cloudstack-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Andrija Panic <andrija.pa...@gmail.com>
Subject Re: database high availability question vs haproxy
Date Fri, 05 Jun 2015 14:33:01 GMT
True..Thanks Simon...

On 5 June 2015 at 16:28, Simon Weller <sweller@ena.com> wrote:

> I'm not sure whether that's configurable and  I haven't seen any examples
> out there that point to it being configurable. Having said that, there are
> people a lot more familiar with that than I am on the list.
>
> One option you do have for this particular failure situation, is to use
> monit to monitor the pid of the CS management service and if it's not
> running, force it to start up again.
>
> Losing a load balancer completely is very rare, so it's not likely to
> happen often at all.
>
> - Si
> ________________________________________
> From: Andrija Panic <andrija.panic@gmail.com>
> Sent: Friday, June 5, 2015 9:07 AM
> To: users@cloudstack.apache.org
> Cc: dev@cloudstack.apache.org
> Subject: Re: database high availability question vs haproxy
>
> 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
>



-- 

Andrija Panić

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message