I’ve presented at two different venues about HandlerSocket recently and the number one question that always arises is:

Why hasn’t HandlerSocket become more popular than it is?

Considering how fast and awesome HandlerSocket is, it’s not seeing as rapid adoption as some might expect. I theorize that there are five reasons for this:

Bugs, Bugs, Bugs

Up until the beginning of the year, HandlerSocket had a couple of bugs that a lot of people considered deal-breakers, and it’s not widely known that these issues have been fixed.

• Write operations do not invalidate the query cache – Exactly what it sounds like, if you performed a write operation via HandlerSocket, you could potentially read stale data from the MySQL interface.
• …

Amazon’s Relational Database Service (RDS) is a cloud-hosted MySQL solution. I’ve had some clients hitting performance limitations on standard EC2 servers with EBS volumes (see SSD versus EBS death match), and one of them wanted to evaluate RDS as a replacement. It is built on the same technologies, but the hardware and networking are supposed to be dedicated to RDS, not shared with the general usage of AWS as you get on normal EC2 servers with EBS.

I benchmarked the largest available RDS instance, which is listed as “High-Memory Quadruple Extra Large DB Instance: 68 GB of memory, 26 ECUs (8 virtual cores with 3.25 ECUs each), 64-bit platform, High I/O Capacity.” I used sysbench’s oltp benchmark, with 400,000,000 rows. This creates a table+index data size approximately twice as big as memory, so the …

On March 29th, I’ll be giving a webinar whose title is “Understanding HandlerSocket – A NoSQL PlugIn For MySQL”. This is a continuation and extension of the talk I gave during the Percona Live Event in San Francisco back in February. We’ll ask, and answer, the following questions:

• What is HandlerSocket?
• Where does HandlerSocket fit in my application stack?
• Why would I want to use HandlerSocket?
• How do I use Handlersocket?

Description:

http://www.percona.com/webinars/2011-03-29-understanding-handlersocket-a-nosql-plugIn-for-mysql/

To register:

…

Is it a good idea to deploy your database into the cloud? It depends. I have seen it work well many times, and cause trouble at other times. In this blog post I want to examine cloud-based I/O. I/O matters a lot when a) the database’s working set is bigger than the server’s memory, or b) the workload is write-heavy. If this is the case, how expensive is it to get good performance, relative to what you get with physical hardware? Specifically, how does it compare to commodity solid-state drives? Let’s put them in the ring and let them duke it out.

I could do benchmarks, but that would not be interesting — we already know that benchmarks are unrealistic, and we know that SSDs would win. I’d rather look at real systems and see how they behave. Are the theoretical advantages of SSDs really a big advantage in practice? I will show the performance of two real customer systems running web applications.

Let’s begin with a system …

This post is the fifth of a series that started here.

From the previous posts of this series, we now have nearly everything setup, only a few pieces are missing. One of the missing pieces is the Pacemaker script that run on the MySQL instance.

First, this script is optional, Pacemaker will accept a noop bash script but since we have the opportunity to run a script on the MySQL host, let’s take it. At minimum, let’s use mysqladmin to ping the database to see if it is available. If not, the recommended action is to stop the heartbeat service (pacemaker). Stopping Pacemaker will trigger a resource transfer to the monitoring instance which will in turn cause the running MySQL instance to be killed and a new one started. Here is a simple instance script, more complex ones are …