One of our colleagues, Dimitri, at the Paris Sun solution center has developed a real neat and useful tool called dim_STAT. To make it short it's a tool for both high-level and detailed, monitoring and performance analysis of Solaris and Linux systems.

Data is collected and saved in a MySQL database, and it provides a very functional web base user interface. It allows real time or off line monitoring, multi-host etc.

Actually what is really interesting with dim_STAT is that, when I'm benchmarking or tryinng to find a performance bottleneck, I can collect all the data I need and come back later for analysis.

Recently, Dimitri has added a new tool db_STRESS, that allows us to put load on a database system and gives a high level metric (TPS: Transactions per seconds) and therefor allows us to compare how different systems compare together.
The point of this post is …

Hi all,

Hmmmm...

I switched on my machine this morning thinking a new day will bring new results. Nope. Same old results. As I mentioned in an earlier blog entry, I created a server instance using Fedora with LAMP, complete with MySQL. Hmmm.. Sound good? Well, it comes with MySQL 4.1. Normally an update would be a straightforward process. Since Fedora 8 doesn't come with an

apt-get

command, I chose to go the

yum

route. I tried

 yum update mysql-server

. No dice. problems. I spent another 30 minutes or so, trying to correct the problem, but to no avail. So I decided to create a whole new server instance with Fedora 8 and no MySQL. I manually installed MySQL on the machine, by doing the following:

• I download the MySQL sever, cient, and headers and libraries from the MySQL.com.

      wget …

Hi all,

Hmmmm...

I switched on my machine this morning thinking a new day will bring new results. Nope. Same old results. As I mentioned in an earlier blog entry, I created a server instance using Fedora with LAMP, complete with MySQL. Hmmm.. Sound good? Well, it comes with MySQL 4.1. Normally an update would be a straightforward process. Since Fedora 8 doesn't come with an

apt-get

command, I chose to go the

yum

route. I tried

 yum update mysql-server

. No dice. problems. I spent another 30 minutes or so, trying to correct the problem, but to no avail. So I decided to create a whole new server instance with Fedora 8 and no MySQL. I manually installed MySQL on the machine, by doing the following:

• I download the MySQL sever, cient, and headers and libraries from the MySQL.com.

      wget …

I see a lot of people filtering replication with binlog-do-db, binlog-ignore-db, replicate-do-db, and replicate-ignore-db. Although there are uses for these, they are dangerous and in my opinion, they are overused. For many cases, there's a safer alternative.

The danger is simple: they don't work the way you think they do. Consider the following scenario: you set binlog-ignore-db to "garbage" so data in the garbage database (which doesn't exist on the slave) isn't replicated. (I'll come back to this in a second, so if you already see the problem, don't rush to the comment form.)

Now you do the following:

PLAIN TEXT CODE:

1. $ mysql
2. mysql> delete from garbage.junk;
3. mysql> use garbage;
4. mysql> update production.users set disabled = 1 where user …

When I worked with Dimitri on the analysis of the
Split Rollback Segment Mutex he came up with numbers
on InnoDB Thread Concurrency set to 16 and 32 and I was curious
to see if 24 was the optimal setting. So he made some new runs and
some new graphs that I found interesting.

The first graph analyses behaviour of MySQL 5.4.0 on a SPARC
Server using InnoDB Thread Concurrency set to 0, 16, 24 and 32.
Interestingly for both readonly and readwrite benchmarks the
optimal setting for concurrency is 16 whereas the top numbers
(at 32 threads) is achieved with concurrency set to 24 or 32.



…

Sometimes I miss the coding I did last century. Today I was reminded of some of the fun, when I had set my mind to doing some statistics on my blogging.

In a blog entry on http://blogs.arno.fi/isit/2009/05/14/home-made-blog-statistics-from-wordpress-mu/ I describe what I did.

The blog entry may be of interest for those who use WordPress and are set back by the huge amounts of tables it generates. I happen to host 18 blogs and with each blog requiring 8 tables, that’s a total of 144 tables. Add the 9 top-level blogs and I’ve got 153 tables to navigate.

The blog entry I wrote 

• identifies the key fields
• shows how to …

When I read the blog about Split Rollback Segment Mutex,
I was interested to verify those results in the context of MySQL 5.4.0.

The patch can be found here.

We've analysed this patch both on a large SPARC system and on my
benchmark x86/Linux machine. Our results tend to be positive for
readwrite benchmarks but sometimes negative for readonly
benchmarks. Also the gain is much smaller than found in the
blog.

Also this patch has two negative effects, the first is that it
provides an upgrade problem, this can probably be handled in the
InnoDB code, but requires quite some digging. The other is that
instead of writing UNDO results to one UNDO log, we write …

Now that installing MySQL in Solaris zones is even officially supported by the MySQL support group (see http://www.mysql.com/about/legal/supportpolicies/policies-06.html#q03), the question is: What is the right way of installing MySQL in a zone. Of course this depends on what you want to achieve. The following description is based on Solaris 10. On Opensolaris this is different (somewhat easier, as there are no more sparse root zones.)
If you run a local zone as a whole root zone, you can easily install MySQL from tarball or the package installer.
If you run a local zone as a sparse root zone, there are different options:
First you cannot use the package installer, as this procedure will copy binaries to /usr/bin. But /usr/bin is inherited from the global zone and write protected. You have to use the tarball installation. …

At http://trubix.blogspot.com I've written a blog on the importance of peripheral DBA skills. In the MySQL world, the following peripheral skills are very helpful for managing MySQL environments:LAMP skills - Linux, Apache, PHP/Perl/Python.Application Servers - knowledge of Apache, JBoss, LightHTTP, connection pooling, etc.Monitoring skills - Enterprise Monitor, Nagios, Cacti, etc.Ability to