High Availability is one of the hottest topics for MySQL DBAs. As a matter of fact, when we (SkySQL) are called by users and customers, the top two questions for our PS team are:
- How can I make my MySQL database scalable?
- How can I make my MySQL database highly available
Since MySQL is the most used online database, these two questions are totally appropriate. Although the two concepts walk together, they should not be confused.
We refer to scalability when we define that a system must sustain a specific workload, measured in different ways – response time, latency, transactions or operations per second to name few, or a combination of them. So, we define the level of scalability we want to achieve and we design a system that can scale to that level.
We refer to high availability when we define that a system must be available, within the boundaries of the scalability mentioned above, also in case of malfunctions of one or more of its components. The latter, as many of you know, is called fault tolerance.Developers and administrators tend to confuse scalability and availability and, even worse, approach the availability and the scalability of their systems all in once. This is wrong for the simple reason that the techniques to adopt to achieve high availability are different to the once to achieve scalability. What is true though, is that these techniques must be ultimately work together and a good system design is a constant reiteration of these techniques. up to the fine tuning of all the aspects that are linked together.
At SkySQL, one of the main goals is to design with our customers scalable and highly available systems. I have seen many presentations on the HA subject and I think most of them are really good – see the one that Henrik has prepared, for example, highly recommended – but I wanted to give you our perspective and show you the various options that we have investigated at SkySQL and that we evaluate for community users and for our customers. This is the reason why I have created this presentation, HA Reloaded.
HA Reloaded is a refresh of all the latest options available for MySQL in terms of HA solutions. I have presented a version of it in Seattle, in San Francisco and in Boston in December, next week I will land in New York City. People who know me, also know that I never do the same presentation twice, so if you are around NYC on Mon 23rd and you want to join us, you will find something completely new, even if you have already attended to my preso.Here are all the details:
- The slides of my presentation so far are on slideshare, available here.
- The Meetup in NYC will start on Monday 23rd at 7pm – the venue is:
General Assembly NY
902 Broadway, 4th Floor
New York, NY 10010
- The URL to the MySQL Meetup in NYC is here: http://www.databasemonth.com/database/high-availability
For those of you who are attending the User Conference – no, I have not submitted this speech. As I said, there are already so many HA presos, I hope Henrik Ingo will do a refresh of his presentation and I am sure that our friends at Percona will talk a lot about their new solutions. But enough of this, please come and poke me at the meetup!/iz