Oracle SupportStars’ Bar - RainFocusfk_rental_inventory`; Query OK, 0 rows affected (0.25 sec) ... Copyright©2016,Oracleand/oritsaﬃliates.Allrightsreserved.**| Examplemysqldumpslowoutput

Copyright © 2016, Oracle and/or its affiliates. All rights reserved. 9/6/16 Oracle Confiden1al – Internal/Restricted/Highly Restricted

Oracle Support Stars Bar

• Ask the Experts your toughest product quesCons.

• View My Oracle Support and Product DemonstraCons.

• Learn what’s new and more!

9Monday, September 19, 16

Copyright © 2016, Oracle and/or its affiliates. All rights reserved. |

A MySQL DBA PrimerLigaya Turmelle

Principal Technical Support Engineer -‐ MySQL

[email protected]

@lig

, Oracle and/or its affiliates. All rights reserved. | 2Monday, September 19, 16


Safe Harbor Statement

The following is intended to outline our general product direc1on. It is intended for informa1on purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or func1onality, and should not be relied upon in making purchasing decisions. The development, release, and 1ming of any features or func1onality described for Oracle’s products remains at the sole discre1on of Oracle.



Agenda -‐ First Half

• Founda1on

• Installa1on

• Talking to MySQL

• Architecture

• Log Files

1

2

3

4

5



Agenda -‐ Second Half

• Log Files (con’t)

• Security

• Backup

• Monitoring

• Basic Troubleshoo1ng

5

6

7

8

9



FoundaCon



FoundaCon

• Basics

• Commercial

1

2



MySQL in a Nutshell

• Worlds most popular open source database

• “M” of LAMP

• Main site: mysql.com



MySQL.com

• mysql.com- Commercial site

• dev.mysql.com (AKA mysql.org)- Developer Zone

• downloads.mysql.com• dev.mysql.com/doc/

- Documentation

• bugs.mysql.com


http://dev.mysql.com

http://dev.mysql.com

http://downloads.mysql.com

http://downloads.mysql.com

http://dev.mysql.com/doc/

http://dev.mysql.com/doc/


GeXng Help

• Manual

• MySQL Support

• MySQL Forums (forums.mysql.com)

• Mailing Lists (lists.mysql.com)

• Search the Web

• IRC on freenode -‐ #mysql



Main Features

• Works on mul1ple plaborms

• Mul1-‐layered server design

• Pluggable architecture-‐ Storage engine

-‐ Misc plugins (Ex: validate_password, SHA256_password)

• Mul1-‐threaded

• “Plays well” with most programming languages



FoundaCon

• Basics

• Commercial22

1



Enterprise EdiCon Add-‐Ons

• MySQL Enterprise Backup (MEB)

• MySQL Enterprise Monitor (MEM)

• Workbench

• Plugins• Threadpool, Audit, Firewall, TDE, Encryp1on, PAM, etc

• Oracle Enterprise Manager for MySQL



InstallaCon



InstallaCon

• Files

• Installa1on

1

2



OpCon Files

• AKA configura1on files• Lists specific startup op1ons

# The following options will be passed to all MySQL clients

[client]#password! = your_passwordport! ! = 3626socket!! = /tmp/mysql.5.6.26.sock

# Here follows entries for some specific programs

# The MySQL server[mysqld]port! = 3626socket!= /tmp/mysql.5.6.26.socklog-error = /Users/ligaya/mysql_installs/

mysql-5.6.26-osx10.9-x86_64/data/error.logserver-id! = 1table_open_cache = 4000



Common LocaCons of OpCon File

• Windows-INSTALLDIR\my.ini

-INSTALLDIR\my.cnf

• Linux & Mac-/etc/my.cnf

-/etc/mysql/my.cnf



Generic Unix/Linux Binary File Layout

Directory Contents

bin, scripts Client programs, mysqld server and u1lity programs

data Log files and databases

docs Manual in Info format

man Unix manual pages

include Include (header) files

lib Libraries

shareMisc support files including error messages, sample op1on files and SQL for database installa1on



Linux RPM File Layout

Directory Contents

/usr/bin Client programs and scripts

/usr/sbin mysqld server

/var/lib/mysql log files and databases

/usr/share/info Manual in Info format

/usr/share/man Unix manual pages

/usr/include/mysql Include (header) files

/usr/lib/mysql Libraries

/usr/share/mysqlMisc support files including error messages, character set files, sample op1on files and SQL for database installa1on



Windows File Layout

Directory Contents Notes

bin, scripts Client programs, mysqld server and u1li1es scripts

%ALLUSERSPROFILE%\MySQL\MySQL Server 5.7\

Log files and databases (Windows XP, Windows Server 2003)

The Windows system variable %ALLUSERSPROFILE% defaults to C:\Documents and Settings\All Users\Application Data

%PROGRAMDATA%\MySQL\MySQL Server 5.7\

Log files and databases (Vista, Windows 7, Windows Server 2008 and newer)

The Windows system variable %PROGRAMDATA% defaults to C:\ProgramData

examples Example programs and scripts

include include (header) files

lib Libraries

shareMisc support files including error messages, character set files, sample op1on files and SQL for database installa1on



InstallaCon

• Files

• Installa1on22

1



InstallaCon

• Well documented in the Manual

• Each OS is documented -‐ some with mul1ple ways to do it-‐ Unix/Linux Generic Binaries

-‐ Windows

-‐ Mac

-‐ Various Linux (MySQL Repositories, RPM, Na1ve Repositories)

-‐ Solaris

-‐ Source



Generic Binary InstallaConshell> groupadd mysqlshell> useradd -r -g mysql mysqlshell> cd /usr/localshell> tar zxvf /path/to/mysql-VERSION-OS.tar.gzshell> ln -s full-path-to-mysql-VERSION-OS mysqlshell> cd mysqlshell> mkdir mysql-filesshell> chmod 770 mysql-filesshell> chown -R mysql .shell> chgrp -R mysql .shell> bin/mysql_install_db --user=mysql # Before 5.7.6shell> bin/mysqld --initialize --user=mysql # 5.7.6 and upshell> bin/mysql_ssl_rsa_setup # 5.7.6 and upshell> chown -R root .shell> chown -R mysql data mysql-filesshell> bin/mysqld_safe --user=mysql & # optionally start the server# Next command is optionalshell> cp support-files/mysql.server /etc/init.d/mysql.server



StarCng it up

• Various methods-mysqld_safe

-mysqld

-mysql.server

-service mysqld start

-‐ Windows Service

• Unix/Linux -‐ run as a non-‐root account• Windows -‐ admin rights



ShuXng it down

• Manually-mysqladmin shutdown

-/etc/init.d/mysql stop

-service mysqld stop

-NET STOP MySQL

- Services Manager

-SHUTDOWN (5.7)



Talking to MySQL



CLI -‐ mysql client

• Easy to use• Simple SQL shell

• Server side help• Many op1ons-‐ Example: --i-am-a-dummy

• Has its own commands

mysql> select count(*) from inventory;+----------+| count(*) |+----------+| 4581 |+----------+1 row in set (0.08 sec)

mysql> ALTER TABLE rental DROP FOREIGN KEY `fk_rental_inventory`;

Query OK, 0 rows affected (0.25 sec)Records: 0 Duplicates: 0 Warnings: 0

mysql> SELECT rental_id from rental order by RAND() LIMIT 10;

+-----------+| rental_id |+-----------+| 12539 || 8592 || 15699 |



Workbench

• GUI-‐ SQL Development

-‐ Data Modeling

-‐ Server Administra1on

-‐ Data Migra1on

-‐ Performance Tools and Reports

-‐ Integrated with MEB and Audit

-‐ MySQL U1li1es



SQL Editor in Windows



Data Modeling in Mac



Performance Dashboard in Linux



Architecture



Architecture

• High Level

• Storage Engines

1

2



High Level



Architecture

• High Level

• Storage Engines22

1



InnoDB

• General-‐purpose storage engine• As of 5.5, is the default engine• Features:-‐ ACID compliant

-‐ Row level locking with consistent reads

-‐ Foreign keys

-‐ Clustered primary key index

-‐ FullText Indexes (5.6) & Geospa1al data and indexes (5.7)



InnoDB (con’t)

• Features Con1nued:-‐ Tablespaces

• file per table

-‐ transportable

-‐ encrypted

• undo logs

• general

-‐ Compressed Data



Others

• MyISAM

• Memory

• CSV• Archive• Blackhole• 3rd Party



Log Files



Error Log

• --log-error[=file_name]• Default loca1on: host_name.err in datadir• Examples of stuff logged-‐ Start and stops & Cri1cal errors

-‐ MyISAM tables that need to be checked or repaired

-‐ some OS’s -‐ stack trace if mysqld crashes

• (5.7) log_syslog to send MySQL error log to syslog

• (5.7) log_error_verbosity40

Monday, September 19, 16


Slow Query Log

• First line of offense for tuning queries• Why?-‐ Performance usually

• Enable dynamically or with --slow-query-log-‐ Default file loca1on: host_name-slow.log in the datadir

-‐ Can also go to a table

• Mul1ple op1ons for controlling it

• Aggregate its data with mysqldumpslow u1lity41



EXPLAIN

• Displays query execu1on plan• Syntax:-‐ Prior to 5.6:

• EXPLAIN [explain_type] SELECT select_options

-‐ 5.6:• EXPLAIN [explain_type] explainable_stmt



EXPLAIN

• Talk all by itself• 1 row == 1 table• Order maqers

• EXTENDED + SHOW WARNINGS = rewriqen query• Columns:-‐ id, select_type, table, par11ons, type, possible_keys, key, key_length, ref, rows, filtered, Extra

(con’t)



Example CLI EXPLAIN

mysql> EXPLAIN EXTENDED SELECT ci.Name, -> co.Name, -> cl.IsOfficial -> FROM City ci -> INNER JOIN Country co -> ON ci.CountryCode = co.Code -> INNER JOIN CountryLanguage cl -> ON co.Code = cl.CountryCode -> WHERE cl.Language = 'ENGLISH' -> LIMIT 100;+----+-------------+-------+------------+--------+---------------------+-------------+---------+----------------------+------+----------+-------------+| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | filtered | Extra |+----+-------------+-------+------------+--------+---------------------+-------------+---------+----------------------+------+----------+-------------+| 1 | SIMPLE | cl | NULL | ALL | PRIMARY,CountryCode | NULL | NULL | NULL | 984 | 10.00 | Using where || 1 | SIMPLE | co | NULL | eq_ref | PRIMARY | PRIMARY | 3 | world.cl.CountryCode | 1 | 100.00 | NULL || 1 | SIMPLE | ci | NULL | ref | CountryCode | CountryCode | 3 | world.cl.CountryCode | 1 | 100.00 | NULL |+----+-------------+-------+------------+--------+---------------------+-------------+---------+----------------------+------+----------+-------------+3 rows in set, 2 warnings (0.00 sec)



Workbench Visual EXPLAIN -‐ Mac



mysqldumpslow

• Parses slow query log and aggregates the data• Default -‐ groups queries that are similar-‐ “abstracts” out specific string and number data values

• Op1ons for sor1ng:-‐ t, at -‐ sort by query 1me or average query 1me

-‐ l, al -‐ sort by lock 1me or average lock 1me

-‐ r, ar -‐ sort by rows or average rows sent

-‐ c -‐ sort by count



Example mysqldumpslow outputCount: 6 Time=0.36s (2s) Lock=0.00s (0s) Rows=1.0 (6), agent[agent]@localhost SELECT @@version NOT LIKE "S" AND (SELECT COUNT(*) < N FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA != 'S') AND (SELECT COUNT(*) = N FROM INFORMATION_SCHEMA.TABLES WHERE CREATE_OPTIONS LIKE 'S')

Count: 2 Time=0.24s (0s) Lock=0.10s (0s) Rows=1.0 (2), agent[agent]@localhost SELECT ROUND(SUM(sum_timer_wait)/N) total_wait_time_ms, SUM(count_star) total_statements, ROUND(MAX(max_timer_wait)/N) max_wait_time_ms, SUM(sum_errors) total_errors, SUM(sum_warnings) total_warnings, SUM(sum_rows_sent) total_rows_returned, ROUND(SUM(sum_lock_time)/N) total_lock_time_ms FROM performance_schema.events_statements_summary_by_digest

Count: 100 Time=0.22s (22s) Lock=0.00s (0s) Rows=0.0 (0), root[root]@localhost CREATE TABLE `t1` (id serial,id0 varchar(N) unique key,intcol1 INT(N) ,intcol2 INT(N) ,intcol3 INT(N) ,intcol4 INT(N) ,intcol5 INT(N) ,charcol1 VARCHAR(N),charcol2 VARCHAR(N),charcol3 VARCHAR(N),charcol4 VARCHAR(N),charcol5 VARCHAR(N),charcol6 VARCHAR(N),charcol7 VARCHAR(N),charcol8 VARCHAR(N),charcol9 VARCHAR(N),charcol10 VARCHAR(N))

Count: 300 Time=0.20s (60s) Lock=0.00s (0s) Rows=0.0 (0), root[root]@localhost CREATE TABLE `t1` (id serial,id0 varchar(N) unique key,intcol1 INT(N) ,intcol2 INT(N) ,intcol3 INT(N) ,intcol4 INT(N) ,intcol5 INT(N) ,intcol6 INT(N) ,intcol7 INT(N) ,intcol8 INT(N) ,intcol9 INT(N) ,intcol10 INT(N) ,charcol1 VARCHAR(N),charcol2 VARCHAR(N),charcol3 VARCHAR(N),charcol4 VARCHAR(N),charcol5 VARCHAR(N),charcol6 VARCHAR(N),charcol7 VARCHAR(N),charcol8 VARCHAR(N),charcol9 VARCHAR(N),charcol10 VARCHAR(N))



General Query Log

• General Record• Why:-‐ Order is important

-‐ Exact query that came in

-‐ minimal audit of what a connec1on did

• Enable Dynamically or with --general-log-‐ Default loca1on: host-name.log in datadir

• Mul1ple op1ons for controlling it



Binary Log

• Logs database *change* events• Why?-‐ Replica1on or Data Recovery

• Enable with --log-bin• A LOT of op1ons• “Read” with mysqlbinlog• To disable binary logging for the current session, use sql_log_bin



mysqlbinlog

• Display binary/relay logs in text format

• Syntax: mysqlbinlog [options] logfile• Can work with any replica1on format-‐ Reading Row Based Replica1on

• --verbose --base64-output=DECODE-ROWS

• Can backup binary logs to remote server-‐ Sta1c or streaming

• --read-from-remote-server



Example mysqlbinlog output# at 316#130512 20:22:57 server id 1 end_log_pos 364 CRC32 0xa7a9fe8c !GTID [commit=yes]SET @@SESSION.GTID_NEXT= '6e521de8-bb62-11e2-836e-821afda5425c:2'/*!*/;# at 364#130512 20:22:57 server id 1 end_log_pos 443 CRC32 0xf9bf1aaa !Query! thread_id=3! exec_time=0!error_code=0SET TIMESTAMP=1368404577/*!*/;BEGIN/*!*/;# at 443#130512 20:22:57 server id 1 end_log_pos 542 CRC32 0x1b82a82c !Query! thread_id=3! exec_time=0!error_code=0SET TIMESTAMP=1368404577/*!*/;insert into t1 values (1)/*!*/;# at 542#130512 20:22:57 server id 1 end_log_pos 573 CRC32 0x22965d3b !Xid = 29COMMIT/*!*/;# at 573#130512 20:23:01 server id 1 end_log_pos 621 CRC32 0x89e5d253 !GTID [commit=yes]SET @@SESSION.GTID_NEXT= '6e521de8-bb62-11e2-836e-821afda5425c:3'/*!*/;



Security



Securing a New InstallaCon Prior to 5.7

• Ini1al user accounts-‐ Superuser (root)

-‐ Anonymous (“”)



User Account

• 2 parts-‐ username

-‐ hostname

-‐ Ex:• ‘root’@‘localhost’

• ‘’@‘127.0.0.1’

• ‘root’@‘192.168.1.%’

• ‘lig’@’%’




• Ini1al accounts-‐ Superuser (root)


• test database

(con’t)






• test database• Securing the easy way-mysql_secure_installation

(con’t)






• test database• Securing the easy way-mysql_secure_installation

• Hard way

(con’t)



Securing a New InstallaCon in 5.7

58

• Done during data directory installa1on• mysqld --initialize -‐ Secure by default

• Generate random password for `root`@`localhost` account and writes message with it

• Password marked as expired

• mysqld --initialize-insecure-‐ Empty password for `root`@`localhost` account

-‐ Does *NOT* mark password as expired



Securing a New InstallaCon in 5.7

59

• Assigning a new `root`@localhost` password

(con’t)

mysql> ALTER USER ‘root’@‘localhost’ IDENTIFIED BY ‘new-password’;



Access Control

• 2 stages



Access Control

• 2 stages-‐ Stage 1: Connec1ng

• Who are you?

-‐ host

-‐ username



User Accounts

• CREATE USER

• ALTER USER (5.6)

62

mysql> CREATE USER ‘lig’@‘localhost’ IDENTIFIED BY ‘S3cr3t’;

mysql> ALTER USER ‘lig’@‘localhost’ IDENTIFIED BY ‘new-password’;



Access Control


• Who are you?

-‐ host

-‐ username

• Prove it!



Passwords

• Expira1on-‐ Manually (5.6) or with a Policy (5.7)

• Hashing-‐ Mul1ple authen1ca1on plugins available

• Policy-‐ Use Password Valida1on plugin (validate_password)

• cleartext supplied password checked against password policy

• 3 levels of password checking which can be modified



Access Control


• Who are you?

-‐ host

-‐ username

• Prove it!

-‐ Stage 2: Request• For each request

-‐ What are you doing and are you allowed to do that?



GRANT

• Defines privileges and account characteris1cs• Mul1ple privileges-‐ Ex: SUPER, CREATE, ALTER, SELECT, INSERT

• Mul1ple levels-‐ Ex: Global, Database, Table, Column

• Account characteris1cs-‐ Ex: REQUIRE SSL or MAX_QUERIES_PER_HOUR



Sample GRANTSmysql> SHOW GRANTS;+---------------------------------------------------------------------+| Grants for root@localhost |+---------------------------------------------------------------------+| GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' WITH GRANT OPTION || GRANT ALL PRIVILEGES ON `mysql`.* TO 'root'@'localhost' || GRANT PROXY ON ''@'' TO 'root'@'localhost' WITH GRANT OPTION |+---------------------------------------------------------------------+3 rows in set (0.00 sec)

mysql> SHOW GRANTS FOR 'test'@'localhost';+--------------------------------------------------------+| Grants for test@localhost |+--------------------------------------------------------+| GRANT USAGE ON *.* TO 'test'@'localhost' || GRANT ALL PRIVILEGES ON `test`.* TO 'test'@'localhost' |+--------------------------------------------------------+2 rows in set (0.00 sec)



REVOKE

• Removes the privileges GRANTed-‐ Does not extrapolate

• Does not remove the user

• If no host is given-‐ % is used

-‐ Again -‐ Does not extrapolate



REVOKEmysql> SHOW GRANTS FOR 'test'@'localhost';+--------------------------------------------------------+| Grants for test@localhost |+--------------------------------------------------------+| GRANT USAGE ON *.* TO 'test'@'localhost' || GRANT ALL PRIVILEGES ON `test`.* TO 'test'@'localhost' |+--------------------------------------------------------+2 rows in set (0.00 sec)

mysql> REVOKE DELETE ON test.t1 FROM 'test'@'localhost';ERROR 1147 (42000): There is no such grant defined for user 'test' on host 'localhost' on table 't1'

mysql> REVOKE USAGE ON *.* FROM 'test'@'localhost';Query OK, 0 rows affected (0.02 sec)



Backups



Backups Types

• Logical

• Physical

1

2



Logical Backups

• Saved-‐ Logical structure

-‐ Content

• Machine Independent

• Slower• Server Up/Warm

• Full Granularity



mysqldump

• Logical• Commonly used

• Editable text files• Very flexible• Ques1onable scalability



mysqlpump

• Logical• Similar to mysqldump

• Parallel processing to speed up dump process

• Dump user accounts with CREATE USER/GRANT

• Default: I_S, P_S, ndbinfo and SYS not included• Reloading: faster secondary index crea1on for InnoDB



Backup Types

• Logical

• Physical22

1



Physical Backup

• Raw copies• Faster then logical (orders of magnitude)

• Compact

• File based granularity• Usually server is down or locked



Filesystem Snapshot

• Physical• OS Dependent• Basic Steps-FLUSH TABLES WITH READ LOCK

-‐ Take the snapshot

-UNLOCK TABLES

-‐ Copy files from snapshot



MySQL Enterprise Backup

• Official physical backup solu1on

• Mul1-‐plaborm

• “Hot” InnoDB backup• “Warm” backup for other storage engines

• Binlog and Relay log backup• Fast Recovery



MySQL Enterprise Backup

• Features:-‐ Par1al and incremental backups

-‐ Streaming, direct to tape and single file backup

-‐ Throqling and Parallel backup opera1ons

-‐ Compression

-‐ Encryp1on

-‐ Valida1on

-‐ Supports TDE



Monitoring



SHOW

• MySQL specific command

• Commands for

-‐ Metadata

-‐ Status informa1on

• Metric crap-‐ton



Examples

Metadata

SHOW DATABASES SHOW TRIGGERS SHOW PLUGINS

SHOW CREATE PROCEDURE SHOW ENGINES SHOW VARIABLES

SHOW INDEXES SHOW GRANTS SHOW BINARY LOGS

Status

SHOW SLAVE STATUS SHOW OPEN TABLES SHOW RELAYLOG EVENTS

SHOW ENGINE INNODB STATUS

SHOW FULL PROCESSLIST SHOW GLOBAL STATUS



INFORMATION_SCHEMA

• Mostly metadata-PROCESSLIST

-GLOBAL_VARIABLES / GLOBAL_STATUS

-FILES / INNODB_SYS_TABLESPACES / INNODB_SYS_DATAFILES

• But-INNODB_TRX / INNODB_LOCKS / INNODB_LOCK_WAITS

-INNODB_TEMP_TABLE_INFO



SYS SCHEMA

• Included in 5.7.7-‐ Installed by default with --initialize

•Originally known as ps_helper-‐ Originally created by Mark Leith

-‐ hqp://www.markleith.co.uk/ps_helper

-‐ Can work with 5.6 -‐ download from Github• hqps://github.com/mysql/mysql-‐sys

• Easy, human readable access to P_S and I_S info for typical use cases



SYS SCHEMA

•Pair views -‐ Ex: host_summary_by_file_io and x$host_summary_by_file_io

•Example views-‐ statements_with_full_table_scans

-‐ statements_with_runtimes_in_95th_percentile

-‐ io_by_thread_by_latency

-‐ memory_by_user_by_current_bytes

-‐ schema_redundent_indexes-‐



PERFORMANCE_SCHEMA

• Monitors at a low level

• Uses PERFORMANCE_SCHEMA storage engine• Available-‐ Current events

-‐ Event histories / Event summa1ons

• Configura1on is dynamic

• Query using SQL



PERFORMANCE_SCHEMA

• Using the PERFORMANCE_SCHEMA-‐ Manual

• Diagnose Problems -‐ hqps://dev.mysql.com/doc/en/performance-‐schema-‐examples.html

• Query Profiling -‐ hqps://dev.mysql.com/doc/en/performance-‐schema-‐query-‐profiling.html

-‐ Blog posts• Marc Alff’s blog -‐ hqp://marcalff.blogspot.com

• Mark Leith’s blog -‐ hqp://www.markleith.co.uk/

-‐ Many Presenta1ons/Webinars

(con’t)



MySQL Enterprise Monitor -‐ MEM

• Real 1me monitoring-‐ Performance

-‐ Replica1on

-‐ Query analysis

-‐ InnoDB

-‐ Backup

-‐ Disk and OS


Copyright © 2016, Oracle and/or its affiliates. All rights reserved. | 89

MEM -‐ Dashboard



MEM -‐ Query Analysis



MEM -‐ ReplicaCon



Oracle Enterprise Manager for MySQL

• Monitoring of MySQL servers in familiar OEM interface

• Real 1me monitoring-‐ Performance

-‐ Replica1on

-‐ InnoDB

-‐ Metric Collec1on

•Won’t lie -‐ doesn’t do everything MEM does



OEM MySQL -‐ Performance Monitoring



OEM MySQL -‐ Performance Reports



Basic TroubleshooCng



Step 1

• Define the problem• Must know what is “normal”, so you know when it is not -‐ and how much

• Be exact!• Read and understand the manual for the area that is problema1c



Step 2

• Collect the diagnos1c data-‐ OS data

-‐ MySQL data

• May need to collect the diagnos1c data during the problem-‐ Monitoring

-‐ Maybe pt-stalk



Error Log

• First place to look• Can give history and context to any problem.

• Error message(s)



Server Crash

• Error log-‐ Stack trace and error message(s)

• OS error log around the crash 1me

• Any and all diagnos1c data available-‐ MySQL and OS monitoring data (graphs or raw data)

-‐ core file?

• Any informa1on about what was happening before and during the crash-‐ External Scripts running / Applica1ons / Cronjobs / Backups / Etc.



ReplicaCon Issues

• Error log• SHOW MASTER STATUS• my.cnf / my.ini

• SHOW GLOBAL VARIABLES• SHOW SLAVE STATUS



Performance Issues

• Error log • OS data (Ex: IO, CPU, Memory, NUMA, etc.)

• SHOW GLOBAL VARIABLES• SHOW GLOBAL STATUS• SHOW FULL PROCESSLIST• SHOW ENGINE INNODB STATUS• Informa1on from PERFORMANCE_SCHEMA



Query Performance Issues

• Error log• Slow Query Log• EXPLAIN • SHOW CREATE TABLE• SHOW TABLE STATUS• SHOW INDEXES• Profile the query



QuesCons?


Copyright © 2016, Oracle and/or its affiliates. All rights reserved. | 104Monday, September 19, 16

Copyright © 2016, Oracle and/or its affiliates. All rights reserved. | 105Monday, September 19, 16


A MySQL DBA Primer

Ligaya Turmelle

Principal Technical Support Engineer -‐ MySQL

[email protected]

@lig

, Oracle and/or its affiliates. All rights reserved. | 106Monday, September 19, 16



Documents

Oracle SupportStars’ Bar - RainFocusfk_rental_inventory`; Query OK, 0 rows affected (0.25 sec) ... Copyright©*2016,*Oracle*and/or*its*aﬃliates.*All*rights*reserved.**| Example*mysqldumpslow*output

Oracle SupportStars’ Bar - RainFocusfk_rental_inventory`; Query OK, 0 rows affected (0.25 sec) ... Copyright©2016,Oracleand/oritsaﬃliates.Allrightsreserved.**| Examplemysqldumpslowoutput