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While the Release Notes show a long list of improvements, I would like to focus on some of them that improve the handling of multi-master deployments.
When we released version 2.0.6, we added the first revision of the cookbook recipes in the build. That was still a green addition, which caused several bug reports. But since then, we have integrated the cookbook in our internal testing, making these recipes more robust and reliable. We are also planning to improve[Read more...]
The latest releases of MySQL Sandbox, in addition to deal with minor bugs, have mostly been necessary because of compatibility issues in MySQL, both 5.5 and 5.6.
When I found that MySQL 5.6 has some InnoDB tables inside the 'mysql' schema, I had to change the way that the sandbox used to remove all contents (the
Unfortunately, when 5.5.30 was released, this operation resulted in a warning, due to a behavioral change.
After a careful change, and about 1200 unit tests, the latest version of MySQL Sandbox should work well with every MySQL release from 5.0 to 5.6.
The blog title says it all: Do we need a MySQL Cookbook? I tend to think so.
This seems to be something that is missing with current MySQL documentation. There is lots of information available but finding the appropriate bit can be quite tedious and it often requires looking in multiple places.
A lot of other software has such books, but for some reason MySQL seems to be missing one.
A recent example comes from a “documentation feature request” I posted today: http://bugs.mysql.com/bug.php?id=68171. MySQL 5.6 provides a way to “move InnoDB tables” from one server to another. There are many reasons why you may want to do it, but the documentation is currently rather sparse. A simple “example recipe” for this would be good, as would an equivalent recipe for other[Read more...]
On Friday last week, after the intensive days of the conference, Ars Technica wrote and published a nice article about MariaDB including many of the messages we had been delivering during the conference, http://arstechnica.com/business/news/2012/04/mysql-founders-latest-mariadb-release-takes-enterprise-features-open-source.ars.
Last year, when it became clear that O’Reilly wasn’t going to arrange the MySQL user conference in the future, there was a lot of discussion on who should arrange it. In the end Percona was pretty fast informing everyone that[Read more...]
I have to say that I am pleased. The quality of the organization was very high, with a very good lineup of speakers and an excellent technical support.
As usual, I have learned a lot during this week, either directly, by attending talks, or indirectly, by meeting people who told me what was juicy at the talks that I had missed. And I have met new interesting people, and caught up with the people that I know already.
This conference was particularly intense also because I got myself involved in 5 talks, which was probably more than I should have. How did[Read more...]
We are pleased to announce the immediate availability of MariaDB 5.5.23. This stable (GA) release incorporates MariaDB 5.3.6 and MySQL 5.5.23, some performance improvements, and bug fixes.
Please see the What is MariaDB 5.5 page for an overview of MariaDB 5.5.
Sources, binaries, and package downloads are available from our network of MariaDB mirrors. Debian and Ubuntu packages are available from our[Read more...]
We are pleased to announce the immediate availability of MariaDB 5.5.20-alpha. MariaDB 5.5.20 is the first Alpha release in the 5.5 series. We hope to follow it up soon with a beta 5.5 release.
MariaDB 5.5.20-alpha is a merge of MariaDB 5.3 and MySQL 5.5 with some limited additional bug fixes. This is the first 5.5-based release, and we are releasing it now, intentionally without any extra features (and with it missing some planned features) to get it into the hands of any who might want to test it. Extra features planned for MariaDB 5.5 will be pushed into future releases.
As with any alpha release, MariaDB 5.5.20-alpha should not be used on production systems.
The Release Notes page has some notes on the release. There is also a[Read more...]
I see that MySQL 5.5.21 has just been released. This sounds interesting. I’m mainly running 5.5.16 which has been broadly stable, but I have been caught by a few important issues which 5.5.21 fixes according to the change list:
These together with a few earlier fixes after 5.5.16 are certainly interesting to me, so I’m eager to try out 5.5.21 and see how it fairs.
MySQL, like a lot of other software, has many knobs you can tweak. Most of these knobs may affect behaviour, but more importantly most affect the memory usage of the server, so getting these settings right is very important.
Most of MySQL’s memory is really used just as a cache, in one form or another, information that otherwise is on disk. So ensuring you have as large a cache as possible is important. However, making these memory sizes too large will trigger the server to start swapping and possibly can cause it to crash or cause the kernel to kill the process when it runs out of memory. So that’s something we want to avoid.
Certain settings affect memory allocation on a per connection/thread basis, being bounded by thread_cache_size and max_connections. If you configure for the worst behaviour (max_connections) you may end up not actually using all[Read more...]
For those who saw my previous post about the crashing (regression) bug with SELECT COUNT(DISTINCT) on InnoDB with Primary Key (PK), you’ll be interested to know my test case does not crash in 5.5.18 (which was just released).
I’ve only tested my test case thus far, but it seems fine.
Unfortunately, the fix is not mentioned in the 5.5.18 changelogs though.
And there is no mention (yet, anyway) of a fix in the bug report I filed (though it was designated a ‘duplicate’, so it wouldn’t necessarily be updated).
I’m trying to get confirmation from the MySQL Dev Team on this (via the bug report), and will update this post if/when I hear anything.
I’ll also perform some of[Read more...]
In 5.5, a crashing, regression bug exists if you use SELECT COUNT(DISTINCT) *and* one of the WHERE operands is in the Primary Key (or just a unique index).
This simple crash (if only one row is in the table) will crash mysqld.
Of course I’ve filed a bug report, but that has been nearly 3 months and no updates yet.
Here is the bug I filed (which you won’t be able to view):
Really, the only thing that happened to my bug report was that it was designated a duplicate of another bug (which we also cannot view):
Based on the id, and the submitted dates of bugs 61100 and 61102, this initial bug (61101) was filed on May 9, 2011. So, in fact, this bug has been present for over 5[Read more...]
I recently gave a presentation at the New York Effective MySQL Meetup on the new features of, and some of the compelling reasons to upgrade to MySQL 5.5. There are also a number of new MySQL variables that can have a dramatic effect on performance in a highly transactional environment, innodb_buffer_pool_instances and innodb_purge_threads are just two to consider.
For more information on all the new variables, status, reserved words and benchmarks of new features you can Download Presentation Slides.
There are a number of significant new features in MySQL 5.5 including semi-synchronous replication, SIGNAL and RESIGNAL, the PERFORMANCE_SCHEMA, additional STATUS variables, new partitioning options, different default storage engine, better UTF8 support and removal of deprecated functions just to list key considerations.
However some of the performance improvements are worth the[Read more...]
GRANT INSERT,DELETE,UPDATE on world.* to myuser identified by 'mypass';[Read more...]
GRANT SELECT on world.* to myuser identified by 'mypass' WITH GRANT OPTION;
show grants for myuser\G
*************************** 1. row ***************************
Grants for myuser@%: GRANT USAGE ON *.* TO 'myuser'@'%' IDENTIFIED BY PASSWORD '*6C8989366EAF75BB670AD8EA7A7FC1176A95CEF4'
*************************** 2. row ***************************
Grants for myuser@%:
I have been looking forward to the general availability (GA) release of MySQL 5.5 since is was publically announced in September that we would see this in 2010. While I already have a production client with 5.5.7rc, the badge of general availability is a great way to promote why environments should consider moving to using MySQL 5.5. Here is my quick short list of why I’d promote moving to MySQL 5.5.
The first significant improvement is that InnoDB is now again firmly a default included storage engine. The InnoDB plugin 1.1.x is now the builtin version of the engine, not a plugin version. Also the 1.1.x version has continued improvements over the 1.0.x version available as an included but not enabled plugin in current MySQL 5.1.x versions. Removing the complexity for end users over the choice of InnoDB and the necessary[Read more...]
An update of MySQL from 5.0 to 5.5 on CentOS 5.5 64bit has not resulted in a good experience. The mysqld process would then crash every few minutes with the following message.
101120 8:29:27 InnoDB: Operating system error number 22 in a file operation. InnoDB: Error number 22 means ‘Invalid argument’. InnoDB: Some operating system error numbers are described at InnoDB: http://dev.mysql.com/doc/refman/5.1/en/operating-system-error-codes.html InnoDB: File name /tmpfs/#sql6cf3_5c_0.ibd InnoDB: File operation call: ‘aio write’. InnoDB: Cannot continue operation.
The work around was to change the tmpdir=/tmpfs (which was a 16G tmpfs filesystem) to a physical disk.
The referenced URL didn’t provide any more information of help. Unlike Bug #26662 O_DIRECT is not specified as the flush method.
./configure --help, but that is no longer necessary. MySQL 5.5 is built using cmake, the cross platform make.
autoconf/automake/libtoolshorror syntax. Not only that, but there is a GUI!
So, MySQL 6.0 was ditched, and a few weeks ago 5.4 was also – its features to be added in other (earlier) versions (I’m told 5.2 but not sure). I reckon that’s good news, regardless of the version number. There was also an announcement about a change in the release mechanism at Sun/MySQL.
Now for practicals. If I look on Launchpad, the 5.1 branch is the only active one (next to 5.0 fixes, of course). 5.4 was last updated 15 weeks ago. There is no 5.2 on there that I can find. Wasn’t looking for it really, just happened to notice its absence while I was trying to find 5.5. And the reason for that was that Miguel closed a bug I was following, noting it was no longer reproducible in 5.5. He pastes some code that reports mysql as 5.5, so it’s not a[Read more...]
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