maas-devel team mailing list archive

[Raphaël Badin <raphael.badin@xxxxxxxxxxxxx>]

On 01/14/2014 01:55 PM, Raphaël Badin wrote:
> A recent upgrade of the python-celery package in Trusty's archive
> (https://launchpad.net/ubuntu/+source/celery/3.1.6-1ubuntu1/+publishinghistory)
> broke MAAS on trusty.  The symptom is that celery eats up a lot of
> memory before segfaulting.  This issue, being related to a dependency of
> MAAS, affects all Trusty versions (the daily PPA package, the package in
> main and the package in the cloud archive).
>
> Our investigation thus far seems to indicate that librabbitmq might be
> responsible for the crash (see http://paste.ubuntu.com/6750300/ for
> details).
>
> We're working on both identifying the issue precisely and finding a
> workaround.

We worked on that problem yesterday.  We've identified the source of the 
crash (a call to amqp_pool_alloc in librabbitmq/amqp_mem.c). We're still 
not sure why this happens but I'll let the server team comment on that 
if they have any insight.

The good news is that we found a workaround:

Turns out python-librabbitmq was a dependency of python-kombu (itself a 
dependency of python-celery) but python-kombu could also work with 
python-amqp instead of python-librabbitmq.

We've changed the packaging of MAAS to make sure python-amqp is used 
instead of python-librabbitmq.  With that fix, the MAAS package is 
working again.

The new package has been uploaded to Trusty main and to the cloud archive.

Cheers,

R.