High Availability

Have you ever wondered if your application should be able to work in read-only mode? How important is that question?

MySQL seems to be the most popular database solution for web-based products. Most typical Internet application workloads consist of many reads, with usually few writes. There are exceptions of course – MMO games for instance – but often the number of reads is much bigger then writes. So when your database infrastructure looses its ability to accept writes, either because traditional MySQL replication topology lost its master or Galera cluster lost its quorum, why would you want to the application to declare total …

A question I often hear when customers want to set up a production PXC cluster is: “How many nodes should we use?”

Three nodes is the most common deployment, but when are more nodes needed? They also ask: “Do we always need to use an even number of nodes?”

This is what we’ll clarify in this post.

This is all about quorum

I explained in a previous post that a quorum vote is held each time one node becomes unreachable. With this vote, the remaining nodes will estimate whether it is safe to keep on serving queries. If quorum is not reached, all remaining nodes will set themselves in a state where they cannot process any query (even reads).

To get the right size for you cluster, the only question you should answer is: how many nodes can simultaneously fail while leaving the …

For an online shop, the website is the cash register. It has to be open for business 24 hours a day.

As the ops person on duty, when you get a call at 3am after your website went down, your priority number one is to restore the service asap. But why can we not have our application stack automatically recover, and not have the pager wake us at all? Why do we still stick to tedious manual processes, which take up time and resources, and hinder future growth?

Infrastructure automation isn’t easy, but it’s not rocket science either, says Riaan Nolan. Riaan has been in operations for the past decade, and has built over a dozen eCommerce properties. Automation is a worthwhile investment for retailers serious about eCommerce, but deciding on which tools to invest in can be a confusing and overwhelming process.

Join us for this webinar to understand the key pain points that online retailers experience which indicate it’s time …

Building clusters is usually a fun time. Here’s one of my setups at the Equinix LAX1 facility that is being used for VPN services, OpenVZ clustering, and general RADIUS and MySQL clustering integration. Once the clustering design is finalized, it’s still in flux state while I try out different setups, I’ll post some physical+logical architecture diagrams to show “How to Build a Fault Tolerant Infrastructure for Virtualized MySQL NDB Cluster + Python-based VPN systems.” Stay tuned for more.

Been at the MySQL conference the last few days, and I have to say, I’m really blown away by MySQL 5.5.4‘s improvements.  Last year I keynoted and I begged Oracle on stage to realize that MySQL and InnoDB under one roof represented opportunity.  It’s clear they heard the community – this is some serious progress, and right when we needed it.

Jeremy Zawodny’s blog post covers most of the stuff I’m really excited about, and there are some great detailed technical slides …

Been asked a few times in the last few days about where my slides are from my MySQL keynote from *last* year.

Ooops.

Um, yeah.  Sorry about that.  Here’s a link to ‘The SmugMug Tale’ slides, and you can watch the video below:

Sorry for the extreme lag.  I suck.

The important highlights go something like this:

• Use transactional replication.  Without it, you’re dead in the water. You have no idea where a crashed slave was.
• Use a …

Ian Bullard asserts that you should never use the RAND() function. The Ayn Rand Google Ad is pretty funny. The new Zend Server is coming out as a web stack. Although it can be easier to install a Xampp style … Continue reading →

tl;dr: The MySQL community rocks. Percona, XtraDB, Drizzle, SSD storage, InnoDB IO scalability challenges.

For anyone who lives and dies by MySQL and InnoDB, things are finally starting to heat up and get interesting. I’ve been banging the “MySQL/InnoDB scales poorly” drums for years now, and despite having paid Enterprise licenses, I haven’t been able to get anywhere. I was pretty excited when Sun …

In high school, I had a great programmable calculator. I’d program it to solve complicated math and science problems “automatically” for me. Most of my teachers got upset if they found out, but I’ll always remember one especially enlightened teacher who didn’t. He said something to the effect of “Hey, if you managed to write software to solve the equation, you must thoroughly understand the problem. Way to go!”.

George Reese wrote up a blog post over at O’Reilly the other day called On Why I Don’t Like Auto-Scaling in the Cloud. His main argument seems to be that auto-scaling is bad and reflects poor capacity planning. In the comments, he specifically calls SmugMug out, saying we’re “using auto-scaling as a crutch for poor or non-existent capacity planning”.

George is like one of those math teachers who …

FYI, Sun is announcing some sweet new storage stuff on Monday at 3:30pm PT.

I’m reviewing a few of the things they’re announcing, and hope to publish my thoughts here soon (one of them joins my production network tonight if all goes well). However, I’m at Disneyland with my kids (first trip!) from Monday through Thursday, so I don’t know (yet) when I’ll be able to write them up. Bear with me if it takes a few days.

But the gear is exciting, and the direction Sun is headed is even more exciting!

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