While I prepared for my Hands-On Lab about the Performance Schema at MySQL Connect last year, one of the things that occurred to me was how difficult it was quickly getting an overview of which consumers, instruments, actors, etc. are actually enabled. For the consumers things are made more complicated as the effective setting also depends on parents in the hierarchy. So my thought was: “How difficult can it be to write a stored procedure that outputs a tree of the hierarchies.” Well, simple enough in principle, but trying to be general ended up making it into a lengthy project and as it was a hobby project, it often ended up being put aside for more urgent tasks.

However here around eight months later, it is starting to shape up. While there …

Starting with MySQL 5.6, MySQL commercial-license builds use OpenSSL.  yaSSL – previously used as the default SSL library for all builds – remains the implementation for Community (GPL) builds, and users comfortable building from source can choose to build with OpenSSL instead.  Daniel van Eeden recently requested a global variable to indicate which SSL library was used to compile the server (bug#69226), and it’s a good request.  It’s something I’ve previously requested as well, having been fooled by the use of have_openssl as a synonym for …

The MySQL general query log can be a useful debugging tool, showing commands received from clients.  In versions through MySQL 5.5, you could count on the GQL to log every command it received – the logging happened before parsing.  That can be helpful – for example, the GQL entries might have records of somebody unsuccessfully attempting to exploit SQL injection vulnerabilities that result in syntax exceptions.

Here’s a sample, which I’ll run in both 5.5 and 5.6 and show the resulting GQL:

mysql> SELECT 1;
+---+
| 1 |
+---+
| 1 |
+---+
1 row in set (0.00 sec)

mysql> SELECT NOTHING();
ERROR 1305 (42000): FUNCTION NOTHING does not exist
mysql> SELECT 2;
+---+
| 2 |
+---+
| 2 |
+---+
1 row in set (0.00 sec)

In 5.5, this produces the following in the general query log:

130513 18:26:34        1 Query    SELECT 1
130513 18:26:40        1 Query    SELECT NOTHING()
130513 18:26:44        1 Query …

This Wednesday, May 15 at 10 a.m. Pacific, I’ll be leading  a Webinar titled, “Using MySQL 5.6 Performance Schema to Troubleshoot Typical Workload Bottlenecks.”

In this Webinar I will offer an overview of Performance Schema, focusing on new features that have been added in MySQL 5.6, go over the configuration and spend most time showing how you can use the wealth of information Performance Schema gathers to understand some of the typical performance bottlenecks.

Other areas of focus include:

• Bottlenecks with Disk IO
• Problems with excessive temporary tables and external sorts
• Excessive internal mutex contention …

MySQL Connector/J 5.1.25 has been released, and is available in Community and Enterprise flavors on dev.mysql.com and My Oracle Support, respectively.  I’ve already noted the addition of support for connection attributes for MySQL 5.6 – 5.1.25 adds this functionality.  This release also includes a fix for Bug#68733, which caused the special light-weight ping operation to execute only against the master and currently-selected slave, rather than …

2010 was a good year for implementing many small feature requests. Lets start by thanking those responsible for requesting these enhancements: Matt Lord, Mikiya Okuno, Matthew Montgomery, Mark Callaghan, Domas Mituzas and Mats Kindahl.
MySQL 5.6 has lots of big and shinny new replication features. In fact some, like global transaction identifiers or multi-threaded slave, are multiple features together under one big headline. Therefore, they get a lot of buzz and since they are complex, game-changing and very exciting to the end user, they deserve a lot of blog posts. But what about other smaller enhancements that are in 5.6 but that do not get so much highlight? 
Let me present a few that I think are particularly interesting, especially for monitoring and/or configuration purposes. To get more details, click on the links and they will take you to the feature requests or worklog entries. 1. …

Even frequent visitors to bugs.mysql.com can sometimes miss the little note in the bottom right corner of each page:

Page generated in 0.017 sec. using MySQL 5.6.11-enterprise-commercial-advanced-log

That text changed this past weekend, going from MySQL Enterprise 5.6.10 to 5.6.11.  But more importantly, the collection of MyISAM tables which support the bugs system were also converted to InnoDB.  There’s a little story to tell here about eating this particular helping of dogfood which also amplifies changelog comments, so here it is:

We like to keep bugs.mysql.com on a current release of MySQL, and we started looking to upgrade from 5.5.27 shortly after GA.  In doing so, …

Stewart Smith recently questioned the current relevance of the MERGE storage engine, and it prompted me to finish a similar recent exercise I’ve been thinking about related to MySQL clients (UPDATE: and programs).  This originally came up when I listed the contents of the MySQL bin directory:

D:\mysql-advanced-5.6.11-win32>dir bin\*.exe
Volume in drive D is Data
Volume Serial Number is 4015-B2FF

Directory of D:\mysql-advanced-5.6.11-win32\bin

04/05/2013  06:52 AM           123,392 echo.exe
04/05/2013  06:53 AM         4,696,064 innochecksum.exe
04/05/2013  06:54 AM         5,084,672 myisamchk.exe
…

Looking for some substantial reading material as the days grow longer?  You might consider dedicating a good chunk of time to review the MySQL 5.6.11 changelog.  The MySQL Engineering team at Oracle has been busy, and it shows in this maintenance release.  Stewart Smith recently noted the growth of the code base in 5.6 compared to 5.5.  That may or may not be the best measure of productivity, but the number of fixed bugs in a maintenance release like 5.6.11 is sure a good indicator.  A few general observations based on my quick study:

• 201 individual notes in the changelog
• 198 referenced bug reports (total, not de-duplicated)
• 61 bugs from community bugs system
• The oldest bug …

Some bugs can have a high impact if it causes data corruption, security issues or simply causes MySQL to crash. But what about small bugs and small usability issues?

This entry from the MySQL 5.6.8 release notes is an interesting one:
InnoDB: On startup, MySQL would not start if there was a mismatch between the value of the innodb_log_file_size configuration option and the actual size of the ib_logfile* files that make up the redo log. This behavior required manually removing the redo log files after changing the value of innodb_log_file_size. The fix causes MySQL to write all …