Monday, March 6, 2017

Better InnoDB Crash Recovery in MariaDB 10.1

Recently, I had to go through crash recovery of a large MariaDB 10.1.21 instance.  After starting MariaDB, I started tailing the error logs expecting to wait many minutes while InnoDB was scanning ibd files.  I was surprised (and actually delighted) with this:

Wednesday, February 8, 2017

A Metric for Tuning Parallel Replication in MySQL 5.7

MySQL 5.7 introduced the LOGICAL_CLOCK type of multi-threaded slave (MTS).  When using this type of parallel replication (and when slave_parallel_workers is greater than zero), slaves use information from the binary logs (written by the master) to run transactions in parallel.  However, enabling parallel replication on slaves might not be enough to get a higher replication throughput (VividCortex blogged about such a situation recently in Solving MySQL Replication Lag with LOGICAL_CLOCK and Calibrated Delay).  To get a faster slave with parallel replication, some tuning is needed on the master.

Friday, January 20, 2017

How upgrading MariaDB Server failed because 50M warnings were ignored

This post is part of the series "please do not ignore warnings in MySQL/MariaDB".  The previous post of the series can be found here.

In this post, I will present why ignoring warnings made me lose time in upgrading MariaDB Server.  I think this war story is entertaining to read and it is also worth presenting to people claiming that ignoring warnings is no big deal.

Wednesday, January 18, 2017

Why I wrote "please do not ignore warnings" and "to always investigate/fix warnings" (in MySQL/MariaDB)

In a last post, I wrote the two following sentences:
  • please do not ignore warnings
  • always investigate/fix warnings
I realized that without context, this might be hard to understand.  In this post, I want to give more background about these two sentences.

Friday, January 13, 2017

Oracle MySQL and the funny replication breakage of Friday, January 13

In my previous post, I talked about a funny replication breakage that I experienced with MariaDB.  So what about different versions of MySQL...

Funny replication breakage of Friday, January 13

A funny replication breakage kept me at the office longer than expected today (Friday 13 is not kind with me).

So question of the day: can you guess what the below UPDATE statement does (or what is wrong with it)?