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.pa...@gmail.com> Sent: Friday, June 5, 2015 8:37 AM To: users@cloudstack.apache.org Cc: d...@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 <swel...@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.pa...@gmail.com> > Sent: Friday, June 5, 2015 2:41 AM > To: d...@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 <swel...@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.pa...@gmail.com> > > Sent: Thursday, June 4, 2015 9:08 AM > > To: d...@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.pa...@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
