Hello all, I am using zmq 2.0.6 on Ubuntu 9.04 boxes. I am using PUB/SUB with the epgm protocol. I have one publisher on host A and 2 subscribers on host B. The ZMQ_RATE is set to 20000 on both publishers and subscribers. I do not filter anything on the subscribers side. On the publisher side, I have a ZMQ_HWM set to 100 and ZMQ_LWM set to 50. I am sending 4 kbytes messages. The first byte within each message is a counter which allows me to check that I haven't lost any message. My problem is that I am loosing messages!
I have wireshark on both sides (Host A and Host B). I have studied a little bit what happened during my transmission. On Host B (the receiver), I notice a hole in the ODATA sequence number sent by Host A. Then, Host B send a NAK packet requesting the missing datagram. Host A reply to this NAK packet by a NCF packet which according to what I have read in RFC 3208 is correct. But I do not see any RDATA packet sent by the source (Host A) and therefore my subscribers loose the concerned messages!! I agree that the wireshark on host A (the sender) tells me that the datagram missing on Host B (the receiver) have been sent but I guess these packets have been lost by the switch between the 2 hosts. But as far as I have understood PGM, it is a reliable protocol and this case should be covered by some re-transmission which apparently in my case is only half-done. Are you aware of some similar cases? Thank's for your answers Regards Emmanuel Taurel _______________________________________________ zeromq-dev mailing list [email protected] http://lists.zeromq.org/mailman/listinfo/zeromq-dev
