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From Andrija Panic <andrija.pa...@gmail.com>
Subject Re: database high availability question vs haproxy
Date Fri, 05 Jun 2015 13:37:13 GMT
Thanks Simon - that is what I thought...

So my question would be then, haproxy vs native ACS/mysql connector going
to galera1/galera2/etc...will figure out, for now we use haproxy for
mysql/galera loadbalancing...


THanks a lot Simon,
Andrija

On 5 June 2015 at 15:18, Simon Weller <sweller@ena.com> wrote:

>
> Personally, I think that Gallera is always going to be a safer option, as
> it handles conflict resolution natively. Having said that, it appears care
> has been taken in designing the ACS MGMT DB integration so that the chance
> of conflicts is very low. Galera requires a 3 nodes minimum, so it's a lot
> of hardware unless you've got plans to use it elsewhere in your
> organisation.
>
> The downside to Galera, is that it's synchronous replication, so it needs
> very low latency between nodes. That doesn't make it a good candidate for
> geographic separation between DB nodes for a DR scenario.
>
> You're understanding of the replication structure, as based on the design
> document is correct. MySQL (or Galera) handles all the replication. ACS
> just handles which node it's writing and reading from. In a 2 node native
> MySQL cluster, it's expected that you are setup for cross master-master
> replication.
>
> - Si
> ________________________________________
> From: Andrija Panic <andrija.panic@gmail.com>
> Sent: Friday, June 5, 2015 2:41 AM
> To: dev@cloudstack.apache.org
> Cc: users@cloudstack.apache.org
> Subject: Re: database high availability question vs haproxy
>
> Hi Simon,
>
> thanks for the link - actually I have already read this - but Im still
> seaking for some answeres :) :
>
> - real world experience with DB HA in general  - is i better to use
> haproxy(clustered/redudant) for mysql towards Galera cluster - or simply to
> reference 2 nodes (1 as master, another as slave) with native ACS DB HA  -
> silly question but anyway...
> - my understanding - ACS just pings and connects to master or slave (all
> replication etc, is done from my side, not from ACS) ?
>
> Thanks again and any info is greatly appreciated.
>
> Andrija
>
> On 4 June 2015 at 16:23, Simon Weller <sweller@ena.com> wrote:
>
> > Andrija,
> >
> > Here is the original design document, and it should give you a better
> idea
> > of what is implemented today:
> >
> >
> https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=34838207
> >
> > We have plans to test this in our lab soon, but just haven't got around
> to
> > it yet.
> >
> > - Si
> >
> > ________________________________________
> > From: Andrija Panic <andrija.panic@gmail.com>
> > Sent: Thursday, June 4, 2015 9:08 AM
> > To: dev@cloudstack.apache.org; users@cloudstack.apache.org
> > Subject: Re: database high availability question vs haproxy
> >
> > Anyone :) ?
> >
> > On 31 May 2015 at 00:26, Andrija Panic <andrija.panic@gmail.com> wrote:
> >
> > > Hi,
> > >
> > > I would have a question on database HA feature in db.properties (
> > >
> >
> http://cloudstack-administration.readthedocs.org/en/latest/reliability.html#configuring-database-high-availability
> > > )
> > >
> > > If I understand correctly, it is up to the admin to provide appropriate
> > > mysql HA (active-active, galera, etc) and ACS management server will
> > JUST
> > > try to connect to slaves if the master is down ?
> > >
> > > We are running Galera, with haproxy/keepalived, and by using stoping
> > > haproxy, it takes i.e. 6sec for keepalived to detect haproxy is down,
> and
> > > failover IP to another host.
> > >
> > > During these 6 seconds, ACS managemnt server goes dead, because of this
> > DB
> > > unavailability.
> > >
> > > So my wondering, is better to use ACS db HA feature, instead of
> > > loadbalancer for this specific purpose ?
> > > (we are also using haproxy/keepalived for management server
> loadbalancing
> > > - 2 servers in backend...)
> > >
> > > Any experience shared is really appreciated !
> > > --
> > >
> > > Andrija Panić
> > >
> >
> >
> >
> > --
> >
> > Andrija Panić
> >
>
>
>
> --
>
> Andrija Panić
>



-- 

Andrija Panić

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