August 2, 2014

128GB or RAM finally got cheap

I did not usually go to “Elite” servers on Dell web site but looking at customers system today I went to check Dell Poweredge R900. This monster takes up to 4 Quad Core CPUs and has 32 memory slots, which allows to get 128GB of memory with 4GB of memory chips. This means upgrade to […]

Reference architecture for a write-intensive MySQL deployment

We designed Percona Cloud Tools (both hardware and software setup) to handle a very high-intensive MySQL write workload. For example, we already observe inserts of 1bln+ datapoints per day. So I wanted to share what kind of hardware we use to achieve this result. Let me describe what we use, and later I will explain […]

ZFS on Linux and MySQL

I am currently working with a large customer and I am involved with servers located in two data centers, one with Solaris servers and the other one with Linux servers. The Solaris side is cleverly setup using zones and ZFS and this provides a very low virtualization overhead. I learned quite a lot about these […]

DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL

Suppose you have turned on innodb_file_per_table (which means that each table has its own tablespace), and you have to drop tables in a background every hour or every day. If its once every day then you can probably schedule the table dropping process to run during off-peak hours. But I have seen cases where the […]

Using any general purpose computer as a special purpose SIMD computer

Often times, from a computing perspective, one must run a function on a large amount of input. Often times, the same function must be run on many pieces of input, and this is a very expensive process unless the work can be done in parallel. Shard-Query introduces set based processing, which on the surface appears […]

The two even more fundamental performance metrics

In a recent blog post, I wrote about four fundamental metrics for system performance analysis. These are throughput, residence time, “weighted time” (the sum of all residence times in the observation period — the terminology is mine for lack of a better name), and concurrency. I derived all of these metrics from two “even more […]

MySQL Limitations Part 4: One thread per connection

This is the third in a series on what’s seriously limiting MySQL in core use cases (links: part 1, 2, 3). This post is about the way MySQL handles connections, allocating one thread per connection to the server.


(cross posting from ) All modern solid state drives use NAND memory based on SLC (single level cell) or MLC (multi level cell) technologies. Not going into physical details – SLC basically stores 1 bit of information, while MLC can do more. Most popular option for MLC is 2 bit, and there is movement […]

Should I buy a Fast SSD or more memory?

While a scale-out solution has traditionally been popular for MySQL, it’s interesting to see what room we now have to scale up – cheap memory, fast storage, better power efficiency.  There certainly are a lot of options now – I’ve been meeting about a customer/week using Fusion-IO cards.  One interesting choice I’ve seen people make […]

“Shard early, shard often”

I wrote a post a while back that said why you don’t want to shard.  In that post that I tried to explain that hardware advances such as 128G of RAM being so cheap is changing the point at which you need to shard, and that the (often omitted) operational issues created by sharding can […]