Hi all, Firstly thanks for the great responses already.
Secondly, regarding HA vs failover, I had been assuming these as much the same. Based on what I had read about the new changes in 4.3, I had assumed that the new feature allows you to configure standard MySQL (clustering not required - Galera or otherwise) in a multimaster replication setup and that while management servers only speak with a single server at a time, failover to a backup server is automatic and does not need any work on the MySQL side to promote a slave to a master as with a basic master/slave setup. I'm personally not interested in load balancing just yet, simply having a hot standby DB that takes over automatically. This is what I take the term HA to mean. >From the wiki, I'm also taking it that the use of the auto increment and offset values ensure that the two DBs can safely run as master-master in the event that each gets written to concurrently (split brain or just two mgmt servers failing over at slightly different times). It seems that this thread is already highlighting some of the confusion I and others have faced. Hopefully it will help someone else. Thanks again, Adrian On 6 Jun 2014 07:18, "Shanker Balan" <shanker.ba...@shapeblue.com> wrote: > Hi Damodar, > > Comments inline. > > On 06-Jun-2014, at 10:53 am, Damoder Reddy <damoder.re...@citrix.com> > wrote: > > > Hi Adrian, > > > > For your question, . Is the CS side purely for failover or does it > actually set up part of the replication for you? The answer is, the Cloud > Stack does only failover configuration and the actual replication process > on the mysql side has to be done by own. > > > https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=34838207 > > > For the second question, Can you easily enable an existing DB for HA or > is this best done before there’s any data? The answer is, we can setup > replication even with existing data and then start the management servers. > The mysql documentation contains the clear steps how to setup replication > with existing documentation. Probably that is the reason why we might not > have included these steps in the doc. > > > > > The OP is looking for HA, not failover. HA is possible in ACS 4.3.0 > using MySQL Clustering. > > Once you have MySQL Clustering, its multi-master and not one master to > many slaves. > ACS should not fence itself like it currently does when the master is not > available. > > > > The configuraiton we need to do on each management server is as below. > > > > You can follow the design doc steps if you think there is a minimal > documentation in the 4.3 doc. The design doc also contains the links to > mysql site for setting up the replication for fresh as well as existing > setups. > > > > From the cloud stack side it is purely failover and falling back between > the IPs configured for the master/salve databases. > > > > https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=34838207 > > > > > -----Original Message----- > > From: Adrian Lewis [mailto:adr...@alsiconsulting.co.uk] > > Sent: Friday, June 6, 2014 6:46 AM > > To: users@cloudstack.apache.org > > Subject: Examples of configuring DB HA? > > > > Hi all, > > > > > > > > Does anyone have any example configs or blog posts explaining the DB HA > features introduced in 4.3? Between the section in the design docs on the > wiki and the official docs, I’m a little confused as to how it’s supposed > to be set up – they appear to differ although there’s a lot more detail in > the design docs. Some of it is clearly MySQL stuff that’s outside of > Cloudstack but some of it is Cloudstack config as well. I’m just trying to > get a feel for what is the best way to use what’s made it into 4.3 final > (if different to the design docs). I’m not too strong on MySQL so I can’t > easily work out what’s a requirement, what’s just recommended (and > > implications) and what the Cloudstack side actually does. Is the CS side > purely for failover or does it actually set up part of the replication for > you? Can you easily enable an existing DB for HA or is this best done > before there’s any data? Before you run cloudstack-setup-databases? > > > > > > > > Shanker – I don’t suppose this subject could add to your already > excellent blog post collection? > > > > > > > > Thanks in advance, > > > > > > > > Adrian > > -- > @shankerbalan > > M: +91 98860 60539 | O: +91 (80) 67935867 > shanker.ba...@shapeblue.com | www.shapeblue.com | Twitter:@shapeblue > ShapeBlue Services India LLP, 22nd floor, Unit 2201A, World Trade Centre, > Bangalore - 560 055 > > Find out more about ShapeBlue and our range of CloudStack related services > > IaaS Cloud Design & Build< > http://shapeblue.com/iaas-cloud-design-and-build//> > CSForge – rapid IaaS deployment framework<http://shapeblue.com/csforge/> > CloudStack Consulting<http://shapeblue.com/cloudstack-consultancy/> > CloudStack Infrastructure Support< > http://shapeblue.com/cloudstack-infrastructure-support/> > CloudStack Bootcamp Training Courses< > http://shapeblue.com/cloudstack-training/> > > This email and any attachments to it may be confidential and are intended > solely for the use of the individual to whom it is addressed. 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