So it's been a bit more difficult updating the blog with my
travels. If it weren't for Twitter and Facebook I suspect some
people would have thought I had disappeared off the face of the
planet, perhaps even swallowed up by America's midwest, maybe
even never have left Detroit... but truth to tell, all has been
going fine so far. I've travelled Greyhound and Amtrak, dodged
cars with my backpack and had deep philosophical conversations
with taxi drivers. So 17 days to go, 9 more campuses and 1800
miles to go before I reach the 2009 MySQL Users Conference!
In Detroit, I met the Wayne State University Sun Campus
Ambassador, Mumtaz Dawoodi, and WSU Linux Users Group
President, Jason Rogers. They had organized a talk at WSU for
about 25 people or so with huge amounts of Pizza courtesy of Sun.
I gave my, now standard, What the MySQL is this presentation and
went on to a light session …
Marco Tabini has a great post discussing the cost of the cloud, and the current state of affairs. He calls for a simpler cloud platform, not just in terms of cost, but ease of use and products and services that adapt to changes in the market. Though the $100/month Mosso offering is mentioned (this site is hosted on Mosso), I would like to point out the recent acquisitions by Rackspace/Mosso that make their cloud offerings even more compelling than AWS for me.
- Slicehost : Rackspace announced the acquisition in late 2008. This allows me to spin up virtual instances or Slicehost’s version of AMI’s called Slices (this was updated due to Ian’s comment below. You cannot migrate an AMI from EC2 to …
There will be big changes for those taking certification exams at
the MySQL Users Conference. Once again we are offering $25 MySQL
exams which is a big discount from the regular $200 price.
Last year we ran the exams as a drop-in service and it was well
received. So we will continue to run it as a drop-in service. No
need for an appointment. We will be in the Magnolia Room from
8:30 AM to about 4:00 PM but will not let anyone start an exam
later than 3:00PM.
Be sure to bring your WiFi enabled laptop! Last year we killed a
lot of trees and got a big workout printing thousands of exams
and moving them around. This year the exams will be online. We
will be reserving some hard lines for those taking the hands-on
DBA 5.1 exam as they need to connect to the virtual servers in
Colorado (that is if the O'Reilly folks can get the network gear)
but everyone else will be using the wireless connections. Last
year the wireless was …
Continuing on from CPU, we turn our attention to Memory. One of the first steps when addressing a MySQL performance tuning problem is to perform a system audit of the physical hardware resources, then identify any obvious bottlenecks in these resources.
In auditing, I start with the ‘free’ command, the already used ‘vmstat’ command, the /proc/meminfo and /proc/sys/vm/swappiness files to get an indication of memory and swap resources. While we are looking at the Memory, the configuration of Swap is also very important. I will discuss this in more detail later.
$ free -m
total used free shared buffers cached
Mem: 3955 3838 117 0 402 2366
-/+ buffers/cache: 1069 2886
Swap: 1027 0 …[Read more]
Amazon today launched a beta of it's Elastic
MapReduce (hosted hadoop). This is exciting and just in
time for my upcoming, Hadoop and MySQL: Friends with benefits,
session at the MySQL Conference & Expo.
I can't wait to try it out!
There are two problems with the CAST function in all versions of
MySQL:
bug#43774CAST(CAST(value) as TIME as DATETIME )
returns the wrong value.
example:
mysql> select '0000-00-00 21:00:00' expected,
cast(cast('21:00:00' as time) as datetime) actual;
+---------------------+---------------------+
| expected | actual |
+---------------------+---------------------+
| 0000-00-00 21:00:00 | 2021-00-00 00:00:00 |
+---------------------+---------------------+
1 row in set (0.00 sec)
bug#43865CAST( -1.0 as UNSIGNED) yields 0 instead
of MAXINT and returns a warning.
example:
create table t1(c1 int signed,
c2 decimal(5,2),
c3 float(5,2)
);
insert into t1 values …
MySQL Connector/Net 6.0.1, a new version of the all-managed .NET driver for MySQL has been released. This is a beta release and is intended to introduce you to the new features and enhancements we are planning. This release should not be used in a production environment.
We had three major goals with this release. Speed, Entity Framework support, and a better Visual Studio experience. I'm happy to report that we have met all three. Please see the complete list of changes below.
It is now available in source and binary form from [http://dev.mysql.com/downloads/connector/net/6.0.html] and mirror sites (note that not all mirror sites may be up to date at this point of time - if you can't find this version on some mirror, please try again later or choose another download site.)
- Massive speedups. We have increased the speed of the provider. In many situations it now matches or exceeds the speed of the native C connector. …
I just learned that there will be a Webinar “What’s New in the Next Generation of MySQL Cluster?”, April 30th. From what I know, the webinar is supposed to be at a good technical level, it is not a marketing like introduction. If you are interested, just register at: http://www.mysql.com/news-and-events/web-seminars/display-320.html
Why should a performance engineer care about SSDs
There has a been lot of buzz regarding SSDs lately. SSDs change the dynamics of the IO subsystem. You are no longer limited by rotational latency and vibration effects. For a performance engineer this has many implications. Since performance engineers care mostly about performance, the first thought that comes to mind is "Are we going to see a big impact in benchmarks?".
The answer is really easy for IO bound benchmarks. How about CPU bound benchmarks? Many database benchmarks are CPU limited. Does a faster disk really change anything?
So what does an SSD really give you?
- Faster IOPS
- Decreased Latency for an IO
Faster IOPS
SSD's have a huge random IO capability. During a recent experiment with a SSD, I got around 12,000 random IO operations per second! I have seen SSDs where you can get more. If you have ever …
[Read more]Spreading the word about Jay’s awesome findings on the libdrizzle benchmark against the original library inherited from MySQL. For those that aren’t familiar with libdrizzle, it is a fresh new (modern implementation) MySQL compatible client library for Drizzle that leverages asynchronous I/O and smarter memory usage founded by Eric Day.
You can read how this library came to life in this thread:
As you can see in Jay’s findings with sysbench, libdrizzle outperforms the original library in all concurrency …
[Read more]