Based on MySQL 5.1.61, including all the bug fixes in it, Percona Server 5.1.61-13.2 is now the current stable release in the 5.1 series. All of Percona ‘s software is open-source and free, all the details of the release can be found in the 5.1.61-13.2 milestone at Launchpad.

The full release notes can be found in our online documentation: http://www.percona.com/doc/percona-server/5.1/release-notes/Percona-Server-5.1.61-13.2.html

This release is purely composed of bug fixes and is the current stable release of Percona XtraBackup.

There are some important bug fixes around incremental backups, parallel backups and backups on databases with the system tablespace being multiple files. The full release notes and details are available here: http://www.percona.com/doc/percona-xtrabackup/release-notes/1.6/1.6.5.html

This sounds like it would be great, doesn’t it? We’ve considered doing this, and even partially implemented it. But during our pre-release testing, we found a lot of potentially serious problems with the idea. It turns out to be very subtle — perhaps too subtle to be done with any computer program, no matter how smart, because there might be a lot of assumptions it’s forced to make, which could turn out to be dangerous. Every approach we considered carried a high risk of de-optimizing a server so it performs worse than before.

So in the end, although our tool is excellent for creating a starting my.cnf, my old blog post about the ultimate my.cnf tuner tool, which claims that an expert human is the only safe way to do this, might be an evergreen truth.

PS: my favorite user feedback so far is this one:

Great job, very good results! Now please take it offline before I am rendered obsolete.

Based on MySQL 5.5.20, including all the bug fixes in it, Percona Server 5.5.20-24.1 is now the current stable release in the 5.5 series. All of Percona ‘s software is open-source and free, all the details of the release can be found in the 5.5.20-24.1 milestone at Launchpad.

For those of you who don’t know what this is, it’s another of the O’Reilly traditions we’re trying to continue. (We are trying very hard to make this event as close to a clone of O’Reilly’s as we can.) It’s a free table in the expo hall where people who participate in a non-commercial open source project can exhibit. I organized a Maatkit booth a few times in the past, and was always really grateful to O’Reilly for making the space available. Space in the expo hall is at a premium, but we think that these dot-org booths are even more valuable to the open-source projects and the conference attendees.

So, please tell your friends who care about open source, and ask them to tell their friends too. Let’s get some great open-source projects into the expo hall, alongside the commercial vendors!

What’s new? You can read the changelog for the details, but here are the highlights:

Brand new pt-diskstats, thanks to Brian Fraser. This tool is completely rewritten, and it’s finally the iostat replacement I always wanted. Not only does it have the functionality I want (interactive, slice and dice, smart defaults) but it has the detailed statistics on I/O, so you can see whether your reads are slow versus your writes, and whether things are waiting on the disk or waiting on the queue scheduler (cfq, hint hint). Finally, it has transparency, so you can read the documentation and understand, really, what it’s doing at the low level and what that means for your server. We really need specific, precise information on exactly how the I/O is behaving so we can make good decisions when there are problems or when doing things like capacity planning.

Brand new pt-stalk, courtesy of Daniel Nichter. This tool is also completely rewritten. Instead of a Bash script that you have to configure with environment variables and run in a screen session, this is now a first-class fault detection daemon. Everyone needs post-mortem forensic data when there is a problem, and pt-stalk aims to be a core part of your infrastructure that fills this gap. It now supports things a “real” Percona Toolkit tool ought to have, such as command-line options and a configuration file. In addition, we merged pt-collect into it, so as of Percona Toolkit 2.0.3, there isn’t a separate pt-collect tool anymore.

There’s a lot more to this release, but those are the major points. Download it and let us know how it works, please! If you find bugs, file them on Launchpad, and if you need support, you know where to get it.

So how are you supposed to check for corruption that might be introduced by bad hardware, a bug, or so forth?

It’s a great question. The answer I would give for most cases is “check your backups for corruption instead of your live server.” You need to do this anyway — a backup that isn’t checked is a ticking time bomb. You need to verify (at least periodically) that your backups are recoverable.

The usual procedure goes like this: copy your backup somewhere, start a server instance on it, and run CHECK TABLES. You can use the mysqlcheck program to do this conveniently.

You could also use innochecksum, which doesn’t require starting the server. But it only verifies that each page’s checksum matches the page’s data, it doesn’t do all the other checks that are built into InnoDB (making sure that the LSNs are sane, for example).

How often? As often as possible. Some people refresh their dev/staging environment every day with last night’s backup, which is a great way to make failures obvious, as long as you verify that it truly does happen (e.g. what if it fails and you keep running with yesterday’s without knowing it?). If you can’t do it daily, then weekly is perfectly acceptable to most people. I’m not saying a specific interval should/ought to be your goal, I’m just remarking on what a lot of people seem to feel good about.

We’ve gotten really good feedback on this tool, including this nice mention on Stack Exchange:

Percona just built a tool to do just that called the Configuration Wizard. I tested it out once just to see what it would return and the results were pretty darn close to what we were using on our servers, whose cnf’s were put together by highly trained mysql certified dba’s.

So what’s changed in the new version of the Configuration Wizard? Quite a few things. We’ve rolled out the first iteration of the account and profile features. Now you get a homepage with your configuration files, so you can manage them and return to them anytime you like.

From this page (click on the image for a fullsize view) you can do things like sharing configuration files and emailing them to yourself. The new release also adds features like downloading the configuration files so you don’t have to copy-paste them.

If you share a configuration file, then the URL can be loaded by anyone, even if they’re not logged in. It’s kind of like sending someone a link to a pastebin or something like that. Screenshot:

Another new feature is something I’ve wanted for a long time: the ability to generate a more strict, safer configuration file. There’s a new page in the Wizard that lets you set a lot of sanity/safety options to prevent common problems MySQL users run into because of too-permissive MySQL behaviors. These are the kinds of things that Drizzle fixes — and should be fixed by default in MySQL — but never will be because they might break applications that rely on the default behaviors. If you’re building an application from the ground up, now you can prevent bad things from getting a nose under the tent. Here’s a screenshot:

In addition to these things, we have added a number of other features you might not notice, which I won’t spend much time on — they’re things like an integrated feedback form at the left of the page and so on.

What’s next? Well, next I think we’re going to turn our attention to adding new tools, rather than improving this one. I have a list of tools that people have requested or suggested: a SQL formatter, a visual EXPLAIN tool, a configuration advisor, a query analysis tool, a way to register a server’s essential characteristics and then get advice when there’s a new release that might be beneficial for you, and so on. I have selected the next priorities, but I don’t want to spoil the surprise or promise something if it turns out to be harder than I think it will be. What ideas do you have? Let me know by leaving your feedback in the comments.

We hope this suite of free browser-based tools helps you become a more productive MySQL user and administrator!