Microslow patch has been there for some time, but only for earlier MySQL editions such as 4.1 and 5.0. Now it's also available for the latest 5.1.

Because MySQL went through a lot of internal changes, the patch had to be written from scratch. It introduces some minor change in existing functionality and also adds new.

For the patch to work you must of course enable slow logging with --slow-query-log parameter. MySQL 5.1 has this nice feature which allows you to redirect query log (it's actually called general log now) and slow log to CSV tables mysql.general_log and mysql.slow_log respectively. …

Given a chance, I always check www.zmanda.com on different gadgets with various browsers and form factors. As soon as iPhone became available, I was at the Apple store checking out the new device and especially its web browsing capabilities.

It took me a couple of attempts to type the URL, but then I got it right and I could see our web site, wiki and forums. Everything looked great. Surprisingly, I could see most of the page without too much zooming and moving the window. Our upcoming Management Console for backup and recovery of MySQL is built on a LAMP stack with a look and feel similar to our website. What if we could actually manage all or at least some frequent day to day backup activities of MySQL DBA via iPhone?

Here at Zmanda we are moving fast, and within a few days we presented to a couple of our customers how to manage MySQL backups via iPhone. Here is a use case. A …

In my previous post I was a bit wrong giving Innodb some properties it does not have.
In fact Innodb does not currently sort pages in their position order flushing them to disk. Pages to be flushed are instead identified by other means - LRU and pages which contain oldest LSN (so which were flushed longest time ago).

As pages are to be flushed are identified Innodb looks at pages pages N-1 and N+1 and if they are dirty schedules flush for these as well. Such approach allows to merge few pages together and perform flushes in larger blocks.

It is really interesting to see how much sorting would speed things up, ie how much flushing pages 1 10000 200 20000 300 30000 in order 1, 200, 300, 10000, 20000, 30000 will help compared to random order and if it is worth to bother or if optimization Innodb performs is good enough and IO subsystem and RAID can do the rest.

So I need to create a portal site, where we will require multiple frontends. As most portal's we need to store some state information inside a session. We also need to show how many users are online, but more importantly be able to filter searches in the member database by who is online (we do not need to filter by how long the last site interaction as been, but you never know with changing requirements).

Now in order to filter by users in the member search, we need to have some information about active sessions by user id inside MySQL database. But if we were to put the entire session data inside the database we would have to hit the master on every request to update the session timeout. More importantly we would have to deal with replication lag.

The alternative approach to working around replication lag is using memcache. But with memcache we would not have access to who is currently online in an easy queryable way when we are …

And again we're on our mission to keep XAMPP up-to-date and put the first beta version of the upcoming XAMPP release in our public beta download area.

In this beta we updated: PHP 5 (to 5.2.3), MySQL (to 5.0.45), and phpMyAdmin (to 2.10.2).

Get the downloads at XAMPP BETA.

XAMPP beta versions are always for testing purposes only. There will be no upgrade packages from and to beta versions. To all testers: Many thanks in advance!!

A few weeks back, I posted a couple of blog entries on my recent trip to China. We have seen huge MySQL download numbers from Brazil, Russia, India, China (or "BRIC") with very significant growth in the last few years in China. I tried reading a book by Robert Buderi called "Guanxi (The Art of Relationships) - Microsoft, China and Bill Gates's Plan to Win the Road Ahead" on the development of Microsoft's research lab in China. However, the title should have been a warning to me. As much as I wanted to dive into this book it was just... READ MORE

OK, so we're going to get pretty down-and-dirty in the C source code that handles concurrent inserts... you've been warned. For background on the MyISAM concurrent insert functionality, see my previous article. Before I get going, I'd like to give a big shout out and thank you to Ingo Strüwing and Sergei Golubchik, whose comments and insight on the MySQL internals mailing list helped me keep from exploding while digging through the source code. Ingo and Serg are great resources that any developer looking to better understand the MySQL sources should be grateful to have around.

The way I approached delving into the concurrent insert functionality was actually quite different from the way I looked at the overall MySQL server architecture in Pro MySQL. When writing the book, I relied heavily on the …

And again we're on our mission to keep XAMPP up-to-date and put the first beta version of the upcoming XAMPP release in our public beta download area.

In this beta we updated: PHP 5 (to 5.2.3), MySQL (to 5.0.45), and phpMyAdmin (to 2.10.2).

Get the downloads at XAMPP BETA.

XAMPP beta versions are always for testing purposes only. There will be no upgrade packages from and to beta versions. To all testers: Many thanks in advance!!

Many businesses are now interested in implementing MySQL Cluster as a general high availability solution for their existing databases. This is certainly not a good approach and will often fail due to the limitations currently in the MySQL Cluster implementation (particularly 5.0) and the type of data within the business. However, many are still seeing MySQL Cluster as a magical solution to take out their potential downtime instead of other standard measures such as DRBD, multimaster or scale-out replication.

read more

Many businesses are now interested in implementing MySQL Cluster as a general high availability solution for their existing databases. This is certainly not a good approach and will often fail due to the limitations currently in the MySQL Cluster implementation (particularly 5.0) and the type of data within the business. However, many are still seeing MySQL Cluster as a magical solution to take out their potential downtime instead of other standard measures such as DRBD, multimaster or scale-out replication.

read more