Drizzle 7.1 Released

Drizzle 7.1 was released!

The laundry list for features and improvements are pretty long, so I will leave that to the main blog announcement.

The part that I find the most interesting? 7.1 was the effort of a lot of developers and people who do the heavy lifting of promoting the project (and the efforts around a project like this are huge). It takes the resources of a half a dozen companies directly, and a number of companies indirectly.

Compared to 7.0, Drizzle was done by volunteers, not paid Drizzle employees, who find the project fun and interesting. These are people who want to be involved with the Open Source Community, and who find value in the work (and looking at our incoming Google Summer of Code applicants there are more people to come).

The biggest surprise that some might fine? Much of the 7.1 effort was done by new developers. These are people who never worked at MySQL, Sun, or Oracle.

Contributions by new individuals make up the bulk of the 7.1 effort, and I am very happy to see that. It it is evidence of the ongoing growth of the Drizzle community.

One Fat Bird

Opscode's Chef, MySQL, Best Practices

If Chef manages a CNF file, please have it put a comment in the top of the file that it is managed by Chef. Do not assume that everyone will believe that every file is being managed by Chef. In general, you should have Chef leave a comment in every file that it manages (and someone at Opscode should make this a default feature in Chef).

Do not have Chef reboot the database. Databases are designed to run for years at a time. Many parameters can be set while the databases is running in such a way that it does not need to be bounced in order to make the parameter work. There are exceptions to this in non-production environments.

Need to change the schema? Do not have the Chef create a table, and then do alter table after alter table to install a new system. This is very painful to watch.

* Thanks to Alex Howells for the idea of always putting a comment in the top of the Chef script.

Patrick!

MySQL Conference, Percona, the Ecosystem...

This year O'Reilly isn't running the MySQL conference, Percona is doing it. Santa Clara, April 10-12. The usual time and place.

This is great news. They run a great conference. They always get rave reviews.

This isn't the first one they've done. They've done San Francisco, New York, London, more.

What's different about Santa Clara?

This isn't their typical 300-person one-day conference. They're picking up the annual MySQL users conference and carrying the torch forward. This is a 1000+ person, huge expo hall, 8 concurrent tracks, several days conference.

This year is a banner year for the MySQL ecosystem.  Why?

Because now the conference is focused on MySQL again. This is the central conference for the ecosystem. And now it's managed by a company that understands both the community and business side.


And the MySQL Ecosystem? Thanks to cloud vendors it continues to grow.
The sessions? Better than ever. In the past there was a lot of auxiliary content. Take a look. This year it's easily the best technical content I've ever seen. And I've led the selection committee for years.

The sponsors and exhibitors? Pretty much anyone who's anyone will be there.  Looking for solutions to your MySQL problems? You'll meet the folks who can help you. Visit the expo hall. There is great sponsor support for this year's event. HPCloud, Facebook, Clustrix, Google, et cetera.

The keynotes are nothing to sneeze at too. There will be talks from Marten Mickos, Mark Callaghan, myself, and more of the old gang.

Is there more? Yes there is.

There are the community awards, BOFs, lightning talks. There is a Tuesday welcome reception, Wednesday community networking.

More? Yes. There is not one, not two, but three follow-on events. Stay an extra day and on Friday you can attend Drizzle Day, SkySQL and MariaDB Day, or Sphinx Search Day.  Three awesome technologies for MySQL users.

This is a really big deal. If you are even slightly interested in MySQL, this is the event of the year. Don't miss it. By the way, early-bird pricing is almost expired. Register before March 12th or you'll pay more for the ticket and the hotel.

Drizzle Day at the Percona MySQL Conference

The major annual event in both the MySQL and Drizzle worlds is the conference week in April. This year Percona is organizing the Percona Live MySQL Conference and Expo from Apr 10-12 and as usual we follow up with a Drizzle Day on Apr 13. It's the 4th Drizzle Day!

I will be giving a keynote at the main conference, on Wednesday April 11. I will be giving a keynote on the state of the MySQL Ecosystem and how cloud is evolving it. (HPCloud is a sponsor of the conference.) Of course, it is about Databases in the Cloud so MySQL and Drizzle are still with me :-)

There are a few Drizzle specific talks though. Check out Scripting MySQL with Lua and libdrizzle inside Nginx and  Getting Started with Drizzle 7.1.

Then on Friday, April 13 it's all about Drizzle. I will be giving a mini-keynote to start the day, and then we have great talks about new and old features in Drizzle. The Drizzle Day is free entry, so even if you're not attending the main conference, but if you're interested to learn about using Drizzle, please consider joining us. At the end of the day there is also some content for those who might want to start hacking on Drizzle itself. Especially if you live in the Bay area, just pop in, it would be great to meet Drizzle users and hackers in person.

Oh, and I also want to say it is really great that Percona and Technocation are sponsoring this event and also that SkySQL has invited us to their lunch and after party. Since Drizzle is purely a community project, we really appreciate this. It is what makes Drizzle Day happen.

Speaking of lunch: Please RSVP to us so we know how many are coming.

Error Messages

I have written a number of libraries that are frequently used, and I have yet to find a pattern for error messages that I am completely happy with.

Let me tell you about a few of my thoughts on this.

I have found that there are two parts to an error, the code and the message. The code is a numerical value, and the message is an expression that you expect a human to read.

Error codes and messages do not have to map one for one.

You only really want to provide a specific error code if you believe the developer who is working with your code can do something about the error.

I've definitely gotten myself into the trap of creating a dozen or so error codes that all relate to how a host has failed a connection. In almost all cases of a connection failure there is very little that the end user of the end user of the library can do.

While one error code might be fine, you should create specific error messages which provide more information for an end user to diagnose a problem.

The developer who is looking at the error will appreciate the message. It might make the difference between someone spending five minutes, instead of five hours diagnosing the problem.

Never return an error message that is just a number.

No one wants to try to figure out what "error 13" means. A number tells me nothing, and while I could google the number, that is an extra step I don't want to have to take each time I look at a problem.

If you need a paragraph to explain the error, make the error searchable.

If a developer wants more information on the error, they will search for it. Make this a very simple process. It drives your users to your website. This may sound obvious, but I continue to meet people who haven't realized this.

Do not map to ERRNO.

Mapping to ERRNO. ERRNO is not very flexible, and it comes with the baggage of a preconceived notion of what the error means (which does not map across operating systems).

Give yourself enough information to diagnose a problem for the end user.

In the last few years I have taken to embedding the line of the code, and the file that the error was in, every error messages. This has allowed me to better support software that I write by creating context for me. An error is not only a tool for the end user, it is a tool for you to provide support.

Consider the case that multiple failures may occur.

Sometimes you don't have one failure in a given context, so try to store up all of the errors that occur. If you can, design your error system so that you store all of what failed.

In the end,...

Be consistent. Format your error codes and messages in a consistent manner. Make sure that if someone wants to, they can parse them in batch. Never under estime the creativity of an end user armed with a regular expression.