Welcome to MySQL QA Episode #5! In this episode we’ll be setting up and running pquery for the first time… and I’ll also trigger some actual bugs (fun guaranteed)! I’ll also introduce you to mtr_to_sql.sh and pquery-run.sh.
pquery-run.sh (the main wrapper around pquery) is capable of generating 80-120 MySQL Server crashes – per hour! See how it all works in this episode…
If you have not read our introductory blog post on pquery yet, I’d recommend reading that one first to get a bit of background. The community is enthuastic about pquery, and today I am happy to announce a full training series on pquery and more. Whether you are a Linux or MySQL newbie or a seasoned QA engineer, there is something here for you. From Bash scripting (see episode 1 below), to every aspect of the new pquery framework, it is my hope that you enjoy this series. If you do, please leave us a comment
Database quality assurance is not as straightforward as it may seem. It’s not a matter of point-and-click, but rather of many intertwined tools and scripts. Beyond that, due to the complexity of the underlying product, it’s about having an overall plan or vision on how to adequately test the product in every aspect.
Take for example the SELECT statement; it allows specifying about 30 different clauses or modifiers (GROUP BY, WHERE, ORDER, LIMIT, HAVING, …). Then, think further about what one could do inside these clauses, or inside subselects etc. The number of possible combinations (exhaustive testing) of all commands (and all formats and variations thereof) plus all mysqld options (nearly 500 of them) is for all intents and purposes infinite, and thus seemingly impossible to test.
In Episode 13, an approach is proposed which, in our view, adequately solves this test infinite-possibility coverage problem through the use of random spread coverage testing and sql interleaving.Knowing your Bash/Linux/Gnu scripting well is also an almost definite prerequisite to getting started with mysqld QA. Episode 1 in this series is over 3.5 hours of in-depth (from easy to advanced) training on many often-used Bash commands and topics. From ls to sed, from cp to xargs and from variables to arrays. Enjoy!
Without further ado, here are the planned upcoming episodes:
MySQL QA Episode 1: Bash/GNU Tools & Linux Upskill & Scripting Fun MySQL QA Episode 2: Build a MySQL Server: Git, Compiling, Build Tools MySQL QA Episode 3: Debugging: GDB, Backtraces, Frames, Library Dependencies MySQL QA Episode 4: QA Framework Setup Time! percona-qa, pquery, reducer & more MySQL QA Episode 5: Preparing Your QA Run: mtr_to_sql.sh and pquery-run.sh MySQL QA Episode 6: Analyzing & Filtering: pquery-prep-red.sh, -clean-known.sh & pquery-results.sh MySQL QA Episode 7: Reducing Testcases for Beginners: single-threaded reducer.sh MySQL QA Episode 8: Reducing Testcases for Engineers: tuning reducer.sh MySQL QA Episode 9: Reducing Testcases for Experts: multi-threaded reducer.sh MySQL QA Episode 10: Reproducing and Simplifying: How to get it Right MySQL QA Episode 11: Valgrind Testing: Pro’s, Con’s, Why and How MySQL QA Episode 12: Multi-node Cluster Testing Using Docker MySQL QA Episode 13: A Better Approach to all MySQL Regression, Stress & Feature Testing: Random Coverage Testing & SQL Interleaving
A short introduction on each episode:
As episodes are finished, the series titles above will be linked so it’s easy to check this page for updates.
