Date: Wed, 27 Oct 2010 11:27:02 -0700 From: Sean Bruno <seanbru@yahoo-inc.com> To: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org> Subject: Excessive Duplicate ACKs Message-ID: <1288204022.3808.191.camel@home-yahoo>
next in thread | raw e-mail | index | archive | help
We moved an application stack from BSD4(BOO!) to BSD7(YAY!) recently and got a great performance increase, so first: GOOD JOB. Periodically, we are seeing strings of duplicate ACK being sent in <100uSec deltas. I can't imagine that this should be happening, but there it is. I've sanitized an example trace of a transaction, demonstrating an average case that had 8 dup ACKs, some less than 3 microsends in delta! sysctl -a also attached (and sanitized). http://people.freebsd.org/~sbruno/dup_ack_collapsed.txt http://people.freebsd.org/~sbruno/sysctl_dup_acks.txt Sean
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1288204022.3808.191.camel>