Hello, I'm currently investigating some serious performance problems when using courier-0.66.1ubuntu4 in combination with gnutls-3.0.11+really2.12.14-5ubuntu3.5, which would be the usual combination if one were to compile courier using the --with-gnutls config flag in the lastest Ubuntu LTS version 12.04.
I'm already in contact with the courier-mta mailing list and if you want to read the complete history, you can do this here: http://sourceforge.net/mailarchive/forum.php?forum_name=courier-imap&max_rows=25&style=nested&viewmonth=201401 TL;DR: using GnuTLS slows courier down. A lot. I did some benchmarking and while downloading a 10MB attachment through courier-OpenSSL takes 1.6 seconds, with GnuTLS, it takes about 60 seconds. Listing large directories will just time out because it takes too long. Funny thing is: the couriertls process takes <1% CPU usage while on GnuTLS. If I attach strace to that process, CPU usage goes up to 40% and the test download finishes after ~4 seconds. Still not as fast as OpenSSL, but something I could work with. I'm suspecting that this might be some kind of timing problem, maybe even in the GnuTLS library, so maybe someone here has an idea of how to address the problem? Regards, Lenz Weber _______________________________________________ Gnutls-help mailing list [email protected] http://lists.gnupg.org/mailman/listinfo/gnutls-help
