Some links on DTrace + MySQL: http://delicious.com/amitkumarsaha/dtrace%2Bmysql

Some links on DTrace + MySQL: http://delicious.com/amitkumarsaha/dtrace%2Bmysql

For the first time, MySQL includes Dtrace probes in the 6.0 release. On platforms that support Dtrace you can still find out a lot about what's happening, both in the Operating System kernel and in user processes, even without probes in the application. But carefully placed Dtrace probes inserted into the application code can give you a lot more information about what's going on, because they can be mapped to the application functionality. So far only a few probes have been included, but expect more to be added soon.

I decided to take the new probes for a spin. Oh, and rather than do it on a Solaris system, I figured I'd give it a shot on my Intel Core 2 Duo MacBook Pro, since MacOS X 10.5 (Leopard) supports Dtrace.

To begin with I pulled down and built MySQL 6.0.5 from Bit Keeper, thanks to some help from Brian Aker. …

For the first time, MySQL includes Dtrace probes in the 6.0 release. On platforms that support Dtrace you can still find out a lot about what's happening, both in the Operating System kernel and in user processes, even without probes in the application. But carefully placed Dtrace probes inserted into the application code can give you a lot more information about what's going on, because they can be mapped to the application functionality. So far only a few probes have been included, but expect more to be added soon.

I decided to take the new probes for a spin. Oh, and rather than do it on a Solaris system, I figured I'd give it a shot on my Intel Core 2 Duo MacBook Pro, since MacOS X 10.5 (Leopard) supports Dtrace.

To begin with I pulled down and built MySQL 6.0.5 from Bit Keeper, thanks to some help from Brian Aker. …

For the first time, MySQL includes Dtrace probes in the 6.0 release. On platforms that support Dtrace you can still find out a lot about what's happening, both in the Operating System kernel and in user processes, even without probes in the application. But carefully placed Dtrace probes inserted into the application code can give you a lot more information about what's going on, because they can be mapped to the application functionality. So far only a few probes have been included, but expect more to be added soon.

I decided to take the new probes for a spin. Oh, and rather than do it on a Solaris system, I figured I'd give it a shot on my Intel Core 2 Duo MacBook Pro, since MacOS X 10.5 (Leopard) supports Dtrace.

To begin with I pulled down and built MySQL 6.0.5 from Bit Keeper, thanks to some help from Brian Aker. …

We have fixed the issue with the PHP dtrace extension not working in Cool Stack 1.2. As I mentioned in my announcement post, we had already identified the issue but didn't have time to fix it before the release. The issue was that /usr/ccs/bin/ld was being used to do the linking but this doesn't work for dtrace as some initialization code needs to be called from the .init section and this is not setup correctly if we don't use 'cc' to do the linking (rather than 'ld'). 

So a simple addition to the configure line:
LD="cc"

did the trick.

We now have two files : dtrace_1.2_sparc.so and dtrace_1.2_x86.so posted. Download the one for …

We have fixed the issue with the PHP dtrace extension not working in Cool Stack 1.2. As I mentioned in my announcement post, we had already identified the issue but didn't have time to fix it before the release. The issue was that /usr/ccs/bin/ld was being used to do the linking but this doesn't work for dtrace as some initialization code needs to be called from the .init section and this is not setup correctly if we don't use 'cc' to do the linking (rather than 'ld'). 

So a simple addition to the configure line:
LD="cc"

did the trick.

We now have two files : dtrace_1.2_sparc.so and dtrace_1.2_x86.so posted. Download the one for …

We have fixed the issue with the PHP dtrace extension not working in Cool Stack 1.2. As I mentioned in my announcement post, we had already identified the issue but didn't have time to fix it before the release. The issue was that /usr/ccs/bin/ld was being used to do the linking but this doesn't work for dtrace as some initialization code needs to be called from the .init section and this is not setup correctly if we don't use 'cc' to do the linking (rather than 'ld'). 

So a simple addition to the configure line:
LD="cc"

did the trick.

We now have two files : dtrace_1.2_sparc.so and dtrace_1.2_x86.so posted. Download the one for …

In a previous post, I mentioned the availability of the dtrace extension for Cool Stack's PHP.  Using this extension and the Cool Stack MySQL, it is possible to analyze the performance of your application running on this stack. At JavaOne, we demoed this using the open source MediaWiki and SugarCRM applications.  dtrace is especially useful in analyzing complex multi-tier applications like AMP. Thanks to Angelo Rajadurai for the creation of the scripts that I describe below.

Analyzing PHP calls

So, let's look at a simple dtrace script that counts how many times a particular PHP function is called :

#!/usr/sbin/dtrace -Zqs

php*:::function-entry
/arg0/
{
        @[copyinstr(arg0)]=count();
}

You can copy the …

During JavaOne this year Rags and I did a hands on lab on DTrace. The topic was "Using DTrace on Java and other Web 2.0 Languages in Solaris". Due to some unforeseen reason the lab was scheduled from 8:45 PM to 10:45 PM (Yes PM) and that to on the day of the big party at JavaOne. So I was expecting to be speaking to an empty room but lo and behold we had close to 100 engineers ( a few pretty drunk) and most stayed until the finished the lab.It was pretty heartening and was worth all the efforts that went into …