No I did NOT post the following comment

This is ridiculous. You didn't test MySQL, you tested a failing DNS lookup on authentication.

resulting in the follow up post :

My previous post Redis, Memcache, Tokyp Tyrant, MySQL comparison had a flaw as pointed out by this comment. The MySQL was taking a huge time for doing a reverse DNS lookup.

But as always ... Everything is just a Freaking dns problem :)

Technorati Tags: dns dnsproblem mysql …

While at MySQL, one of the complaints I used to receive every now and then had to do with MySQL’s performance in the area of UNION’s. I distinctly remember one user group meeting where folks from one government agency told me they couldn’t use UNION at all in their application because the performance was so slow.

Now this isn’t always the case with MySQL, but I’ll admit I have seen bad speed on some UNION queries. And that’s one of the reasons I&rsquRead More...

This Thursday (November 26th, 14:00 UTC), Giuseppe Maxia will present the Spider Storage Engine. This session was originally scheduled for October 15th but had to be postponed for technical reasons.

Here's from the abstract: Everybody needs sharding. Which is not easy to maintain. Being tied to the application layer, sharding is hard to export and to interact with. The Spider storage engine, a plugin for MySQL 5.1 and later, solves the problem in a transparent way. It is an extension of partitioning. Using this engine, the user can deal transparently with multiple backends in the server layer. This means that the data is accessible from any application without code changes. This lecture …

A number of people have recently raised the issue of the threat that cloud computing poses to the monetization of open source by specialist vendors, including Savio Rodrigues, Matt Asay, and Mike Hogan.

I believe that cloud computing provides an opportunity for open source specialists, but agree that cloud services based on open source code could potentially eat into the business opportunities for open source specialists since the cloud providers have no …

My previous post Redis, Memcache, Tokyp Tyrant, MySQL comparison had a flaw as pointed out by this comment. The MySQL was taking a huge time for doing a reverse DNS lookup.

I turned on the skip-name-resolve parameter in the my.cnf and the Throughput of MySQL grew considerably, almost more than double.

read more

I had an interesting discussion with 2 colleagues about the possible interest of putting the swap space of a system on a SSD.

If I consider the gain in latency that an SSD brings versus a capacity disk - in the region of 100x - the solution seems obvious. Swapping - or more precisely paging - must be much faster/ with an SSD. Since RAM is expensive versus SSD, I could even be tempted to design a system with a small amount of RAM and a large amount of swap space on SSDs. In other words, I can ask myself if trying to prevent my system to page is still a good fight?

Let's try to shed some light on these questions.

Paging takes place when my system runs out of RAM because more processes are created or because existing processes requires more memory (check this article for details about how to monitor …

While at MySQL, one of the complaints I used to receive every now and then had to do with MySQL’s performance in the area of UNION’s. I distinctly remember one user group meeting where folks from one government agency told me they couldn’t use UNION at all in their application because the performance was so slow.

Now this isn’t always the case with MySQL, but I’ll admit I have seen bad speed on some UNION queries. And that’s one of the reasons I&rsquRead More...

While at MySQL, one of the complaints I used to receive every now and then had to do with MySQL’s performance in the area of UNION’s. I distinctly remember one user group meeting where folks from one government agency told me they couldn’t use UNION at all in their application because the performance was so slow.

Now this isn’t always the case with MySQL, but I’ll admit I have seen bad speed on some UNION queries. And that’s one of the reasons I&rsquRead More...

This Thursday (November 26th, 14:00 UTC), Giuseppe Maxia will present the Spider Storage Engine. This session was originally scheduled for October 15th but had to be postponed for technical reasons.

Here's from the abstract: Everybody needs sharding. Which is not easy to maintain. Being tied to the application layer, sharding is hard to export and to interact with. The Spider storage engine, a plugin for MySQL 5.1 and later, solves the problem in a transparent way. It is an extension of partitioning. Using this engine, the user can deal transparently with multiple backends in the server layer. This means that the data is accessible from any application without code changes. This lecture …

This Thursday (November 26th, 14:00 UTC), Giuseppe Maxia will present the Spider Storage Engine. This session was originally scheduled for October 15th but had to be postponed for technical reasons.

Here's from the abstract: Everybody needs sharding. Which is not easy to maintain. Being tied to the application layer, sharding is hard to export and to interact with. The Spider storage engine, a plugin for MySQL 5.1 and later, solves the problem in a transparent way. It is an extension of partitioning. Using this engine, the user can deal transparently with multiple backends in the server layer. This means that the data is accessible from any application without code changes. This …