[Monotone-devel] Re: BSD Buildbots

[Lapo Luchini]

William Uther wrote:
> Hi,
>   The BSD buildbots have been failing for a while.  This itches.

I do agree =)

> (The VMware settings gave the virtual machine
> a minimal 256Mb of RAM).  Everything passed.  The buildbots are
> "softlimit"ed to "-d256000000" from memory.  I couldn't find softlimit
> on my FreeBSD install,

softlimit is from sysutils/daemontools port.
("pkg_add -r daemontools" should do it)

> but I tried ulimit -d250000 and everything still
> passed.  Then I tried -m250000 as well, and everything still passed.

That's strange... "ulimit -d250000" should be just the same as
"softlimit -d256000000".

>   Anyone have any ideas how I might go about making this fail as it does
> on the buildbot?

It runs on daemontools... but that doesn't change anything in execution,
it should be just the same as executing its 'run' script, that is:

% cat /var/service/bot_mtn/run
#!/bin/sh
exec 2>&1
exec setuidgid bot_mtn envdir ./env softlimit -d256000000 nice \
  /usr/local/bin/twistd --nodaemon --no_save \
    --python=../slave-dir/buildbot.tac \
    --pidfile=../slave-dir/twistd.pid \
    --logfile=../slave-dir/twistd.log \
    --prefix=slave

The difference in our different tests may be, in fact, that on my box
the 256MB memory limit is shared by mtn and the python buildbot script.

Recap of my buildbots:

The current FreeBSD6/amd64 buildbot has 1GB RAM, but has many services
running on it and remaining RAM is a bit low, so I don't feel like
dedicating more than 256MB of RAM to the bot itself.
The current FreeBSD6/i386 buildbot has only 512MB RAM, but now that I
think about it I should have an extra 512MB SDRAM around, in that case I
could double or triple the ulimit.
I also am configuring a new server at home (that will eventually
obsolete the server that currently is the FreeBSD6/i386 buildbot), it
runs FreeBSD7/amd64 and has 2GB RAM, so I could run a third buildbot on
it (and with no need for memory limits), or simply move there the
current FreeBSD6/amd64 buildbot and relieve that server of that load.

OTOH it is interesting to understand WHY it fails on my box while
running succesfully on Willu's virtualized FreeBSD 6.3... and in the and
if we prefer mtn to run succesfully with 256MB RAM, simply removing the
limit from the buildbots could not be the best approach ;-)

    Lapo