[Rdo-list] Concerning Rabbits

[John Eckersberg]

(In the spirit of "Concerning Hobbits")

Ryan O'Hara and I have been investigating RabbitMQ as it pertains to RDO
recently.  There has been a lot of discussion on several disparate
threads, so I wanted to try and capture it on the list for the benefit
of everyone.

Ryan has been working on getting RabbitMQ running in a multi-node HA
configuration.  I won't steal his thunder, and he can speak to it better
than I can, so I'll defer to him on the details.

As for me, I've been working on el7 support and bug squashing along the
way.

The first bug[1] causes the daemon to load incredibly slow, or outright
fail by timing out.  This is due to the SELinux policy disallowing
name_bind on ports lower than 32768.  RabbitMQ tries to name_bind to a
port starting at 10000, and increments if it fails.  So if you have
SELinux in enforcing mode, you'll get 22768 AVC denials in the log
before it finally starts.

The second bug[2] causes the daemon to intermittently fail to start due
to a race condition in the creation of the erlang cookie file.  This
happens only the first time the service starts.  Really this is an
Erlang bug, but there's a workaround for the RabbitMQ case.

I've submitted patches for both issues.  Until those get merged in, I've
rebuilt[3] RabbitMQ for F20 which includes the fixes.

Beyond bugs, I've also built out RabbitMQ and all the build/runtime
dependencies for el7.  I have a yum repo[4] on my fedorapeople page
containing all the bits.  This is all the stuff that is presently
missing from EPEL7.  In time, I would hope the maintainers build all
this stuff, but for now it'll work for testing.  You will also need the
EPEL 7 Beta repository[5] enabled.

As a side note, I built everything using mock with a local override repo
on my workstation.  I've not used copr before but it seems relevant to
this sort of thing, so if it's any benefit I'll look to rebuilt the el7
stack there for easier consumption.

Hopefully this helps get the discussion into one place, and provide a
baseline for further investigation by everyone interested in RabbitMQ.

John.

---
[1] Is really two bugzillas, but the same bug:
[1a] https://bugzilla.redhat.com/show_bug.cgi?id=998682
[1b] https://bugzilla.redhat.com/show_bug.cgi?id=1032595
[2] https://bugzilla.redhat.com/show_bug.cgi?id=1059913
[3] http://jeckersb.fedorapeople.org/rabbitmq-server-3.1.5-3.fc20.noarch.rpm
[4] http://jeckersb.fedorapeople.org/rabbitmq-el7/
[5] http://dl.fedoraproject.org/pub/epel/beta/7/x86_64/