During my talk and hands on labs at MySQL Connect 2013 I used several views, functions, and procedures from ps_helper and ps_tools.

The slides from the two talks can be downloaded from Thanks For Attending MySQL Connect or from the MySQL Connect 2013 Content Catalogue.

You can read more about ps_helper on Mark Leith’s blog and you can download ps_helper from github.

To get ps_tools, download …

After a slight delay (travel and catching up with “real work”), I’ve now uploaded the talks that I gave at MySQL Connect and Oracle Open World.

They are available on my Presentations Page, and inline below for convenience. The “Introduction to MySQL Enterprise Monitor” talk was actually a full demo, but there are some screenshots of MEM 3.0 in there if you’re interested in seeing a high level picture of what it looks like now.

Thanks to all that attended my talks, I got a lot of good questions and feedback!

Performance Schema and ps_helper MySQL Administration and Monitoring …

MySQL Connect 2013 was held this past Saturday through Monday, and I would like to extend a big thank you to everyone who attended my sessions, I talked to or otherwise took part in the conference.

I had two sessions as well as participated in a Birds of the Feather session with the Community and Support teams. The slides have been uploaded the the Content Catalog but they are not available for download from there yet. Until then you can download them from the the links below:

• CON5282: Making the Performance Schema Easier to Use
• …

I was testing out the latest MySQL 5.6 on Windows (having used the auto-installer) and happened to notice my RAM usage (via Windows Task Manager) was reporting quite a high value, when I had very modest ram/buffer settings (should have been around 40M, but instead it was around 400M).

After double/triple-checking my settings to make sure I didn’t overlook something obvious, I searched the bugs database, and ran across bug #68287:

“High Memory Usage with MySQL 5.6.12 GA in ‘Development Machine’ mode”

Turns out, using the auto-installer set the value of table_definition_cache=1400, when the minimum value is 400. Reducing it to 400, and restarting MySQL immediately lowered the RAM usage, and is the “work-around” identified in the bug report.

Having encountered this, …

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 …

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 …

Along with lots of new features in performance schema, a new summary table, event_statement_summary_by_digest, has been added to MySQL 5.6. This tables gives a consolidated view of different statements executed/executing on MySQL server.

WHAT IS DIGEST?
Digest is a hash calculated on normalized form of statement text which removes general property of a statement but keeps specific property. For ex. for two statements X and Y,

Removing general property means
normalized (X) == normalized (Y)
Preserving specific property after normalization means:
normalized (X) != normalized (Y)

On these normalized statement, a hash is calculated which is called DIGEST. So digest is a unique representation of statements having same structure.


Example :
SELECT 1 FROM t1; 
SELECT 2 FROM t1; 
Above two statements have same general structure …

Here is the MySQL-Performance Schema presentation which I used at OSI, 2012.

http://www.slideshare.net/mayankmysql/osimysqlperformance-schema

Here is the MySQL-Performance Schema presentation which I used at OSI, 2012.

http://www.slideshare.net/mayankmysql/osimysqlperformance-schema

The improved Performance Schema in MySQL 5.6 provides a new way of investigating issues in the database. Many issues that previously required tools such as strace, dtrace, etc. can now be investigated directly from inside MySQL in a platform independent way using standard SQL statements.

The Performance Schema is enabled by default starting from the latest milestone release, 5.6.6. You have instruments which are the things you can measure, and consumers which are those that use the measurements. Not all instruments and consumers are enabled out of the box, however once the plugin is enabled, individual instruments and consumers can be switched on and off dynamically.

As an example take the case mentioned in What’s the innodb main thread really doing? where the main InnoDB thread appears to be stuck in “doing …