On Thursday/Friday this week, I visited Linbit in Vienna. They are the creators of DRBD. Quoting Wikipedia,

DRBD is an acronym for Distributed Replicated Block Device. It is a Linux kernel module, that, working together with some scripts, offer a distributed storage system, frequently used on high availability clusters. DRBD works as a kind of network RAID.

This means DRBD can give high availability to MySQL users. Through configuring DRBD to be used on your system, you can have synchronous replication between two different servers, giving a MySQL database a failover server to redirect to instantaneously, should the main server running MySQL fail.

For those interested in more detail on how to combine DRBD …

When I work on Apache I need to normally run my regression tests against many different versions of Apache, and I do this across Linux, OSX, and Solaris. I commit, and the bots on different hosts poll the repository for pushes to build against (and the data on the results is then sent via HTTP/XML back to my logging host for me to see).

I had a request this week to add Solaris X86 for testing... now I don't have Solaris X86 and I am not too inclined to add a new machine for it (even if the hardware was to be a donation). But... I do have an EC2 account, and access to a Solaris Omni. It would be easy for me to kick it on long enough in the EC2 cloud, to run through a test and get a result back.

My cost for a test build? 10cents? The Electricity is more then that for me to keep the machine running at home.

Now my regression test for my Apache modules is only about half of what the MySQL regression test is …

In his well-written blog entry Open Development: Diversity matters, Gianugo Rabellino quickly replied to my blog entry from yesterday on Defining “Participatory Open Source”. He sees plenty of common ground in our reasoning, but defends the existence of requirements for neutrality in the definition. I agree with nearly all of his reasoning for why neutrality is important for the development of a community of contributors, but I draw partially different conclusions.

The main reason why my conclusions are different from Gianugo’s is the starting point for my reasoning: There is no inherent conflict of interest between participatory open source and pursuing for-profit business goals, so we must not create artificial …

Red Hat enforces open source project trademark…HP may resell Oracle Linux…Bruce Perens speaks out regarding the GPLv3…and more…

Is Red Hat Acting Like Microsoft?, eWeek, Darryl Taft (Article)

Novell, Red Hat compare desktop Linux programs, Computerworld, Robert Mullins (Article)

The Year of OpenSolaris, eWeek, Jason Brooks (Article)

HP Gearing Up to Resell Oracle Linux, Internetnews.com, Sean Michael Kerner (Article)

…

During last couple of months I had number of consulting projects with MySQL Query Cache being source of serious problems. One would see queries both for MyISAM and Innodb tables mysteriously stalling for few seconds with "NULL" in State column.

These could be troubleshooted to waiting on Query Cache which at the same time had massive amount of entries invalidated by some batch data load job.

When you should worry ? If you set query_cache_size relatively high at 256MB or more. It can be seen worse if your query cache size is in Gigabytes. At the same time check how many queries do you have in cache - Qcache_queries_in_cache - if it is in hundreds of thousands it may take a while to invalidate them. But first of all you should have something which causes massive amount of invalidations like tens-hundreds of thousands queries being invalidated by single insert - this typically happens if you have …

In just about 12 hours, we will close Proven Scaling’s Free Ride to MySQL Conference and Expo 2007 form to new entries, and start deliberating on the winners. Get your entry in now if you want a chance to go to the MySQL event of the year for free!

Guy Bowerman has published on Informix Application Development, the 37th edition of Log Buffer, the weekly compendium of database blogs. Log Buffer always wants more editors and story suggestions, so if you read it, please also look at Log Buffer’s homepage to see how you can get involved. Next week, LB will appear on Padraig [...]

The Open Source thinker and BSD advocate Gianugo Rabellino just made me aware of a year-old blog entry by Susan Wu in Planet Apache on “Should OSI redefine the label Open Source?”. As I read the entry, it proposes a term “Open Development” and lists these “first stab” requirements:

1. an Open Source license, of course;
2. a non-discriminatory access to the developer?s community;
3. a well-defined and stated process for people to get involved;
4. a neutral and self-elected governing body;
5. (more difficult, could mean having a preferential lane) a neutral party such as a foundation owning the code.

I think Gianugo and Susan are …

As Kaj Arnö already mentioned in his blog, we have a vision for MySQL and it is called a scalable BLOB streaming infrastructure. Our plan is to build this into and around the MySQL architecture with the help of MySQL and the community.

It is a "big picture" idea and in this way a response to Robin Schumacher's question: The MySQL Vision - What do you see?. But at the same time it is very relevant and practical in the context of the Web 2.0 world.

The design of the system includes a client-side library which extends the existing MySQL client API, a stream based communications protocol and a scalable back-end which is (at least partially) linked into the MySQL server. In short, we want to make it possible to put BLOBs of any size in the database.

The …

Hello,

For those of you interested in learning about how to design high availability architectures using MySQL, DRBD and Linux Heartbeat, please check out next Wednesday's (3/28) webinar.

Info and registration:

http://www.mysql.com/news-and-events/web-seminars/mysql-drbd.php

See you there,

Jimmy