MySQL Performance Schema and SYS Schema

Copyright © 2014, Oracle and/or its affiliates. All rights reserved.Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Insert Information Protection Policy Classification from Slide 12!1

Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Insert Information Protection Policy Classification from Slide 12!2
MySQL Tech Day, Paris
Performance Schema & MySQL sys
Mark Leith 
Senior Software Development Manager
MySQL @ Oracle

Copyright © 2014, Oracle and/or its affiliates. All rights reserved.!3
Program Agenda
▪ What is Performance Schema anyway?
▪ Performance Schema Configuration
▪ Profiling General Instance Activity
▪ Profiling Statement Activity
▪ Improvements made to date in MySQL 5.7
▪ The MySQL SYS Schema
▪ Things still to come

Know Your Audience
▪ Using 5.1 (yes, still)?
▪ Using 5.5 (but I’ll upgrade soon, honest)?
▪ Using 5.6?
▪ Using … 5.7?
▪ Used Performance Schema?
▪ #monitoringlove
▪ #monitoringhate

What is Performance Schema anyway?

▪ Introduced in MySQL 5.5
▪ A storage engine, built for recording instrumentation
– PERFORMANCE_SCHEMA
– Manages fixed buffers in memory with lock free hashes
– Real engine, unlike INFORMATION_SCHEMA
▪ A database schema to expose the instrumentation
– performance_schema
▪ A set of interfaces in the MySQL Server wrapping calls to trace
– i.e. pthread_mutex_lock() -> mysql_mutex_lock()

▪ Records latency of events that happen within the server
▪ All latency exposed to picosecond (a trillionth of a second) precision
▪ Though may be tracked at different precisions internally
▪ 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/%

▪ Laid out the framework for instrumentation
▪ Focused early on low level instruments
– Prove it could handle load, build from ground up
▪ Not turned on by default, had some overhead issues

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

▪ Fixed lots of performance issues
▪ Focused on bringing the instrumentation to the DBA / Developer
▪ Statements / Statement Digests
▪ Execution Stages
▪ Object tracking (table / index IO, table locks)
▪ Network IO
▪ Turned on by default, with a subset of instrumentation disabled

▪ 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

“I really think Performance Schema overhead is reasonable for most
workloads. …
On my old server I got some 20.2K QPS with Performance Schema
Disabled and 19.4 QPS with Performance Schema enabled which is
overhead of less than 5%.
For most workloads paying 5% to have insight about what is
happening with the system is a very fair trade.”
▪ Peter Zaitsev, CEO, Percona
http://www.mysqlperformanceblog.com/2014/02/11/performance_schema-vs-slow-query-log/

Statement & Stage Events (5.6)
!
▪ Statements have two types of event
▪ SQL Statements statement/sql/%
▪ Protocol Commands statement/com/%
▪ Stages are the thread states. Like SHOW PROFILE output, but
available across connections
▪ Mostly one form stage/sql/%
▪ Apart from .. stage/mysys/Waiting for table level lock

Stage Events
mysql> select * from events_stages_history limit 2G!
*************************** 1. row ***************************!
THREAD_ID: 23!
EVENT_ID: 18898!
END_EVENT_ID: 18898!
EVENT_NAME: stage/sql/Master has sent all binlog to slave; waiting for more updates!
SOURCE: rpl_binlog_sender.cc:420!
TIMER_START: 87465041640516000!
TIMER_END: 87465045562629000!
TIMER_WAIT: 3922113000!
NESTING_EVENT_TYPE: STATEMENT!
*************************** 2. row ***************************!
THREAD_ID: 23!
EVENT_ID: 18899!
EVENT_NAME: stage/sql/Sending binlog event to slave!
SOURCE: rpl_binlog_sender.cc:432!
TIMER_START: 87465045562629000!
TIMER_END: 87465045593812000!
NESTING_EVENT_TYPE: STATEMENT

Statement Events
mysql> select * from events_statements_history_long limit 1G!
*************************** 1. row ***************************!
THREAD_ID: 138683!
EVENT_ID: 11268!
EVENT_NAME: statement/sql/update!
SOURCE: socket_connection.cc:94!
TIMER_START: 87644080265364000!
TIMER_END: 87644080504810000!
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!
…………

Statement Events (cont.)
mysql> select * from events_statements_history_long limit 1G!
*************************** 1. row ***************************!
……!
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

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 |!
+-------------------+

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 |!
+-------------------------------------------+

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

Performance Schema Configuration
▪ There are three distinct types of configuration
▪ A way to configure how much memory to allocate for instruments
▪ Set with various system variables in options files, not dynamic
▪ A way to enable/disable instrumentation at startup
▪ Again set with options files, only available as of 5.6
▪ A way to enable/disable instrumentation dynamically
▪ Set by updating the various setup_% tables dynamically

Performance Configuration
History / Summary Size
▪ Define total rows per type
▪ The %_history_size are per-thread
▪ The %_history_long_size are total
rows
▪ Only settable in my.[cnf|ini]
mysql> select variable_name,!
-> variable_value!
-> from information_schema.global_variables!
-> where variable_name like 'perf%'!
-> and variable_name not like '%instances'!
-> and variable_name not like '%classes'!
-> order by variable_name;!
+--------------------------------------------------------+----------------
| variable_name | variable_value
+--------------------------------------------------------+----------------
| PERFORMANCE_SCHEMA | ON
| PERFORMANCE_SCHEMA_ACCOUNTS_SIZE | 100
| PERFORMANCE_SCHEMA_DIGESTS_SIZE | 5000
| PERFORMANCE_SCHEMA_EVENTS_STAGES_HISTORY_LONG_SIZE | 1000
| PERFORMANCE_SCHEMA_EVENTS_STAGES_HISTORY_SIZE | 10
| PERFORMANCE_SCHEMA_EVENTS_STATEMENTS_HISTORY_LONG_SIZE | 1000
| PERFORMANCE_SCHEMA_EVENTS_STATEMENTS_HISTORY_SIZE | 10
| PERFORMANCE_SCHEMA_EVENTS_WAITS_HISTORY_LONG_SIZE | 1000
| PERFORMANCE_SCHEMA_EVENTS_WAITS_HISTORY_SIZE | 10
| PERFORMANCE_SCHEMA_HOSTS_SIZE | 100
| PERFORMANCE_SCHEMA_MAX_FILE_HANDLES | 32768
| PERFORMANCE_SCHEMA_MAX_TABLE_HANDLES | 732
| PERFORMANCE_SCHEMA_SESSION_CONNECT_ATTRS_SIZE | 512
| PERFORMANCE_SCHEMA_SETUP_ACTORS_SIZE | 100
| PERFORMANCE_SCHEMA_SETUP_OBJECTS_SIZE | 100
| PERFORMANCE_SCHEMA_USERS_SIZE | 100
+--------------------------------------------------------+----------------

Max Classes / Instances
▪ Classes count instrument
implementations, i.e:
▪ “wait/io/file/sql/binlog”
▪ Instances are the different runtime
instances of those things, i.e:
▪ “/data/logs/binlog.000123”
mysql> select variable_name, variable_value!
-> from information_schema.global_variables!
-> where variable_name like 'perf%classes'!
-> or variable_name like 'perf%instances'!
+------------------------------------------------------+----------------+!
| variable_name | variable_value |!
+------------------------------------------------------+----------------+!
| PERFORMANCE_SCHEMA_MAX_COND_CLASSES | 80 |!
| PERFORMANCE_SCHEMA_MAX_COND_INSTANCES | 946 |!
| PERFORMANCE_SCHEMA_MAX_FILE_CLASSES | 50 |!
| PERFORMANCE_SCHEMA_MAX_FILE_INSTANCES | 2170 |!
| PERFORMANCE_SCHEMA_MAX_MUTEX_CLASSES | 200 |!
| PERFORMANCE_SCHEMA_MAX_MUTEX_INSTANCES | 4586 |!
| PERFORMANCE_SCHEMA_MAX_RWLOCK_CLASSES | 40 |!
| PERFORMANCE_SCHEMA_MAX_RWLOCK_INSTANCES | 3283 |!
| PERFORMANCE_SCHEMA_MAX_SOCKET_CLASSES | 10 |!
| PERFORMANCE_SCHEMA_MAX_SOCKET_INSTANCES | 86 |!
| PERFORMANCE_SCHEMA_MAX_STAGE_CLASSES | 150 |!
| PERFORMANCE_SCHEMA_MAX_STATEMENT_CLASSES | 189 |!
| PERFORMANCE_SCHEMA_MAX_TABLE_INSTANCES | 569 |!
| PERFORMANCE_SCHEMA_MAX_THREAD_CLASSES | 50 |!
| PERFORMANCE_SCHEMA_MAX_THREAD_INSTANCES | 143 |!
+------------------------------------------------------+----------------+

Max Classes / Instances
▪ Monitor the %_lost status variables
opposite to see whether these
need tweaking
▪ You will generally not need to
modify classes, only when loading
new plugins
mysql> select variable_name, variable_value!
-> from information_schema.global_status!
-> where variable_name like 'perf%classes_lost'!
-> or variable_name like 'perf%instances_lost'!
+-------------------------------------------+----------------+!
| variable_name | variable_value |!
+-------------------------------------------+----------------+!
| PERFORMANCE_SCHEMA_COND_CLASSES_LOST | 0 |!
| PERFORMANCE_SCHEMA_COND_INSTANCES_LOST | 0 |!
| PERFORMANCE_SCHEMA_FILE_CLASSES_LOST | 0 |!
| PERFORMANCE_SCHEMA_FILE_INSTANCES_LOST | 0 |!
| PERFORMANCE_SCHEMA_MUTEX_CLASSES_LOST | 0 |!
| PERFORMANCE_SCHEMA_MUTEX_INSTANCES_LOST | 0 |!
| PERFORMANCE_SCHEMA_RWLOCK_CLASSES_LOST | 0 |!
| PERFORMANCE_SCHEMA_RWLOCK_INSTANCES_LOST | 0 |!
| PERFORMANCE_SCHEMA_SOCKET_CLASSES_LOST | 0 |!
| PERFORMANCE_SCHEMA_SOCKET_INSTANCES_LOST | 0 |!
| PERFORMANCE_SCHEMA_STAGE_CLASSES_LOST | 0 |!
| PERFORMANCE_SCHEMA_STATEMENT_CLASSES_LOST | 0 |!
| PERFORMANCE_SCHEMA_TABLE_INSTANCES_LOST | 0 |!
| PERFORMANCE_SCHEMA_THREAD_CLASSES_LOST | 0 |!
| PERFORMANCE_SCHEMA_THREAD_INSTANCES_LOST | 0 |!
+-------------------------------------------+----------------+

setup_instruments
▪ Turn on/off individual instruments,
or whether to just count and not
time events
▪ Use UPDATE to modify
dynamically
mysql> select * from setup_instruments limit 5;!
+-------------------------------------------------------+---------+-------
| NAME | ENABLED | TIMED
+-------------------------------------------------------+---------+-------
| wait/synch/mutex/sql/TC_LOG_MMAP::LOCK_tc | NO | NO
| wait/synch/mutex/sql/LOCK_des_key_file | NO | NO
| wait/synch/mutex/sql/MYSQL_BIN_LOG::LOCK_commit | NO | NO
| wait/synch/mutex/sql/MYSQL_BIN_LOG::LOCK_commit_queue | NO | NO
| wait/synch/mutex/sql/MYSQL_BIN_LOG::LOCK_done | NO | NO
+-------------------------------------------------------+---------+-------
5 rows in set (0.00 sec)!
!mysql> update setup_instruments!
-> set enabled = 'yes', timed = 'yes'!
-> where name like '%MYSQL_BIN_LOG%';!
Query OK, 16 rows affected (0.00 sec)!
Rows matched: 16 Changed: 16 Warnings: 0!
!mysql> select * from setup_instruments limit 5;!
+-------------------------------------------------------+---------+-------
| NAME | ENABLED | TIMED
+-------------------------------------------------------+---------+-------
| wait/synch/mutex/sql/TC_LOG_MMAP::LOCK_tc | NO | NO
| wait/synch/mutex/sql/LOCK_des_key_file | NO | NO
| wait/synch/mutex/sql/MYSQL_BIN_LOG::LOCK_commit | YES | YES
| wait/synch/mutex/sql/MYSQL_BIN_LOG::LOCK_commit_queue | YES | YES
| wait/synch/mutex/sql/MYSQL_BIN_LOG::LOCK_done | YES | YES
+-------------------------------------------------------+---------+-------

setup_consumers
▪ Define how much to record, either
in history, or summaries (by
enabling the %_current for the
class of event)
mysql> select * from setup_consumers;!
+----------------------------------+---------+!
| NAME | ENABLED |!
+----------------------------------+---------+!
| events_stages_current | NO |!
| events_stages_history | NO |!
| events_stages_history_long | NO |!
| events_statements_current | YES |!
| events_statements_history | NO |!
| events_statements_history_long | NO |!
| events_transactions_current | NO |!
| events_transactions_history | NO |!
| events_transactions_history_long | NO |!
| events_waits_current | NO |!
| events_waits_history | NO |!
| events_waits_history_long | NO |!
| global_instrumentation | YES |!
| thread_instrumentation | YES |!
| statements_digest | YES |!
+----------------------------------+---------+

Performance Schema Consumer Hierarchy

setup_objects (5.6)
▪ Define exactly which database
objects to monitor
▪ Filters standard databases by
default
▪ Allows explicit enable/disable,
matches on most specific
mysql> select * from setup_objects;!
+-------------+--------------------+-------------+---------+-------+!
| OBJECT_TYPE | OBJECT_SCHEMA | OBJECT_NAME | ENABLED | TIMED |!
+-------------+--------------------+-------------+---------+-------+!
| TABLE | mysql | % | NO | NO |!
| TABLE | performance_schema | % | NO | NO |!
| TABLE | information_schema | % | NO | NO |!
| TABLE | % | % | YES | YES |!
+-------------+--------------------+-------------+---------+-------+!
!mysql> insert into setup_objects!
-> values ('TABLE', 'foo', 'bar', 'no', 'no');!
Query OK, 1 row affected (0.01 sec)!
!mysql> select * from setup_objects;!
+-------------+--------------------+-------------+---------+-------+!
| OBJECT_TYPE | OBJECT_SCHEMA | OBJECT_NAME | ENABLED | TIMED |!
+-------------+--------------------+-------------+---------+-------+!
| TABLE | mysql | % | NO | NO |!
| TABLE | performance_schema | % | NO | NO |!
| TABLE | information_schema | % | NO | NO |!
| TABLE | % | % | YES | YES |!
| TABLE | foo | bar | NO | NO |!
+-------------+--------------------+-------------+---------+-------+

setup_actors (5.6)
▪ Define exactly which users to
monitor
▪ By default monitors all connections
(% is wildcard)
▪ Modifications only apply to new
connections
mysql> select * from setup_actors;!
+------+------+------+!
| HOST | USER | ROLE |!
+------+------+------+!
| % | % | % |!
+------+------+------+!
1 row in set (0.00 sec)!
!
mysql> delete from setup_actors;!
!
mysql> insert into setup_actors!
-> values ('%', 'mark', '%');!
!
mysql> select * from setup_actors;!
+------+------+------+!
| HOST | USER | ROLE |!
+------+------+------+!
| % | mark | % |!
+------+------+------+!
1 row in set (0.00 sec)

Performance Schema Options Files Config
▪ As of 5.6, allows altering configuration at start up
▪ Enabling / disabling instrumentation
▪ performance_schema_instrument = ‘instrument_name=value’
▪ Value = [on|1|true] | [off|0|false] | counted
▪ instrument_name can have wildcards (‘wait/synch/mutex/%=off’)
▪ Enabling / disabling consumers
▪ performance_schema_consumer_consumer_name=value
▪ Value = [on|1|true] | [off|0|false]

Profiling General Instance Activity

Profiling Considerations
▪ It is easy to just enable everything, but there are overhead concerns
▪ On busy systems mutexes can be locked millions of times per second
▪ It is best to just pick higher latency event types
▪ Statements, Stages, Table IO, File IO, maybe Network IO
▪ It is good to enable all %_current consumers, and statement history
▪ For concurrency/profiling debugging toggle other instruments on an
as needed basis

Profiling Types
▪ Once you’ve narrowed down what you’re interested in, there are two
ways to start monitoring
▪ View raw data in the summary views
▪ Gives you an overall picture of usage on the instance
▪ Snapshot data, and compute deltas over time
▪ Gives you an idea of the rates of change for the events

Analyzing Global Waits
▪ Some waits can include other waits
▪ Table IO latency may also include some mutex and file IO latency
▪ Wait times include concurrency across all threads
▪ Do not assume you can sum all events in global tables and compare
to wall clock times

Top Waits By Latency
mysql> select event_name,!
-> count_star as count,!
-> sys.format_time(sum_timer_wait) as total_latency,!
-> sys.format_time(avg_timer_wait) as avg_latency,!
-> sys.format_time(max_timer_wait) as max_latency!
-> from events_waits_summary_global_by_event_name!
-> where event_name != 'idle'!
-> order by sum_timer_wait desc limit 5;!
+--------------------------------------+----------+---------------+-------------+-------------+!
| event_name | count | total_latency | avg_latency | max_latency |!
+--------------------------------------+----------+---------------+-------------+-------------+!
| wait/io/table/sql/handler | 21888502 | 1.27h | 208.06 us | 2.21 s |!
| wait/io/file/innodb/innodb_data_file | 4276800 | 00:48:12.49 | 676.32 us | 1.49 s |!
| wait/io/file/innodb/innodb_log_file | 1948199 | 00:25:24.36 | 782.45 us | 1.30 s |!
| wait/io/file/myisam/kfile | 4566406 | 00:13:45.92 | 180.87 us | 1.17 s |!
| wait/io/file/myisam/dfile | 1277589 | 00:05:46.23 | 271.01 us | 1.18 s |!
+--------------------------------------+----------+---------------+-------------+-------------+

▪ 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 …

▪ 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)

Top Files By Total IO
mysql> select sys.format_path(file_name) as file,!
-> count_read,!
-> sys.format_bytes(sum_number_of_bytes_read) as total_read,!
-> sys.format_bytes(IFNULL(sum_number_of_bytes_read / count_read, 0)) as avg_read,!
-> count_write,!
-> sys.format_bytes(sum_number_of_bytes_write) as total_written,!
-> sys.format_bytes(IFNULL(sum_number_of_bytes_write / count_write, 0)) as avg_write,!
-> sys.format_bytes(sum_number_of_bytes_read + sum_number_of_bytes_write) as total,!
-> IFNULL(ROUND(100-((sum_number_of_bytes_read/(sum_number_of_bytes_read + sum_number_of_bytes_write))*100), 2), 0.00) as write_pct!
-> from file_summary_by_instance!
-> order by (sum_number_of_bytes_read + sum_number_of_bytes_write) desc limit 5;!
+----------------------------------+------------+------------+-----------+-------------+---------------+-----------+-------------+-----------+
| file | count_read | total_read | avg_read | count_write | total_written | avg_write | total | write_pct |
+----------------------------------+------------+------------+-----------+-------------+---------------+-----------+-------------+-----------+
| @@datadir/ibdata1 | 888 | 15.84 MiB | 18.27 KiB | 1089824 | 61.99 GiB | 59.64 KiB | 62.00 GiB | 99.98 |
| @@datadir/mem__events/events.ibd | 114 | 1.80 MiB | 16.14 KiB | 117370 | 2.14 GiB | 19.14 KiB | 2.14 GiB | 99.92 |
| @@datadir/cerberus-bin.000010 | 296103 | 1.01 GiB | 3.59 KiB | 362852 | 1.00 GiB | 2.89 KiB | 2.01 GiB | 49.63 |
| @@datadir/ib_logfile0 | 6 | 68.00 KiB | 11.33 KiB | 506837 | 1.46 GiB | 3.03 KiB | 1.46 GiB | 100.00 |
| @@datadir/ib_logfile1 | 0 | 0 bytes | 0 bytes | 476961 | 1.45 GiB | 3.19 KiB | 1.45 GiB | 100.00 |
+----------------------------------+------------+------------+-----------+-------------+---------------+-----------+-------------+-----------+
High IO on InnoDB per-tablespace tables can
show candidates for a separate mountpoint/disk
using “DATA DIRECTORY” in CREATE TABLE

Analyzing User Activity
▪ All event_% summaries are exposed with a number of dimensions
▪ To analyze connection activity you can do this in 4 ways
▪ By User
▪ By Host
▪ By Account (User@Host)
▪ By Thread
▪ The follow examples are by user, but could be replaced with the host,
account or thread summary views

Top Users By Statement Latency
mysql> select user,!
-> sum(count_star) as statements,!
-> sys.format_time(sum(sum_timer_wait)) as total_latency,!
-> sys.format_time(sum(sum_timer_wait) / sum(count_star)) as avg_latency!
-> from events_statements_summary_by_user_by_event_name!
-> where user is not null!
-> group by user!
-> order by sum(sum_timer_wait) desc;!
+------+------------+---------------+-------------+!
| user | statements | total_latency | avg_latency |!
+------+------------+---------------+-------------+!
| root | 7229032 | 15.17h | 7.55 ms |!
| mark | 3072 | 1.77 s | 575.29 us |!
+------+------------+---------------+-------------+!

Top Users By IO Latency
mysql> select user, sum(count_star) as count,!
-> sys.format_time(sum(sum_timer_wait)) as total_latency!
-> from events_waits_summary_by_user_by_event_name!
-> where event_name like 'wait/io/file/%'!
-> and user is not null!
-> group by user!
-> order by sum(sum_timer_wait) desc;!
+------+----------+---------------+!
| user | count | total_latency |!
+------+----------+---------------+!
| root | 10892980 | 00:46:19.67 |!
| mark | 20043 | 346.79 ms |!
+------+----------+---------------+!
Replace with some other
pattern here for “Top user by
wait class”

Top Users By Connections
mysql> select * from users where user is not null order by current_connections desc;!
+------+---------------------+-------------------+!
| USER | CURRENT_CONNECTIONS | TOTAL_CONNECTIONS |!
+------+---------------------+-------------------+!
| root | 8 | 151655 |!
| mark | 1 | 1 |!
+------+---------------------+-------------------+!
!
mysql> select * from accounts where user is not null order by current_connections desc;!
+------+-----------+---------------------+-------------------+!
| USER | HOST | CURRENT_CONNECTIONS | TOTAL_CONNECTIONS |!
+------+-----------+---------------------+-------------------+!
| root | localhost | 39 | 151698 |!
| mark | localhost | 1 | 1 |!
+------+-----------+---------------------+-------------------+!
2 rows in set (0.00 sec)

User Statement Activity
mysql> select *!
-> from events_statements_summary_by_user_by_event_name!
-> where user is not null!
-> order by user, sum_timer_wait desc limit 20G!
*************************** 1. row ***************************!
USER: mark!
EVENT_NAME: statement/sql/select!
COUNT_STAR: 4!
SUM_TIMER_WAIT: 1692883853000!
MIN_TIMER_WAIT: 88330000!
AVG_TIMER_WAIT: 423220963000!
MAX_TIMER_WAIT: 1692583043000!
SUM_LOCK_TIME: 408000000!
SUM_ERRORS: 0!
SUM_WARNINGS: 0!
SUM_ROWS_AFFECTED: 0!
SUM_ROWS_SENT: 212!
SUM_ROWS_EXAMINED: 15067!
SUM_CREATED_TMP_DISK_TABLES: 3!
SUM_CREATED_TMP_TABLES: 4
SUM_SELECT_FULL_JOIN: 0!
SUM_SELECT_FULL_RANGE_JOIN: 0!
SUM_SELECT_RANGE: 0!
SUM_SELECT_RANGE_CHECK: 0!
SUM_SELECT_SCAN: 2!
SUM_SORT_MERGE_PASSES: 6!
SUM_SORT_RANGE: 0!
SUM_SORT_ROWS: 6458!
SUM_SORT_SCAN: 2!
SUM_NO_INDEX_USED: 1!
SUM_NO_GOOD_INDEX_USED: 0
Summarized by
statement type, e.g:
!
statement/sql/select
statement/sql/update

User Top Stages
mysql> select user, event_name as stage,!
-> count_star as total,!
-> sys.format_time(avg_timer_wait) as avg_latency,!
-> from events_stages_summary_by_user_by_event_name!
-> where sum_timer_wait > 0!
-> order by user, sum_timer_wait desc;!
+------+--------------------------------+--------+---------------+-------------+-------------+!
| user | stage | total | total_latency | avg_latency | max_latency |!
+------+--------------------------------+--------+---------------+-------------+-------------+!
| root | stage/sql/starting | 591184 | 00:47:52.47 | 4.86 ms | 3.96 s |!
| root | stage/sql/update | 193940 | 00:15:00.84 | 4.64 ms | 4.02 s |!
| root | stage/sql/updating | 50334 | 00:01:41.38 | 2.01 ms | 2.35 s |!
| root | stage/sql/statistics | 73869 | 00:01:41.38 | 1.37 ms | 4.54 s |!
| root | stage/sql/Sending data | 73211 | 00:01:38.31 | 1.34 ms | 1.04 s |!
| root | stage/sql/Opening tables | 404230 | 00:01:23.48 | 206.51 us | 473.72 ms |!
| root | stage/sql/closing tables | 567351 | 00:01:13.40 | 129.38 us | 79.52 ms |!
| root | stage/sql/removing tmp table | 11603 | 56.87 s | 4.90 ms | 964.17 ms |!
| root | stage/sql/freeing items | 567520 | 19.75 s | 34.80 us | 219.19 ms |!
| root | stage/sql/init | 316805 | 8.26 s | 26.06 us | 217.54 ms |!
………

Analyzing Table Activity
▪ 3 summary views have been added to 5.6 on top of Table IO
▪ objects_summary_global_by_type
▪ A high level aggregate view of database object latency
▪ table_io_waits_summary_by_table
▪ A detailed aggregate by table, breaking down reads, writes, etc.
▪ table_io_waits_summary_by_index_usage
▪ Further breaking down usage per index

Top Tables By Latency
mysql> select object_schema,!
-> object_name,!
-> count_star,!
-> sys.format_time(sum_timer_wait / count_star) as avg_latency,!
-> from objects_summary_global_by_type!
+------------------+-------------------+------------+---------------+-------------+-------------+!
| object_schema | object_name | count_star | total_latency | avg_latency | max_latency |!
+------------------+-------------------+------------+---------------+-------------+-------------+!
| mem__inventory | mysqlserver | 1049496 | 00:04:48.32 | 274.72 us | 1.50 s |!
| mem__events | events | 227939 | 00:01:00.50 | 265.41 us | 2.15 s |!
| mem__events | event_chain_heads | 328664 | 50.80 s | 154.57 us | 2.21 s |!
| mem__inventory | agent | 442751 | 44.82 s | 101.23 us | 1.69 s |!
| mem__instruments | fsstatistics | 2233484 | 16.53 s | 7.40 us | 269.27 ms |!
+------------------+-------------------+------------+---------------+-------------+-------------+
Less events, yet higher latency, is
a sign that there could be
concurrency issues

Table Usage Detailed Breakdown
!mysql> select object_schema, object_name,!
-> count_fetch as selects, sys.format_time(sum_timer_fetch) as select_latency,!
-> count_insert as inserts, sys.format_time(sum_timer_insert) as insert_latency,!
-> count_update as updates, sys.format_time(sum_timer_update) as update_latency,!
-> count_delete as deletes, sys.format_time(sum_timer_delete) as delete_latency!
-> from table_io_waits_summary_by_table!
+------------------+-------------------+---------+----------------+---------+----------------+---------+----------------+---------+----------------+!
| object_schema | object_name | selects | select_latency | inserts | insert_latency | updates | update_latency | deletes | delete_latency |!
+------------------+-------------------+---------+----------------+---------+----------------+---------+----------------+---------+----------------+!
| mem__inventory | mysqlserver | 418518 | 00:04:32.21 | 0 | 0 ps | 48534 | 15.51 s | 0 | 0 ps |!
| mem__events | events | 58512 | 5.54 s | 2701 | 4.01 s | 52414 | 50.83 s | 0 | 0 ps |!
| mem__events | event_chain_heads | 156194 | 6.93 s | 78 | 59.75 ms | 52366 | 43.60 s | 0 | 0 ps |!
| mem__inventory | agent | 188113 | 40.06 s | 0 | 0 ps | 6998 | 4.54 s | 0 | 0 ps |!
| mem__instruments | fsstatistics | 2222058 | 15.12 s | 1517 | 1.37 s | 1 | 72.69 us | 0 | 0 ps |!
| mem__instruments | qrtidata | 2771546 | 2.57 s | 3030 | 12.52 s | 0 | 0 ps | 0 | 0 ps |!
| mem__inventory | network | 91187 | 2.24 s | 0 | 0 ps | 11864 | 8.42 s | 0 | 0 ps |!
| mem__inventory | os | 79736 | 6.08 s | 0 | 0 ps | 8827 | 4.07 s | 0 | 0 ps |!
| mem__inventory | networking | 99114 | 4.24 s | 0 | 0 ps | 5928 | 5.54 s | 0 | 0 ps |!
| mem__inventory | environment | 100445 | 5.29 s | 0 | 0 ps | 6540 | 2.53 s | 0 | 0 ps |!
+------------------+-------------------+---------+----------------+---------+----------------+---------+----------------+---------+----------------+

Tables with full scans
▪ Search in
table_io_waits_summary_by_index_usage
where index_name is null
▪ This is a catch all row for rows that
are read without indexes
mysql> select concat(object_schema, '.', object_name) as object,!
-> count_read as rows_scanned,!
-> sys.format_time(sum_timer_wait) as latency!
-> from table_io_waits_summary_by_index_usage!
-> where index_name is null!
-> and count_read > 0!
+---------------------------------------+--------------+-----------
| object | rows_scanned | latency
+---------------------------------------+--------------+-----------
| mem__instruments.qrtidata | 2735434 | 14.56 s
| mem__instruments.databaseactivitydata | 2735633 | 4.68 s
| mem__instruments.diskiototaldata | 31813 | 3.26 s
| mem__instruments.connectionsdata | 2530816 | 3.17 s
| mem__inventory.agent | 117544 | 2.89 s
| mem__instruments.fsstatistics | 738626 | 2.69 s
| mem__instruments.diskioopstotaldata | 25955 | 2.43 s
| mem__inventory.environment | 42549 | 1.55 s
| mem__enterprise.whats_new_entries | 1453 | 1.16 s
| mem__inventory.networking | 42549 | 559.14 ms
+---------------------------------------+--------------+-----------

Host Cache Usage and Errors
▪ New host_cache view within 5.6, exposing hosts in the host cache
▪ Counts errors, by the type of error that can occur
▪ Can show when errors started happening
▪ Compare the sum_connect_errors counter to the
max_connect_errors system variable

host_cachemysql> desc host_cache;!
+--------------------------------------------+------------------+------+-----+---------------------+-------+!
| Field | Type | Null | Key | Default | Extra |!
+--------------------------------------------+------------------+------+-----+---------------------+-------+!
| IP | varchar(64) | NO | | NULL | |!
| HOST | varchar(255) | YES | | NULL | |!
| HOST_VALIDATED | enum('YES','NO') | NO | | NULL | |!
| SUM_CONNECT_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_HOST_BLOCKED_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_NAMEINFO_TRANSIENT_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_NAMEINFO_PERMANENT_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_FORMAT_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_ADDRINFO_TRANSIENT_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_ADDRINFO_PERMANENT_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_FCRDNS_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_HOST_ACL_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_NO_AUTH_PLUGIN_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_AUTH_PLUGIN_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_HANDSHAKE_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_PROXY_USER_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_PROXY_USER_ACL_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_AUTHENTICATION_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_SSL_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_MAX_USER_CONNECTIONS_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_MAX_USER_CONNECTIONS_PER_HOUR_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_DEFAULT_DATABASE_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_INIT_CONNECT_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_LOCAL_ERRORS | bigint(20) | NO | | NULL | |!
| COUNT_UNKNOWN_ERRORS | bigint(20) | NO | | NULL | |!
| FIRST_SEEN | timestamp | NO | | 0000-00-00 00:00:00 | |!
| LAST_SEEN | timestamp | NO | | 0000-00-00 00:00:00 | |!
| FIRST_ERROR_SEEN | timestamp | YES | | 0000-00-00 00:00:00 | |!
| LAST_ERROR_SEEN | timestamp | YES | | 0000-00-00 00:00:00 | |

Computing Rates Of Change
▪ To look at how things change over time, you have a couple of options
▪ Record the events you are interested in within persistent history tables
▪ Get current stats from performance_schema, the last rows of history,
compute the time delta and event count deltas, store new deltas along
with the raw values
▪ Or use some tool like MySQL Enterprise Monitor
▪ Read the tables regularly, and run TRUNCATE TABLE on them
immediately afterwards
▪ Some users have done this by dumping local traces to files on
disk, and resetting stats every 15 minutes, for example

▪ For an example, the following event tracks the time spent waiting in
the replication SQL thread for new events to be written to the relay log
by the IO thread
▪ wait/synch/cond/sql/MYSQL_RELAY_LOG::update_cond
▪ This is essentially the SQL thread idle time, for a single SQL thread, if
we snapshot this over time, we can find overall busy time

Slave SQL Load Average
▪ An example of monitoring this event over time
!
http://www.markleith.co.uk/2012/07/24/a-mysql-replication-load-average-with-performance-schema/

Slave SQL Load Average
http://www.markleith.co.uk/2012/07/24/a-mysql-replication-load-average-with-performance-schema/

▪ If interested in calculating percentages, copy the approach shown in
the replication load average – you have to take in to account waiting
100% on other events, or just this event, etc.
▪ Note, this method can not be used generally, you have to be able to
correlate it to specific thread(s)
▪ As latency is per thread, and you have to compare to a known
time delta, summary views do not give this to you (you don’t get
thread counts per interval)
▪ Should still compute the deltas for global events however, for
event throughput / latency statistics over time
!

Profiling Statement Activity

Statement Profiling Options
▪ The new instrumentation in 5.6 gives many options
▪ See statements running currently with events_statements_current
▪ Summary views by user, host, account
▪ Statement histories within events_statements_history% tables
▪ A normalized view within events_statements_summary_by_digest

Currently Executing Statements
mysql> select * from events_statements_current where timer_end is nullG!
*************************** 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!
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
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
All counters are live, and
increment whilst the statements
execute

Per Thread Statement History
mysql> select thread_id,!
-> sys.format_statement(sql_text) as stmt,!
-> sys.format_time(timer_wait) as latency!
-> from events_statements_history!
-> order by thread_id, event_id;!
+-----------+-------------------------------------------------------------------+-----------+!
| thread_id | stmt | latency |!
+-----------+-------------------------------------------------------------------+-----------+!
...!
| 158162 | /* mem dbpool.default */ commit | 5.39 ms |!
| 158162 | /* mem dbpool.default */ inser ... currentlyOpen), currentlyOpen) | 1.25 ms |!
| 158162 | /* mem dbpool.default */ inser ... , VALUES(lastSeen)), lastSeen) | 259.75 us |!
| 158162 | /* mem dbpool.default */ inser ... (bytesTotal), bytesTotal), col | 383.05 us |!
| 158162 | /* mem dbpool.default */ inser ... ullScan), rowsReadviaFullScan) | 147.04 ms |!
| 158162 | /* mem dbpool.default */ inser ... ALUES(indexUsage), indexUsage) | 1.10 ms |!
...!
+-----------+-------------------------------------------------------------------+-----------+!
Also has same columns as
events_statements_current

Statement Digests
▪ A new summary view introduced in 5.6
▪ Aggregates statistics based on normalised statements
▪ Can be used to drill in to your problem statements instead of using the
slow query log (with less contention, and no need for post-processing)
▪ Each statement gets an MD5 ‘DIGEST’, that is also available to link in
to events_statements_history% etc. for raw per-query statistics

events_statements_summary_by_digest
mysql> desc events_statements_summary_by_digest;!
+-----------------------------+---------------------+------+-----+---------------------+-------+!
+-----------------------------+---------------------+------+-----+---------------------+-------+!
| SCHEMA_NAME | varchar(64) | YES | | NULL | |!
| DIGEST | varchar(32) | YES | | NULL | |!
| DIGEST_TEXT | longtext | YES | | NULL | |!
| COUNT_STAR | bigint(20) unsigned | NO | | NULL | |!
| SUM_TIMER_WAIT | bigint(20) unsigned | NO | | NULL | |!
| MIN_TIMER_WAIT | bigint(20) unsigned | NO | | NULL | |!
| AVG_TIMER_WAIT | bigint(20) unsigned | NO | | NULL | |!
| MAX_TIMER_WAIT | bigint(20) unsigned | NO | | NULL | |!
| SUM_LOCK_TIME | bigint(20) unsigned | NO | | NULL | |!
| SUM_ERRORS | bigint(20) unsigned | NO | | NULL | |!
| SUM_WARNINGS | bigint(20) unsigned | NO | | NULL | |!
| SUM_ROWS_AFFECTED | bigint(20) unsigned | NO | | NULL | |!
| SUM_ROWS_SENT | bigint(20) unsigned | NO | | NULL | |!
| SUM_ROWS_EXAMINED | bigint(20) unsigned | NO | | NULL | |!
| SUM_CREATED_TMP_DISK_TABLES | bigint(20) unsigned | NO | | NULL | |!
| SUM_CREATED_TMP_TABLES | bigint(20) unsigned | NO | | NULL | |!
| SUM_SELECT_FULL_JOIN | bigint(20) unsigned | NO | | NULL | |!
| SUM_SELECT_FULL_RANGE_JOIN | bigint(20) unsigned | NO | | NULL | |!
| SUM_SELECT_RANGE | bigint(20) unsigned | NO | | NULL | |!
| SUM_SELECT_RANGE_CHECK | bigint(20) unsigned | NO | | NULL | |!
| SUM_SELECT_SCAN | bigint(20) unsigned | NO | | NULL | |!
| SUM_SORT_MERGE_PASSES | bigint(20) unsigned | NO | | NULL | |!
| SUM_SORT_RANGE | bigint(20) unsigned | NO | | NULL | |!
| SUM_SORT_ROWS | bigint(20) unsigned | NO | | NULL | |!
| SUM_SORT_SCAN | bigint(20) unsigned | NO | | NULL | |!
| SUM_NO_INDEX_USED | bigint(20) unsigned | NO | | NULL | |!
| SUM_NO_GOOD_INDEX_USED | bigint(20) unsigned | NO | | NULL | |!
| FIRST_SEEN | timestamp | NO | | 0000-00-00 00:00:00 | |!
| LAST_SEEN | timestamp | NO | | 0000-00-00 00:00:00 | |

Statement Normalization
▪ Normalization folds certain constructs of statements
▪ Strip whitespace / comments
▪ Replace literals with ?
▪ “WHERE foo = 1” becomes “WHERE foo = ?”
▪ Fold lists of things
▪ “IN (1,2,3)” becomes “IN (…)”
▪ Fold multi-row inserts
▪ “VALUES (1), (2), (3)” becomes “VALUES (?) /*, … */”
!

Statement Digest Output
mysql> select * from events_statements_summary_by_digest order by sum_timer_wait desc limit 5G!
...!
*************************** 4. row ***************************!
SCHEMA_NAME: mem!
DIGEST: 5f41a0036bae4fa1c79339c1c7da3c9e!
DIGEST_TEXT: SELECT DISTINCTROW `agent0_` . `hid` AS `hid1239_` ...!
COUNT_STAR: 64136!
SUM_TIMER_WAIT: 1835031591954000!
SUM_LOCK_TIME: 31388434000000!
SUM_ERRORS: 0!
SUM_WARNINGS: 0!
SUM_ROWS_SENT: 64133!
SUM_CREATED_TMP_TABLES: 59624!
SUM_SELECT_SCAN: 59625!
SUM_SORT_RANGE: 0!
SUM_SORT_ROWS: 0!
SUM_SORT_SCAN: 0!
SUM_NO_GOOD_INDEX_USED: 0!
FIRST_SEEN: 2014-05-20 11:26:54!
LAST_SEEN: 2014-05-21 14:50:54

Statements With Temporary Tables
mysql> select sys.format_statement(digest_text) as stmt,!
-> sum_created_tmp_tables as in_memory,!
-> sum_created_tmp_disk_tables as on_disk,!
-> round(sum_created_tmp_tables / count_star) as avg_per_stmt,!
-> round((sum_created_tmp_disk_tables/sum_created_tmp_tables) * 100) as to_disk_pct!
-> from events_statements_summary_by_digest!
-> where sum_created_tmp_tables > 0!
-> order by sum_created_tmp_disk_tables desc, sum_created_tmp_tables desc limit 5;!
+-------------------------------------------------------------------+-------+-----------+---------+--------------+-------------+!
| stmt | total | in_memory | on_disk | avg_per_stmt | to_disk_pct |!
+-------------------------------------------------------------------+-------+-----------+---------+--------------+-------------+!
| SELECT DISTINCTROW àgent0_` . ... gent` àgent0_` INNER JOIN ... | 64668 | 60116 | 60116 | 1 | 100 |!
| SELECT DISTINCTROW `mysqlconne ... conne0_` . `socketPath` AS ... | 5605 | 5604 | 5604 | 1 | 100 |!
| SELECT * FROM ( SELECT digest ... ed AS `noIndexUsedCount` , ... | 1431 | 10017 | 4293 | 7 | 43 |!
| SELECT `s` . ìdentityId` , `s ... `subject_id` = `s` . ìd` ... | 1406 | 4218 | 2812 | 3 | 67 |!
| SELECT plugin_name FROM inform ... atus = ? ORDER BY plugin_name | 1726 | 1726 | 1726 | 1 | 100 |!
+-------------------------------------------------------------------+-------+-----------+---------+--------------+-------------+!

Statements With Full Table Scans
mysql> select sys.format_statement(digest_text) as stmt,!
-> sum_no_index_used as scan_count,!
-> round((sum_no_index_used/count_star) * 100) as scan_pct,!
-> sum_rows_examined as rows_scanned!
-> from events_statements_summary_by_digest!
-> where digest_text like 'select%'!
-> and (sum_no_index_used > 0 OR sum_no_good_index_used > 0)!
-> order by rows_scanned desc limit 5;!
+-------------------------------------------------------------------+-------+------------+----------+--------------+!
| stmt | total | scan_count | scan_pct | rows_scanned |!
+-------------------------------------------------------------------+-------+------------+----------+--------------+!
| SELECT `hid` , TIMESTAMP , `en ... DIV ? AS `slice` , `hid` , ... | 4258 | 4257 | 100 | 31644768 |!
| SELECT TIMESTAMP , SUM ( `sele ... by_bucket` GROUP BY TIMESTAMP | 807 | 807 | 100 | 4657959 |!
| SELECT TIMESTAMP , SUM ( `opti ... by_bucket` GROUP BY TIMESTAMP | 807 | 807 | 100 | 4656726 |!
| SELECT TIMESTAMP , SUM ( `tota ... by_bucket` GROUP BY TIMESTAMP | 807 | 807 | 100 | 4454821 |!
| SELECT * FROM ( SELECT digest ... ed AS `noIndexUsedCount` , ... | 1434 | 1434 | 100 | 3874018 |!
+-------------------------------------------------------------------+-------+------------+----------+--------------+

Tracing Individual Statement Activity
▪ By taking all available data within the %_history_long tables, we can
build a complete picture of where latency lines within statements
▪ We can link the histories of Statements, Stages and Waits using the
event_id and nesting_event_id columns, which define hierarchy
!
!

This means we can graph their relationships!

▪ This is only really effective on development / test systems, production
systems with high concurrency / throughput age history very quickly,
and turning the %_history_long tables on with all instrumentation on is
not recommend generally
▪ Good to disable all other threads, or all actors, and just enable a
single thread in development / test environments, to get a full trace
▪ Procedure to dump the graph data is available within the MySQL
SYS schema
!
!

Improvements made to date in MySQL 5.7

Copyright © 2014, Oracle and/or its affiliates. All rights reserved.Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Insert Information Protection Policy Classification from Slide 12
Insert Picture Here
!76
▪ Memory Usage
▪ Metadata Locking
▪ Replication Configuration & Status
▪ Prepared Statements
▪ Transactions
▪ Stored Programs

▪ 75 Tables (+23)
▪ 784 Instruments (+239)
Instrument Type Event Class
Transactions transaction
Memory memory/%
Metadata Locks wait/lock/metadata/%

WL#3249!
PERFORMANCE SCHEMA, Instrument memory usage

“Understanding where MySQL can allocate memory can help us to find
the cause in most cases. It is not as straightforward as it should be and
I’m very hopeful future releases of MySQL, MariaDB or Drizzle bring
improvements in this space allowing us to see directly for what
purpose memory is allocated and so detect all kinds of memory usage
problems easier.”
▪ Peter Zaitsev, CEO, Percona
http://www.mysqlperformanceblog.com/2012/03/21/troubleshooting-mysql-memory-usage/

Instrument memory usage
▪ Added 212 different memory instrumentation types so far
▪ Records current, high and low water marks of allocations
▪ Does not track latency of memory allocation
▪ 5 new tables
▪ memory_summary_by_account_by_event_name
▪ memory_summary_by_host_by_event_name
▪ memory_summary_by_thread_by_event_name
▪ memory_summary_by_user_by_event_name
▪ memory_summary_global_by_event_name

Instrument memory usage - global summary
mysql> SELECT * FROM sys.memory_global_by_current_allocatedG!
*************************** 1. row ***************************!
event_name: memory/performance_schema/internal_buffers!
current_count: 60!
current_alloc: 497.00 MiB!
current_avg_alloc: 8.28 MiB!
high_count: 60!
high_alloc: 497.00 MiB!
high_avg_alloc: 8.28 MiB!
*************************** 2. row ***************************!
event_name: memory/mysys/KEY_CACHE!
current_count: 3!
current_avg_alloc: 2.67 MiB!
high_count: 3!
high_alloc: 8.00 MiB!
high_avg_alloc: 2.67 MiB

Instrument memory usage - thread summaries
mysql> select * from memory_by_thread_by_current_allocatedG!
*************************** 1. row ***************************!
user: sql/main!
current_count: 2407!
current_avg_alloc: 4.63 KiB!
current_max_alloc: 8.00 MiB!
total_allocated: 30.55 MiB!
thread_id: 1!
*************************** 2. row ***************************!
user: mem@localhost!
current_count: 1914!
current_avg_alloc: 824 bytes!
current_max_alloc: 816.67 KiB!
total_allocated: 9.25 GiB!
thread_id: 4336

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 |!
| memory/myisam/MYISAM_SHARE | 3.29 KiB |!
…

Instrument memory usage - other details
!
▪ Disabled by default
!
!
!
!
▪ Still requires InnoDB instrumentation
UPDATE setup_instruments
SET enabled = ‘YES’
WHERE name LIKE ‘memory/%’;

WL#5879!
PERFORMANCE SCHEMA, MDL lock instrumentation

“Unfortunately, it’s unlikely that I’ll be able to create a reproducible test
case, because there’s no way to actually see what is happening. I
hope that a future version of MySQL will include a more
comprehensive set of tables for inspecting locks, requests, and waits
at all layers of the server.”
▪ Baron Schwartz, CEO, VividCortex
http://www.xaprb.com/blog/2012/08/28/debugging-metadata-locking-in-mysql-5-5/

MDL Lock Instrumentation
▪ Added the wait/lock/metadata/sql/mdl instrument
▪ 2 new tables
▪ metadata_locks
▪ table_handles

MDL Lock Instrumentation
▪ OBJECT_TYPE
▪ GLOBAL, SCHEMA, TABLE, FUNCTION, PROCEDURE, TRIGGER, EVENT,
COMMIT
▪ LOCK_TYPE
▪ INTENTION_EXCLUSIVE, SHARED, SHARED_HIGH_PRIO,
SHARED_READ, SHARED_WRITE, SHARED_UPGRADABLE,
SHARED_NO_WRITE, SHARED_NO_READ_WRITE, EXCLUSIVE
▪ LOCK_DURATION
▪ STATEMENT, TRANSACTION, EXPLICIT
▪ LOCK_STATUS
▪ PENDING, GRANTED, VICTIM, TIMEOUT, KILLED

WL#3656!
PERFORMANCE SCHEMA table for!
SHOW SLAVE STATUS

Replication Instrumentation
▪ 6 new tables
▪ replication_connection_configuration
▪ replication_connection_status
▪ replication_execute_configuration
▪ replication_execute_status
▪ replication_execute_status_by_coordinator
▪ replication_execute_status_by_worker

Replication Instrumentation

Replication Connection Configuration
mysql> select * from performance_schema.replication_connection_configurationG
*************************** 1. row ***************************!
HOST: 127.0.0.1!
PORT: 3306!
USER: rpl!
NETWORK_INTERFACE:!
AUTO_POSITION: 1!
SSL_ALLOWED: YES!
SSL_CA_FILE:!
SSL_CA_PATH:!
SSL_CERTIFICATE:!
SSL_CIPHER:!
SSL_KEY:!
SSL_VERIFY_SERVER_CERTIFICATE: YES!
SSL_CRL_FILE:!
SSL_CRL_PATH:!
CONNECTION_RETRY_INTERVAL: 40!
CONNECTION_RETRY_COUNT: 10

Replication Connection Status
mysql> select * from replication_connection_statusG!
*************************** 1. row ***************************!
SOURCE_UUID:!
THREAD_ID: NULL!
SERVICE_STATE: CONNECTING!
RECEIVED_TRANSACTION_SET:!
LAST_ERROR_NUMBER: 1045!
LAST_ERROR_MESSAGE: error connecting to master 'repl@localhost:
5613' - retry-time: 60 retries: 1!
LAST_ERROR_TIMESTAMP: 2014-04-02 05:41:20

Replication Coordinator Status
mysql> select * from replication_execute_status_by_coordinatorG!
*************************** 1. row ***************************!
THREAD_ID: 1281!
SERVICE_STATE: ON!
LAST_ERROR_NUMBER: 0!
LAST_ERROR_MESSAGE:!
LAST_ERROR_TIMESTAMP: 0000-00-00 00:00:00
▪ Status of Coordinator thread in multi-threaded replication

Replication Worker Status
mysql> select * from replication_execute_status_by_worker;!
+-----------+-----------+---------------+-----------------------------------------+-------------------+--------------------+----------------------+!
| WORKER_ID | THREAD_ID | SERVICE_STATE | LAST_SEEN_TRANSACTION | LAST_ERROR_NUMBER | LAST_ERROR_MESSAGE | LAST_ERROR_TIMESTAMP |!
+-----------+-----------+---------------+-----------------------------------------+-------------------+--------------------+----------------------+!
| 1 | 1282 | ON | | 0 | | 0000-00-00 00:00:00 |!
| 2 | 1283 | ON | | 0 | | 0000-00-00 00:00:00 |!
| 3 | 1284 | ON | | 0 | | 0000-00-00 00:00:00 |!
| 4 | 1285 | ON | | 0 | | 0000-00-00 00:00:00 |!
| 5 | 1286 | ON | | 0 | | 0000-00-00 00:00:00 |!
| 6 | 1287 | ON | | 0 | | 0000-00-00 00:00:00 |!
| 7 | 1288 | ON | | 0 | | 0000-00-00 00:00:00 |!
| 8 | 1289 | ON | 181f2b36-a0b4-11e3-9ac7-1025863574a7:16 | 0 | | 0000-00-00 00:00:00 |!
+-----------+-----------+---------------+-----------------------------------------+-------------------+--------------------+----------------------+
▪ Status of worker threads within multi-threaded replication

WL#5768!
PERFORMANCE SCHEMA, prepared statements
instrumentation

Prepared Statement Instrumentation
▪ Instrumentation depends on already existing statement instruments
▪ statement/com/prepare, statement/com/execute
▪ statement/sql/prepare_sql, statement/sql/execute_sql
▪ 1 new table
▪ prepared_statements_instances

Prepared Statement Instances
mysql> select * from performance_schema.prepared_statements_instancesG!
*************************** 1. row ***************************!
OBJECT_INSTANCE_BEGIN: 140198306602144!
STATEMENT_ID: 1!
STATEMENT_NAME: stmt1!
SQL_TEXT: select * from test.t1!
OWNER_THREAD_ID: 54003!
OWNER_EVENT_ID: 935!
OWNER_OBJECT_TYPE: NULL!
OWNER_OBJECT_SCHEMA: NULL!
OWNER_OBJECT_NAME: NULL!
TIMER_PREPARE: 15386274000!
COUNT_REPREPARE: 0!
COUNT_EXECUTE: 1!
SUM_TIMER_EXECUTE: 217699000!
MIN_TIMER_EXECUTE: 217699000!
AVG_TIMER_EXECUTE: 217699000!
MAX_TIMER_EXECUTE: 217699000
SUM_LOCK_TIME: 0!
SUM_ERRORS: 0!
SUM_WARNINGS: 0!
SUM_ROWS_SENT: 0!
SUM_SELECT_SCAN: 0!
SUM_SORT_RANGE: 0!
SUM_SORT_ROWS: 0!
SUM_SORT_SCAN: 0!

WL#5864!
PERFORMANCE SCHEMA, instrument
TRANSACTIONS

Transaction Instrumentation
▪ Added the transaction instrument
▪ 8 new tables
▪ events_transactions_current
▪ events_transactions_history
▪ events_transactions_history_long
▪ events_transactions_summary_by_account_by_event_name
▪ events_transactions_summary_by_host_by_event_name
▪ events_transactions_summary_by_thread_by_event_name
▪ events_transactions_summary_by_user_by_event_name
▪ events_transactions_summary_global_by_event_name

Transaction Instrumentation
▪ Exposes details of transactions in raw or summary views
▪ Show details such as
▪ Transaction latency
▪ Isolation levels
▪ Auto commit
▪ Savepoint info
▪ GTID or transaction IDs
▪ Link transactions to the statements within the transactions

Current Transaction Details
mysql> select * from events_transactions_currentG!
*************************** 1. row ***************************!
THREAD_ID: 1!
EVENT_ID: 23733!
EVENT_NAME: transaction!
STATE: COMMITTED!
TRX_ID: 281479898269256!
GTID: NULL!
XID: NULL!
XA_STATE: NULL!
SOURCE: handler.cc:1246!
TIMER_START: 31140612726000!
TIMER_END: 31140647445000!
TIMER_WAIT: 34719000
ACCESS_MODE: READ WRITE!
ISOLATION_LEVEL: REPEATABLE READ!
AUTOCOMMIT: YES!
NUMBER_OF_SAVEPOINTS: 0!
NUMBER_OF_ROLLBACK_TO_SAVEPOINT: 0!
NUMBER_OF_RELEASE_SAVEPOINT: 0!
NESTING_EVENT_ID: NULL!
NESTING_EVENT_TYPE: NULL

Transaction Summary - per user
mysql> select * from events_transactions_summary_by_user_by_event_nameG!
*************************** 1. row ***************************!
USER: mem!
EVENT_NAME: transaction!
COUNT_STAR: 400044!
SUM_TIMER_WAIT: 21208048458267000!
MAX_TIMER_WAIT: 24028520397000!
COUNT_READ_WRITE: 400044!
SUM_TIMER_READ_WRITE: 21208048458267000!
MIN_TIMER_READ_WRITE: 160744000!
AVG_TIMER_READ_WRITE: 53014289000!
MAX_TIMER_READ_WRITE: 24028520397000!
COUNT_READ_ONLY: 0!
SUM_TIMER_READ_ONLY: 0!
MIN_TIMER_READ_ONLY: 0!
AVG_TIMER_READ_ONLY: 0!
MAX_TIMER_READ_ONLY: 0

WL#5766!
PERFORMANCE SCHEMA, stored programs
instrumentation

Stored Program Instrumentation
▪ Tracks Stored Procedures, Stored Functions, Triggers and Events
▪ Added 16 new statement/sp/% instruments
▪ Expose the different work flows that stored programs use, such as
cursor operations, workflow controls etc.
▪ Integrated in to the normal statement instrumentation
▪ 1 new tables
▪ events_statements_summary_by_program

Stored Program Summary
mysql> select * from events_statements_summary_by_programG!
*************************** 1. row ***************************!
OBJECT_TYPE: PROCEDURE!
OBJECT_SCHEMA: ps_demo!
OBJECT_NAME: ps_demo_proc!
COUNT_STAR: 1!
SUM_TIMER_WAIT: 6970931000!
COUNT_STATEMENTS: 5!
SUM_STATEMENTS_WAIT: 6802181000!
MIN_STATEMENTS_WAIT: 16372000!
AVG_STATEMENTS_WAIT: 1360436000!
MAX_STATEMENTS_WAIT: 6484366000!
SUM_LOCK_TIME: 176401000000!
SUM_ERRORS: 0!
SUM_WARNINGS: 0!
SUM_ROWS_SENT: 0
SUM_SELECT_SCAN: 0!
SUM_SORT_RANGE: 0!
SUM_SORT_ROWS: 0!
SUM_SORT_SCAN: 0!

Stored Program Instrumentation
▪ Like Transaction instrumentation, stored programs link to the
statements within them, or even link to transactions within them,
which in turn link to their statements

Full Hierarchy of New Instrumentation

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

Loading MySQL SYS
$ git clone https://github.com/MarkLeith/mysql-sys.git /tmp/mysql-sys
$ cd /tmp/mysql-sys
$ mysql -u user -p < sys_<version>.sql
!
<version> can be 56 or 57, for 5.6 and 5.7 respectively

Loading MySQL SYS
▪ Once loaded creates a new “sys” schema containing all objects
mysql> select object_type, count!
-> from sys.schema_object_overview!
-> where db = 'sys';!
+-------------+-------+!
| object_type | count |!
+-------------+-------+!
| PROCEDURE | 16 |!
| FUNCTION | 8 |!
| VIEW | 71 |!
+-------------+-------+

MySQL SYS Functions
▪ Make the raw data more readable to a human
▪ format_time() / format_bytes()
▪ Compress data for CLI output
▪ format_statement() / format_path()
▪ Extract some data to assist with JOIN in certain cases
▪ extract_[schema|table]_from_file_name()
▪ Other functions
▪ ps_is_account_enabled() / ps_thread_stack()

MySQL SYS Views
▪ Reference set of views solving various admin use cases
▪ Build upon both Performance Schema and INFORMATION_SCHEMA
▪ Both formatted and raw views are available
▪ All raw views are prefixed with x$
▪ Allows tooling to poll raw views, but humans to use normal ones

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 |!
+-----------------------------------+

User Summary (5.7)
mysql> select * from user_summaryG!
*************************** 1. row ***************************!
user: mark!
statements: 3072!
statement_latency: 1.77 s!
statement_avg_latency: 575.29 us!
table_scans: 7!
file_ios: 20043!
file_io_latency: 346.79 ms!
current_connections: 1!
total_connections: 1!
unique_hosts: 1!
current_memory: 515.81 KiB!
total_memory_allocated: 30.69 MiB

User File IO Summary
mysql> select * from user_summary_by_file_io_type where user != 'background';!
+------+--------------------------------------+---------+-------------+-------------+!
| user | event_name | total | latency | max_latency |!
+------+--------------------------------------+---------+-------------+-------------+!
| mark | wait/io/file/myisam/dfile | 19540 | 215.20 ms | 120.79 ms |!
| mark | wait/io/file/myisam/kfile | 501 | 131.58 ms | 57.74 ms |!
| mark | wait/io/file/sql/dbopt | 2 | 17.29 us | 9.17 us |!
| root | wait/io/file/innodb/innodb_log_file | 2079432 | 00:28:27.62 | 1.30 s |!
| root | wait/io/file/myisam/kfile | 5195927 | 00:17:07.33 | 1.17 s |!
| root | wait/io/file/myisam/dfile | 1533813 | 00:07:27.59 | 1.18 s |!
| root | wait/io/file/sql/binlog | 3517008 | 00:03:07.34 | 1.42 s |!
| root | wait/io/file/innodb/innodb_data_file | 20720 | 00:02:37.81 | 492.23 ms |!
| root | wait/io/file/sql/FRM | 41412 | 3.17 s | 80.43 ms |!
| root | wait/io/file/sql/dbopt | 110993 | 1.23 s | 63.27 ms |!
| root | wait/io/file/sql/binlog_index | 80 | 1.16 s | 439.79 ms |!
| root | wait/io/file/csv/metadata | 16 | 175.97 ms | 79.53 ms |!
| root | wait/io/file/archive/data | 3345 | 18.35 ms | 5.05 ms |!
| root | wait/io/file/sql/file_parser | 142 | 5.80 ms | 331.82 us |!
| root | wait/io/file/sql/misc | 99 | 760.67 us | 25.19 us |!
| root | wait/io/file/csv/data | 6 | 596.99 us | 348.11 us |!
+------+--------------------------------------+---------+-------------+-------------+

User Statement Latency Summary
mysql> select * from user_summary_by_statement_latency where user != 'background';!
+------+---------+---------------+-------------+--------------+-----------+---------------+---------------+------------+
| user | total | total_latency | max_latency | lock_latency | rows_sent | rows_examined | rows_affected | full_scans |
+------+---------+---------------+-------------+--------------+-----------+---------------+---------------+------------+
| root | 8322401 | 19.37h | 00:07:08.11 | 00:40:26.25 | 10110692 | 68391445 | 4198113 | 189531 |
| mark | 3072 | 1.77 s | 1.73 s | 1.96 ms | 534 | 15389 | 0 | 7 |
+------+---------+---------------+-------------+--------------+-----------+---------------+---------------+------------+

User Statement Type Summary
mysql> select * from user_summary_by_statement_type where user != 'background';!
+------+-----------------------+---------+---------------+-------------+--------------+-----------+---------------+---------------+------------+!
| user | statement | total | total_latency | max_latency | lock_latency | rows_sent | rows_examined | rows_affected | full_scans |!
+------+-----------------------+---------+---------------+-------------+--------------+-----------+---------------+---------------+------------+!
| mark | select | 4 | 1.69 s | 1.69 s | 408.00 us | 212 | 15067 | 0 | 1 |!
| mark | Field List | 146 | 67.91 ms | 40.02 ms | 1.11 ms | 0 | 0 | 0 | 0 |!
| mark | jump_if_not | 2496 | 2.68 ms | 7.07 us | 0 ps | 0 | 0 | 0 | 0 |!
| mark | show_tables | 4 | 1.70 ms | 545.41 us | 296.00 us | 292 | 292 | 0 | 4 |!
| mark | freturn | 418 | 1.15 ms | 9.29 us | 0 ps | 0 | 0 | 0 | 0 |!
| mark | show_databases | 2 | 849.40 us | 431.05 us | 146.00 us | 30 | 30 | 0 | 2 |!
| mark | Init DB | 2 | 114.95 us | 59.58 us | 0 ps | 0 | 0 | 0 | 0 |!
| root | commit | 2463190 | 13.33h | 12.18 s | 0 ps | 0 | 0 | 0 | 0 |!
| root | insert | 2501839 | 3.78h | 6.64 s | 00:31:18.63 | 192 | 0 | 3674716 | 0 |!
| root | select | 1119999 | 1.74h | 16.34 s | 00:07:42.99 | 6187336 | 63933992 | 0 | 163913 |!
| root | update | 494217 | 00:15:23.09 | 4.83 s | 00:01:05.05 | 126 | 496604 | 495334 | 0 |!
| root | Binlog Dump GTID | 1 | 00:06:12.69 | 00:06:12.69 | 0 ps | 0 | 0 | 0 | 0 |!
| root | delete | 206176 | 00:01:59.54 | 2.22 s | 6.69 s | 12 | 20201 | 20203 | 0 |!
| root | set_option | 1068360 | 00:01:10.73 | 45.37 ms | 0 ps | 0 | 0 | 0 | 0 |!
| root | show_engine_status | 2222 | 46.62 s | 4.96 s | 0 ps | 0 | 0 | 0 | 0 |!
| root | rollback | 64527 | 26.21 s | 407.15 ms | 0 ps | 0 | 0 | 0 | 0 |!
| root | show_variables | 11219 | 12.28 s | 255.00 ms | 1.19 s | 2542172 | 2542172 | 0 | 11219 |!
| root | show_binlogs | 1850 | 8.96 s | 1.64 s | 0 ps | 0 | 0 | 0 | 0 |!
| root | show_tables | 4250 | 6.86 s | 123.34 ms | 182.80 ms | 5277 | 5277 | 0 | 4250 |!
| root | show_status | 5485 | 6.50 s | 242.60 ms | 581.02 ms | 1331264 | 1331264 | 0 | 5485 |!

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 |!
+------------------------------+

IO Per Thread Summary
mysql> select * from io_by_thread_by_latency;!
+---------------------+---------+---------------+-------------+-------------+-------------+-----------+----------------+!
| user | total | total_latency | min_latency | avg_latency | max_latency | thread_id | processlist_id |!
+---------------------+---------+---------------+-------------+-------------+-------------+-----------+----------------+!
| io_write_thread | 1270599 | 00:28:51.42 | 1.46 us | 1.36 ms | 1.39 s | 9 | NULL |!
| page_cleaner_thread | 3356577 | 00:21:01.53 | 410.93 ns | 2.08 ms | 1.49 s | 19 | NULL |!
| io_write_thread | 338216 | 00:14:31.16 | 1.67 us | 2.58 ms | 1.17 s | 12 | NULL |!
| io_log_thread | 47023 | 00:04:06.10 | 3.65 us | 5.23 ms | 538.77 ms | 4 | NULL |!
| io_write_thread | 290066 | 00:02:20.99 | 2.78 us | 486.07 us | 703.20 ms | 10 | NULL |!
| io_write_thread | 221417 | 00:02:12.64 | 1.85 us | 599.05 us | 773.64 ms | 11 | NULL |!
| root@localhost | 587531 | 00:02:03.29 | 444.86 ns | 200.24 us | 372.09 ms | 2515 | 2495 |!
| io_read_thread | 5102 | 00:01:09.66 | 12.24 us | 13.65 ms | 281.13 ms | 5 | NULL |!
| srv_master_thread | 55199 | 58.11 s | 693.68 ns | 1.40 ms | 504.03 ms | 17 | NULL |!
| root@localhost | 1622373 | 41.20 s | 486.33 ns | 25.40 us | 359.49 ms | 23 | 3 |!
| io_read_thread | 2401 | 37.27 s | 11.86 us | 15.52 ms | 258.97 ms | 6 | NULL |!
| srv_purge_thread | 3874 | 12.16 s | 433.55 ns | 3.14 ms | 246.79 ms | 18 | NULL |!
| main | 11083 | 3.12 s | 588.12 ns | 547.21 us | 234.02 ms | 1 | NULL |!
| root@localhost | 5985 | 1.48 s | 625.82 ns | 1.06 ms | 239.17 ms | 137759 | 137739 |!
| root@localhost | 157 | 434.38 ms | 497.64 ns | 8.09 ms | 205.84 ms | 178521 | 178501 |!
| mark@localhost | 20043 | 346.79 ms | 418.47 ns | 94.10 us | 120.79 ms | 150606 | 150586 |!
| root@localhost | 138 | 204.72 ms | 486.33 ns | 2.68 ms | 86.54 ms | 178524 | 178504 |!
| root@localhost | 415 | 126.43 ms | 471.25 ns | 195.15 us | 37.21 ms | 178269 | 178249 |!
| root@localhost | 9 | 106.21 ms | 6.40 us | 8.85 ms | 103.88 ms | 178522 | 178502 |!
+---------------------+---------+---------------+-------------+-------------+-------------+-----------+----------------+!

IO Per File Summaries
mysql> select * from io_global_by_file_by_latency limit 1G!
*************************** 1. row ***************************!
file: @@datadir/ibdata1!
total: 1395714!
total_latency: 00:28:53.06!
count_read: 1006!
read_latency: 4.51 s!
count_write: 1326529!
write_latency: 33.39 s!
count_misc: 68179!
misc_latency: 00:28:15.16!
!
mysql> select * from io_global_by_file_by_bytes limit 1G!
*************************** 1. row ***************************!
file: @@datadir/ibdata1!
count_read: 1006!
total_read: 17.69 MiB!
avg_read: 18.00 KiB!
count_write: 1327221!
total_written: 77.82 GiB!
avg_write: 61.48 KiB!
total: 77.84 GiB!
write_pct: 99.98

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 |!
+-------------------------------------+

Schema Object Overview
mysql> select * from schema_object_overview;!
+-------------------------+---------------+-------+!
| db | object_type | count |!
+-------------------------+---------------+-------+!
| information_schema | SYSTEM VIEW | 60 |!
| mem__advisors | BASE TABLE | 3 |!
| mem__advisors | INDEX (BTREE) | 5 |!
| mem__advisor_text | BASE TABLE | 2 |!
| mem__advisor_text | INDEX (BTREE) | 5 |!
| mem__bean_config | BASE TABLE | 4 |!
| mem__bean_config | INDEX (BTREE) | 6 |!
| mem__config | BASE TABLE | 12 |!
| mem__config | INDEX (BTREE) | 21 |!
| mem__enterprise | BASE TABLE | 2 |!
| mem__enterprise | INDEX (BTREE) | 3 |!
| mem__events | BASE TABLE | 32 |!
| mem__events | INDEX (BTREE) | 69 |!
| mem__instruments | BASE TABLE | 117 |!
| mem__instruments | INDEX (BTREE) | 582 |

Table statistics
mysql> select * from schema_table_statistics limit 1G!
*************************** 1. row ***************************!
table_schema: mem__quan!
table_name: normalized_statements_by_server_by_schema_data!
rows_fetched: 239685!
fetch_latency: 17.10 s!
rows_inserted: 1102895!
insert_latency: 00:52:18.10!
rows_updated: 55910!
update_latency: 00:02:28.62!
rows_deleted: 17899!
delete_latency: 3.98 s!
io_read_requests: 20639!
io_read: 324.94 MiB!
io_read_latency: 00:03:04.10!
io_write_requests: 1965973!
io_write: 40.36 GiB!
io_write_latency: 25.46 s!
io_misc_requests: 18217!
io_misc_latency: 00:14:06.02

Index statistics
mysql> select * from schema_index_statistics limit 1G!
*************************** 1. row ***************************!
table_schema: mem__inventory!
table_name: mysqlconnectionconfiguration!
index_name: PRIMARY!
rows_selected: 131399!
select_latency: 00:07:05.03!
rows_inserted: 0!
insert_latency: 0 ps!
rows_updated: 41608!
update_latency: 21.96 s!
rows_deleted: 0!
delete_latency: 0 ps

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 |!
+-------------------------------+

Buffer Usage By Schema
mysql> select * from innodb_buffer_stats_by_schema;!
+------------------+------------+------------+-------+--------------+-----------+-------------+!
| object_schema | allocated | data | pages | pages_hashed | pages_old | rows_cached |!
+------------------+------------+------------+-------+--------------+-----------+-------------+!
| mem__quan | 69.94 MiB | 45.39 MiB | 4476 | 4476 | 4476 | 123226 |!
| mem__instruments | 20.70 MiB | 10.75 MiB | 1325 | 1325 | 1325 | 82812 |!
| mem__events | 3.08 MiB | 2.09 MiB | 197 | 197 | 197 | 3411 |!
| mem__inventory | 1.34 MiB | 52.49 KiB | 86 | 86 | 86 | 18 |!
| mysql | 432.00 KiB | 251.34 KiB | 27 | 27 | 27 | 2252 |!
| mem__config | 144.00 KiB | 3.86 KiB | 9 | 9 | 9 | 29 |!
+------------------+------------+------------+-------+--------------+-----------+-------------+

Buffer Usage By Table
mysql> select * from innodb_buffer_stats_by_table limit 20;!
+------------------+------------------------------------------------+------------+------------+-------+--------------+-----------+-------------+!
| object_schema | object_name | allocated | data | pages | pages_hashed | pages_old | rows_cached |!
+------------------+------------------------------------------------+------------+------------+-------+--------------+-----------+-------------+!
| mem__quan | normalized_statements_by_server_by_schema_data | 49.97 MiB | 33.12 MiB | 3198 | 3198 | 3198 | 238845 |!
| mem__quan | example_statements | 15.95 MiB | 9.71 MiB | 1021 | 1021 | 1021 | 32435 |!
| mem__events | events | 2.75 MiB | 1.97 MiB | 176 | 176 | 176 | 5044 |!
| mem__quan | normalized_statements | 2.19 MiB | 1.42 MiB | 140 | 140 | 140 | 2297 |!
| mem__quan | normalized_statements_by_server_by_schema | 1.06 MiB | 693.58 KiB | 68 | 68 | 68 | 3840 |!
| mem__instruments | innodbundologsdata | 1.05 MiB | 754.07 KiB | 67 | 67 | 67 | 5529 |!
| mem__instruments | fsstatistics | 736.00 KiB | 603.64 KiB | 46 | 46 | 46 | 2092 |!
| mem__instruments | networktrafficadvisor_networktraffic | 496.00 KiB | 291.38 KiB | 31 | 31 | 31 | 1160 |!
| mysql | innodb_index_stats | 384.00 KiB | 230.37 KiB | 24 | 24 | 24 | 1986 |!
| mem__quan | explains | 368.00 KiB | 274.42 KiB | 23 | 23 | 23 | 333 |!
| mem__instruments | innodbchangebufferusagedata | 272.00 KiB | 126.94 KiB | 17 | 17 | 17 | 1104 |!
| mem__instruments | rowscanratiodata | 272.00 KiB | 141.18 KiB | 17 | 17 | 17 | 1207 |!
| mem__instruments | connectionsmaxdata | 256.00 KiB | 150.98 KiB | 16 | 16 | 16 | 1262 |!
| mem__instruments | innodbopenfilesdata | 256.00 KiB | 145.30 KiB | 16 | 16 | 16 | 1170 |!
| mem__instruments | myisamkeybufferusagedata | 256.00 KiB | 155.60 KiB | 16 | 16 | 16 | 1192 |!
| mem__instruments | connectionsdata | 240.00 KiB | 129.12 KiB | 15 | 15 | 15 | 1106 |!
| mem__instruments | diskioopstotaldata | 240.00 KiB | 143.94 KiB | 15 | 15 | 15 | 533 |!
| mem__instruments | diskiototaldata | 240.00 KiB | 143.94 KiB | 15 | 15 | 15 | 533 |!
| mem__instruments | innodbchangebufferactivitydata | 240.00 KiB | 124.43 KiB | 15 | 15 | 15 | 1003 |!
| mem__instruments | innodbcheckpointagedata | 240.00 KiB | 122.65 KiB | 15 | 15 | 15 | 1052 |!
+------------------+------------------------------------------------+------------+------------+-------+--------------+-----------+-------------+

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 |!
+---------------------------------------------+

Statement Analysis
mysql> select * from statement_analysis limit 11G!
*************************** 1. row ***************************!
query: INSERT INTO `mem__quan` . `nor ... nDuration` = IF ( VALUES ( ...!
db: mem!
full_scan:!
exec_count: 1110067!
err_count: 0!
warn_count: 0!
total_latency: 1.93h!
max_latency: 5.03 s!
avg_latency: 6.27 ms!
lock_latency: 00:18:29.18!
rows_sent: 0!
rows_sent_avg: 0!
rows_examined: 0!
rows_examined_avg: 0!
tmp_tables: 0!
tmp_disk_tables: 0!
rows_sorted: 0!
sort_merge_passes: 0!
digest: d48316a218e95b1b8b72db5e6b177788!
first_seen: 2014-05-20 10:42:17

Statement With Errors And Warnings
mysql> select * from statements_with_errors_or_warnings limit 1G!
*************************** 1. row ***************************!
query: CREATE TEMPORARY TABLE IF NOT ... _logs` ( `id` INT8 NOT NULL )!
db: mem!
exec_count: 1725!
errors: 1725!
error_pct: 100.0000!
warnings: 0!
warning_pct: 0.0000!
first_seen: 2014-05-20 10:42:32!
last_seen: 2014-05-21 18:39:22!
digest: 51fb979dbc3910a6294c7cdabd7839c3

Statement With Sorting
mysql> select * from statements_with_sorting limit 1G!
*************************** 1. row ***************************!
query: SELECT `s` . `identityId` , `s ... `subject_id` = `s` . `id` ...!
db: mem!
exec_count: 1406!
sort_merge_passes: 0!
avg_sort_merges: 0!
sorts_using_scans: 1406!
sort_using_range: 1406!
rows_sorted: 39865!
avg_rows_sorted: 28!
first_seen: 2014-05-20 10:42:08!
last_seen: 2014-05-21 14:04:02!
digest: 9972d1d2cc12b92fe938ec5bd74d2f1d

Wait Analysis Views
▪ 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 |!
+------------------------------------+

MySQL Performance Schema and SYS Schema

MySQL Performance Schema and SYS Schema

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