
> Thanks
> Siva
> On Tuesday, November 16, 2021, 02:35:37 PM GMT+5:30, Stephane Vales <
> vales at ingenuity.io> wrote:
>
>
> Hello Siva,
>
> Rather than pointing the code by itself, maybe it would be better if you
> could write some minimal examples testing your assumptions. Then, if they
> are confirmed, you could use them to expose problems in this list or to
> create issues on github.
>
> Cheers.
>
>
> Stéphane.
>
>
> Le 16 nov. 2021 à 07:51, donthamsetty sivaprasad via zeromq-dev <
> zeromq-dev at lists.zeromq.org> a écrit :
>
> Hi ,
> The stream engine ( ZMQ dealer=>ZMQ dealer using TCP connection) in the
> I/O thread at a time reads at most 8172 from the below code. But the writer
> sends the notification to the I/O thread only if it completely drains the
> queue in ypie.hpp: flush() based on the compare and swap _c_ptr .
>
> src/config.hpp:    out_batch_size = 8192,
> src/stream_engine.cpp:        while (_outsize < static_cast<size_t>
> (out_batch_size)) {
> src/stream_engine.cpp:            size_t n = _encoder->encode (&bufptr,
> out_batch_size - _outsi
>
>
> Could you please confirm if this is a real problem ? If more than 8172
> bytes are lying in pipe and I?O threads drains only 8172 , How does writer
> sends read notification to I/O thread since it is not fully drained?
>
> Could you please answer this ?
>
> Thanks
> Siva
> On Sunday, November 14, 2021, 08:49:10 AM GMT+5:30, donthamsetty
> sivaprasad via zeromq-dev <zeromq-dev at lists.zeromq.org> wrote:
>
>
> The version used is zeromq 4.3.1
>
> Thanks in advance .
> Response is highly appreciated.
>
> Thanks
> Siva
>
> On Sunday, November 14, 2021, 08:42:00 AM GMT+5:30, donthamsetty
> sivaprasad via zeromq-dev <zeromq-dev at lists.zeromq.org> wrote:
>
>
> Hi ,
> The pipe_t between Dealer socket and I/O thread has been stuck in the
> sense that msgs are continuously written into the pipe but not drained. And
> the sender is not doing the flush because the compare and swap pointer is
> NOT null.
> I have gone through the code. After the sender has notified the I/O thread
> for read , I/O thread reads atmost output_batch_size(8072).. Please correct
> me if I am wrong . If the I/O thread does not fully drain the pipe for any
> reason , the sender will not notify again since sender depends on c_ptr
> (cas ptr) being NULL , which will not be set to NULL unless the I/O thread
> drains the pipe fully.
> Basically the case is sender is NOT nitifying the I/O thread sicne the
> c_ptr is not NULL at all and I/O thread is not reading because it will not
> get the notifcation ..The pipe is continuously filled and messages are not
> sent out to the ultimate destination due to this..
>
> OR
> The above situtation could be there is some race in multi core
> environment where compare and swap operation is not operating consistently
> . Our system is ARM v7 system .
>
> Please let me know if there are known problems.
>
> THanks
> Siva
> _______________________________________________
> zeromq-dev mailing list
> zeromq-dev at lists.zeromq.org
> https://lists.zeromq.org/mailman/listinfo/zeromq-dev
> _______________________________________________
> zeromq-dev mailing list
> zeromq-dev at lists.zeromq.org
> https://lists.zeromq.org/mailman/listinfo/zeromq-dev
> _______________________________________________
> zeromq-dev mailing list
> zeromq-dev at lists.zeromq.org
> https://lists.zeromq.org/mailman/listinfo/zeromq-dev
>
>
> _______________________________________________
> zeromq-dev mailing list
> zeromq-dev at lists.zeromq.org
> https://lists.zeromq.org/mailman/listinfo/zeromq-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.zeromq.org/pipermail/zeromq-dev/attachments/20211116/6e634e55/attachment.htm>