Version sans cache


Mise en cache désactivé. Réglage défaut pour cette page : actif (code DEF204)
Si l'affichage est trop lent, vous pouvez désactiver le mode utilisateur pour visualiser la version en cache.

Rechercher dans le manuel MySQL

26.12.4 Performance Schema Wait Event Tables

Table des matières

[+/-]

26.12.4.1 The events_waits_current Table
26.12.4.2 The events_waits_history Table
26.12.4.3 The events_waits_history_long Table

The Performance Schema instruments waits, which are events that take time. Within the event hierarchy, wait events nest within stage events, which nest within statement events, which nest within transaction events.

These tables store wait events:

The following sections describe the wait event tables. There are also summary tables that aggregate information about wait events; see Section 26.12.17.1, “Wait Event Summary Tables”.

For more information about the relationship between the three wait event tables, see Section 26.9, “Performance Schema Tables for Current and Historical Events”.

Configuring Wait Event Collection

To control whether to collect wait events, set the state of the relevant instruments and consumers:

  • The setup_instruments table contains instruments with names that begin with wait. Use these instruments to enable or disable collection of individual wait event classes.

  • The setup_consumers table contains consumer values with names corresponding to the current and historical wait event table names. Use these consumers to filter collection of wait events.

Some wait instruments are enabled by default; others are disabled. For example:

  1. mysql> SELECT NAME, ENABLED, TIMED
  2.        FROM performance_schema.setup_instruments
  3.        WHERE NAME LIKE 'wait/io/file/innodb%';
  4. +-------------------------------------------------+---------+-------+
  5. | NAME                                            | ENABLED | TIMED |
  6. +-------------------------------------------------+---------+-------+
  7. | wait/io/file/innodb/innodb_tablespace_open_file | YES     | YES   |
  8. | wait/io/file/innodb/innodb_data_file            | YES     | YES   |
  9. | wait/io/file/innodb/innodb_log_file             | YES     | YES   |
  10. | wait/io/file/innodb/innodb_temp_file            | YES     | YES   |
  11. | wait/io/file/innodb/innodb_arch_file            | YES     | YES   |
  12. | wait/io/file/innodb/innodb_clone_file           | YES     | YES   |
  13. +-------------------------------------------------+---------+-------+
  14. mysql> SELECT NAME, ENABLED, TIMED
  15.        FROM performance_schema.setup_instruments
  16.        WHERE NAME LIKE 'wait/io/socket/%';
  17. +----------------------------------------+---------+-------+
  18. | NAME                                   | ENABLED | TIMED |
  19. +----------------------------------------+---------+-------+
  20. | wait/io/socket/sql/server_tcpip_socket | NO      | NO    |
  21. | wait/io/socket/sql/server_unix_socket  | NO      | NO    |
  22. | wait/io/socket/sql/client_connection   | NO      | NO    |
  23. +----------------------------------------+---------+-------+

The wait consumers are disabled by default:

  1. mysql> SELECT *
  2.        FROM performance_schema.setup_consumers
  3.        WHERE NAME LIKE 'events_waits%';
  4. +---------------------------+---------+
  5. | NAME                      | ENABLED |
  6. +---------------------------+---------+
  7. | events_waits_current      | NO      |
  8. | events_waits_history      | NO      |
  9. | events_waits_history_long | NO      |
  10. +---------------------------+---------+

To control wait event collection at server startup, use lines like these in your my.cnf file:

  • Enable: 

    [mysqld]
performance-schema-instrument='wait/%=ON'
performance-schema-consumer-events-waits-current=ON
performance-schema-consumer-events-waits-history=ON
performance-schema-consumer-events-waits-history-long=ON

  • Disable: 

    [mysqld]
performance-schema-instrument='wait/%=OFF'
performance-schema-consumer-events-waits-current=OFF
performance-schema-consumer-events-waits-history=OFF
performance-schema-consumer-events-waits-history-long=OFF

To control wait event collection at runtime, update the setup_instruments and setup_consumers tables:

  • Enable:

    1. UPDATE performance_schema.setup_instruments
    2. SET ENABLED = 'YES', TIMED = 'YES'
    3. WHERE NAME = 'wait/%';
    4.  
    5. UPDATE performance_schema.setup_consumers
    6. SET ENABLED = 'YES'
    7. WHERE NAME LIKE 'events_waits%';

  • Disable:

    1. UPDATE performance_schema.setup_instruments
    2. SET ENABLED = 'NO', TIMED = 'NO'
    3. WHERE NAME = 'wait/%';
    4.  
    5. UPDATE performance_schema.setup_consumers
    6. SET ENABLED = 'NO'
    7. WHERE NAME LIKE 'events_waits%';

To collect only specific wait events, enable only the corresponding wait instruments. To collect wait events only for specific wait event tables, enable the wait instruments but only the wait consumers corresponding to the desired tables.

For additional information about configuring event collection, see Section 26.3, “Performance Schema Startup Configuration”, and Section 26.4, “Performance Schema Runtime Configuration”.


Rechercher dans le manuel MySQL

Traduction non disponible

Le manuel MySQL n'est pas encore traduit en français sur l'infobrol. Seule la version anglaise est disponible pour l'instant.

Document créé le 26/06/2006, dernière modification le 26/10/2018
Source du document imprimé : https://www.gaudry.be/mysql-rf-performance-schema-wait-tables.html

L'infobrol est un site personnel dont le contenu n'engage que moi. Le texte est mis à disposition sous licence CreativeCommons(BY-NC-SA). Plus d'info sur les conditions d'utilisation et sur l'auteur.

Références

  1. Consulter le document html Langue du document :en Manuel MySQL : https://dev.mysql.com/

Ces références et liens indiquent des documents consultés lors de la rédaction de cette page, ou qui peuvent apporter un complément d'information, mais les auteurs de ces sources ne peuvent être tenus responsables du contenu de cette page.
L'auteur de ce site est seul responsable de la manière dont sont présentés ici les différents concepts, et des libertés qui sont prises avec les ouvrages de référence. N'oubliez pas que vous devez croiser les informations de sources multiples afin de diminuer les risques d'erreurs.

Table des matières Haut