在 setup_consumers 表中,消费者设置形成了从高级别到低级别的层次结构。以下讨论描述了消费者如何工作,展示了特定的配置及其效果,因为消费者设置从高到低逐步启用。所示的消费者值是代表性的。这里描述的通用原则也适用于其他可能可用的消费者值。
配置描述按照增加的功能和开销顺序出现。如果您不需要启用较低级别设置所提供的信息,请禁用它们,以便 Performance Schema 执行较少的代码,并且需要浏览的信息较少。
The setup_consumers 表包含以下层次结构的值:
global_instrumentation
thread_instrumentation
events_waits_current
events_waits_history
events_waits_history_long
events_stages_current
events_stages_history
events_stages_history_long
events_statements_current
events_statements_history
events_statements_history_long
events_transactions_current
events_transactions_history
events_transactions_history_long
statements_digest
在消费者层次结构中,等待、阶段、语句和事务的消费者都在同一级别。这与事件嵌套层次结构不同,wait 事件嵌套在阶段事件中,阶段事件嵌套在语句事件中,语句事件嵌套在事务事件中。
如果给定的消费者设置为 NO,Performance Schema 将禁用与消费者关联的仪器并忽略所有较低级别的设置。如果给定的设置为 YES,Performance Schema 将启用与其关联的仪器并检查下一个最低级别的设置。有关每个消费者的规则描述,请参见 第 29.4.7 节,“按消费者预过滤”。
例如,如果 global_instrumentation 启用,thread_instrumentation 将被检查。如果 thread_instrumentation 启用,events_ 消费者将被检查。如果这些 xxx_currentevents_waits_current 启用,events_waits_history 和 events_waits_history_long 将被检查。
每个以下配置描述都指出了 Performance Schema 检查的设置元素和它维护的输出表(即,它为哪些表收集信息)。
服务器配置状态:
mysql> SELECT * FROM performance_schema.setup_consumers;
+---------------------------+---------+
| NAME | ENABLED |
+---------------------------+---------+
| global_instrumentation | NO |
...
+---------------------------+---------+
在此配置中,什么都不被仪器。
检查的设置元素:
-
表
setup_consumers,消费者global_instrumentation
维护的输出表:
-
无
服务器配置状态:
mysql> SELECT * FROM performance_schema.setup_consumers;
+---------------------------+---------+
| NAME | ENABLED |
+---------------------------+---------+
| global_instrumentation | YES |
| thread_instrumentation | NO |
...
+---------------------------+---------+
在此配置中,仅全局状态被仪器。每线程仪器被禁用。
相比前一个配置,检查的附加设置元素:
-
表
setup_consumers, 消费者thread_instrumentation
相比前一个配置,额外的输出表格:
服务器配置状态:
mysql> SELECT * FROM performance_schema.setup_consumers;
+----------------------------------+---------+
| NAME | ENABLED |
+----------------------------------+---------+
| global_instrumentation | YES |
| thread_instrumentation | YES |
| events_waits_current | NO |
...
| events_stages_current | NO |
...
| events_statements_current | NO |
...
| events_transactions_current | NO |
...
+----------------------------------+---------+
在这个配置中,instrumentation 是在全局和每个线程中维护的。当前事件表和事件历史表中没有收集单个事件。
相比前一个配置,额外的 setup 元素被检查:
-
表
setup_consumers, 消费者events_, 其中xxx_currentxxx是waits,stages,statements,transactions -
列
threads.instrumented
相比前一个配置,额外维护的输出表:
-
events_, 其中xxx_summary_by_yyy_by_event_namexxx是waits,stages,statements,transactions; 和yyy是thread,user,host,account
服务器配置状态:
mysql> SELECT * FROM performance_schema.setup_consumers;
+----------------------------------+---------+
| NAME | ENABLED |
+----------------------------------+---------+
| global_instrumentation | YES |
| thread_instrumentation | YES |
| events_waits_current | YES |
| events_waits_history | NO |
| events_waits_history_long | NO |
| events_stages_current | YES |
| 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 | YES |
| events_transactions_history | NO |
| events_transactions_history_long | NO |
...
+----------------------------------+---------+
在这个配置中,仪表是全局和每个线程维护的。单个事件被收集在当前事件表中,但不在事件历史表中。
相比前一个配置,额外检查的设置元素:
-
消费者
events_, 其中xxx_historyxxx是waits,stages,statements,transactions -
消费者
events_, 其中xxx_history_longxxx是waits,stages,statements,transactions
相比前一个配置,额外维护的输出表:
-
events_, 其中xxx_currentxxx是waits,stages,statements,transactions
前一个配置不收集事件历史,因为 events_ 和 xxx_historyevents_ 消费者被禁用。这些消费者可以单独或一起启用以收集事件历史。xxx_history_long
这个配置收集每个线程的事件历史,但不收集全局事件历史:
mysql> SELECT * FROM performance_schema.setup_consumers;
+----------------------------------+---------+
| NAME | ENABLED |
+----------------------------------+---------+
| global_instrumentation | YES |
| thread_instrumentation | YES |
| events_waits_current | YES |
| events_waits_history | YES |
| events_waits_history_long | NO |
| events_stages_current | YES |
| events_stages_history | YES |
| events_stages_history_long | NO |
| events_statements_current | YES |
| events_statements_history | YES |
| events_statements_history_long | NO |
| events_transactions_current | YES |
| events_transactions_history | YES |
| events_transactions_history_long | NO |
...
+----------------------------------+---------+
事件历史表维护为这个配置:
-
events_, 其中xxx_historyxxx是waits,stages,statements,transactions
这个配置收集全局事件历史,但不收集每个线程的事件历史:
mysql> SELECT * FROM performance_schema.setup_consumers;
+----------------------------------+---------+
| NAME | ENABLED |
+----------------------------------+---------+
| global_instrumentation | YES |
| thread_instrumentation | YES |
| events_waits_current | YES |
| events_waits_history | NO |
| events_waits_history_long | YES |
| events_stages_current | YES |
| events_stages_history | NO |
| events_stages_history_long | YES |
| events_statements_current | YES |
| events_statements_history | NO |
| events_statements_history_long | YES |
| events_transactions_current | YES |
| events_transactions_history | NO |
| events_transactions_history_long | YES |
...
+----------------------------------+---------+
事件历史表维护为这个配置:
-
events_, 其中xxx_history_longxxx是waits,stages,statements,transactions
这个配置收集每个线程和全局事件历史:
mysql> SELECT * FROM performance_schema.setup_consumers;
+----------------------------------+---------+
| NAME | ENABLED |
+----------------------------------+---------+
| global_instrumentation | YES |
| thread_instrumentation | YES |
| events_waits_current | YES |
| events_waits_history | YES |
| events_waits_history_long | YES |
| events_stages_current | YES |
| events_stages_history | YES |
| events_stages_history_long | YES |
| events_statements_current | YES |
| events_statements_history | YES |
| events_statements_history_long | YES |
| events_transactions_current | YES |
| events_transactions_history | YES |
| events_transactions_history_long | YES |
...
+----------------------------------+---------+
事件历史表维护为这个配置:
-
events_, 其中xxx_historyxxx是waits,stages,statements,transactions -
events_, 其中xxx_history_longxxx是waits,stages,statements,transactions