[ClusterLabs] Antw: [EXT] Re: Sub‑clusters / super‑clusters?

[Antony Stone]

On Wednesday 04 August 2021 at 13:31:12, Andrei Borzenkov wrote:

> On Wed, Aug 4, 2021 at 1:48 PM Antony Stone wrote:
> > On Tuesday 03 August 2021 at 12:12:03, Strahil Nikolov via Users wrote:
> > > Won't something like this work ? Each node in LA will have same score
> > > of 5000, while other cities will be -5000.
> > > 
> > > pcs constraint location DummyRes1 rule score=5000 city eq LA
> > > pcs constraint location DummyRes1 rule score=-5000 city ne LA
> > > stickiness -> 10000
> > 
> > Thanks for the idea, but no difference.
> > 
> > Basically, as soon as zero nodes in one city are available, all
> > resources, including those running perfectly at the other city, stop.
> 
> That is not what you originally said.
> 
> You said you have 6 node cluster (3 + 3) and 2 nodes are not available.

No, I don't think I said that?

With the new setup, if 2 nodes are not available, everything carries on 
working; it doesn't matter whether the two nodes are in the same or different 
locations.  That's fine.

My problem is that with the new setup, if three nodes at one location go down, 
then *everything* stops, including the resources I want to carry on running at 
the other location.

Under my previous, working arrangement with two separate clusters, one data 
centre going down does not affect the other, therefore I have a fully working 
system (since the two data centres provide identical services with redundant 
routing).

A failure of one data centre taking down working services in the other data 
centre is not the high availability solution I'm looking for - it's more like 
high unavailability :)


Antony.

-- 
BASIC is to computer languages what Roman numerals are to arithmetic.

                                                   Please reply to the list;
                                                         please *don't* CC me.