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10 Newer Entries Showing entries 31 to 40 of 98 10 Older Entries

Displaying posts with tag: performance_schema (reset)

PERFORMANCE_SCHEMA vs Slow Query Log
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A couple of weeks ago, shortly after Vadim wrote about Percona Cloud Tools and using Slow Query Log to capture the data, Mark Leith asked why don’t we just use Performance Schema instead? This is an interesting question and I think it deserves its own blog post to talk about. …

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MySQL 5.6 GA one year – What is next?
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MySQL 5.6 has been GA for just over a year now. See MySQL 5.6.10 Release Notes.  Congratulations on your birthday! That is quite a long time. I was using it earlier in production because it worked and could do things that 5.5 could not do, but earlier versions were to use at your own risk, and indeed if prodded incorrectly would fall on the floor. That is fair enough because they were work in progress, yet if you poked them the right way they did a very good job.  Those dev versions have been long since upgraded which is good so they do not need quite as much care …

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Exploring MySQL Metadata Lock Instrumentation in Closer Detail
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I recently wrote a post on tracking metadata locks (MDL) in MySQL 5.7, and I wanted to take a moment to expand on it by explaining a couple of the associated variables in more detail.

First off, once you have enabled the performance_schema *and* the metadata lock instrumentation, you can verify it with:

mysql> SELECT * FROM performance_schema.setup_instruments
    -> WHERE NAME = 'wait/lock/metadata/sql/mdl';
+----------------------------+---------+-------+
| NAME                       | ENABLED | TIMED |
+----------------------------+---------+-------+
| wait/lock/metadata/sql/mdl | YES     | YES   | …
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Tracking Metadata Locks (MDL) in MariaDB 10.0
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I recently blogged about tracking metadata locks in the latest MySQL, and now I want to discuss how to track these metadata locks in MariaDB.

In MySQL 5.7, there is a table named `metadata_locks` added to the performance_schema (performance_schema must be enabled *and* the metadata_locks instrument must be specifically enabled as well.

In the MariaDB 10.0 implementation (as of 10.0.7), there is a table named METADATA_LOCK_INFO added to the *information_schema*. This is a new plugin, so the plugin must be installed, but that is very simple with:

INSTALL SONAME 'metadata_lock_info';

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Tracking Metadata Locks (MDL) in MySQL 5.7
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I’ve blogged about metadata locks (MDL) in the past (1 2 3) and in particular discussed how best to track them down and troubleshoot threads stuck waiting on metadata locks.

If you’ve had any experience with these, you’ll know finding them isn’t always the most straight-forward task.

So I was glad to see metadata lock instrumentation added to MySQL 5.7.3 as part of performance_schema, which makes tracking these down a breeze! (Note this is only in 5.7.3 currently, and …

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SF MySQL Meetup Presentation: Changes in MySQL 5.7
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Last Wednesday, I spoke at the San Francisco MySQL Meetup on the topic of changes coming in MySQL 5.7 (and later).  We actually went through two different slide decks; the first on features being considered for deprecation in MySQL 5.7 (or later), and the second set providing a brief overview of the new features and benefits already introduced in MySQL 5.7 via the development milestone releases (DMRs) published to date.  A big thanks to the entire SF Meetup group, and in particular the organizers (Erin, Mike and Darren), for having me.  The event was streamed and recorded, and you can view the …

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Fun with Bugs #26 - MySQL bugs Oracle had not fixed for me (yet)
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In the previous post in this series I've listed 15 MySQL bug reports, documentation and feature requests I've made in 2013 that got fixes or any other kind of solution. Now it's time to check what happened to the rest and try to think why.

First of all, no MySQL bug reporter is perfect (if only …

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Fun with Bugs #25 - MySQL bugs Oracle fixed for me this year
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I've checked recently and noted that I've sent 50 reports about MySQL bugs, features I'd like to see and unclear/missing manual pages this year. It all started with famous Bug #68079 (reported on January 14, 2013), that got a lot of attention, valuable workaround from Oracle and caused a lot of work that is going to improve MySQL scalability substantially in the future.

Oracle had also implemented this my (and not only mine!) feature request, Bug #69527, and in MySQL 5.7.3 PERFORMANCE_SCHEMA …

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What SQL is running in MySQL
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Using the MySQL 5.6 Performance Schema it is very easy to see what is actually running on your MySQL instance. No more sampling or installing software or worrying about disk I/O performance with techniques like SHOW PROCESSLIST, enabling the general query log or sniffing the TCP/IP stack.

The following SQL is used to give me a quick 60 second view on a running MySQL system of ALL statements executed.

use performance_schema;
update setup_consumers set enabled='YES' where name IN ('events_statements_history','events_statements_current','statements_digest');
truncate table events_statements_current; truncate table events_statements_history; truncate table …
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Teaser on my upcoming Percona Live London 2013 session
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As you probably know already, I have a session on PERFORMANCE_SCHEMA at the conference, scheduled at 12 November 4:00pm - 4:50pm @ Orchard 1. Presentation is mostly ready, but I had not decided yet when to publish it. In the meantime, for those really interested, here is a teaser.

Below I list one link for each slide (in order of presentation) having more than one of them mentioned or listed in my notes. Now try to guess what I am going to say there and why. Note that it's not a tutorial (my half a day …

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10 Newer Entries Showing entries 31 to 40 of 98 10 Older Entries

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