The MySQL SYS Schema
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The document describes the MySQL SYS schema, which provides views, procedures, and functions to help database administrators, developers, and operations teams perform common debugging and tuning tasks. It includes summary views that breakdown user activity by I/O usage, stages, and statement details. The SYS schema also includes views and functions for analyzing I/O performance and retrieving the latest file I/O events. It can be installed on MySQL servers to provide a standardized way of accessing performance data.
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cerberus:~ mark$ more Documents/statement_graphs/deletes.dot!
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Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
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……! !](https://image.slidesharecdn.com/mysqlsysschemaoow2014-141002125628-phpapp02/85/The-MySQL-SYS-Schema-52-320.jpg)
The MySQL SYS Schema
- 2. The MySQL SYS Schema Mark Leith Senior Software Development Manager MySQL Enterprise Tools, Oracle Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 3. Safe Harbor Statement The following is intended to outline our general product direction. It is intended for information purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions. The development, release, and timing of any features or functionality described for Oracle’s products remains at the sole discretion of Oracle. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 4. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | Program Agenda Introduction to the MySQL sys schema Installation Summary Views Procedures and Functions 1 2 3 4
- 5. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | Program Agenda Introduction to the MySQL sys schema Installation Summary Views Procedures and Functions 1 2 3 4
- 6. Introduction to the MySQL sys schema • Originally called “ps_helper” • A collection of views, procedures and functions, designed to help DBA, Developer, and Ops teams • Implements many of the common day to day DBA and Developer debugging and tuning use cases Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 7. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | Why the sys schema? • Performance Schema exposes a huge amount of data, that can be sliced and diced in many ways • Many of its tables can implement many different use cases when looking at the raw data • The sys schema layers on top the (sometimes complex) queries in to a packaged set of easy to use views • The sys schema also layers on a number of functions and procedures that help format, and record the raw data
- 8. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | Program Agenda Introduction to the MySQL sys schema Installation Summary Views Procedures and Functions 1 2 3 4
- 9. Installation from the command line • $ git clone https://github.com/MarkLeith/mysql-sys.git /tmp/sys • $ cd /tmp/sys • $ mysql -u user -p < sys_<version>.sql ! ! <version> can be 56 or 57, for 5.6 and 5.7 respectively Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 10. Installation from MySQL Workbench 6.1+ Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 11. ! ! select * from sys.version;! +-------------+---------------+! | sys_version | mysql_version |! +-------------+---------------+! | 1.1.0 | 5.6.17 |! +-------------+---------------+ Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | 11 Checking sys is loaded select *! from sys.schema_object_overview! where db = 'sys';! +-----+-------------+-------+! | db | object_type | count |! +-----+-------------+-------+! | sys | VIEW | 78 |! | sys | PROCEDURE | 22 |! | sys | FUNCTION | 11 |! +-----+-------------+-------+
- 12. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | Program Agenda Introduction to the MySQL sys schema Installation Summary Views Procedures and Functions 1 2 3 4
- 13. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | MySQL sys views • Reference set of views solving various administrator use cases • Simple views, create/copy your own, sys is not “locked down” • Build upon both performance_schema and INFORMATION_SCHEMA • Both formatted and raw views are available • All raw views are prefixed with x$ • Raw views are there for tools to poll • Formatted views are for humans and the command line
- 14. ! • High level user/host overviews • Breakdowns by: • IO usage • Stages • Statement details Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | ! • Following show users only 14 User / Host Summary Views 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 host_summary host_summary_by_file_io host_summary_by_file_io_type host_summary_by_stages host_summary_by_statement_latency host_summary_by_statement_type
- 15. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | user_summary view 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 MySQL 5.7.4+
- 16. user_summary_by_file_io_type view mysql> select * from user_summary_by_file_io_type;! +------+--------------------------------------+---------+-------------+-------------+! | 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 |! ! Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 17. user_summary_by_statement_latency view mysql> select * from user_summary_by_statement_latencyG! *************************** 1. row ***************************! Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | user: mark! total: 176! total_latency: 1.26 s! max_latency: 583.33 ms! lock_latency: 216.95 ms! rows_sent: 311! rows_examined: 307! rows_affected: 0! full_scans: 7!
- 18. user_summary_by_statement_type view mysql> select * from user_summary_by_statement_typeG! *************************** 1. row ***************************! Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | user: mark! statement: commit! total: 2463190! total_latency: 13.33h! max_latency: 12.18 s! lock_latency: 0 ps! rows_sent: 0! rows_examined: 0! rows_affected: 0! full_scans: 0!
- 19. ! • IO by current threads • Global summaries by file and class, aggregating by bytes or latency • Stream of last file IO events in raw form Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | 19 IO Summary Views ! 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
- 20. io_by_thread_by_latency view mysql> select * from io_by_thread_by_latencyG! *************************** 1. row ***************************! Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | user: main! total: 1193! total_latency: 136.45 ms! min_latency: 731.38 ns! avg_latency: 269.99 us! max_latency: 20.72 ms! thread_id: 1! processlist_id: NULL! *************************** 2. row ***************************! user: root@localhost! total: 533! total_latency: 53.81 ms! min_latency: 780.39 ns! avg_latency: 8.41 ms! max_latency: 25.06 ms! thread_id: 23! processlist_id: 4
- 21. io_global_by_file_by_latency view mysql> select * from io_global_by_file_by_latency limit 1G! *************************** 1. row ***************************! file: @@datadir/ibdata1! total: 1395714! Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | 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
- 22. latest_file_io view mysql> select * from latest_file_io;! +-----------------------------+----------------------------------+-----------+-----------+-----------+! | thread | file | latency | operation | requested |! +-----------------------------+----------------------------------+-----------+-----------+-----------+! | root@localhost:63153:179371 | @@datadir/ib_logfile1 | 7.16 us | lock | NULL |! | root@localhost:63153:179371 | @@datadir/ib_logfile1 | 6.16 us | write | 1.50 KiB |! | root@localhost:63153:179371 | @@datadir/ib_logfile1 | 14.36 ms | sync | NULL |! | root@localhost:63153:179371 | @@datadir/cerberus-bin.000012 | 28.25 us | write | 905 bytes |! | root@localhost:63177:179394 | @@datadir/ib_logfile1 | 15.25 us | write | 1.00 KiB |! | root@localhost:57487:3 | @@datadir/cerberus-bin.000012 | 32.12 us | read | 905 bytes |! | root@localhost:63177:179394 | @@datadir/ib_logfile1 | 6.65 us | write | 1.00 KiB |! | root@localhost:63177:179394 | @@datadir/ib_logfile1 | 213.32 us | sync | NULL |! | root@localhost:63177:179394 | @@datadir/ib_logfile1 | 17.27 us | write | 1.00 KiB |! | root@localhost:63177:179394 | @@datadir/ib_logfile1 | 286.01 us | sync | NULL |! | root@localhost:63177:179394 | @@datadir/cerberus-bin.000012 | 18.77 us | write | 601 bytes |! | root@localhost:57487:3 | @@datadir/cerberus-bin.000012 | 7.55 us | read | 601 bytes |! | root@localhost:63177:179394 | @@datadir/ib_logfile1 | 10.67 us | write | 1.00 KiB |! | root@localhost:63177:179394 | @@datadir/ib_logfile1 | 200.28 us | sync | NULL |! | root@localhost:63177:179394 | @@datadir/cerberus-bin.000012 | 12.91 us | write | 601 bytes |! | root@localhost:57487:3 | @@datadir/cerberus-bin.000012 | 6.47 us | read | 601 bytes |! | root@localhost:63177:179394 | @@datadir/ib_logfile1 | 9.22 us | write | 1.50 KiB |! …… Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 23. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | ! • Object overview • Table usage statistics • Index usage statistics • Following show users only 23 Schema Analysis Views schema_index_statistics schema_object_overview schema_table_statistics schema_table_statistics_with_buffer schema_tables_with_full_table_scans schema_unused_indexes
- 24. schema_table_statistics view mysql> select * from schema_table_statistics limit 1G! *************************** 1. row ***************************! Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | table_schema: mem__quan! table_name: normalized_statements_by_server_by_schema_data! total_latency: 00:55:07.80! 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
- 25. schema_index_statistics view mysql> select * from schema_index_statistics limit 1G! *************************** 1. row ***************************! table_schema: mem__inventory! table_name: mysqlconnectionconfiguration! index_name: PRIMARY! Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | 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
- 26. schema_tables_with_full_table_scans view mysql> select * from schema_tables_with_full_table_scans limit 10;! +--------------------+--------------------------------+-------------------+-----------+! | object_schema | object_name | rows_full_scanned | latency |! +--------------------+--------------------------------+-------------------+-----------+! | mem30__instruments | fsstatistics | 10207042 | 13.10 s |! | mem30__instruments | preparedstatementapidata | 436428 | 973.27 ms |! | mem30__instruments | mysqlprocessactivity | 411702 | 282.07 ms |! | mem30__instruments | querycachequeriesincachedata | 374011 | 767.15 ms |! | mem30__instruments | rowaccessesdata | 322321 | 1.55 s |! | mem30__instruments | connectionsmaxdata | 301242 | 857.63 ms |! | mem30__instruments | innodbdatadictionarymemorydata | 292564 | 495.38 ms |! | mem30__instruments | innodbbufferpooldata | 277112 | 1.95 s |! | mem30__instruments | avgrowaccessesdata | 269236 | 1.25 s |! | mem30__instruments | innodbrowdetailsdata | 248208 | 653.25 ms |! +--------------------+--------------------------------+-------------------+-----------+ Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 27. schema_unused_indexes view mysql> select * from schema_unused_indexes limit 10;! +--------------------+-----------------------------------+--------------------+! | object_schema | object_name | index_name |! +--------------------+-----------------------------------+--------------------+! | mem30__bean_config | plists | path |! | mem30__config | group_selections | name |! | mem30__config | notification_groups | name |! | mem30__config | user_form_defaults | FKC1AEF1F9E7EE2CFB |! | mem30__enterprise | whats_new_entries | entryId |! | mem30__events | action_logs | policyId |! | mem30__events | action_logs | eventId |! | mem30__events | action_logs | ts |! | mem30__events | advisor_scopes_advisorcategoryids | FKF0CB0DB962CAB4 |! | mem30__events | advisor_scopes_advisorclassids | FK650AF1BF962CAB4 |! +--------------------+-----------------------------------+--------------------+ You should ensure you have representative time frame before taking any actions! Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 28. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | ! • Wait summaries by class • Wait details per: • User • Host • Globally 28 Wait Analysis Views wait_classes_global_by_avg_latency wait_classes_global_by_latency waits_by_host_by_latency waits_by_user_by_latency waits_global_by_latency !
- 29. waits_global_by_latency view mysql> select * from waits_global_by_latency limit 10;! +--------------------------------------+----------+---------------+-------------+-------------+! | events | total | total_latency | avg_latency | max_latency |! +--------------------------------------+----------+---------------+-------------+-------------+! | wait/io/table/sql/handler | 24196659 | 1.75h | 259.72 us | 2.29 s |! | wait/io/file/innodb/innodb_data_file | 5964255 | 1.36h | 822.01 us | 1.49 s |! | wait/io/file/innodb/innodb_log_file | 2272647 | 00:36:41.37 | 968.64 us | 1.30 s |! | wait/io/file/myisam/kfile | 5463587 | 00:18:14.16 | 200.26 us | 1.17 s |! | wait/io/file/myisam/dfile | 1715187 | 00:08:00.18 | 279.96 us | 1.18 s |! | wait/io/file/sql/binlog | 3722079 | 00:03:23.71 | 54.73 us | 1.42 s |! | wait/lock/table/sql/handler | 10074274 | 00:01:56.63 | 11.58 us | 186.90 ms |! | wait/io/socket/sql/client_connection | 3879827 | 25.36 s | 6.54 us | 219.25 ms |! | wait/io/file/sql/FRM | 43994 | 3.27 s | 74.35 us | 80.43 ms |! | wait/io/file/sql/dbopt | 116765 | 1.29 s | 11.03 us | 63.27 ms |! +--------------------------------------+----------+---------------+-------------+-------------+ InnoDB only instance, this MyISAM IO is all temporary tables, focus tuning there! Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 30. waits_by_user_by_latency view mysql> select * from waits_by_user_by_latency;! +------+--------------------------------------+----------+---------------+-------------+-------------+! | user | event | total | total_latency | avg_latency | max_latency |! +------+--------------------------------------+----------+---------------+-------------+-------------+! | mark | wait/io/file/myisam/dfile | 19540 | 215.20 ms | 11.01 us | 120.79 ms |! | mark | wait/io/file/myisam/kfile | 501 | 131.58 ms | 262.63 us | 57.74 ms |! | mark | wait/io/file/sql/dbopt | 2 | 17.29 us | 8.64 us | 9.17 us |! | root | wait/io/table/sql/handler | 24189319 | 1.74h | 258.77 us | 2.29 s |! | root | wait/io/file/innodb/innodb_log_file | 2162650 | 00:30:52.87 | 856.76 us | 1.30 s |! | root | wait/io/file/myisam/kfile | 5460992 | 00:18:12.83 | 200.11 us | 1.17 s |! | root | wait/io/file/myisam/dfile | 1694624 | 00:07:59.50 | 282.95 us | 1.18 s |! | root | wait/io/file/sql/binlog | 3711637 | 00:03:23.16 | 54.74 us | 1.42 s |! | root | wait/io/file/innodb/innodb_data_file | 22577 | 00:03:05.73 | 8.23 ms | 492.23 ms |! | root | wait/lock/table/sql/handler | 10069000 | 00:01:56.59 | 11.58 us | 186.90 ms |! …… root is doing the most temporary table IO Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 31. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | ! • Statement overview • Find statements by: • Those with errors • Those with full table scans • Those creating temp tables • Those that cause sorting • With latency in 95th %ile 31 Statement Analysis Views statement_analysis statements_with_errors_or_warnings statements_with_full_table_scans statements_with_runtimes_in_95th_p ercentile statements_with_sorting statements_with_temp_tables
- 32. statement_analysis view mysql> select * from statement_analysis limit 2G! *************************** 1. row ***************************! query: INSERT INTO `mem30__quan` . `n ... nDuration` = IF ( VALUES ( ...! Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | db: mem! full_scan:! exec_count: 4657! err_count: 0! warn_count: 0! total_latency: 00:03:57.40! max_latency: 10.54 s! avg_latency: 50.98 ms! lock_latency: 00:03:00.93! rows_sent: 0! rows_sent_avg: 0! rows_examined: 0! rows_examined_avg: 0! rows_affected: 4794! rows_affected_avg: 1 tmp_tables: 0! tmp_disk_tables: 0! rows_sorted: 0! sort_merge_passes: 0! digest: b98bfe333642e8e4e72c73515810d865! first_seen: 2014-09-24 11:27:01! last_seen: 2014-09-24 11:53:00
- 33. statements_with_errors_or_warnings view mysql> select * from statements_with_errors_or_warnings limit 1G! *************************** 1. row ***************************! query: CREATE TEMPORARY TABLE IF NOT ... _logs` ( `id` INT8 NOT NULL )! Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | 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
- 34. statements_with_temp_tables view mysql> select * from statements_with_temp_tables limit 1G! *************************** 1. row ***************************! query: SELECT * FROM ( SELECT `digest ... ` , Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | `sum_no_index_used` AS ...! db: mysql! exec_count: 68! total_latency: 2.31 s! memory_tmp_tables: 476! disk_tmp_tables: 204! avg_tmp_tables_per_query: 7! tmp_tables_to_disk_pct: 43! first_seen: 2014-09-24 11:26:18! last_seen: 2014-09-24 12:33:00! digest: 50761c6a1818824328745d8a136b9ed6
- 35. statements_with_full_table_scans view mysql> select * from statements_with_full_table_scans limit 1G! *************************** 1. row ***************************! query: SELECT `pojotimese0_` . `id` A ... Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | ty_timeseries` `pojotimese0_`! db: mem! exec_count: 1! total_latency: 940.89 us! no_index_used_count: 1! no_good_index_used_count: 0! no_index_used_pct: 100! rows_sent: 116! rows_examined: 116! rows_sent_avg: 116! rows_examined_avg: 116! first_seen: 2014-09-24 11:25:03! last_seen: 2014-09-24 11:25:03! digest: f81b5ce10baee9be754cf35fd245a516
- 36. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | ! • Better SHOW PROCESSLIST • No mutex contention • Live statistics for query 36 Miscellaneous Views processlist !
- 37. processlist view mysql> select * from processlistG! *************************** 1. row ***************************! Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | thd_id: 7890! conn_id: 7870! user: root@localhost! db: mem! command: Query! state: update! time: 0! current_statement: /* mem dbpool.default */ inser ...<truncated>! lock_latency: 0 ps! rows_examined: 0! rows_sent: 0! rows_affected: 0! tmp_tables: 0! ! ! tmp_disk_tables: 0! full_scan: NO! last_statement: NULL! last_statement_latency: NULL! last_wait: wait/io/table/sql/handler! last_wait_latency: Still Waiting! source: handler.cc:7274
- 38. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | Program Agenda Introduction to the MySQL sys schema Installation Summary Views Procedures and Functions 1 2 3 4
- 39. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | ! • Make output human readable • Format time appropriately • Format bytes appropriately • Truncate output for large width values for CLI • Extract object names • Dump a thread stack • Check instrumented actors 39 Functions format_time format_bytes format_path format_statement extract_table_from_file_name extract_schema_from_file_name ps_thread_stack ps_is_account_enabled !
- 40. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | format_time() function mysql> select format_time(23849723429) as time! -> union select format_time(8327423749233)! -> union select format_time(83274237492335);! +-------------+! | time |! +-------------+! | 23.85 ms |! | 8.33 s |! | 00:01:23.27 |! +-------------+! ! !
- 41. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | format_bytes() function mysql> select format_bytes(23423) as bytes! -> union select format_bytes(23432423)! -> union select format_bytes(42839479283)! -> union select format_bytes(2293848203489);! +-----------+! | bytes |! +-----------+! | 22.87 KiB |! | 22.35 MiB |! | 39.90 GiB |! | 2.09 TiB |! +-----------+!
- 42. Performance Schema Config Helper Procedures • ps_setup_show_disabled() / ps_setup_show_enabled() • ps_setup_disable_thread() / ps_setup_enable_thread() • ps_setup_disable_background_threads() / ps_setup_enable_background_threads() • ps_setup_disable_instrument() / ps_setup_enable_instrument() • ps_setup_disable_consumer() / ps_setup_enable_consumer() • ps_setup_save() / ps_setup_reload_saved() • ps_setup_reset_to_default() / ps_truncate_all_tables() Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 43. ! • Dump all P_S data to a dot graph file to trace a thread • Look in the statement history table to capture more info on a statement digest Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | 43 Statement Tracing Procedures ps_trace_thread ps_trace_statement_digest ps_statement_avg_latency_histogram !
- 44. ps_trace_statement_digest procedure • ps_trace_statement_digest() analyses live traffic looking for certain statement digest for a period of time • Captures statistics on each matching statement it finds • Returns a report of the captured stats • An overall summary • A break down for the longest running example • An EXPLAIN (if the statement is not truncated) Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 45. ps_trace_statement_digest procedure • ps_trace_statement_digest() parameters • in_digest The statement digest to analyse • in_runtime How long to run analysis for • in_interval How often to snapshot data • in_start_fresh Whether to truncate P_S tables first • in_auto_enable Whether to auto enable required config Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 46. ps_trace_statement_digest procedure example !!! mysql> call analyze_statement_digest('6134e9d6f25eb8e6cddf11f6938f202a', 60, 1, true, true); +--------------------+ | SUMMARY STATISTICS | +--------------------+ | SUMMARY STATISTICS | +--------------------+ 1 row in set (59.93 sec) ! +------------+-----------+-----------+-----------+---------------+------------+------------+ | executions | exec_time | lock_time | rows_sent | rows_examined | tmp_tables | full_scans | +------------+-----------+-----------+-----------+---------------+------------+------------+ | 360 | 1.41 s | 138.39 ms | 720 | 0 | 0 | 0 | +------------+-----------+-----------+-----------+---------------+------------+------------+ 1 row in set (59.93 sec) ! +--------------------------------+-------+-----------+ | event_name | count | latency | +--------------------------------+-------+-----------+ | stage/sql/Sending data | 14 | 1.10 s | | stage/sql/update | 198 | 667.34 ms | | stage/sql/removing tmp table | 9 | 240.48 ms | ... Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 47. ps_trace_statement_digest procedure example !!! +---------------------------+ | LONGEST RUNNING STATEMENT | +---------------------------+ | LONGEST RUNNING STATEMENT | +---------------------------+ ! 1 row in set (59.95 sec) +-----------+-----------+-----------+-----------+---------------+------------+-----------+ | thread_id | exec_time | lock_time | rows_sent | rows_examined | tmp_tables | full_scan | +-----------+-----------+-----------+-----------+---------------+------------+-----------+ | 23277 | 77.64 ms | 97.00 us | 2 | 0 | 0 | 0 | +-----------+-----------+-----------+-----------+---------------+------------+-----------+ ! 1 row in set (59.95 sec) +-------------------------------------------------------------------------------------------+ | sql_text | +-------------------------------------------------------------------------------------------+ | /* mem dbpool.default */ insert into `mem__quan`.`normalized_statements_by_server_by_schema` (firstSeen, lastSeen, normalized_statement_id, `schema`, server, id) values (1378983745000, 1378998600000, x'808ACEB88FC4B45BC47C4FE9D86C7F26', 'mem', '753c939e-1b99-11e3-b6d4-bc761a1f4f2f', x'7CFE81F98B1E3FE0895D1AA2C39B326D') ON DUPLICATE KEY UPDATE ... +-------------------------------------------------------------------------------------------+ ... Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 48. ps_trace_statement_digest procedure example +--------------------------------+----------+ | event_name | latency | +--------------------------------+----------+ | stage/sql/init | 10.41 ms | | stage/sql/checking permissions | 2.35 us | | stage/sql/Opening tables | 10.32 us | | stage/sql/init | 13.53 us | | stage/sql/System lock | 3.66 us | | stage/sql/update | 61.74 ms | | stage/sql/end | 1.11 us | | stage/sql/query end | 1.31 us | | stage/sql/closing tables | 5.44 ms | | stage/sql/freeing items | 23.31 us | +--------------------------------+----------+ 10 rows in set (59.99 sec) ! +----+-------------+-------+------+---------------+------+---------+------+------+----------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+------+----------------+ | 1 | SIMPLE | NULL | NULL | NULL | NULL | NULL | NULL | NULL | No tables used | +----+-------------+-------+------+---------------+------+---------+------+------+----------------+ ... !!! Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 49. ps_trace_thread procedure • ps_trace_thread() monitors a specific thread for a period • Captures as much information on the thread activity as possible • Returns a “dot” formatted file, that can graph the event hierarchy • http://en.wikipedia.org/wiki/DOT_(graph_description_language) Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 50. ps_trace_statement_digest procedure • ps_trace_statement_digest() parameters • in_thread_id The thread to analyse • in_outfile The file to dump the data to (INTO OUTFILE) • in_max_runtime How long to run analysis for • in_interval How often to snapshot for data • in_start_fresh Whether to truncate P_S tables first • in_auto_setup Whether to auto enable required config • in_debug Whether to also print debug info (source info) Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 51. ps_trace_thread procedure example mysql> call ps_trace_thread(27768, '/tmp/stack_27768.dot', 60, 0.1, true, true, true); +------------------------------------------------+ | Info | +------------------------------------------------+ | Data collection starting for THREAD_ID = 27768 | +------------------------------------------------+ 1 row in set (4.82 sec) ! +---------------------------------------------+ | Info | +---------------------------------------------+ | Stack trace written to /tmp/stack_27768.dot | +---------------------------------------------+ 1 row in set (60.90 sec) ! +--------------------------------------------------------+ | Convert to PDF | +--------------------------------------------------------+ | dot -Tpdf -o /tmp/stack_27768.pdf /tmp/stack_27768.dot | +--------------------------------------------------------+ 1 row in set (60.90 sec) ! +--------------------------------------------------------+ | Convert to PNG | +--------------------------------------------------------+ | dot -Tpng -o /tmp/stack_27768.png /tmp/stack_27768.dot | +--------------------------------------------------------+ 1 row in set (60.90 sec)+ ! Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 52. ps_trace_thread procedure example cerberus:~ mark$ more Documents/statement_graphs/deletes.dot! digraph events {! graph [rankdir=LR, nodesep="0.10"];! node [label="N"];! graph [bb="0,0,1860,17476"];! 1 [label="(0.20μ) mysys/THR_LOCK_threadsn", style=filled, color=lightskyblue, pos="209,18", width="3.19", height="0.50"];! 2 [label="(0.18μ) sql/THD::LOCK_thd_datan", style=filled, color=lightskyblue, pos="209,61", width="3.06", height="0.50"];! 3 [label="(0.24μ) sql/hash_filo::lockn", style=filled, color=lightskyblue, pos="209,104", width="2.42", height=“0.50"];! 4 [label="(0.31μ) sql/LOGGER::LOCK_logger - read_lockn", style=filled, color=orchid, pos="209,147", width="4.22", Copyright © 2014, Oracle and/or its affiliates. All rights reserved. | height="0.50"];! 5 [label="(0.08μ) sql/LOG::LOCK_logn", style=filled, color=lightskyblue, pos="209,190", width="2.64", height="0.50"];! 6 [label="(12.97μ) wait/io/file/sql/query_log - write 49 bytesn/Users/mark/mysql/lp-mysql-trunk/mysql-test/var/mysqld.1/ mysqld.logn", style=filled, color=red, shape=box, pos="209,235", width="5.78", height="0.56"];! 7 [label="(176.14μ) sql/selectnselect @@version_comment limit 1nerrors: 0nwarnings: 0nlock time: 0.00μnrows affected: 0nrows sent:! 209,18", width="3.19", height="0.50"];mp disk tables: 0nselect scan: 0nselect full join: :! 2 [label="(0.18μ) sql/THD::LOCK_thd_datan", style=filled, color=lightskyblue, pos="209,61", width="3.06", height="0.50"];! 3 [label="(0.24μ) sql/hash_filo::lockn", style=filled, color=lightskyblue, pos="209,104", width="2.42", height="0.50"];! 4 [label="(0.31μ) sql/LOGGER::LOCK_logger - read_lockn", style=filled, color=orchid, pos="209,147", width="4.22", height="0.50"];! 5 [label="(0.08μ) sql/LOG::LOCK_logn", style=filled, color=lightskyblue, pos="209,190", width="2.64", height="0.50"];! ……! !
- 53. ps_trace_thread procedure example MySQL 5.7 ! Procedures Transactions Statements Stages Waits Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 54. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 55. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 56. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 57. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 58. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 59. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |
- 60. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. |