Memcached is the de-facto distributed caching server used to scale many web2.0 sites today. With the requirement to support a very large number of users as sites grow, memcached aids scalability by effectively cutting down on MySQL traffic and improving response times.

Memcached is a very light-weight server but is known not to scale beyond 4-6 threads. Some scalability improvements have gone into the 1.3 release (still in beta). With the new Intel Nehalem based systems improved hyper-threading providing twice as much performance as current systems, we were curious to see how memcached would perform on these systems. So we ran some tests, the results of which are shown below :

memcached 1.3.2 does scale slightly better than 1.2.5 after 4 threads. However, both versions reach their …

Working on server-based index analysis I once again recalled a topic I wanted to write about for many times. The topic is redundant “Using where” in query plans. Suppose we have a table like this:

mysql> show create table t1 \G
*************************** 1. row ***************************
Table: t1
Create Table: CREATE TABLE `t1` (
`a` int(11) NOT NULL DEFAULT ‘0′,
`b` int(11) NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`a`,`b`)
) ENGINE=PBXT AUTO_INCREMENT=25651 DEFAULT CHARSET=latin1
1 row in set (0.02 sec)

now let’s try to analyse 2 simple queries with EXPLAIN SELECT:

1. SELECT a FROM t1 WHERE a>1;
2. SELECT a FROM t1 WHERE a>1 AND b>1;

mysql> explain select * from t1 where a>1 \G
*************************** 1. row ***********
id: 1
select_type: SIMPLE
table: t1
type: range
…

In my mind, Location Based Services (LBS) could well be the next great thing. There are so many things out there that means we are "always on" and there are advantages to that and things that can be done with LBS that this just cannot go unnoticed.

On the other hand, I have found little in the way in frameworks for this, because this is complex, at least if you want it to be useful, and there are many integrations points and the technologies to be integrated are often very different, from end user interaction via maps and by just moving around with a GPS, to back-end services and databases.

Some of you might have read my blog post on a call to action for advancement of the GIS capabilities with MySQL. This (LBS) is exactly why I think this is important. As for any scientific use of GIS, this is of less …

PLEASE NOTE: I am currently reviewing and extending this document. While caring for a remarkable amount of MySQL server instances, troubleshooting becomes a common task. It might of interest for you which Recovering a crashed MySQL server After a server … Weiterlesen →

Memcached is the de-facto distributed caching server used to scale many web2.0 sites today. With the requirement to support a very large number of users as sites grow, memcached aids scalability by effectively cutting down on MySQL traffic and improving response times.

Memcached is a very light-weight server but is known not to scale beyond 4-6 threads. Some scalability improvements have gone into the 1.3 release (still in beta). With the new Intel Nehalem based systems improved hyper-threading providing twice as much performance as current systems, we were curious to see how memcached would perform on these systems. So we ran some tests, the results of which are shown below :

memcached 1.3.2 does scale slightly better than 1.2.5 after 4 threads. However, both versions reach their …

Memcached is the de-facto distributed caching server used to scale many web2.0 sites today. With the requirement to support a very large number of users as sites grow, memcached aids scalability by effectively cutting down on MySQL traffic and improving response times.

Memcached is a very light-weight server but is known not to scale beyond 4-6 threads. Some scalability improvements have gone into the 1.3 release (still in beta). With the new Intel Nehalem based systems improved hyper-threading providing twice as much performance as current systems, we were curious to see how memcached would perform on these systems. So we ran some tests, the results of which are shown below :

memcached 1.3.2 does scale slightly better than 1.2.5 after 4 threads. However, both versions reach their …

The Kickfire appliance is designed for business intelligence and analytical workloads, as opposed to OLTP (online transaction processing) environments.  Most of the focus in the MySQL area right now revolves around increasing performance for OLTP type workloads, which makes sense as this is the traditional workload that MySQL has been used for.  In contrast,  Kickfire focuses squarely on analytic environments, delivering high performance execution of analytical and reporting queries .

A MySQL server with fast processors, fast disks (or ssd) and lot of memory will answer many OLTP queries easily.  Kickfire will outperform such a server for typical analytical queries such as aggregation over a large number of rows.

A typical OLTP query might ask “What is the shipping address for this invoice?”.  Contrast this with a typical analytical query, which asks “How much of this item did we sell in all of …

The BoF schedule for MySQL Conference and Expo (2009) is now published. Lenz Grimmer, Sergei Golubchik, Tomas Ulin and myself will be available during a BoF which focuses on MySQL Community Code Contributions. Lenz will be moderating. For background material, you may start here.

I’m presenting about Maatkit, the toolkit I created to make life better with MySQL, at the MySQL conference next week.

I’m going to give you a whirlwind tour throught some of Maatkit’s features and functionality. The toolkit is much too large and complex to cover more than a small part of it in depth. So here is your advance warning: I’m going to go through a lot of material, and I won’t be stopping for lengthy discussions :-) The Maatkit documentation is very thorough, and I hope to introduce you to things that could be of use to you, so you can go learn about those topics from the documentation.

Let me give you an idea: when I’m optimizing queries, I open up the output of mk-query-digest in …

Having written about what I think is cool about the upcoming MySQL Conference and the MySQL Camp, now I want to finish up with what I’d like to see at the Percona Performance Conference. Just to recap, this is a conference we created to serve those who want to learn about performance — not “learn about MySQL,” not “learn about database performance,” just learn about performance, period.

I want to see everything. I think this is going to be the single best conference I’ve ever been to. Even the way the conference is organized is exciting. For example, it’s running from early morning till late at night, nonstop. The sessions are also (mostly) only 25 minutes. This means if you decide a session isn’t all that interesting, you didn’t spend much time on it, and you don’t have long to wait for the next one.

So here is a small sample of the …