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Showing entries 1 to 10 of 428 10 Older Entries

Displaying posts with tag: Insight for DBAs (reset)

Slow query graphs using Performance Schema and Graphite
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I love graphs. They just make things easier when it comes to finding patterns. I also love visibility. Having the ability to known what is going on inside the database is priceless. How about having visibility of the slow queries execution time on a graph? Let’s do it.

We’ve already described how to get query digest using performance schema. Since the MySQL server is already doing the heavy lifting for you with little-to-no overhead, this information is available practically at will. So let’s make some …

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When mysqld kills mysqld
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The other day a colleague and friend of mine, Peter Boros, had a case where one of our clients had to track down the process shutting down MySQL. This blog is based on the discussion we had about that internally.

Our client wanted Peter to identify the culprit behind periodic shutdowns. This proved to be slightly more difficult than usual, for reasons that you might guess from the title of this blog.

Here is what Peter saw in the logs:

150928 15:15:33 [Note] /usr/sbin/mysqld: Normal shutdown
150928 15:15:36 [Note] Event Scheduler: …
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Capture database traffic using the Performance Schema
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Capturing data is a critical part of performing a query analysis, or even just to have an idea of what’s going on inside the database.

There are several known ways to achieve this. For example:

  • Enable the General Log
  • Use the Slow Log with long_query_time = 0
  • Capture packets that go to MySQL from the network stream using TCPDUMP 
  • Use the …
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Webinar: Introduction to MySQL SYS Schema follow up questions
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Thanks to all who attended my webinar Introduction to MySQL SYS Schema. This blog is for me to address the extra questions I didn’t have time to answer on the stream.

Can i have the performance_schema enabled in 5.6 and then install the sys schema? Or they are one and the same?

You need to have enabled the performance_schema in order to use it through the sys schema. They are different entities. In general, performance_schema collects and stores the data, and sys schema reads and presents the data.

The …

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Percona Server audit log plugin best practices
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Auditing your database means tracking access and changes to your data and db objects. The Audit Log Plugin has been shipped with Percona Server since 5.5.37/5.6.17, for a little over 12 months. Prior to the Audit Log Plugin, you had to work in darker ways to achieve some incarnation of an audit trail.

We have seen attempts at creating audit trails using approaches such as ‘sniffing the wire’, init files, in-schema ‘on update’ fields, triggers, proxies and trying to parse the traditional logs of MySQL (slow, general, binary, error). All of these attempts miss a piece of the pie, i.e. if you’re sniffing …

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MySQL is crashing: a support engineer’s point of view
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In MySQL QA Episode #12, “MySQL is Crashing, now what?,” Roel demonstrated how to collect crash-related information that will help Percona discover what the issue is that you are experiencing, and fix it.

As a Support Engineer I (Sveta) am very happy to see this post – but as a person who better understands writing than recording – I’d like to have same information, in textual form. We discussed it, and decided to do a joint blog post. Hence, this post …

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MySQL Quality Assurance: A Vision for the Future by Roel Van de Paar (Final Episode 13)
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Welcome to the final – but most important – episode in the MySQL QA Series.

In it, I present my vision for all MySQL Quality Assurance – for all distributions – worldwide.

Episode 13: A Better Approach to all MySQL Regression, Stress & Feature Testing: Random Coverage Testing & SQL Interleaving

1. pquery Review
2. Random Coverage Testing
3. SQL Interleaving
4. The past & the future

Presented by Roel Van de Paar. Full-screen viewing @ 720p resolution recommended

Interested in the full MySQL QA Series?

The …

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MySQL QA Episode 12: My server is crashing… Now what? For customers or users experiencing a crash
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My server is crashing… Now what?

This special episode in the MySQL QA Series is for customers or users experiencing a crash.

  1. A crash?
    1. Cheat sheet:
    2. Sever install & crash. Note this is as a demonstration: do not action this on a production server!
      sudo yum install -y
      sudo yum install -y Percona-Server-client-56 …

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MySQL QA Episode 11: Valgrind Testing: Pro’s, Con’s, Why and How
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Today’s episode is all about Valgrind – from the pro’s to the con’s, from the why to the how! This episode will be of interest to anyone who is or wants to work with Valgrind on a regular or semi-regular basis.

  1. Pro’s/Why
  2. Con’s
  3. How
    1. Using the latest version
      sudo [yum/apt-get] install valgrind
      sudo [yum/apt-get] remove valgrind
      sudo [yum/apt-get] install bzip2 glibc*
      tar -xf valgrind-3.10.1.tar.bz2; cd valgrind-3.10.1

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MySQL QA Episode 10: Reproducing and Simplifying: How to get it Right
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Welcome to the 10th episode in the MySQL QA series! Today we’ll talk about reproducing and simplifying: How to get it Right.

Note that unless you are a QA engineer stuck on a remote, and additionally difficult-to-reproduce or difficult-to-reduce bug, this episode will largely be non-interesting for you.

However, what you may like to see – especially if you watched episodes 7 (and possibly 8 and 9) – is how reducer automatically generates handy start/stop/client (cl) etc. scripts, all packed into a handy bug tarball, in combination with the reduced SQL testcase.

This somewhat separate part is covered …

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Showing entries 1 to 10 of 428 10 Older Entries

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