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Showing entries 1 to 5

Displaying posts with tag: Quality Assurance (reset)

How to find bugs in MySQL
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Finding bugs in MySQL is not only fun, it’s also something I have been doing the last four years of my life.

Whether you want to become the next Shane Bester (who is generally considered the most skilled MySQL bug hunter worldwide), or just want to prove you can outsmart some of the world’s best programmers, finding bugs in MySQL is a skill not reserved anymore to top QA engineers armed with a loads of scripts, expensive flash storage and top-range server hardware. Off course, for professionals that’s still the way to go, …

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QA: Advanced Option Combinatorics (Pairwise Testing): Combinatorial mysqld Option Test Case Generation
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How do we ensure that, when we have 35+ testable option combinations for mysqld, we test each and every combination of them? For example: will a different innodb_log_file_size combined with more innodb_log_files_in_group and a modified innodb_fast_shutdown setting truly not affect Percona’s log archiving feature?

Most option-related bugs are caused by the setting of 1 or 2 mysqld options to a non-standard value. Maybe in an odd situation 3 mysqld options need to be set in …

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How to Extract All Running Queries (Including the Last Executed Statement) from a Core File?
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This post builds on the How to obtain the “LES” (Last Executed Statement) from an Optimized Core Dump? post written about a year ago.

A day after that post was released, Shane Bester wrote an improved version, How to obtain all executing queries from a core file on his blog. Reading that post is key to understanding what follows.

I …

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Profiling MySQL Memory Usage With Valgrind Massif
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There are times where you need to know exactly how much memory the mysqld server (or any other program) is using, where (i.e. for what function) it was allocated, how it got there (a backtrace, please!), and at what point in time the allocation happened.

For example; you may have noticed a sharp memory increase after executing a particular query. Or, maybe mysqld is seemingly using too much memory overall. Or again, maybe you noticed mysqld’s memory profile slowly growing overtime, indicating a possible memory bug.

Whatever the reason, there is a simple but powerful way to profile MySQL memory …

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MySQL Wish for 2013 – Better Memory Accounting
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With Performance Schema improvements in MySQL 5.6 I think we’re in the good shape with insight on what is causing performance bottlenecks as well as where CPU resources are spent. (Performance Schema does not accounts CPU usage directly but it is something which can be relatively easily derived from wait and stage information). Where we’re still walking blind with MySQL is resource usage – specifically Memory Usage.

I can’t count how many time I had to scratch my head with system configured to consume only few GBs in global buffers growing to consume much more for some unknown needs leaving me puzzled whenever it is …

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Showing entries 1 to 5

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