Monthly Archives - July 2015

MySQL QA Episode 10: Reproducing and Simplifying: How to get it Right

MySQL QA Episode 10

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 – […]

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Why base64-output=DECODE-ROWS does not print row events in MySQL binary logs

Lately I saw many cases when users specified option
–base64-output=DECODE-ROWS  to print out a statement representation of row events in MySQL binary logs just to get nothing. Reason for this is obvious: option
–base64-output=DECODE-ROWS  does not convert row events into its string representation, this is job of option
–verbose . But why users mix […]

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Multi-source replication in MySQL 5.7 vs Tungsten Replicator

MySQL 5.7 comes with a new set of features and multi-source replication is one of them. In few words this means that one slave can replicate from different masters simultaneously.
During the last couple of months I’ve been playing a lot with this trying to analyze its potential in a real case that I’ve been […]

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MySQL QA Episode 9: Reducing Testcases for Experts: multi-threaded reducer.sh

Welcome to MySQL QA Episode 9. This episode will go more in-depth into reducer.sh: Reducing Testcases for Experts: multi-threaded reducer.sh
We will explore how to use reducer.sh to do true multi-threaded testcase reduction – a world’s first.
Topics:

Expert configurable variables & their default reducer.sh settings

PQUERY_MULTI
PQUERY_MULTI_THREADS
PQUERY_MULTI_CLIENT_THREADS
PQUERY_MULTI_QUERIES
PQUERY_REVERSE_NOSHUFFLE_OPT

Full-screen viewing @ 720p resolution recommended.

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InnoDB vs TokuDB in LinkBench benchmark

Previously I tested Tokutek’s Fractal Trees (TokuMX & TokuMXse) as MongoDB storage engines – today let’s look into the MySQL area.
I am going to use modified LinkBench in a heavy IO-load.
I compared InnoDB without compression, InnoDB with 8k compression, TokuDB with quicklz compression.
Uncompressed datasize is 115GiB, and cachesize is 12GiB for InnoDB and 8GiB […]

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The Q&A: Creating best-in-class backup solutions for your MySQL environment

Thank you for attending my July 15 webinar, “Creating Best in Class Backup solutions for your MySQL environment.” Due to the amount of content we discussed and some minor technical difficulties faced near the end of webinar we have decided to cover the final two slides of the presentation along with the questions asked […]

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MySQL QA Episode 8: Reducing Testcases for Engineers: tuning reducer.sh

Welcome to MySQL QA Episode 8: Reducing Testcases for Engineers: tuning reducer.sh

Advanced configurable variables & their default/vanilla reducer.sh settings

FORCE_SKIPV
FORCE_SPORADIC
TIMEOUT_COMMAND & TIMEOUT_CHECK
MULTI_THREADS
MULTI_THREADS_INCREASE
QUERYTIMEOUT
STAGE1_LINES
SKIPSTAGE
FORCE_KILL

Some examples

FORCE_SKIPV/FORCE_SPORADIC
TIMEOUT_COMMAND/TIMEOUT_CHECK

Full-screen viewing @ 720p resolution recommended.

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SELinux and the MySQL init script

I recently worked with a customer who had a weird issue: when their MySQL server was started (Percona Server 5.5), if they try to run service mysql start a second time, the init script was not able to detect that an instance was already running. As a result, it tried to start a second […]

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Percona now offering 24/7 support for MongoDB and TokuMX

Today Percona announced the immediate availability of 24/7, enterprise-class support for MongoDB and TokuMX. The new support service helps organizations achieve maximum application performance without database bloat. Customers have round-the-clock access (365 days a year) to the most trusted team of database experts in the open source community.
The news means that Percona now offers […]

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MySQL QA Episode 7: Reducing Testcases for Beginners – single-threaded reducer.sh!

Welcome to MySQL QA Episode #7 – Reducing Testcases for Beginners: single-threaded reducer.sh!
In this episode we’ll learn how to use reducer.sh. Topics discussed;

reducer.sh introduction/concepts
Basic configurable variables & their default reducer.sh settings

INPUTFILE options
MODE=x
TEXT=”text”
WORKDIR_LOCATION & WORKDIR_M3_DIRECTORY
MYEXTRA
MYBASE
PQUERY_MOD & PQUERY_LOC
MODE5_COUNTTEXT, MODE5_ADDITIONAL_TEXT & MODE5_ADDITIONAL_COUNTTEXT
How to learn more about each of the settings

Manual example
Introduction to the script’s self-recursion concept – subreducer
Quick […]

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