MySQL's Performance Schema, SYS Schema and Workbench Integration

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Mario Beck

MySQL Sales Consulting Manager EMEA

[email protected]

Performance Schema & SYS schema


Program Agenda

What is Performance Schema?

Profiling Examples

Improvements made to date in MySQL 5.7

The MySQL SYS Schema

Easy to Use with MySQL Workbench


What is Performance Schema?


What is Performance Schema anyway?

A storage engine, built for recording instrumentation – PERFORMANCE_SCHEMA

A database schema to expose the instrumentation – performance_schema

Records latency of events that happen within the server

All latency exposed to picosecond

Also tracks other information as appropriate

- Bytes, source position, object metadata, etc.


Performance Schema in MySQL 5.5

17 Tables

222 Instruments

Instrument Event Class

File IO wait/io/file/%

Mutexes wait/synch/mutex/%

Read/Write Locks wait/synch/rwlock/%

Conditions wait/synch/cond/%


Wait Events mysql> select * from events_waits_history_long where

event_name like 'wait/io/table/%'\G

*************************** 1. row ***************************

THREAD_ID: 137746

EVENT_ID: 3604

END_EVENT_ID: 3604

EVENT_NAME: wait/io/table/sql/handler

SOURCE: handler.cc:2568

TIMER_START: 17101711846046490

TIMER_END: 17101711857643010

TIMER_WAIT: 11596520

SPINS: NULL

OBJECT_SCHEMA: mem__events

OBJECT_NAME: events

INDEX_NAME: PRIMARY

OBJECT_TYPE: TABLE

OBJECT_INSTANCE_BEGIN: 140246283168288

NESTING_EVENT_ID: 3603

NESTING_EVENT_TYPE: STAGE

OPERATION: fetch

NUMBER_OF_BYTES: NULL

FLAGS: NULL

Event Context

Event type and origin

Timing (~11.5 microseconds)

Database object info

Object type

Whether the event was nested

Further info as appropriate


Performance Schema in MySQL 5.6

52 Tables (+35)

545 Instruments (+323)

Instrument Type Event Class

Statements statement/%

Stages stage/%

Table IO wait/io/table/%

Table Locks wait/lock/table/%

Network IO wait/io/socket/%

Idle Timing idle


Statement Events

mysql> select * from events_statements_history_long limit 1\G

*************************** 1. row ***************************

THREAD_ID: 138683

EVENT_ID: 11268

END_EVENT_ID: 11295

EVENT_NAME: statement/sql/update

SOURCE: socket_connection.cc:94

TIMER_START: 87644080265364000

TIMER_END: 87644080504810000

TIMER_WAIT: 239446000

LOCK_TIME: 63000000

SQL_TEXT: /* mem dbpool.default */ update

`mem__inventory`.`Agent` set `hasHostname`=1400665852927,

`hasReachable`=1400665852927, `timestamp`=1400665852927,

`hasVersion`=1400665852927 where hid=x'FA8FDC4C1BC344A0899DAB320757CDF2'

DIGEST: cc389abfcb093ae95cacfe42ed085191

DIGEST_TEXT: UPDATE `mem__inventory` . `Agent` SET `hasHostname` = ?

, `hasReachable` = ? , `timestamp` = ? , `hasVersion` = ? WHERE `hid` = ?

CURRENT_SCHEMA: mem

OBJECT_TYPE: NULL

OBJECT_SCHEMA: NULL

OBJECT_NAME: NULL

OBJECT_INSTANCE_BEGIN: NULL

…………

MYSQL_ERRNO: 0

RETURNED_SQLSTATE: 00000

MESSAGE_TEXT: Rows matched: 1 Changed: 1 Warnings: 0

ERRORS: 0

WARNINGS: 0

ROWS_AFFECTED: 1

ROWS_SENT: 0

ROWS_EXAMINED: 1

CREATED_TMP_DISK_TABLES: 0

CREATED_TMP_TABLES: 0

SELECT_FULL_JOIN: 0

SELECT_FULL_RANGE_JOIN: 0

SELECT_RANGE: 0

SELECT_RANGE_CHECK: 0

SELECT_SCAN: 0

SORT_MERGE_PASSES: 0

SORT_RANGE: 0

SORT_ROWS: 0

SORT_SCAN: 0

NO_INDEX_USED: 0

NO_GOOD_INDEX_USED: 0


NESTING_EVENT_TYPE: TRANSACTION

NESTING_EVENT_LEVEL: 0

Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |

Stored Programs

Transactions

9

Nested Events

Statements

Stages

Waits MySQL 5.5

MySQL 5.6

MySQL 5.7

mysql> select * from events_waits_history_long

******************** 1. row ********************

...

EVENT_NAME: wait/io/table/sql/handler

...


NESTING_EVENT_TYPE: STAGE


0

Performance Schema Table Types

Setup Tables

Used to define certain configuration dynamically

Can perform DML against these tables

mysql> select table_name

-> from information_schema.tables

-> where table_schema like 'perf%'

-> and table_name like 'setup%';

+-------------------+

| table_name |

+-------------------+

| setup_actors |

| setup_consumers |

| setup_instruments |

| setup_objects |

| setup_timers |

+-------------------+


1


Raw Data Tables

Expose events, objects, or instances of instruments in a raw manner

Allow seeing a (brief) history of raw event metrics as well

+-------------------------------------------+

| table_name |

+-------------------------------------------+

| accounts |

| cond_instances |

| events_stages_current |

| events_stages_history |

| events_stages_history_long |

| events_statements_current |

| events_statements_history |

| events_statements_history_long |

| events_waits_current |

| events_waits_history |

| events_waits_history_long |

| file_instances |

| host_cache |

| hosts |

| mutex_instances |

| performance_timers |

| rwlock_instances |

| session_account_connect_attrs |

| session_connect_attrs |

| socket_instances |

| threads |

| users |

+-------------------------------------------+


2


Summary Tables

Summarise event information over multiple dimensions

Useful for longer term monitoring of activity

+------------------------------------------------------+

| table_name |

+------------------------------------------------------+

| events_stages_summary_by_account_by_event_name |

| events_stages_summary_by_host_by_event_name |

| events_stages_summary_by_thread_by_event_name |

| events_stages_summary_by_user_by_event_name |

| events_stages_summary_global_by_event_name |

| events_statements_summary_by_account_by_event_name |

| events_statements_summary_by_digest |

| events_statements_summary_by_host_by_event_name |

| events_statements_summary_by_program |

| events_statements_summary_by_thread_by_event_name |

| events_statements_summary_by_user_by_event_name |

| events_statements_summary_global_by_event_name |

| events_waits_summary_by_account_by_event_name |

| events_waits_summary_by_host_by_event_name |

| events_waits_summary_by_instance |

| events_waits_summary_by_thread_by_event_name |

| events_waits_summary_by_user_by_event_name |

| events_waits_summary_global_by_event_name |

| file_summary_by_event_name |

| file_summary_by_instance |

| objects_summary_global_by_type |

| socket_summary_by_event_name |

| socket_summary_by_instance |

| table_io_waits_summary_by_index_usage |

| table_io_waits_summary_by_table |

| table_lock_waits_summary_by_table |

+------------------------------------------------------+


Performance Schema Configuration

Configure Description

Variables like “perf%” Fixed RAM allocation, fixed size

Status like “perf%lost” Lost events due to too low buffers

Table “setup_instruments” Turn on/off individual instruments

Table “setup_consumers” Configure history / summary tables

Table “setup_objects” Filter events by table/schema

Table “setup_actors” Filter events by user/host


4

Profiling Examples


Analyzing Global Waits

Some mutex events that can affect global concurrency (if high in list): wait/synch/mutex/innodb/buf_pool_mutex

Increase innodb_buffer_pool_instances

wait/synch/mutex/sql/Query_cache::structure_guard_mutex

Look in to disabling the Query Cache

wait/synch/mutex/myisam/MYISAM_SHARE::intern_lock

Use Innodb …


Analyzing Global Waits

Some File IO events to watch for (if high in list): wait/io/file/sql/FRM

Tune table_open_cache / table_definition_cache

wait/io/file/sql/file_parser (view definition parsing)

If high on 5.5, upgrade to 5.6, (which can cache these like tables)

wait/io/file/sql/query_log and wait/io/file/sql/slow_log

Disable the general

Disable or tune what is logged to the slow log (decent long_query_time)


Slave SQL Load Average

Watch wait/synch/cond/sql/MYSQL_RELAY_LOG::update_cond http://www.markleith.co.uk/2012/07/24/a-mysql-replication-load-average-with-performance-schema/


Currently Executing Statements

SELECT_FULL_JOIN: 0

SELECT_FULL_RANGE_JOIN: 0

SELECT_RANGE: 1

SELECT_RANGE_CHECK: 0

SELECT_SCAN: 0

SORT_MERGE_PASSES: 0

SORT_RANGE: 0

SORT_ROWS: 0

SORT_SCAN: 0

NO_INDEX_USED: 0

NO_GOOD_INDEX_USED: 0

NESTING_EVENT_ID: NULL

NESTING_EVENT_TYPE: NULL

NESTING_EVENT_LEVEL: 0

mysql> select * from events_statements_current where timer_end is null\G

*************************** 8. row ***************************

THREAD_ID: 156945

EVENT_ID: 15312

END_EVENT_ID: NULL

EVENT_NAME: statement/sql/select

SOURCE: socket_connection.cc:94

TIMER_START: 99343994725205000

TIMER_END: NULL

TIMER_WAIT: NULL

LOCK_TIME: 145000000

SQL_TEXT: /* mem dbpool.ui */ select normalized0_.round_robin_bin as round1_1256_, /* ..snip .. */

DIGEST: NULL

DIGEST_TEXT: NULL

CURRENT_SCHEMA: mem

OBJECT_TYPE: NULL

OBJECT_SCHEMA: NULL

OBJECT_NAME: NULL

OBJECT_INSTANCE_BEGIN: NULL

MYSQL_ERRNO: 0

RETURNED_SQLSTATE: NULL

MESSAGE_TEXT: NULL

ERRORS: 0

WARNINGS: 0

ROWS_AFFECTED: 0

ROWS_SENT: 27

ROWS_EXAMINED: 0

CREATED_TMP_DISK_TABLES: 0

CREATED_TMP_TABLES: 0

All counters are live, and increment whilst the statements

execute


9

Improvements made to date in MySQL 5.7


Insert Picture Here

20

Memory Usage

Metadata Locking

Replication Configuration & Status

Prepared Statements

Transactions

Stored Programs


1

Instrument memory usage - thread details

mysql> SELECT event_name,

-> sys.format_bytes(current_number_of_bytes_used) AS current_used

-> FROM performance_schema.memory_summary_by_thread_by_event_name

-> WHERE thread_id = 24

-> ORDER BY current_number_of_bytes_used DESC;

+-----------------------------------------------------+--------------+

| event_name | current_used |

+-----------------------------------------------------+--------------+

| memory/sql/Filesort_buffer::sort_keys | 255.94 KiB |

| memory/sql/sp_head::main_mem_root | 103.64 KiB |

| memory/mysys/IO_CACHE | 64.05 KiB |

| memory/mysys/lf_dynarray | 46.17 KiB |

| memory/mysys/array_buffer | 24.20 KiB |

| memory/sql/thd::main_mem_root | 23.95 KiB |

| memory/sql/String::value | 16.13 KiB |

| memory/sql/TABLE | 9.44 KiB |

| memory/sql/TABLE_SHARE::mem_root | 8.70 KiB |

| memory/myisam/MI_INFO | 7.07 KiB |

| memory/sql/THD::transactions::mem_root | 4.02 KiB |


2

The MySQL SYS Schema


MySQL SYS Schema Overview

Originally called “ps_helper”

Started as a collection of views, procedures and functions, designed to make reading raw Performance Schema data easier

Implements many of the common DBA and Developer use cases, including many of those shown already

Now bundled within MySQL Workbench 6.1

Available on GitHub

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






4

User Summary Views

High level user overview

Breakdowns of IO usage

Drill in to stages per user

Drill in to statement details per user

mysql> show tables like 'user%';

+-----------------------------------+

| Tables_in_sys (user%) |

+-----------------------------------+

| user_summary |

| user_summary_by_file_io |

| user_summary_by_file_io_type |

| user_summary_by_stages |

| user_summary_by_statement_latency |

| user_summary_by_statement_type |

+-----------------------------------+


5

IO Summary Views

IO breakdown by thread

Global summaries by file and wait class, by both bytes and latency

Stream of last raw file IO stats

mysql> show tables like 'io_%';

+------------------------------+

| Tables_in_sys (io_%) |

+------------------------------+

| io_by_thread_by_latency |

| io_global_by_file_by_bytes |

| io_global_by_file_by_latency |

| io_global_by_wait_by_bytes |

| io_global_by_wait_by_latency |

| latest_file_io |

+------------------------------+


6

Schema Analysis Views

Object overview

Table usage stats

Index usage stats

mysql> show tables like 'schema%';

+-------------------------------------+

| Tables_in_sys (schema%) |

+-------------------------------------+

| schema_index_statistics |

| schema_object_overview |

| schema_table_statistics |

| schema_table_statistics_with_buffer |

| schema_tables_with_full_table_scans |

| schema_unused_indexes |

+-------------------------------------+


7

InnoDB Buffer Usage Views

Buffer usage by schema

Buffer usage by table

mysql> show tables like 'innodb%';

+-------------------------------+

| Tables_in_sys (innodb%) |

+-------------------------------+

| innodb_buffer_stats_by_schema |

| innodb_buffer_stats_by_table |

+-------------------------------+


8

Statement Analysis Views

Statement overview

Find statements by errors, full scans, sorting, temporary tables

Find the statements with the longest runtimes

mysql> show tables like 'statement%';

+---------------------------------------------+

| Tables_in_sys (statement%) |

+---------------------------------------------+

| statement_analysis |

| statements_with_errors_or_warnings |

| statements_with_full_table_scans |

| statements_with_runtimes_in_95th_percentile |

| statements_with_sorting |

| statements_with_temp_tables |

+---------------------------------------------+


9

Wait summaries by class and per instrument globally

Wait details per user

mysql> show tables like 'wait%';

+------------------------------------+

| Tables_in_sys (wait%) |

+------------------------------------+

| wait_classes_global_by_avg_latency |

| wait_classes_global_by_latency |

| waits_by_user_by_latency |

| waits_global_by_latency |

+------------------------------------+

Wait Analysis Views


0

Easy to use with MySQL Workbench


MySQL Workbench Overview Design, Develop, Administer, Migrate And now adding – Performance

• MySQL Database IDE

• Millions of Users

• Millions of Downloads

• Windows, OS X, Linux


Performance Schema Reports

• Connect

• (DB Click or Open and Connect)

• Go to Management Tab

• If needed (Bottom Left)

• Go to Performance Reports

• New Performance Section


New Screen – Performance Schema Setup

YES – its on NO – its off Advanced – for power users


Open Settings Before Running Performance Reports


First Run – Install SYS Schema


SYS now Added

• No Tables

• Only

• Views

• SPs

• Functions

• Operates on

• Performance Schema

• Information Schema


sys.<table> versus sys.x$<table>

• Providing 2 options

• One is easy

• To read in a query

• Other (x$) is easier

• To compare

• To Export to spreadsheet

• To Graph

• To consume in code


SYS - SPs and Functions

SPs Used to simplify management

FUNCTIONS Used for Formatting and Simple Checks


Many WB Performance Reports

• WB wrappers many SYS views

• If we’ve missed a needed report or view

• Let us know

• Happy to add more

• Even if not performance related

• Could go in an Inspector


General Lay Out - Header Title and Brief Description

Sortable Columns

Column Labels indicate Units


General Lay Out – Footer


Reports #1: IO Reports

• For

– Files, Event Categories, User/Thread

• Quickly

– View, Sort

– By #, Time, Reads, Writes, Percentages

• Look for Hot Spots

– Use to determine system requirements, tuning, etc.


Reports #2: High Cost SQL Statements

• Look at query statements and statistics

• Look for Full Table Scans

• Frequency of execution

• Errors, Warnings

• Long Runtimes – Total, Max, Ave

• Large numbers of Rows – Total, Max, Ave

• Usage of Temp Tables


Reports #3: Database Schema Statistics

• Quickly Review Various Stats

– Counts

– Rows

– Timing

– Paging

– Buffering

– IOs

• Easily find Full Scans

• Spot Unused Indexes

• Also See Schema/Table Inspectors

– Table, Column, Index,… Statis


Reports #5: Wait Event Times (For Experts)

• Wait Event Analysis is Complex

• However for power expert users

– These reports show collected data

– Show the queries used to collect

– Provides Statistics

– Breaks out events by Users and Classes


Reports #6: InnoDB Statistics

• Quick views

– Aggregated • By Schema

• By Table

– Easy to sort by • Allocation, Data,

• Pages, Pages hashed, Old Pages

• Rows cached


Quick Links

• Download:

–http://dev.mysql.com/downloads/tools/workbench/

• Bugs:

–http://bugs.mysql.com

• Forums:

–http://forums.mysql.com/index.php?151

http://dev.mysql.com/downloads/tools/workbench/

http://bugs.mysql.com/

http://forums.mysql.com/index.php?151


Supporting Resources

• Oracle and MySQL

• MySQL

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• Team Blog

–https://blogs.oracle.com/mysqlworkbench/

• MySQL Community Edition

• MySQL Enterprise Edition

• MySQL Blog, Twitter, Facebook

• Optimizer Blog

–http://oysteing.blogspot.co.uk/

http://www.oracle.com/us/products/mysql/index.html

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Technology

MySQL's Performance Schema, SYS Schema and Workbench Integration