On 5 February 2015 at 11:33, Branko Čibej <br...@wandisco.com> wrote: > On 05.02.2015 01:59, Branko Čibej wrote: >> On 05.02.2015 01:44, br...@apache.org wrote: >>> Author: brane >>> Date: Thu Feb 5 00:44:57 2015 >>> New Revision: 1657451 >>> >>> URL: http://svn.apache.org/r1657451 >>> Log: >>> On the reuse-ra-session branch: Add explicit session reuse in libsvn_client. >> Anyone who's interested in the RA session cache, please take time to >> review this commit. >> >> All tests pass for me (ra_local, ra_svn and ra_dav) and I re-read the >> diffs about five times to check that sessions are being released to >> cache only when it's certain that they're valid. But I'd really like to >> have a few more pairs of eyes on this, because there's potential for >> some nasty bugs being introduced. > > To get a feeling for what the RA session cache gains us, here are > summarized stats from a few test runs: > > * client-test: > request:21 open:13 close:3 release:18 reuse:8 cleanup:0 > > * merge_tests.py: > request:4079 open:3812 close:20 release:3431 reuse:267 cleanup:62 > > * externals_tests.py: > request:1005 open:597 close:5 release:996 reuse:408 cleanup:4 > > To get a feeling for what this means: during the externals test run, we > got about a thousand requests to open a RA session through > libsvn_client, 40% of which were serviced by the reuse of a previously > released session. Only 9 sessions were closed due to pool clean-up, 4 of > which were owned by pools with a lifetime longer than the client > context's pool. > Wow! That more that I expected. Opening RA session could cost up to 5 round-trips: TCP connect - 1 roundtrip SSL handshake - 2 roundtrips Authenctication - 1 roundtrip Options request - 1 roundtrip
Total 500-1000 ms for overseas connections. > Our tests are not an ideal showcase for session reuse, because they run > a zillion short-lived processes; I expect something like TortoiseSVN > could benefit from the cache far more. Still, the externals-tests > results seem to show that even our command-line client can benefit from > session reuse. > Yes, GUI clients should benefit significantly. -- Ivan Zhakov
