1. MySQL Performance for DevOps
October 26, 2020
Sveta Smirnova

2. • MySQL Support engineer
• Author of
• MySQL Troubleshooting
• JSON UDF functions
• FILTER clause for MySQL
• Speaker
• Percona Live, OOW, Fosdem,
DevConf, HighLoad...
Sveta Smirnova
2

3. •Introduction
•Hardware
Memory
Disk
CPU
Network
•Configuration
Important Options
•Query Tuning on the Server Side
Indexes
Optimizer Histograms
Optimizer Configuration
Table of Contents
3

4. Introduction

5. • Database server
• 25 years of history
• Popular forks
•
Percona Server for MySQL
•
MariaDB Server
• Replication support from the beginning
What is MySQL?
5

6. Connectors: C, JDBC, ODBC, Python, ...
Connection Pool: Authentication, Caches
SQL interface
Parser
Optimizer
Caches and Buffers:
Global
Engine-specific
Storage engines: InnoDB, MyRocks, ...
File system: Data, Index, logs, other files
•
mysqld and its files
•
Connectors
•
Optimizer
• Caches
• Storage Engines
• Management
MySQL Architecture
6

7. • Bare hardware
• Cloud
• Container-orchestration systems
Where MySQL Installed in 2020?
7

8. Percona Kubernetes Operator for PXC
MySQL Operator
MySQL Kubernetes Operators
8

9. Query
ConfigurationHardware
What Affects Performance?
9

10. Hardware

11. • Bare hardware
•
Operating system options
How to Tune?
11

12. • Bare hardware
•
Operating system options
•
Clouds
• Administrator console
How to Tune?
11

13. • Bare hardware
•
Operating system options
•
Clouds
• Administrator console
• Percona Kubernetes Operator for PXC
cr.yaml
pxc.resources.requests.memory
pxc.resources.requests.cpu
pxc.resources.limits.memory
pxc.volumeSpec.resources.requests.storage
How to Tune?
11

14. • Memory
• Disk
• CPU
•
Network
What to Tune?
12

15. Hardware
Memory

16. • No swapping: sysctl vm.swappiness=1
Memory Configuration
14

17. • No swapping: sysctl vm.swappiness=1
• NUMA interleave: enable in BIOS
Memory Configuration
14

18. • No swapping: sysctl vm.swappiness=1
• NUMA interleave: enable in BIOS
• More is better
Memory Configuration
14

19. • No swapping: sysctl vm.swappiness=1
• NUMA interleave: enable in BIOS
• More is better
•
Memory access is faster than disk access
Memory Configuration
14

20. • No swapping: sysctl vm.swappiness=1
• NUMA interleave: enable in BIOS
• More is better
•
Memory access is faster than disk access
•
Frequently accessed data should be in memory
Memory Configuration
14

21. • Global buffers
• Allocated up to the limit and freed at shutdown
InnoDB Buffer Pool Size
Performance Schema tables
How MySQL Uses Memory
15

22. • Global buffers
• Session buffers
•
Allocated when session starts
• Freed at the disconnect
Connection and result buffers: from net buffer length up to max allowed packet
How MySQL Uses Memory
15

23. • Global buffers
• Session buffers
• Operation-specific buffers
• Allocated for the operation life time
• Can be allocated multiple times
join buffer size: for each tables pair in JOIN
tmp table size: for each temporary table
How MySQL Uses Memory
15

24. Hardware
Disk

25. • Faster is better
•
SSD
• NVMe
• Spinning disk
Disk Configuration
17

26. • Faster is better
•
SSD
• NVMe
• Spinning disk
•
Parallel writes
Disk Configuration
17

27. • Faster is better
•
SSD
• NVMe
• Spinning disk
•
Parallel writes
•
Battery-backed cache
Disk Configuration
17

28. • Tables data
How MySQL Uses Disk
18

29. • Tables data
•
Log files
• Binary
• Storage engine
InnoDB redo log file
• Error, general, audit, ...
How MySQL Uses Disk
18

30. • Tables data
•
Log files
• Binary
• Storage engine
InnoDB redo log file
• Error, general, audit, ...
•
Disk-based temporary tables
How MySQL Uses Disk
18

31. • Tables data
•
Log files
• Binary
• Storage engine
InnoDB redo log file
• Error, general, audit, ...
•
Disk-based temporary tables
• You may put these on different disks
How MySQL Uses Disk
18

32. Hardware
CPU

33. •
IO scheduler [noop] or [deadline]
• sudo echo noop >
/sys/block/YOUR DISK/queue/scheduler
or sudo echo deadline >
/sys/block/YOUR DISK/queue/scheduler
CPU Configuration
20

34. •
IO scheduler [noop] or [deadline]
• sudo echo noop >
/sys/block/YOUR DISK/queue/scheduler
or sudo echo deadline >
/sys/block/YOUR DISK/queue/scheduler
•
CPU governor: set to performance
CPU Configuration
20

35. •
IO scheduler [noop] or [deadline]
• sudo echo noop >
/sys/block/YOUR DISK/queue/scheduler
or sudo echo deadline >
/sys/block/YOUR DISK/queue/scheduler
•
CPU governor: set to performance
•
More cores is better
CPU Configuration
20

36. • One thread per connection
•
CPU used only for active threads
How MySQL Uses CPU
21

37. • One thread per connection
•
CPU used only for active threads
• Background work by storage engines
How MySQL Uses CPU
21

38. Server
Storage Engine
Connection and Engine Threads
22

39. ? <= CPU cores?
What Happens with Threads
23

40. ? <= CPU cores?
Yes Executed simultaneously
What Happens with Threads
23

41. ? <= CPU cores?
Yes Executed simultaneously
No Wait in a queue
What Happens with Threads
23

42. ? <= CPU cores?
Yes Executed simultaneously
No Wait in a queue
? Does the disk support parallel write?
What Happens with Threads
23

43. ? <= CPU cores?
Yes Executed simultaneously
No Wait in a queue
? Does the disk support parallel write?
Yes Write happens
What Happens with Threads
23

44. ? <= CPU cores?
Yes Executed simultaneously
No Wait in a queue
? Does the disk support parallel write?
Yes Write happens
No Wait in a queue
What Happens with Threads
23

45. Hardware
Network

46. • As fast as possible
• Speed of the line
RTT
•
Bandwidth
• Stability
To avoid TCP packet re-submission
Network Configuration
25

47. • As fast as possible
• On the Internet connection
•
Clients can work
• Asynchronous replica will delay
• Synchronous clusters will be not functional
Node disconnects with default options
Very slow response times with adjusted configuration
Network Configuration
25

48. • Communication between server and client
•
Regular client
• Application
• Replication connection (IO) thread
•
Traffic between synchronous nodes
How MySQL Uses Network
26

49. Configuration

50. • Server options
•
Components
• Storage engines
InnoDB
•
Plugins
• Server
Binary logging
Optimizer
What can be Configured?
28

51. • Global
• Parameters, necessary for all server processes
Location of server files: datadir etc.
Shared buffers
More
•
Session
• Control connection-specific parameters
MySQL Option Tables
System Variables and Options: Scope
29

52. •
SET [GLOBAL|PERSIST] var = NEW VALUE
System Variables: How to Change
30

53. •
SET [GLOBAL|PERSIST] var = NEW VALUE
•
Command-line option: --var=new value
System Variables: How to Change
30

54. •
SET [GLOBAL|PERSIST] var = NEW VALUE
•
Command-line option: --var=new value
• Configuration file
In the default location
• Specified by option --defaults-file
[mysqld]
var=new_value
System Variables: How to Change
30

55. • PXC Operator Configuration
• In cr.yaml
spec:
secretsName: my-cluster-secrets
pxc:
...
configuration: |
[mysqld]
innodb_log_file_size=8G
System Variables: How to Change
30

56. • PXC Operator Configuration
• In ConfigMap
Create custom configuration file my.cnf
[mysqld]
innodb_log_file_size=8G
System Variables: How to Change
30

57. • PXC Operator Configuration
• In ConfigMap
Create custom configuration file my.cnf
[mysqld]
innodb_log_file_size=8G
Create ConfigMap: kubectl create configmap cluster1-pxc --from-file=my.cnf
System Variables: How to Change
30

58. • PXC Operator Configuration
• In ConfigMap
Create custom configuration file my.cnf
[mysqld]
innodb_log_file_size=8G
Create ConfigMap: kubectl create configmap cluster1-pxc --from-file=my.cnf
Restart PXC
System Variables: How to Change
30

59. • Global options and few session options
< 8.0 A user with privilege SUPER
8.0 + A user with privilege SYSTEM VARIABLES ADMIN
Dynamic Variables: Who Can Change
31

60. • Global options and few session options
< 8.0 A user with privilege SUPER
8.0 + A user with privilege SYSTEM VARIABLES ADMIN
• Session options
< 8.0 Anybody
8.0 + Restricted privileges
SYSTEM VARIABLES ADMIN
SESSION VARIABLES ADMIN
8.0 + Not restricted privileges: anybody
Dynamic Variables: Who Can Change
31

61. • Global options and few session options
< 8.0 A user with privilege SUPER
8.0 + A user with privilege SYSTEM VARIABLES ADMIN
• Session options
< 8.0 Anybody
8.0 + Restricted privileges
SYSTEM VARIABLES ADMIN
SESSION VARIABLES ADMIN
8.0 + Not restricted privileges: anybody
• There are no limits!
Dynamic Variables: Who Can Change
31

62. • Those which control behavior of whole server
• Once at server startup
• Can start with low values, then grow to specified
Buffers: When Allocated
32

63. • Those which control behavior of whole server
• Once at server startup
• Can start with low values, then grow to specified
• Connection options
•
For every connection when connection opens
Buffers: When Allocated
32

64. • Those which control behavior of whole server
• Once at server startup
• Can start with low values, then grow to specified
• Connection options
•
For every connection when connection opens
•
Operation-specific
• For every operation when needed
•
Can be allocated more than once
Buffers: When Allocated
32

65. Configuration
Important Options

66. •
innodb buffer pool size
• Ideally should hold active data set
InnoDB
34

67. •
innodb buffer pool size
• innodb log file size
• Should hold changes for an hour
InnoDB
34

68. •
innodb buffer pool size
• innodb log file size
• Should hold changes for an hour
• Too low
InnoDB
34

69. •
innodb buffer pool size
• innodb log file size
• Should hold changes for an hour
• Good
InnoDB
34

70. •
innodb buffer pool size
• innodb log file size
• innodb thread concurrency
• 0 or number of CPU cores
InnoDB
34

71. •
innodb buffer pool size
• innodb log file size
• innodb thread concurrency
• innodb io capacity
•
Default is too small for fast disks
• Up to number of IOPS your disk can handle
InnoDB
34

72. •
innodb buffer pool size
• innodb log file size
• innodb thread concurrency
• innodb io capacity
•
innodb flush method
•
In most cases: O DIRECT
•
Test on your filesystem!
InnoDB
34

73. • Changing these compromize durability!
Synchronization
35

74. • Changing these compromize durability!
• innodb flush log at trx commit
1: full ACID, default
Synchronization
35

75. • Changing these compromize durability!
• innodb flush log at trx commit
1: full ACID, default
2: logs written at each commit, flushed per second
MySQL can handle up to 1M INSERTs per second
Safe with PXC and InnoDB Cluster
Synchronization
35

76. • Changing these compromize durability!
• innodb flush log at trx commit
1: full ACID, default
2: logs written at each commit, flushed per second
0: logs are written and flushed once per second
Synchronization
35

77. • Changing these compromize durability!
• innodb flush log at trx commit
1: full ACID, default
2: logs written at each commit, flushed per second
0: logs are written and flushed once per second
• Once per second not guaranteed for 0 and 2
DDL can cause faster flushing
Scheduling may delay flushing
Synchronization
35

78. • Changing these compromize durability!
• innodb flush log at trx commit
• sync binlog
0: Synchronization handled by the system
1: At each transaction commit, default
No transaction lost
N: After N binary log group commits
In case of power or OS crash not flushed transactions can be lost
Synchronization
35

79. •
table open cache
• The number of open tables for all threads
•
Increase when
Connections in the PROCESSLIST are waiting for opening a table
Value of global status variable Opened tables is larger than Open tables
Table Handlers
36

80. •
table open cache
• table definition cache
• Size of the cache for table definitions
• Increase when
Value of Opened table definitions is larger than Open table definitions
Table Handlers
36

81. •
table open cache
• table definition cache
• Increase OS open files limit if needed
Table Handlers
36

82. Query Tuning on the Server Side

83. • You communicate with database using queries
•
Even via NoSQL interface
• They are not SQL queries, but still queries
Heart of the application
38

84. • You communicate with database using queries
•
Even via NoSQL interface
• They are not SQL queries, but still queries
• Data, which you request, matters
•
1,000,000,000 rows
vs 1 row
Heart of the application
38

85. Query sent
Connection Pool: Authentication, Caches; SQL interface; Parser
Optimizer
Storage engines
Hardware
Query execution workflow
39

86. • Selecting a lot of data
• SELECT * FROM many columns table
You May not Be Able to Change Slow Query
40

87. • Selecting a lot of data
• SELECT * FROM many columns table
• Badly written
•
LEFT JOIN instead of INNER JOIN
•
Many values in IN()
• Retrieving large result set, then discarding
•
Not effective SQL
For particular MySQL version
You May not Be Able to Change Slow Query
40

88. • Selecting a lot of data
• SELECT * FROM many columns table
• Badly written
•
LEFT JOIN instead of INNER JOIN
•
Many values in IN()
• Retrieving large result set, then discarding
•
Not effective SQL
For particular MySQL version
•
We still can improve performance
You May not Be Able to Change Slow Query
40

89. Query Tuning on the Server Side
Indexes

90. SELECT name FROM users SELECT name FROM users WHERE id=12
1 2 5 6 7 9 12 16 18 21 22 23 24 25
Full Table Scan
42

91. SELECT name FROM users SELECT name FROM users WHERE id=12
1 2 5 6 7 9 12 16 18 21 22 23 24 25
After Index Added
43

92. d001
d003
d008
d009
d003******
d009******
d008******
d009******
d001******
d003******
d009******
d008******
d009******
d001******
d008******
d008******
d001******
• B-Tree (Mostly)
• Fractal Tree
• LSM Tree
• R-Tree (Spatial)
• Hash (Memory SE)
• Engine-dependent
MySQL Indexes
44

93. • Single column
CREATE INDEX index name ON
the table(the column)
• Multiple columns
CREATE INDEX index name ON
the table(column1, column2)
How to Create an Index
45

94. • Single column
ALTER TABLE table name ADD INDEX
[index name] (the column)
• Multiple columns
ALTER TABLE table name ADD INDEX
[index name] (column1, column2)
How to Create an Index
45

95. •
WHERE the column = a value
• WHERE the column IN(value1, value2,
value3)
• WHERE the column LIKE ’value%’
• WHERE the column LIKE ’%value’
When MySQL Uses Indexes: Conditions
46

96. •
WHERE left part = value1 AND
right part = value2
• WHERE left part = value1 OR
right part = value2
• WHERE right part = value1 AND
left part = value2
•
WHERE right part = value1 OR left part =
value2
When MySQL Uses Indexes: Conditions
46

97. •
table1 JOIN table2 ON table1.column1
= table2.column2
When MySQL Uses Indexes: Joins
47

98. •
table1 JOIN table2 ON table1.column1
= table2.column2
• Same as FROM table1, table2 WHERE
table1.column1 = table2.column2
When MySQL Uses Indexes: Joins
47

99. •
GROUP BY the column
• GROUP BY left part, right part
• GROUP BY right part, left part
• GROUP BY the index, another index
When MySQL Uses Indexes: GROUP BY
48

100. •
ORDER BY the column
• ORDER BY left part, right part
• ORDER BY right part, left part
• ORDER BY the index, another index
When MySQL Uses Indexes: ORDER BY
49

101. 5.7 ORDER BY left part DESC, right part ASC
8.0 ORDER BY left part DESC, right part
ASC
• left part must be descending
• right part must be ascending
• the index(left part DESC, right part ASC)
When MySQL Uses Indexes: ORDER BY
49

102. • Deterministic, built-in
•
Return same value for the same argument
• WHERE the column = FLOOR(123.45)
When MySQL Uses Indexes: Expressions
50

103. • Deterministic, built-in
•
Return same value for the same argument
• WHERE the column = FLOOR(123.45)
• Non-deterministic
•
Return different values for different invocations
• WHERE the column = RAND() ∗ 100
When MySQL Uses Indexes: Expressions
50

104. • Deterministic, built-in
•
Return same value for the same argument
• WHERE the column = FLOOR(123.45)
• Non-deterministic
•
Return different values for different invocations
• WHERE the column = RAND() ∗ 100
•
Stored functions and UDFs
• Indexes are not used
Use generated column indexes
When MySQL Uses Indexes: Expressions
50

105. • Identify which queries do not use indexes
•
Status variables
mysql> select * from performance_schema.session_status
-> where variable_name in (’Created_tmp_tables’,
-> ’Created_tmp_disk_tables’, ’Select_full_join’,
-> ’Select_full_range_join’, ’Select_range’,
-> ’Select_range_check’, ’Select_scan’, ’Sort_merge_passes’,
-> ’Sort_range’, ’Sort_rows’, ’Sort_scan’) and variable_value>0;
+------------------------+----------------+
| VARIABLE_NAME | VARIABLE_VALUE |
+------------------------+----------------+
| Select_scan | 2 |
+------------------------+----------------+
Add Indexes
51

106. • Identify which queries do not use indexes
mysql> show global status like ’Handler_read%’;
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| Handler_read_first | 31 |
| Handler_read_key | 1909 |
| Handler_read_last | 0 |
| Handler_read_next | 4393 |
| Handler_read_prev | 0 |
| Handler_read_rnd | 0 |
| Handler_read_rnd_next | 1135 |
+-----------------------+-------+
Add Indexes
51

107. • Identify which queries do not use indexes
•
PERFORMANCE SCHEMA.EVENTS STATEMENTS *
mysql> select * from events_statements_history_long
-> where sql_text like ’select count(*) from employees join %’G
*************************** 1. row ****************************
...
ROWS_SENT: 1 SELECT_RANGE_CHECK: 0
ROWS_EXAMINED: 541058 SELECT_SCAN: 1
CREATED_TMP_DISK_TABLES: 0 SORT_MERGE_PASSES: 0
CREATED_TMP_TABLES: 0 SORT_RANGE: 0
SELECT_FULL_JOIN: 0 SORT_ROWS: 0
SELECT_FULL_RANGE_JOIN: 0 SORT_SCAN: 0
SELECT_RANGE: 0 NO_INDEX_USED: 0
Add Indexes
51

108. • Identify which queries do not use indexes
•
Slow query log
# Time: 2020-10-11T23:34:03.701871Z
# User@Host: root[root] @ localhost [127.0.0.1] Id: 506
# Query_time: 0.024106 Lock_time: 0.000091
Rows_sent: 1 Rows_examined: 1000
SET timestamp=1602459243;
SELECT c FROM sbtest1 WHERE id=996;
Add Indexes
51

109. • Identify which queries do not use indexes
•
QAN in PMM
Add Indexes
51

110. • Identify which queries do not use indexes
• Analyze if adding an index will help
Add Indexes
51

111. • Identify which queries do not use indexes
• Analyze if adding an index will help
• Add the index
Add Indexes
51

112. • Identify which queries do not use indexes
• Analyze if adding an index will help
• Add the index
• Test first!
• ADD INDEX is expensive operation
Use pt-online-schema-change
Add Indexes
51

113. Query Tuning on the Server Side
Optimizer Histograms

114. • Since version 8.0
Histogram Statistics
53

115. • Since version 8.0
• Collected and used by the Optimizer
Histogram Statistics
53

116. • Since version 8.0
• Collected and used by the Optimizer
• Can be examined in Information Schema
mysql> select HISTOGRAM from information_schema.column_statistics
-> where table_name=’example’G
*************************** 1. row ***************************
HISTOGRAM: {"buckets": [[1, 0.6], [2, 0.8], [3, 1.0]],
"data-type": "int", "null-values": 0.0, "collation-id": 8,
"last-updated": "2018-11-07 09:07:19.791470",
"sampling-rate": 1.0, "histogram-type": "singleton",
"number-of-buckets-specified": 3}
1 row in set (0.00 sec)
Histogram Statistics
53

117. • Since version 8.0
• Collected and used by the Optimizer
• Can be examined in Information Schema
• Affects query execution plan, but not access
• SELECT ... FROM a JOIN b
vs SELECT ... FROM b JOIN a
Histogram Statistics
53

118. • Since version 8.0
• Collected and used by the Optimizer
• Can be examined in Information Schema
• Affects query execution plan, but not access
More details
Histogram Statistics
53

119. 1 2 3 4 5 6 7 8 9 10
0
200
400
600
800
Indexes: Number of Items with Same Value
54

120. 1 2 3 4 5 6 7 8 9 10
0
200
400
600
800
Indexes: Cardinality
55

121. 1 2 3 4 5 6 7 8 9 10
0
200
400
600
800
Histograms: Number of Values in Each Bucket
56

122. 1 2 3 4 5 6 7 8 9 10
0
0.2
0.4
0.6
0.8
1
Histograms: Data in the Histogram
57

123. • Data distribution is far from uniform
• Query accesses two or more tables
•
Indexes cannot be used
•
Maintaining them is too expensive
•
They are already used for different condition
Create Histograms
58

124. Query Tuning on the Server Side
Optimizer Configuration

125. mysql> select @@optimizer_switchG
*************************** 1. row ***************************
@@optimizer_switch: index_merge=on,index_merge_union=on,
index_merge_sort_union=on,index_merge_intersection=on,
engine_condition_pushdown=on,index_condition_pushdown=on,
mrr=on,mrr_cost_based=on,
block_nested_loop=on,batched_key_access=off,
materialization=on,semijoin=on,loosescan=on,firstmatch=on,
duplicateweedout=on,subquery_materialization_cost_based=on,
use_index_extensions=on,condition_fanout_filter=on,derived_merge=on
1 row in set (0,00 sec)
Optimizer Switches
60

126. • Turn ON and OFF particular optimization
Optimizer Switches
60

127. • Turn ON and OFF particular optimization
• Can be not helpful
• Especially for queries, tuned for previous versions
Optimizer Switches
60

128. • Turn ON and OFF particular optimization
• Can be not helpful
• Work with them as with any other option
• Turn OFF and try
SET optimizer_switch = ’use_index_extensions=off’;
SELECT ...
EXPLAIN SELECT ...
Optimizer Switches
60

129. • Turn ON and OFF particular optimization
• Can be not helpful
• Work with them as with any other option
•
If helps implement in queries
SELECT /*+ SEMIJOIN(FIRSTMATCH, LOOSESCAN) */ * FROM t1 ...;
SELECT /*+ BKA(t1) NO_BKA(t2) */ * FROM t1 INNER JOIN t2 WHERE ...;
Optimizer Switches
60

130. • Temporary tables
•
tmp table size
•
max heap table size
• default tmp storage engine
Increase Size of Optimizer Temporary Objects
61

131. • Temporary tables
• Buffers for query execution
•
join buffer size
JOIN conditions, not using indexes
Increase Size of Optimizer Temporary Objects
61

132. • Temporary tables
• Buffers for query execution
•
join buffer size
• read buffer size
Caching indexes for ORDER BY
Bulk insert into partitions
Caching result of nesting queries
Increase Size of Optimizer Temporary Objects
61

133. • Temporary tables
• Buffers for query execution
•
join buffer size
• read buffer size
• read rnd buffer size
Multi-Range Read optimization
Increase Size of Optimizer Temporary Objects
61

134. • Temporary tables
• Buffers for query execution
•
join buffer size
• read buffer size
• read rnd buffer size
• select into buffer size
SEELCT INTO OUTFILE
SEELCT INTO DUMPFILE
Increase Size of Optimizer Temporary Objects
61

135. • Temporary tables
• Buffers for query execution
•
join buffer size
• read buffer size
• read rnd buffer size
• select into buffer size
•
sort buffer size
ORDER BY
GROUP BY
Increase Size of Optimizer Temporary Objects
61

136. • Temporary tables
• Buffers for query execution
•
join buffer size
• read buffer size
• read rnd buffer size
• select into buffer size
•
sort buffer size
• Change only at the session level!
Increase Size of Optimizer Temporary Objects
61

137. • Hardware
RAM: more is better
Disk: SSD or NVMe
CPU: more cores, better concurrency
Net: highest speed possible
Conclusion
62

138. • Hardware
• Configuration
•
InnoDB
innodb buffer pool size
innodb log file size
innodb thread concurrency
innodb io capacity
innodb flush method
innodb flush log at trx commit
• Server
sync binlog
table open cache
table definition cache
Conclusion
62

139. • Hardware
• Configuration
• Query Performance
•
Add indexes, histograms
•
Tune Optimizer
• Adjust Optimization buffers
tmp table size
join buffer size
read buffer size
read rnd buffer size
select into buffer size
sort buffer size
Conclusion
62

140. Troubleshooting hardware resource usage
Troubleshooting configuration issues
MySQL Query Tuning for DevOps
Percona Monitoring and Management
Percona Kubernetes Operators
More information
63

141. www.slideshare.net/SvetaSmirnova
twitter.com/svetsmirnova
github.com/svetasmirnova
Thank you!
64