Open Stack

On Fri, 2020-08-14 at 18:45 +0200, Fabian Zimmermann wrote:
> Hi,
> 
> i read somewhere that vexxhosts kubernetes openstack-Operator is running
> one rabbitmq Container per Service. Just the kubernetes self healing is
> used as "ha" for rabbitmq.
> 
> That seems to match with my finding: run rabbitmq standalone and use an
> external system to restart rabbitmq if required.
thats the design that was orginally planned for kolla-kubernetes orrignally

each service was to be deployed with its own rabbit mq server if it required one
and if it crashed it woudl just be recreated by k8s. it perfromace better then a cluster
and if you trust k8s or the external service enough to ensure it is recteated it
should be as effective a solution. you dont even need k8s to do that but it seams to be
a good fit if  your prepared to ocationally loose inflight rpcs.
if you not then you can configure rabbit to persite all message to disk and mont that on a shared
file system like nfs or cephfs so that when the rabbit instance is recreated the queue contency is
perserved. assuming you can take the perfromance hit of writing all messages to disk that is.
> 
>  Fabian
> 
> Satish Patel <satish.txt at gmail.com> schrieb am Fr., 14. Aug. 2020, 16:59:
> 
> > Fabian,
> > 
> > what do you mean?
> > 
> > > > I think vexxhost is running (1) with their openstack-operator - for
> > 
> > reasons.
> > 
> > On Fri, Aug 14, 2020 at 7:28 AM Fabian Zimmermann <dev.faz at gmail.com>
> > wrote:
> > > 
> > > Hello again,
> > > 
> > > just a short update about the results of my tests.
> > > 
> > > I currently see 2 ways of running openstack+rabbitmq
> > > 
> > > 1. without durable-queues and without replication - just one
> > 
> > rabbitmq-process which gets (somehow) restarted if it fails.
> > > 2. durable-queues and replication
> > > 
> > > Any other combination of these settings leads to more or less issues with
> > > 
> > > * broken / non working bindings
> > > * broken queues
> > > 
> > > I think vexxhost is running (1) with their openstack-operator - for
> > 
> > reasons.
> > > 
> > > I added [kolla], because kolla-ansible is installing rabbitmq with
> > 
> > replication but without durable-queues.
> > > 
> > > May someone point me to the best way to document these findings to some
> > 
> > official doc?
> > > I think a lot of installations out there will run into issues if - under
> > 
> > load - a node fails.
> > > 
> > >  Fabian
> > > 
> > > 
> > > Am Do., 13. Aug. 2020 um 15:13 Uhr schrieb Fabian Zimmermann <
> > 
> > dev.faz at gmail.com>:
> > > > 
> > > > Hi,
> > > > 
> > > > just did some short tests today in our test-environment (without
> > 
> > durable queues and without replication):
> > > > 
> > > > * started a rally task to generate some load
> > > > * kill-9-ed rabbitmq on one node
> > > > * rally task immediately stopped and the cloud (mostly) stopped working
> > > > 
> > > > after some debugging i found (again) exchanges which had bindings to
> > 
> > queues, but these bindings didnt forward any msgs.
> > > > Wrote a small script to detect these broken bindings and will now check
> > 
> > if this is "reproducible"
> > > > 
> > > > then I will try "durable queues" and "durable queues with replication"
> > 
> > to see if this helps. Even if I would expect
> > > > rabbitmq should be able to handle this without these "hidden broken
> > 
> > bindings"
> > > > 
> > > > This just FYI.
> > > > 
> > > >  Fabian