[zeromq-dev] PGM throughput testing still terminated short

[Steven McCoy]

Hypothesis:  an zmq::encoder_base_t::peek_data method is required so that
ZMQ does not think the queued data is empty when the rate limiter kicks in.
 This should be reproducible with congestion control on TCP streams.

-- 
Steve-o

On 29 November 2010 12:47, Steven McCoy <steven.mccoy at miru.hk> wrote:

> Adding trace to master you can see the ZMQ messages are sent to the API,
>
> diff --git a/perf/remote_thr.cpp b/perf/remote_thr.cpp
> index c471481..b98021d 100644
> --- a/perf/remote_thr.cpp
> +++ b/perf/remote_thr.cpp
> @@ -85,6 +85,8 @@ int main (int argc, char *argv [])
>              printf ("error in zmq_msg_close: %s\n", zmq_strerror (errno));
>              return -1;
>          }
> +
> +printf ("> %d\n", i);
>      }
>
>      rc = zmq_close (s);
> diff --git a/src/pgm_sender.cpp b/src/pgm_sender.cpp
> index 3fb24c1..d0f9eb9 100644
> --- a/src/pgm_sender.cpp
> +++ b/src/pgm_sender.cpp
> @@ -149,6 +149,8 @@ void zmq::pgm_sender_t::in_event ()
>      }
>  }
>
> +static int txpkts = 0;
> +
>  void zmq::pgm_sender_t::out_event ()
>  {
>      //  POLLOUT event from send socket. If write buffer is empty,
> @@ -185,6 +187,7 @@ void zmq::pgm_sender_t::out_event ()
>      //  We can write either all data or 0 which means rate limit reached.
>      if (nbytes == write_size) {
>          write_size = 0;
> +printf (">> [%d]\n", ++txpkts);
>      } else {
>          zmq_assert (nbytes == 0);
>
> *console output:*
> LD_LIBRARY_PATH=src/.libs/ ./perf/.libs/remote_thr "epgm://eth0;
> 239.192.0.1:7500" 100 1000
> ...
> > 998
> > 999
>
> Followed by the ZMQ IO thread feeding the packets to PGM with the strict
> default rate limit (100kbs) the packet count appears to match ceil(
> 1000*100/1428 )
>
> *console output:*
> >> [1]
> >> [2]
> ...
> >> [69]
> >> [70]
> >> [71]
>
> On the receive side everything that was sent is received without issue
> suggesting a off-by-one error on send as there should be 72 packets?
>
> diff --git a/perf/local_thr.cpp b/perf/local_thr.cpp
> index 98001be..118b3dd 100644
> --- a/perf/local_thr.cpp
> +++ b/perf/local_thr.cpp
> @@ -100,6 +100,8 @@ int main (int argc, char *argv [])
>              printf ("message of incorrect size received\n");
>              return -1;
>          }
> +
> +printf ("%d\n", i+1);
>      }
> diff --git a/src/pgm_receiver.cpp b/src/pgm_receiver.cpp
> index 9773847..7b1f980 100644
> --- a/src/pgm_receiver.cpp
> +++ b/src/pgm_receiver.cpp
> @@ -132,6 +132,8 @@ void zmq::pgm_receiver_t::activate_in ()
>      in_event ();
>  }
>
> +static int rxpkts = 0;
> +
>  void zmq::pgm_receiver_t::in_event ()
>  {
>      // Read data from the underlying pgm_socket.
> @@ -192,6 +194,8 @@ void zmq::pgm_receiver_t::in_event ()
>          data += sizeof (uint16_t);
>          received -= sizeof (uint16_t);
>
> +printf ("<< [%d]\n", ++rxpkts);
> +
>          //  Join the stream if needed.
>          if (!it->second.joined) {
>
> *console output:*
> ...
> << [71]
> 978
> 979
> 980
> 981
> 982
> 983
> 984
> 985
> 986
> 987
> 988
> 989
> 990
> 991
>
> --
> Steve-o
>
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