Ben Collins-Sussman wrote:
>So issue #860 has been giving me nightmares. It looks like it's a
>regression bug, whereby mod_dav_svn is no longer scaling. The bug
>submitter claims that the server's memory use grows in proportion to
>the amount of data it's writing to the server.
>
>Here's my initial findings, just playing around with today's svn:
>
>
>Issue 680 Initial Experiments
>=============================
>
>Using httpd-2.0.43 (released) and svn r3430.
>
>Created a 100M random-data file:
>
> dd if=/dev/urandom of=foo count=100000 bs=1024
>
Naughty, naughty. That's not 100M. Use count=100 bs=1M :-)
>* svn add; commit over ra_dav: svn peaks at 6M, httpd peaks at 17M
>* svn add; commit over ra_local: svn binary peaks at 22M
>
>==> This isn't ideal, but it's not horrible either. It also makes a
>lot of sense. You can see that libsvn_fs seems to be using 17M RAM to
>commit the 100M file.
>
>* checkout new working copy over ra_dav: svn peaks at 5M, httpd at 12M
>* checkout new working copy over ra_local: svn binary peaks at 120M
>
>==> This is absolutely freaky. Can anyone explain this???!
>
Yikes! The only explanation I can think of is that libsvn_ra_local
itself is leaking like a sieve.
>The other thing that's odd is that the original bug report claims that
>the memory lossage happens during mod_dav_svn *commit*.
>
>Why can't I reproduce the problem? Is it simply because I need to
>actually try committing a 2GB file, not a 100M file?
>
Either that, or close the bug and open another one. :-)
Seriously: Do what I suggested on IRC. Repeat the test with a 200M and
300M file, and look at the trends. It's entirely possible that the
commit memory usage increases exponentially, that's why you need more
than one data point if you want to find out what's happening.
--
Brane Čibej <brane_at_xbc.nu> http://www.xbc.nu/brane/
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Received on Mon Oct 21 22:14:16 2002