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The best MySQL high availability solution on the market gets even better! We are happy to announce immediate availability of Continuent Tungsten 1.5.New Continuent Tungsten 1.5 offers significant improvements that help you to deploy cost effective HA clusters fast include:
Easy Installation - One-step command to deploy an entire Tungsten cluster in minutes, either in your data center or in
Henrik just wrote a good article on different ways of achieving high availability with MySQL. I was going to respond in the comments, but decided it is better not to post such a long comment there.
One of the questions I think is useful to ask is what kind of high availability is desired. It is quite possible for a group of several people to stand in a hallway and talk about high availability, all of them apparently discussing the same thing but really talking about very different things.
Henrik says “At MySQL/Sun we recommended against asynchronous replication as a HA solution so that was the end of it as far as MMM was concerned. Instead we recommended DRBD, shared disk or MySQL Cluster based solutions.” Notice that all of those are synchronous technologies (at least, the way MySQL recommended them to be configured), generally …
[Read more]A user on a linux user group mailing list asked about this, and I was one of the people replying. Re-posting here as I reckon it’s of wider interest.
> [...] tens of gigs of data in MySQL databases. > Some in memory tables, some MyISAM, a fair bit InnoDB. According to my > understanding, when one doesn’t have several hours to take a DB > offline and do dbbackup, there was/is ibbackup from InnoBase.. but now > that MySQL and InnoBase have both been ‘Oracle Enterprised’, said > product is now restricted to MySQL Enterprise customers.. > > Some quick searching has suggested Percona XtraBackup as a potential > FOSS alternative. > What backup techniques do people employ around these parts for backups > of large mixed MySQL data sets where downtime *must* be minimised? > > Has your backup plan ever been put to the test?
You should put it to the test regularly, not just when it’s needed. …
[Read more]This month on Database Journal we talk about multi-master MySQL using circular replication to achieve high availability.
This is a Request for Input. Dual MySQL masters with MMM in a single datacentre are in common use, and other setups like DRBD and of course VM/SAN based failover solutions are conceptually straightforward also. Thus, achieving various forms of resilience within a single data-centre is doable and not costly.
Doing the same across multiple (let’s for simplicity sake limit it to two) datacentres is another matter. MySQL replication works well across longer links, and it can use MySQL’s in-built SSL or tools like stunnel. Of course it needs to be kept an eye on, as usual, but since it’s asynchronous the latency between the datacentres is not a big issue (apart from the fact that the second server gets up-to-date a little bit later).
But as those who have tried will know, having a client (application server) connection to a MySQL instance in a remote data-centre is a whole other matter, latency becomes a big issue and is generally …
[Read more]A lot of systems are relatively easy to make HA (highly available). You just slap them into a well-known HA framework such as Linux-HA and you’re done. But databases are different, especially replicated databases, especially replicated MySQL.
The reason has to do with some properties that hold for many systems, but not for most databases. Most systems that you want to make HA are relatively lightweight and interchangeable, with little to zero statefulness, easy to start, easy to stop, don’t care a lot about storage (or at least don’t write a lot of data; that’s usually delegated to the database), and there’s little or no harm done if you ruthlessly behead them. The classic example is a web server or even most application servers. Most of the time these things are all about CPU power and network bandwidth. If I were to compare them to a car, I’d say they are like matchbox cars: there are many of them, and they are cheap …
[Read more]Walter and I are giving a tutorial on Monday morning, MySQL (and MariaDB) Dual Master Setups with MMM, I believe there are still some seats available – tutorials are a bit extra when you register for the conference, so you do need to sign up if you want to be there! It’s a hands-on tutorial/workshop, we’ll be setting up multiple clusters with dual master and the whole rest of the MMM fun, using VMs on your laptops and a separate wired network. Nothing beats messing with something live, breaking it, and seeing what happens!
Then on Tuesday afternoon (5:15pm, Ballroom F), Antony and I will do a session on the OQGRAPH engine: hierarchies/graphs inside the …
[Read more]The next presentation by Piotr Biel from Percona was on Multi-Master Manager for MySQL.
The introduction included a discussion of the popular MySQL HA solutions including:
A key problem that was clarified in the talk is the discussion of Multi-Master and this IS NOT master-master. You only write to a single node. With MySQL is this critical because MySQL replication does not manage collision detection.
The MMM Cluster Elements are:
And the Application Components are:
MMM works with 3 layers.
There is a nagios plugin available on the MMM's google-code page, but if you didn't find it yet, here it is:
http://code.google.com/p/check-mysql-all/wiki/check_mmm
You can call this plugin over nrpe. I'm already working on to fork a version which more useful with passive checks.
This plugin was developed by Ryan Lowe (Percona).