Recently, we were affected by an ignored configuration option introduced in MySQL 5.6. This incident caused us to perform extended planning of downtime and the rebuilding of the slave. In…

The post Still have MySQL 5.6 variable binlog_error_action as IGNORE_ERROR? first appeared on Change Is Inevitable.

Recently, we were affected by an ignored configuration option introduced in MySQL 5.6. This incident caused us to perform extended planning of downtime and the rebuilding of the slave. In this post, we’ll discuss our encounter with binlog_error_action and likely bad default.

The incident started with an alert from our monitoring platform that a check failed to verify a MySQL master’s binary log coordinates. My colleague working from the other side of the globe observed the following:

mysql> show master status;
Empty set (0.00 sec)

mysql> show binary logs;
ERROR 1381 (HY000): You are not using binary logging

Interestingly, the MySQL slave was still reporting that everything was okay!

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: master
                  Master_User: …

This is a story about why it's a good idea to test and verify the behavior of new software releases, even if the change log says that a particular bug was already fixed.
Background MySQL 5.6 and 5.7 both support the following CREATE USER syntax:

CREATE USER 'user'@'host'
  IDENTIFIED BY 'password';

This syntax create a user with the default authentication plugin (mysql_native_password unless configured otherwise) and the password provided. The IDENTIFIED BY syntax is also supported for GRANT command.
Both major versions also support the following syntax:

CREATE USER 'user'@'host'
  IDENTIFIED WITH mysql_native_password AS 'hash_string';

The password hash for "passw0rd" is "*74B1C21ACE0C2D6B0678A5E503D2A60E8F9651A3", you might then expect that the effects of the …

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This post was originally published on the MySQL Support Team Blog at https://blogs.oracle.com/mysqlsupport/entry/innodb_locks_analysis_why_is on 14 April 2017.

Consider the scenario that you execute a query. You expect it to be fast – typically subsecond – but now it take not return until after 50 seconds (innodb_lock_wait_timeout seconds) and then it returns with an error:

mysql> UPDATE world.City SET Population = Population + 999 WHERE ID = 130;
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction

You continue to investigate the issue using the sys.innodb_lock_waits view or the underlying Information Schema tables (INNODB_TRX, …

Yes, another post about my talks at Percona Live Santa Clara: I obviously still have things to share.  This time, I will focus on my parallel replication talks by giving a short preview.

I have two parallel replication talks at Percona Live:

MySQL/MariaDB Parallel Replication: inventory, use cases and limitations (Wednesday talk) MySQL Parallel Replication: all the 5.7 (and some of the 8.0)

In a previous post, I listed all the Booking.com talks at Percona Live.  In this post, I will give more details about my talks.

As a reminder, the list of my talks is the following:

Monitoring Booking.com without looking at MySQL (Thursday keynote) The two little bugs that almost brought down Booking.com (Tuesday Lightning Talk) MySQL/MariaDB Parallel Replication: inventory, use cases and

In a week, me and some Booking.com colleagues will be in Santa Clara for Percona Live.

Booking.com is sponsoring the conference and we will be present at the Monday Evening Reception.  You do not need a tutorial pass to attend the dinner (even if it is on the tutorial day): any valid pass will do.  If you do not have your ticket yet, it is time to register (you can use the discount code “

In my previous post, I talked about a funny replication breakage that I experienced with MariaDB.  So what about different versions of MySQL... > SELECT version(); +------------+ | version() | +------------+ | 5.6.35-log | +------------+ 1 row in set (0.00 sec) > SELECT * FROM test_jfg; +----+--------+-------------+ | id | status

Recently, I was discussing with one of my colleagues about how insert statement performs for MySQL partitioned tables. General prediction is that it should be slower than for non-partitioned tables, but how much that we didn’t know. So, I thought let’s test with different types of partitions (i.e range, list and hash) and also with different number of partitions and check how’s performance. As people says, MySQL 5.7 is must faster than old one, so I also tested partitions with it.

So, I took simple table with 3.2M records on Centos 6.7 VM (4 core with 2GB RAM) with default my.cnf settings and then created tables for range, list and hash partitioning with 5,25,50 and 100 partitions. i.e with 5 partition (range and list), the table structures were like

CREATE TABLE emp_range_5(
 id int,
 fname varchar (30),
 lname varchar (30),
 hired_date date not null,
 separated_date date not null,
 job_code int,
 store_id int
 ) …

When trying out new software there are many other questions you may ask and one of those is going to be the one above. The answer requires you to have built your software to capture and record low level database metrics and often the focus of application developers is slightly different: they focus on how … Continue reading Is MySQL X faster than MySQL Y? – Ask queryprofiler

The post Is MySQL X faster than MySQL Y? – Ask queryprofiler first appeared on Simon J Mudd's Blog.