There are number of people recently blogging about MySQL automated failover, based on production incident which GitHub disclosed. Here is my take on it. When we look at systems providing high availability we can identify 2 cases of system breaking down. First is when the system itself has a bug or limitations which does not [...]
Data Corruption, DRBD and story of bug
Working with customer, I faced pretty nasty bug, which is actually not rare situation , but in this particular there are some lessons I would like to share. The case is pretty much described in bug 55981, or in pastebin. Everything below is related to InnoDB-plugin/XtraDB, but not to regular InnoDB ( i.e in MySQL [...]
MySQL Limitations Part 1: Single-Threaded Replication
I recently mentioned a few of the big “non-starter” limitations Postgres has overcome for specific use cases. I decided to write a series of blog posts on MySQL’s unsolved severe limitations. I mean limitations that really hobble it for major, important needs — not in areas where it isn’t used, but in areas where it [...]
Why you can’t rely on a replica for disaster recovery
A couple of weeks ago one of my colleagues and I worked on a data corruption case that reminded me that sometimes people make unsafe assumptions without knowing it. This one involved SAN snapshotting that was unsafe. In a nutshell, the client used SAN block-level replication to maintain a standby/failover MySQL system, and there was [...]
Finding your MySQL High-Availability solution – Replication
In the last 2 blog posts about High Availability for MySQL we have introduced definitions and provided a list of ( questions that you need to ask yourself before choosing a HA solution. In this new post, we will cover what is the most popular HA solution for MySQL, replication.
Finding your MySQL High-Availability solution – The questions
After having reviewed the definition my the previous post (The definitions), the next step is to respond to some questions. Do you need MySQL High-Availability? That question is quite obvious but some times, it is skipped. It can also be formulated “What is the downtime cost of the service?”. In the cost, you need to [...]
Three key things to know about moving MySQL into the cloud.
The question “what problems will I have when migrating to the cloud” gets asked often enough. If by cloud you mean Amazon EC2, then from a technical perspective there isn’t much that changes. The biggest thing that changes is just how you pay your bill. Having said that, there’s still a few potential gotchas: There [...]
Onsite and Remote – getting best of both worlds
At Percona we provide services both Onsite – visiting the customers and Remote – logging in to their systems or communicating via email,phone,instant messaging. We believe both approaches have their benefits and drawbacks and mixing them right way allows you to get your problems solved most efficient way.
When would you use SAN with MySQL ?
One question which comes up very often is when one should use SAN with MySQL, which is especially popular among people got used to Oracle or other Enterprise database systems which are quite commonly deployed on SAN. My question in such case is always what exactly are you trying to get by using SAN ?
Faster MySQL failover with SELECT mirroring
One of my favorite MySQL configurations for high availability is master-master replication, which is just like normal master-slave replication except that you can fail over in both directions. Aside from MySQL Cluster, which is more special-purpose, this is probably the best general-purpose way to get fast failover and a bunch of other benefits (non-blocking ALTER [...]

