I was interested to hear about semi-sync replication improvements in MySQL’s 5.7.4 DMR release and decided to check it out.  I previously blogged about poor semi-sync performance and was pretty disappointed from semi-sync’s performance across WAN distances back then, particularly with many client threads.

The Test

The basic environment of these tests was:

• AWS EC2 m3.medium instances
• Master in us-east-1, slave in us-west-1 (~78ms ping RTT)
• CentOS 6.5
• innodb_flush_log_at_trx_commit=1
• sync_binlog=1
• Semi-sync replication plugin installed and enabled.
• GTID’s enabled (except on 5.5)
• sysbench 0.5 update_index.lua test, 60 seconds, 250k table size.
• MySQL 5.7 was …

[ this is a re-posting of what I published on the MySQL server team blog a few days ago ]
 
When the MySQL server receives a SELECT query, the query goes through several consecutive phases:

• parsing: SQL words are recognized, the query is split into different parts following the SQL grammar rules: a list of selected expressions, a list of tables to read, a WHERE condition, …
• resolution: the output of the parsing stage contains names of columns and names of tables. Resolution is about making sense out of this. For example, in “WHERE foo=3“, “foo” is a column name without a table name; by applying SQL name resolution rules, we discover the table who contains “foo” (it can be complicated if subqueries or …

A series of related discussions triggered by difficulty in setting passwords via scripts using the mysql command-line client when an account has an expired password caused me to look into the interaction between expired passwords and batch mode, and this blog post resulted.  I hope it’s a useful explanation of the behavior and the workaround to those troubled by it, and amplifies the excellent documentation in the user manual.

The ability to flag accounts as having expired passwords first appeared in MySQL 5.6, with further …

So I figured it was about time I looked at MySQL 5.7. This is a high level overview, but I was looking over the MySQL 5.7 in a nutshell document:

• http://dev.mysql.com/doc/refman/5.7/en/mysql-nutshell.html

So I am starting with a fresh Fedora 20 (Xfce) install.
Overall, I will review a few items that I found curious and interesting with MySQL 5.7. The nutshell has a lot of information so well worth a review.

I downloaded the MySQL-5.7.4-m14-1.linux_glibc2.5.x86_64.rpm-bundle.tar

The install was planned on doing the following
# tar -vxf …

Recently there was a discussion on the webscalesql mailing list started by Chip Turner on a proposed change to the MAX_STATEMENT_TIME patch. This feature has been known as per query variable settings (WL#681) and even shipping in Percona Server 5.6 as per-query variable statement.

This feature has piqued my interest since 2009, when the MySQL project (then owned by Sun Microsystems) participated in Google Summer of Code 2009, and we got code from …

The latest benchmarks show that MySQL 5.7 is now able to scale to 60 cores, which is quite an incredible feat when you compare to the 4-8 core scaling of MySQL 5.1 just a few years ago. These improvements are the result of a lot of heavy lifting to reorganize internal locking structures, and I have an earlier blog post on what is a mutex anyway? which may help serve as an introduction.

While I consider horizontal scaling and projects like MySQL Fabric to be very important, it should be stated that horizontal and vertical scaling are really orthogonal choices. That is to say that a given database technology should ideally support both options, …

MySQL 5.7.4 was recently released (it is the latest MySQL 5.7, and is the “m14″ or “Milestone 14″ release), and is available for download here and here.

The 5.7.4 changelog begins with the following, so I felt it appropriate to include it here as well.

In Memoriam:

“This release is dedicated to the memory of two young engineers of the MySQL Engineering family, Astha and Akhila, whom we lost while they were in their early twenties. This is a small remembrance and a way to recognize your contribution to the 5.7 release. You will be missed.”

http://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-4.html

As for the fixes, there are …

A new MySQL MySQL 5.7 Multi-threaded slave labs load has now been published on MySQL Labs. This represents a signifficant step in the process of speeding up the processing of replication events on the slave – letting it keep up with the master.

The original implementation of MTS made a simple assumption about what events could safely be applied in parallel (with no dependency on the ordering). That assumption was that different schemas had no dependencies on each other and so if you had 5 schemas then one event from each schema could be applied in parallel (this is described in MySQL …

MySQL clients have long had a –ssl option.  Casual users may think specifying this option will cause clients to secure connections using SSL.  That is not the case:

D:\mysql-5.6.13-winx64>bin\mysql -uroot -P3307 --ssl
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.6.13-log MySQL Community Server (GPL)

Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> \s
--------------
bin\mysql  Ver 14.14 Distrib 5.6.13, for Win64 (x86_64)

Connection id:          2
Current database:
Current user:           root@localhost
SSL:                    Not in use
...

This behavior is clearly explained in the …

I’ve previously noted my wish to have a comprehensive password policy in MySQL Server.  MySQL Server 5.7.4 takes a significant step towards this goal by adding native support for enforcing password lifetime policy.  This complements the validate_password plugin introduced in MySQL Server 5.6, which helps ensure adequate password complexity, and builds on the password expiration mechanism also introduced in MySQL Server 5.6.  This new feature has a new documentation page, and is covered in the MySQL Server 5.7.4 change logs, which …