On Fri, Aug 30, 2002 at 04:47:30PM +0530, Saurabh Bansal wrote: > Hi, > > It has been more than a week since I posted this query to the LINUX > group and haven't heard anything from the group-side in this context. > Is my query under processing/observation OR something else?? Slipped in between spam-floods, or something... > Hope to get some positive response from your side this time! > Thanks And Regards > Saurabh > > ----- Original Message ----- > From: Saurabh Bansal > To: netdev@oss.sgi.com > Cc: linux-net@vger.kernel.org > Sent: Wednesday, August 21, 2002 1:26 PM > > Hi all, > > I did this experiment with the a set of two processes behaving as > a sender/receiver set on the same Linux machine. What the experiment was > that--- > > "The sender has to send some fixed-size (20 bytes) mesgs to the > receiver but the receiver has not to pick-up anyone of them." > > What has been observed is, TCP buffers the first 32 messages into the > receive socket queue of receiver, AND THEN it stops sending ack's for > next mesg. As a result, the sender keeps on trying to send the 33rd > mesg, but gets no ack's and connection gets down within 15-20 minutes. Are you sure you are emptying the receiver socket when some new data arrives ? > Another important observations about this experiment are : > > 1) These two processes were running on the same Linux system with > kernel version 2.2.xx. This problem doesn't come with Linux-kernel > 2.4.xx. I recall having seen this kind of problems in 2.1/2.2 series, possibly a bug-fix was added in late 2.2 to restore earlier behaviour in 2.0... I had implemented a problem circumvention in one of my software suites by making the socket non-blocking, and adding proper select() calls. > 2) If these processes are run on different Linux m/c's with kernel > 2.2.xx, the problem doesn't appear. Quite so. > 3) The socket APIs used for sending/receiving mesg are send()/recv(). > 4) The problem has no relevance with the size of mesg. I have seen the > same behavior with 1-byte mesg to 1k-byte mesg. > > Can anyone tell me if there is any bug/limitation with the Linux-kernel > 2.2.xx in comparison to kernel 2.4.xx in the above problem-context?? I faintly recall something which might be what you are describing. > Saurabh Bansal /Matti Aarnio - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
