True..Thanks Simon... On 5 June 2015 at 16:28, Simon Weller <swel...@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.pa...@gmail.com> > Sent: Friday, June 5, 2015 9:07 AM > To: us...@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 <swel...@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.pa...@gmail.com> > > Sent: Friday, June 5, 2015 8:37 AM > > To: us...@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 <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: dev@cloudstack.apache.org > > > Cc: us...@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: dev@cloudstack.apache.org; us...@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 > > > > > > -- > > Andrija Panić > -- Andrija Panić
