Example Consumer Configurations

The consumer settings in the setup_consumers table form a hierarchy from higher levels to lower. The following discussion describes how consumers work, showing specific configurations and their effects as consumer settings are enabled progressively from high to low. The consumer values shown are representative. The general principles described here apply to other consumer values that may be available.

The configuration descriptions occur in order of increasing functionality and overhead. If you do not need the information provided by enabling lower-level settings, disable them and the Performance Schema will execute less code on your behalf and you will have less information to sift through.

Suppose that the setup_consumers table contains the following hierarchy of values:

global_instrumentation
 thread_instrumentation
 events_waits_current
 events_waits_history
 events_waits_history_long

If a given consumer setting is NO, the Performance Schema disables the instrumentation associated with the consumer and ignores all lower-level settings. If a given setting is YES, the Performance Schema enables the instrumentation associated with it and checks the settings at the next lowest level.

Each configuration description indicates which setup elements the Performance Schema checks and which output tables it maintains (that is, for which tables it collects information).No Instrumentation

Server configuration state:

mysql> SELECT * FROM setup_consumers;
+---------------------------+---------+
| NAME | ENABLED |
+---------------------------+---------+
| global_instrumentation | NO |
...
+---------------------------+---------+

In this configuration, nothing is instrumented.

Setup elements checked:

• Table setup_consumers, consumer global_instrumentation

Output tables maintained:

• None

Global Instrumentation Only

Server configuration state:

mysql> SELECT * FROM setup_consumers;
+---------------------------+---------+
| NAME | ENABLED |
+---------------------------+---------+
| global_instrumentation | YES |
| thread_instrumentation | NO |
...
+---------------------------+---------+

In this configuration, instrumentation is maintained only for global states. Per-thread instrumentation is disabled.

Additional setup elements checked, relative to the preceding configuration:

• Table setup_consumers, consumer thread_instrumentation
• Table setup_instruments
• Table setup_objects
• Table setup_timers

Additional output tables maintained, relative to the preceding configuration:

• mutex_instances
• rwlock_instances
• cond_instances
• file_instances
• file_summary_by_instance
• file_summary_by_event_name
• objects_summary_global_by_type
• table_lock_waits_summary_by_table
• table_io_waits_summary_by_index_usage
• table_io_waits_summary_by_table
• events_waits_summary_by_instance
• events_waits_summary_global_by_event_name

Global and Thread Instrumentation Only

Server configuration state:

mysql> SELECT * FROM setup_consumers;
+---------------------------+---------+
| NAME | ENABLED |
+---------------------------+---------+
| global_instrumentation | YES |
| thread_instrumentation | YES |
| events_waits_current | NO |
...
+---------------------------+---------+

In this configuration, instrumentation is maintained globally and per thread. No individual wait events are collected in the current-events or event-history tables.

Additional setup elements checked, relative to the preceding configuration:

• Table setup_consumers, consumer events_waits_current
• Table setup_actors
• Column threads.instrumented

Additional output tables maintained, relative to the preceding configuration:

• events_waits_summary_by_thread_by_event_name

Global, Thread, and Current-Event Instrumentation

Server configuration state:

mysql> SELECT * FROM setup_consumers;
+---------------------------+---------+
| NAME | ENABLED |
+---------------------------+---------+
| global_instrumentation | YES |
| thread_instrumentation | YES |
| events_waits_current | YES |
| events_waits_history | NO |
| events_waits_history_long | NO |
...
+---------------------------+---------+

In this configuration, instrumentation is maintained globally and per thread. Individual wait events are collected in the current-events table, but not in the event-history tables.

Additional setup elements checked, relative to the preceding configuration:

• Consumer events_waits_history
• Consumer events_waits_history_long

Additional output tables maintained, relative to the preceding configuration:

• events_waits_current

Global, Thread, Current-Event, and Event-History instrumentation

The preceding configuration collects no wait event history because the events_waits_history and events_waits_history_long consumers are disabled. Those consumers can be enabled separately or together to collect event history per thread, globally, or both.

This configuration collects event history per thread, but not globally:

mysql> SELECT * FROM setup_consumers;
+---------------------------+---------+
| NAME | ENABLED |
+---------------------------+---------+
| global_instrumentation | YES |
| thread_instrumentation | YES |
| events_waits_current | YES |
| events_waits_history | YES |
| events_waits_history_long | NO |
...
+---------------------------+---------+

Event-history tables maintained for this configuration:

• events_waits_history

This configuration collects event history globally, but not per thread:

mysql> SELECT * FROM setup_consumers;
+---------------------------+---------+
| NAME | ENABLED |
+---------------------------+---------+
| global_instrumentation | YES |
| thread_instrumentation | YES |
| events_waits_current | YES |
| events_waits_history | NO |
| events_waits_history_long | YES |
...
+---------------------------+---------+

Event-history tables maintained for this configuration:

• events_waits_history_long

This configuration collects event history per thread and globally:

mysql> SELECT * FROM setup_consumers;
+---------------------------+---------+
| NAME | ENABLED |
+---------------------------+---------+
| global_instrumentation | YES |
| thread_instrumentation | YES |
| events_waits_current | YES |
| events_waits_history | YES |
| events_waits_history_long | YES |
...
+---------------------------+---------+

Event-history tables maintained for this configuration:

• events_waits_history
• events_waits_history_long

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