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From Andrija Panic <andrija.pa...@gmail.com>
Subject Re: database high availability question vs haproxy
Date Fri, 05 Jun 2015 14:07:44 GMT
Exactly...thanks Simon for the time and help :)

Is there any mysql timeout/retry parameter that is set in db.properties
(like db.cloud.queriesBeforeRetryMaster=5000), but I'm wondering since I'm
using keepalived/haproxy setup, it takes up to 5-6 sec for keepalive to
detect haproxy is down (while testing I shutdown haproxu on active node),
and then keepalvied moves IP to another node - meaning I have 5-6sec of no
connection between ACS mgmt servers and database/haproxy.

Is this timeout configurabile on ACS/mysql connector side ?

Thanks again,
Andrija

On 5 June 2015 at 15:54, Simon Weller <sweller@ena.com> wrote:

> I think haproxy is a better design in my opinion. You're going to have to
> use haproxy to balance the host agents to multiple management servers
> anyway, so you'll already be using it. haproxy can then manage the health
> checks to Galera rather than over complicating it with the CS Management
> configuration.
>
> - Si
>
> ________________________________________
> From: Andrija Panic <andrija.panic@gmail.com>
> Sent: Friday, June 5, 2015 8:37 AM
> To: users@cloudstack.apache.org
> Cc: dev@cloudstack.apache.org
> Subject: Re: database high availability question vs haproxy
>
> 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
>



-- 

Andrija Panić

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