Introduction
When people think about Percona’s microslow patch immediately a question arises how much logging impacts on performance. When we do performance audit often we log every query to find not only slow queries. A query may take less than a second to execute, but a huge number of such queries may significantly load a server. On one hand logging causes sequential writes which can’t impair performance much, on other hand when every query is logged there is a plenty of write operations and obviously performance suffers. Let’s investigate how much.

I took DBT2, an OSDL’s implementation of TPC-C.
Hardware used
The benchmark was run on a DELL server running CentOS release 4.7 (Final)
There are four CPUs Intel(R) Xeon(R) CPU 5150 @ …

Sometime you may need to recover a table when all you have is the .ibd file. In this case, if you try to load it into a new instance, your likely to encounter some errors about the table id not matching. And there is not really a way around this.

However, I’ve found two work-arounds for this:

Note: You will need the .ibd file and the CREATE TABLE statement for each table you want to recover using these methods.

1. Simulate the internal InnoDB table counter. That is, create work tables (with innodb_file_per_table enabled) until you have the internal pointer of table id equal to (1 - id_of_ibd_table_you_need_to_restore). (See Method #1)
2. Manually hex edit the .ibd file, changing the table id. (See Method #2)

*Note: There are some internal structures with this meta information, so you’ll need to dump/import that data after you get it loaded, so you avoid unpleasantries that will inevitably …

Reaction to Marten Mickos’s departure from Sun. On open letter to President Obama. Lots of announcements from Sun, the LIMO Foundation and WS02. Mozilla offers to help EC investigation of Microsoft. Black Duck raises funding and gets a new CEO. The state of Red Hat. And more.

Mickos fallout
Kaj Arno maintained that “MySQL’s culture and business philosophy will live on in Sun.” He added: “In fact, you could say MySQL now becomes mainstream at Sun. Former MySQLers continue in key positions, in some cases with a mandate to generalise and apply MySQL related learnings on other open source products.”

For example, Charles Babcock …

“Welcome to FOSDEM!” Well, FOSDEM ended on Sunday, but I’d like to provide you with a short recap of my Q&A and Roadmap presentation. Warning: I may go into more visual detail than verbal. This is because reports from the community, OlinData and Philippe Back as well as twitterings by Ulf Wendel already post most of what I said. It’s because my presentation (1.5 MB) is posted on MySQL Forge. And it’s because those present are waiting for the following level of detail of …

This is the first public release. Features:

• Top Queries - See which queries are being run the most on your server.
• Top Users - See which users are using your server the most.
• Top Tables - See which database tables are opened the most.
• Top States - See which states your database is most busy doing, such as creating temp tables.
• Replication Profiling - You can measure how much capacity you have left on the replication SQL thread on slaves. If you are using MyISAM a lot, a MyISAM lock analysis will help discover any locks associated with replication, as well as lock-prone queries in general.
• Query Ratings and Visualization - You can get your queries rated using EXPLAIN and see which queries are …

I ran into a problem today where a web application and a suite of servers relying on a MySQL server were not responding, or responding very slowly.

Upon investigation of the issue, we found a high number of "unauthenticated connections" in the MySQL process list. A common cause of this is that MySQL cannot lookup the reverse DNS of the servers connecting, but it was strange this "suddenly" started happening. The servers in question used private IP addresses in the range 10.10.10.x.

The problem with this is if you do not setup a local zone for "10.10.10.x" reverse DNS, and poison your local caches to force those zones to be looked up locally, it heads out to the global internet to try and find a DNS server responsible for the 10.10.10.x reverse DNS (this translates into DNS name x.10.10.10.in-addr.arpa).

Because the root servers spent a lot of time fielding requests for these zones specifically with NULL replies, it was …

As some of you have noticed (and reported) we are having trouble with the CHM builds we do of the various MySQL Reference Manuals.

This is something that we are looking into, but the reasons and issues behind it are complex. One of the basic reasons if the sheer complexity and size of the documents are now building – there are thousands of files in a standard HTML build, constituting more than 2,500 pages of material.

Unfortunately, the final part of the build process, using Microsoft’s own HTML Help Compiler is something we have no control over, and Microsoft no longer support the product. Sometimes it produces a perfectly fine CHM from the source material. Sometimes, using the exact same material, it produces a build that is corrupt in some way.

The CHM building process is automatic – I improved it a couple of years ago to be automated as much as possible using a Windows Powershell script that performs nearly all of …

IP Address Geolocation From MySQL

In this short tutorial I will use a local MySQL database to do IP addresses geolocation.

I’m speaking at the User Conference this year, with a half-day tutorial and three further sessions. The running theme is performance, both in terms of the performance of your queries, and in terms of scaling up.

Scale Up, Scale Out, and High Availability: Solutions and Combinations

This is the big tutorial. It’s difficult to resolve what I’ll be talking about into a few sentences, but think about all of the different technologies available here - replication, partitions, sharding, DRBD, memcached - I’ll be talking about all of them, and more importantly combinations of the different solutions and where the potential performance gains and pitfalls are. I’ll also be using the opportunity to demonstrate some of the more obscure combinations that you can use to provide the environment you need.

…

This Thursday (February 12th, 14:00 UTC), MC Brown will give a MySQL University session on Using DTrace with MySQL. MC has been involved not just with documenting DTrace but also with DTrace development; see his recent blog post for details.

For MySQL University sessions, point your browser to this page. You need a browser with a working Flash plugin. You may register for a Dimdim account, but you don't have to. (Dimdim is the conferencing system we're using for MySQL University sessions. It provides integrated voice streaming, chat, whiteboard, …