May 22, 2013

Common MySQL traps webinar questions followup

Thanks to all attendees of the webinar yesterday! If you missed it, you can watch the video recording. Here are some questions that remained unanswered due to time constraints. Q: Are there any technical considerations or best practice tips to have a replicated slave in the cloud, for example on Amazon AWS? Hardware resources are [...]

How to STOP SLAVE on Amazon RDS read replica

We are doing a migration from Amazon RDS to EC2 with a customer. This, unfortunately, involves some downtime – if you are an RDS user, you probably know you can’t replicate an RDS instance to an external server (or even EC2). While it is annoying, this post isn’t going to be a rant on how [...]

Edge-case behavior of INSERT…ODKU

A few weeks back, I was working on a customer issue wherein they were observing database performance that dropped through the floor (to the point of an outage) roughly every 4 weeks or so. Nothing special about the environment, the hardware, or the queries; really, the majority of the database was a single table with [...]

Minimizing Downtime from Lengthy AWS Outages

Well, it happened again…  Another lengthy EBS outage in the US-East region impacted several sites across the net.  While failures like this are rare, they can be quite costly and translate into headaches for the operations team when impact production systems for any length of time.  At Percona, we routinely help clients architect and deploy [...]

News Flash: SQL Injection Still a Problem

The threat of SQL injection has appeared prominently in the news recently: An SQL injection vulnerability resulted in an urgent June bugfix release of Ruby on Rails 3.x.  Make sure you upgrade if you use Rails 3.0, 3.1, or 3.2!  Also you should disable mass assignment in any Rails project. Yahoo! Voices was hacked in July.  The [...]

Comparing Percona XtraDB Cluster with Semi-Sync replication Cross-WAN

I have a customer who is considering Percona XtraDB Cluster (PXC) in a two colo WAN environment.  They wanted me to do a test comparing PXC against semi-synchronous replication to see how they stack up against each other. Test Environment The test environment included AWS EC2 nodes in US-East and US-West (Oregon).  The ping RTT latency [...]

New distribution of random generator for sysbench – Zipf

Sysbench has three distribution for random numbers: uniform, special and gaussian. I mostly use uniform and special, and I feel that both do not fully reflect my needs when I run benchmarks. Uniform is stupidly simple: for a table with 1 mln rows, each row gets equal amount of hits. This barely reflects real system, [...]

Which Linux distribution for a MySQL database server? A specific point of view.

One of the more common questions I get asked is which Linux distribution I would use for a MySQL database server. Bearing the responsibility for someone else’s success means I should advise something that is stable, reliable, easy to manage and has plenty of resources available online. It should also allow running MySQL without too [...]

Find where your data is replicated, win a Percona Live ticket

Percona Live London starts on Monday, so this is the last in the series of free-Percona-Live tickets we’ll give away. But first — have you ever wondered what servers are in your MySQL replication hierarchy? We have, too. As consultants, a lot of times we need to get a quick overview of the whole replication [...]

MySQL performance on EC2/EBS versus RDS

A while ago I started a series of posts showing benchmark results on Amazon EC2 servers with RAID’ed EBS volumes and MySQL, versus RDS machines. For reasons that won’t add anything to this discussion, I got sidetracked, and then time passed, and I no longer think it’s a good idea to publish those blog posts [...]