The latest from the MySQL community

Although we had previously planned to make MySQL 5.1.26 RC into the GA or production release, we've decided to instead incorporate two more release candidates into the schedule. The goal is to make sure that MySQL 5.1 is absolutely rock solid, even if it takes a few more months to release it as GA. Given the additional two releases candidates, I expect MySQL 5.1 will GA in late November of this year.

First of all, there will be several dozen additional bug fixes included in a 5.1.28 release expected to be available mid-September. Many of these bug fixes were completed and queued up ready to go after the GA release as part of our monthly rapid update cycle. Since the GA obviously didn't happen, we're incorporating these into the RC immediately. The bug fixes generally fall into three areas:
-potential crash bugs
…

I was wondering for quite a while if MySQLs C-API (libmysqlclient) can really do async queries and where it is lacking support.

Scanning through the source (sql/client.c) you see:

int mysql_real_query(MYSQL *mysql, const char *query, ulong length)
{

  if (mysql_send_query(mysql,query,length))
    return 1;

  return((int) (*mysql->methods->read_query_result)(mysql));
}

Digging a bit deeper you discover that mysql_send_query() and mysql_read_query_result() are public, but undocumented. Well, but that doesn't stop us.

When I talk about async queries I mean:

• being able to issue several queries in parallel without using threads

That is usually what you need in event-driven applications and allows you to create parallel application without having to use too many system resources (memory, threads, ...).

As long as you …

This week I will be the moderator for a MySQL Webinar How to secure MySQL data and achieve PCI compliance being held Thursday, September 11, 2008, 10:00 am PST, 1:00 pm EST, 18:00 GMT.

Salle (MySQL EMEA Support Leader) just told me over IRC: “One has to be crazy to do the job Kaj is doing :)”. While it may not be mandatory, it does help. It also helps me in my free time, where I just climbed Mt Blanc with my fourteen year old son.

Die-hard marathoners or mountaineers I recommend to scroll towards the bottom. There, I have an account of the exact times and heights of ascent, how to survive Refuge Gouter etc. But let’s start from the beginning, in the spirit of the http://xkcd.com/77/ web comic “bored with the Internet”.

It all starts with a leisurely walk up the Gran Paradiso, 4061 m.

The usual sight is the heels of my son.

A MySQL cap protects me against excessive Sun.

It also helps when it’s snowy.

Valley panorama.

Specifically this view, of my son’s heels, was next to mandatory as I was …

I recently released some RAID testing I did using the sysbench testing framework.  In light of the recent attention paid to multi-core CPU scalability, I have been working on some related tests trying to identify sources of contention using that same set of tests.

After effectively turning off every single innodb safety setting (like flush_log_at_trx_commit, checksums, doublewrite, etc.), and not seeing any real performance increase, I started to wonder what was going on.  
Surely my test client server wasn't the problem, it had plenty of idle CPU according to top, right?  Wrong.
I've been able to drive more QPS to my mysql test servers by starting up parallel sysbench tests from multiple test servers, but using (more or less) the same number of total test threads.  

read more

I recently released some RAID testing I did using the sysbench testing framework.  In light of the recent attention paid to multi-core CPU scalability, I have been working on some related tests trying to identify sources of contention using that same set of tests.

After effectively turning off every single innodb safety setting (like flush_log_at_trx_commit, checksums, doublewrite, etc.), and not seeing any real performance increase, I started to wonder what was going on.  
Surely my test client server wasn't the problem, it had plenty of idle CPU according to top, right?  Wrong.
I've been able to drive more QPS to my mysql test servers by starting up parallel sysbench tests from multiple test servers, but using (more or less) the same number of total test threads.  

read more

Script To Check If MySQL Master Master Replication Is Working Correctly

This short article explains how you can use a short script to check whether your MySQL master master replication is working as expected or not.

Script To Check If MySQL Master Master Replication Is Working Correctly

This short article explains how you can use a short script to check whether your MySQL master master replication is working as expected or not.

TOTD #9 explained how to configure JDBC connection pooling for Rails application deployed on GlassFish v2. There are several benefits of using using the JDBC connection pools:

• No need to create a new database connection for each Rails instance.
• No need to specify your password in database.yml or create a hack to hide it.
• No garbage collection of connection after each use.

And because of the above mentioned (and other reasons) an improved application performance, scalability and efficiency.
The only way to deploy a Rails application on GlassFish v2 is to create a WAR file using …

Sun Microsystems, Inc. today announced the addition of the leading enterprise resource planning software vendor Stésud to a growing list of customers that have adopted and deployed Sun's open source MySQL™ database and GlassFish™ application server software. This Belgium-based enterprise company joins Australian online travel pioneer Wotif.com and hundreds of other companies that now rely on MySQL and GlassFish as a lower-cost, higher-performance alternative to traditional database and application server software.