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 [...]
DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL
June 22, 2012 By 33 Comments
Using any general purpose computer as a special purpose SIMD computer
May 16, 2011 By 5 Comments
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
May 5, 2011 By 6 Comments
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
October 27, 2010 By 14 Comments
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.
SLC vs MLC
July 14, 2010 By Leave a Comment
(cross posting from SSDPeformanceBlog.com ) 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?
April 8, 2010 By 10 Comments
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”
November 16, 2009 By 6 Comments
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 [...]
RAID vs SSD vs FusionIO
May 1, 2009 By 17 Comments
In benchmarks passion (see my two previous posts) I managed to setup all three devices (RAID was on board; Intel X25-E SSD connected to HighPoint controller, FusionIO card) on our working horse Dell PowerEdge R900 (btw, to do that I had to switch from CentOS 5.2 to Ubuntu 8.10, as CentOS was not able to [...]
How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
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 [...]
Rendundant Array of Inexpensive Servers
August 21, 2008 By 15 Comments
So you need to design highly available MySQL powered system… how do you approach that ? Too often I see the question is approached by focusing on expensive hardware which in theory should be reliable. And this really can work quite well for small systems. It is my experience – with quality commodity hardware (Dell,HP,IBM [...]
