Read the original article at Cloud Operations Interview

What does a cloud computing expert need to know? How do you hire a cloud computing expert? Competition for operations & DBAs is fierce, so you’ll want to know how to find the best.

If you’re a systems administrator or ops guy, you may want to prepare for an interview for such a position. Meanwhile, if you’re a director of it or operations, a recruiter or manager in HR, you’ll want to have some idea how to find the right candidate.

Here’s my guide to do just that. You may also jump to …

Read the original article at AirBNB didn’t have to fail

Today part of Amazon Web Services failed, taking down with it a slew of startups that all run on Amazon’s Cloud infrastructure. AirBNB was one of the biggest, but also Heroku, Reddit, Minecraft, Flipboard & Coursera down with it. Its not the first time. What the heck happened, and why should we care?

1. Root Cause

The AWS service allows companies like AirBNB to build web applications, and host them on servers owned and managed by Amazon. The so-called raw iron of this army of compute power sits in datacenters. Each datacenter is …

I have seen a few posts on DBA.SE (where I answer a lot of questions) recommending the use of semi-synchronous replication in MySQL 5.5 over a WAN as a way to improve the reliability of replication. My gut reaction was that this is a very bad idea with even a tiny write load, but I wanted to test it out to confirm. Please note that I do not mean to disparage the author of those posts, a user whom I have great respect for.

What is semi-synchronous replication?

The short version is that one slave has to acknowledge receipt of the binary log event before the query returns. The slave doesn’t have to execute it before returning control so it’s still an asynchronous commit. …

Read the original article at A CTO Must Never Do This…

A couple years back I was contacted to look at a very strange problem.

The firm ran flash sales. An email goes out at noon, the website traffic explodes for a couple of hours, then settles back down to a trickle.

Of course you might imagine where this is going. During that peak, the MySQL database was brought to its knees. I was asked to do analysis during this peak load, and identify and fix problems. Make it go faster, please!

First day on the job I’m working with a team of outsourced DBAs. I was also working with a sort of swat team chatting on SKYPE, while monitoring the systems closely.

…

Yesterday (4/19) I attended the AWS Summit in NYC (http://aws.amazon.com/aws-summit-2012/nyc).

I'm a big fan and also a heavy user of AWS especially S3, EC2, and naturally, RDS. In every point in time I have several dozens of AWS machines running for me out there in the East region, and in some cases when we do some special benchmarks and tests, number of EC2 and RDS machines can easily reach 3-digit. As I said, I'm a fan...

A few quotes I was able to catch and document on my laptop, on my laps...:
"When you develop an app for facebook, you must be prepared (and be afraid) that to your party, not noone will show up, but everybody will show up!" So true! Simple and true. We all want to succeed, to have success with our app. We have to think about scaling from day 1.
"Database was bottleneck for building of sophisticated apps. This is …

This tutorial will help you register and get ready to use Amazon Web Service (AWS). AWS provides a free tier so it is possible to use these services at ZERO cost.

These instructions are used by the Effective MySQL: Backup and Recovery book examples.

Step 1: Registration

1. Goto AWS site
2. Register email address
3. Enter Login Credentials
4. Enter Contact Information
5. Enter Credit Card details (while this is required, provided you follow free guidelines you will not be charged)
6. Identity verification by Telephone
7. Activation of account

Screenshots
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I've been spending some time lately familiarizing myself with EC2, setting up some MySQL servers & clusters here and there, and doing some really basic configuration testing. One situation you'll run into when interacting with EC2 is that it gets unwieldy to use the AWS Management Console web interface for interacting with your instances. There ends up being lots of scrolling, lots of staring, and lots of sighs. Since I'm using SSH to connect to and interact with my instances, I want a reasonable way to find information about them on the Unix command line.

Amazon has an official set of tools [http://aws.amazon.com/developertools/351] that give you this information , at least theoretically. It is some gigantic distribution of shell scripts and Java madness that, if you are very patient, will …

Modern internet infrastructure are complex.  Components and services are prone to failure.  Resiliency involves building redundancy, best practices and processes into your architecture to make you able to bend and not break.

• Migrating to cloud service providers
• Rearchitecting and refactoring applications to scale
• Scaling the database tier - MySQL and Oracle
• Building redundancy into every layer
• Deploying object caches - memcache
• Deploying page caches - varnish
• Migrating to Innodb - transactional storage engine
• Infrastructure design
• Infrastructure automation
• Disaster Recovery
• Business Continuity with cloud deployments

Call or Skype us in New York City +1-212-533-6828

Deploying in the Amazon cloud is touted as a great way to achieve high scalability while paying only for the computing power you use. How do you get the best scalability from the technology?

1. Use Auto-scaling

Auto-scaling is a unique feature of cloud computing and Amazon's EC2 offering. Setup a load balancer and a couple of webservers for your application as you normally would. Design your webserver based on a template AMI that you'll reuse over and over. Then setup auto-scaling and set thresholds based on the traffic you forecast. When a threshold is passed, AWS will spinup a new instance of your webserver, and roll it into the load balancer pool automatically. Once traffic falls below the scale back threshold, Amazon will take a server out of the pool for you.

Be sure to monitor this …

When I spoke at Percona Live (video here) on running an E-commerce database in Amazon EC2, I briefly talked about using RAID 10 for additional performance and fault tolerance when using EBS volumes. At first, this seems counter intuitive. Amazon has a robust infrastructure, EBS volumes run on RAIDed hardware, and are mirrored in multiple availability zones. So, why bother? Today, I was reminded of just how important it is. Please note that all my performance statistics are based on direct experience running a MySQL database on a m2.4xlarge instance and not on some random bonnie or orion benchmark. I have those graphs floating around on my hard drive in glorious 3D and, while interesting, they do not necessarily reflect real-life performance.

Why? …