It is no secret that bugs related to multithreading–deadlocks, data races, starvations etc–have a big impact on application’s stability and are at the same time hard to find due to their nondeterministic nature. Any tool that makes finding such bugs easier, preferably before anybody is aware of their existence, is very welcome.
“The least expensive query is the query you never run.” Data access is expensive for your application. It often requires CPU, network and disk access, all of which can take a lot of time. Using less computing resources, particularly in the cloud, results in decreased overall operational costs, so caches provide real value by avoiding […]
You probably saw the Twitter storm over Oracle’s pricing changes and InnoDB in the last few days. The fear about Oracle removing InnoDB from the free version of MySQL was baseless — it was just a misunderstanding. Still, in the years since MySQL has been acquired by Sun, and then by Oracle, many MySQL users […]
This post is the third of a series that started here. From the previous of this series, we now have two working EC2 instances that are EBS based. The first instance is the monitor, usually an m1.small type instance and the second instance is hamysql, a large instance type. So far, we have configured Heartbeat […]
This post is the second of a series that started here. The first step to build the HA solution is to create two working instances, configure them to be EBS based and create a security group for them. A third instance, the client, will be discussed in part 7. Since this will be a proof […]
Like many, I have been seduced by the power and flexibility of Amazon EC2. Being able to launch new instances at will depending on the load, is almost too good to be true. Amazon has also some drawbacks, availability is not guaranteed and discovery protocols relying on Ethernet broadcast or multicast cannot be used. That […]
Our customers or prospective customers often ask us how we do a performance audit (it’s our most popular service). I thought I should write a blog post that will both answer their question, so I can just reply “read all about it at this URL” and share our methodology with readers a little bit. This […]
About half a year have passed since me and Vadim have left MySQL to do MySQL Consulting on our own. Bunch of people have been wondering about our experiences so I thought it would be worth to share it here.
MySQL Replication is asynchronous which causes problems if you would like to use MySQL Slave as it can contain stale data. It is true delay is often insignificant but in times of heavy load or in case you was running some heavy queries on the master which not take time to replicate to the slave […]
Thanks for all, who attended my webinar, I got many questions and I wanted to take this opportunity to answer them. Q: Even ntp has a delay of 0.3-0.4 between servers does that mean a 0.25 as from logs can be an issue ? A: My demo vms were running for a few hours before […]