[svn.haxx.se] · SVN Dev · SVN Users · SVN Org · TSVN Dev · TSVN Users · Subclipse Dev · Subclipse Users · this month's index

Re: Comparison testing: { FSFS, BDB } x { 1.5.4, trunk }

From: David Glasser <glasser_at_davidglasser.net>
Date: Sat, 25 Oct 2008 23:45:32 -0700

On Sat, Oct 25, 2008 at 3:10 PM, C. Michael Pilato <cmpilato_at_collab.net> wrote:
> I did a little bit of simple comparison testing between FSFS and BDB in
> 1.5.4 and trunk. My testing involved loading a dumpfile of 5000 revisions
> (taken from our own repository), then doing some single-revision dumps at a
> few time-slices across the loaded repository.
>
> Here are the highlights (percentages are ballpark estimates).
>
> In trunk, FSFS:
>
> is significantly slower (30%) for writes operations. I have no idea why.

As discussed in the other thread, the obvious thing to assume would be
that all the reads and rights of the rep cache DB are slowing you
down... try disabling that (just take out all the calls into
rep-cache.h from fs-fs.c) and try again?

--dave

> is a bit faster for reads (20%).
>
> showed no meaningful disk usage changes. But I'm pretty sure this is
> an artifact of the testing dataset, which isn't as up-to-date-branch-heavy
> as more recent revision ranges in our source tree are.
>
> In trunk, Berkeley DB:
>
> is significantly faster (50%) for write operations. This is almost
> certainly because post-commit deltification is doing a single
> deltification instead of touching a chain of files.
>
> is significantly slower (300%) for read operations. Distance to
> nearest fulltext?
>
> showed significant improvement in disk usage (20% savings) in trunk.
> For the same reasons that FSFS didn't show much improvement here, I
> must assume rep-sharing wasn't the real win here. More likely the
> minimization of fulltexts (one per line of history) is the win here.
>
> In all things except disk usage (now in trunk), FSFS remains a clear winner
> over BDB in this testing.
>
> Attached are the script I used and a spreadsheet with the actual findings.
>
> --
> C. Michael Pilato <cmpilato_at_collab.net>
> CollabNet <> www.collab.net <> Distributed Development On Demand
>
> #!/bin/sh
>
> for svnadmin in \
> /home/cmpilato/projects/subversion/subversion/svnadmin/svnadmin \
> /home/cmpilato/projects/subversion-1.5.x/subversion/svnadmin/svnadmin ; do
> for fstype in fsfs bdb; do
> echo "### ${svnadmin} ${fstype}"
> for i in 1 2 3; do
> rm -rf repos
> ${svnadmin} create --fs-type ${fstype} repos
> echo "--- Dumpfile load"
> time -p ${svnadmin} load -q repos < dumpfile
> done
> echo "### --- Repository size"
> du -sk repos
> for rev in 10 2500 5000; do
> for i in 1 2 3; do
> echo "--- Revision dump (r${rev})"
> time -p ${svnadmin} dump -q repos -r ${rev} > /dev/null
> done
> done
> done
> done
>
>

-- 
David Glasser | glasser@davidglasser.net | http://www.davidglasser.net/
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe_at_subversion.tigris.org
For additional commands, e-mail: dev-help_at_subversion.tigris.org
Received on 2008-10-26 07:45:50 CET

This is an archived mail posted to the Subversion Dev mailing list.