Managing MySQL Senior Consultant at MySQL Inc …...2015.08 EffectiveMySQL.com - Performance, Scalability, Site Reliability About the Author 16 years with MySQL / 26 years with RDBMS

EffectiveMySQL.com - Performance, Scalability, Site Reliability

Managing MySQL Version Upgrades

Ronald Bradfordhttp://ronaldbradford.com

@RonaldBradford

2015.08


About the Author

16 years with MySQL / 26 years with RDBMS

Senior Consultant at MySQL Inc (06-08)

Consultant for Oracle Corporation (96-99)

Published author of 4 MySQL books

Ronald BRADFORD

http://ronaldbradford.com/presentations/


OTN TOUR 2015

Uruguay www.uyoug.org.uy

Argentina www.aroug.org

Chile www.cloug.cl

Peru www.peoug.org

Latin America Oracle User Groups Community www.laouc.net


Operating Systems


Operating Systems

In this presentation will only be discussing RHEL/OL/CentOS versions

MySQL is also available on

Ubuntu/Debian

Windows

Solaris

Mac OS X

FreeBSD

SuSE

...


MySQL versions

MySQL version history

EOL - 3.23, 4.0, 4.1, 5.0, 5.1

GA - 5.5, 5.6

DMR - 5.7


https://en.wikipedia.org/wiki/MySQL

1994

1996MySQL (.com)

1998

2001v3.23

v4.02003

2004v4.1

v5.02005

Sun (.com)

2008

BEFORE Oracle

1995Innobase

Oracle (.com)

2005

MySQL (.com)

2008v5.1

v5.02005

Sun (.com)

2008

DURING SUN

v5.2

v6.0

X X

4/21/2009v5.4 beta

X

Oracle (.com)4/20/2009Acquisition announcement

Proven Scaling

Our Delta

2006 2009

2008 2011

Now

Oracle (.com)12/2010

v5.53/2013

v5.6

Sun (.com)

Percona Server

Maria DB

2006

2009

4/2011v5.5

4/2009v1.0.3

7/2010v5.1

July 2015

10/13v5.6

4/2009 1/2010

4/12v5.5

11/10v5.2

2/12V5.3

2/10v5.1

3/14v10.0


installation types

Installation types for RHEL/OL

Distro repo

3rd Party repo

Webtatic, Remi

Oracle repo

tar.gz

SourceEffectiveMySQL.com - Performance, Scalability, Site Reliability

RHEL/OL Installation


RHEL/OL 6 default ISO

Oracle Linux 6 default iso

mysql-libs-5.1 package


default install

# Install MySQLcd /tmpwget http://dev.mysql.com/get/mysql-community-release-el6-5.noarch.rpmyum localinstall -y mysql-community-release-el6-5.noarch.rpmrm -f mysql-community-release-el6-5.noarch.rpmsudo yum-config-manager --disable mysql56-communitysudo yum-config-manager --enable mysql55-communityyum repolist enabled | grep mysqlyum install -y mysql-community-serverrpm -qa | grep mysqlservice mysqld startchkconfig mysqld onmysql -uroot -e "SELECT VERSION()"

MySQL 5.5

Minimum installed

Additional packages exist


default rpms

$ rpm -qa | grep mysqlmysql-community-client-5.5.44-2.el6.x86_64mysql-community-common-5.5.44-2.el6.x86_64mysql-community-libs-compat-5.5.44-2.el6.x86_64mysql-community-libs-5.5.44-2.el6.x86_64mysql-community-server-5.5.44-2.el6.x86_64


Oracle yum repo

Oracle yum repo supports

MySQL 5.5

MySQL 5.6

MySQL 5.7

MySQL workbench/connectors/utilities


distro conflict

RHEL/OL Distro

mysql-server

Oracle Distro

mysql-community-server


package names

$ yum info mysql-serverLoaded plugins: securityAvailable PackagesName : mysql-serverArch : x86_64Version : 5.1.73Release : 5.el6_6Size : 8.6 MRepo : public_ol6_latestSummary : The MySQL server and related filesURL : http://www.mysql.comLicense : GPLv2 with exceptionsDescription : MySQL is a multi-user, multi-threaded SQL database server. MySQL is a : client/server implementation consisting of a server daemon (mysqld) : and many different client programs and libraries. This package contains : the MySQL server and some accompanying files and directories.

RHEL/OL Default

RHEL/OL 6MySQL 5.1EOL 2013


package names

$ yum info mysql-community-server

Available PackagesName : mysql-community-serverArch : x86_64Version : 5.6.25Release : 2.el6Size : 53 MRepo : mysql56-communitySummary : A very fast and reliable SQL database serverURL : http://www.mysql.com/

Oracle Repo


RHEL/OL Upgrade


default upgrade

$ mysql -e "SELECT VERSION()"+-----------+| VERSION() |+-----------+| 5.5.44 |+-----------+$ sudo yum-config-manager --disable mysql55-community$ sudo yum-config-manager --enable mysql56-community$ sudo yum update mysql-community-server$ mysql -e "SELECT VERSION()"+-----------+| VERSION() |+-----------+| 5.6.25 |+-----------+

This is not a completed upgrade


standard upgrade

yum update is not enough$ tail -20 /var/log/mysqld.log...2015-07-24 17:28:31 31214 [ERROR] Native table 'performance_schema'.'events_statements_summary_by_account_by_event_name' has the wrong structure2015-07-24 17:28:31 31214 [ERROR] Native table 'performance_schema'.'events_statements_summary_by_user_by_event_name' has the wrong structure2015-07-24 17:28:31 31214 [ERROR] Native table 'performance_schema'.'events_statements_summary_by_host_by_event_name' has the wrong structure2015-07-24 17:28:31 31214 [ERROR] Native table 'performance_schema'.'events_statements_summary_global_by_event_name' has the wrong structure2015-07-24 17:28:31 31214 [ERROR] Native table 'performance_schema'.'events_statements_summary_by_digest' has the wrong structure2015-07-24 17:28:31 31214 [ERROR] Native table 'performance_schema'.'users' has the wrong structure2015-07-24 17:28:31 31214 [ERROR] Native table 'performance_schema'.'accounts' has the wrong structure2015-07-24 17:28:31 31214 [ERROR] Native table 'performance_schema'.'hosts' has the wrong structure2015-07-24 17:28:31 31214 [ERROR] Native table 'performance_schema'.'socket_instances' has the wrong structure2015-07-24 17:28:31 31214 [ERROR] Native table 'performance_schema'.'socket_summary_by_instance' has the wrong structure2015-07-24 17:28:31 31214 [ERROR] Native table 'performance_schema'.'socket_summary_by_event_name' has

Always check the error log


mysql_upgrade

$ sudo mysql_upgradeLooking for 'mysql' as: mysqlLooking for 'mysqlcheck' as: mysqlcheckRunning 'mysqlcheck with default connection argumentsWarning: Using a password on the command line interface can be insecure.Running 'mysqlcheck with default connection argumentsWarning: Using a password on the command line interface can be insecure.mysql.columns_priv OKmysql.db OKmysql.event OKmysql.func OKmysql.general_log OKmysql.help_category OKmysql.help_keyword OKmysql.help_relation OKmysql.help_topic OKmysql.host OKmysql.ndb_binlog_index OKmysql.plugin OKmysql.proc OKmysql.procs_priv OKmysql.proxies_priv OKmysql.servers OKmysql.slow_log OKmysql.tables_priv OK

mysql_upgrade must also be run

on a running instance


Repo Change


Legacy installation

No Oracle yum repo before 5.5

No path from non-Oracle repo to Oracle repo

DB data structure is compatible

Software removal and re-installation required

http://ronaldbradford.com/blog/updating-mysql-using-official-repositories-2013-11-05/


Compatibility


MySQL 5.5 to 5.6

Reserved Words

Legacy TIMESTAMP usage

FULLTEXT Indexes

Client libraries

Query Optimizer

Clear text password warnings


reserved words

http://dev.mysql.com/doc/refman/5.6/en/keywords.html


reserved words

http://dev.mysql.com/doc/refman/5.7/en/keywords.html


reserved words

mysql> SELECT VERSION();+-----------+| version() |+-----------+| 5.5.44 |+-----------+

mysql> CREATE TABLE mysql55(only CHAR(1));Query OK, 0 rows affected (0.01 sec)

mysql> INSERT INTO mysql55(only) VALUES('A');Query OK, 1 row affected (0.00 sec)


reserved words

mysql> SELECT VERSION();+-----------+| VERSION() |+-----------+| 5.6.25 |+-----------+

mysql> CREATE TABLE mysql56(only CHAR(1));

mysql> INSERT INTO mysql56(only) VALUES('A');

mysql> CREATE TABLE only(c1 CHAR(1));Query OK, 0 rows affected (0.01 sec)

Not all reserved words are affected in

table strucutre


reserved words

mysql> CREATE TABLE table(c1 CHAR(1));ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'table(c1 CHAR(1))' at line 1

mysql> CREATE TABLE `table`(c1 CHAR(1));Query OK, 0 rows affected (0.01 sec)

mysql> INSERT INTO `table`(c1) VALUES('A');Query OK, 1 row affected (0.01 sec)

Reserved words can be used with

backquotes (`)


timestamp defaults

$ tail /var/log/mysqld.log

[Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).

TIMESTAMP datatype

DEFAULT CURRENT_TIMESTAMP

ON UPDATE CURRENT_TIMESTAMP


timestamp column

https://dev.mysql.com/doc/refman/5.0/en/timestamp-initialization.htmlhttps://dev.mysql.com/doc/refman/5.1/en/timestamp-initialization.htmlhttps://dev.mysql.com/doc/refman/5.5/en/timestamp-initialization.htmlhttps://dev.mysql.com/doc/refman/5.6/en/timestamp-initialization.htmlhttps://dev.mysql.com/doc/refman/5.7/en/timestamp-initialization.html


fulltext

MySQL 5.5 default storage engine changed to InnoDB

CREATE TABLE without ENGINE=MyISAM fails in 5.5

MySQL 5.6 InnoDB now supports FTS

Search results differ between MyISAM and InnoDB


optimizer

Some queries will have a different QEP

Testing is necessary to validate if query is worse in performance

Some queries are definitely better


clear text password

$ mysql -uuser -ppasswordWarning: Using a password on the command line interface can be insecure.

mysql> CHANGE MASTER ...;mysql> SHOW WARNINGS\G************************** 1. row *************************** Level: Note Code: 1759Message: Sending passwords in plain text without SSL/TLS is extremely insecure.*************************** 2. row *************************** Level: Note Code: 1760Message: Storing MySQL user name or password information in the master.info repository is not secure and is therefore not recommended. Please see the MySQL Manual for more about this issue and possible alternatives.


Configuration


new configuration

Upgrade configuration path

Inherit new configuration or keep legacy from prior version?


new defaults

https://dev.mysql.com/doc/refman/5.6/en/upgrading-from-previous-series.html

MySQL 5.6


https://dev.mysql.com/doc/refman/5.6/en/server-default-changes.htmlEffectiveMySQL.com - Performance, Scalability, Site Reliability

https://dev.mysql.com/doc/refman/5.6/en/server-default-changes.html


configuration

innodb_file_per_table

0 - Global tablespace (with multiple data files)

1 - Per table tablespace


configuration

innodb_file_per_table

Benefit

Reclaim diskspace when deleting data

Disadvantage

Higher amount fsyncs


configuration

There is no only migration path to move tables to innodb_file_per_table=1

Must dump, drop, clear files, restart and reload all data to reset global tablespace

Unprepared, you can be left with tables in old and new formats together


configuration

performance_schema

5.5 default is OFF

5.6 default is ON

Performance overhead

Overhead is worth it for not well tuned systems


configuration

innodb_log_file_size

Generally increased for tuning systems

Improvement helps in concurrency of untuned default system

Restart required to implement new default (no additional work needed)


configuration

max_connections

5.6 now supports more concurrent connections and more cores


Recommendations


sys

Install the ‘sys’ schema in MySQL 5.6

Now included by default in MySQL 5.7

https://github.com/MarkLeith/mysql-sys/


Upgrading Options


upgrading

MySQL recommends upgrading to each version separately

The also suggest to dump and load data

This is impractical

Can you upgrade from 5.0 to 5.5?

It is [technically] possible, not recommended


replication

MySQL replication is the easiest way to perform rolling upgrades

A read replica can be a newer version

Validates all writes (via binary log)

Test reads via replay


replication

Do not use new replication configuration features until entire topology is upgraded.

e.g. crash safe replication

Issues with checksum in binary log


Conclusion


conclusion

Moving from non Oracle yum repo is important first step

Moving to 5.5 is the best base version

A 3-6 month upgrade cadence is best

MySQL replication is key for testing

http://ronaldbradford.com [email protected]

@RonaldBradford

Ronald Bradford

Documents

Managing MySQL Senior Consultant at MySQL Inc …...2015.08 EffectiveMySQL.com - Performance, Scalability, Site Reliability About the Author 16 years with MySQL / 26 years with RDBMS