MySQL 5.7 Release Notes
的INNODB_METRICStable provides a wide variety ofInnoDBperformance information, complementing the specific focus areas of the Performance Schema tables forInnoDB. With simple queries, you can check the overall health of the system. With more detailed queries, you can diagnose issues such as performance bottlenecks, resource shortages, and application issues.
Each monitor represents a point within theInnoDBsource code that is instrumented to gather counter information. Each counter can be started, stopped, and reset. You can also perform these actions for a group of counters using their common module name.
By default, relatively little data is collected. To start, stop, and reset counters, set one of the system variablesinnodb_monitor_enable,innodb_monitor_disable,innodb_monitor_reset, orinnodb_monitor_reset_all, using the name of the counter, the name of the module, a wildcard match for such a name using the“%”character, or the special keywordall.
For usage information, seeSection 14.16.6, “InnoDB INFORMATION_SCHEMA Metrics Table”.
的INNODB_METRICStable has these columns:
NAMEA unique name for the counter.
SUBSYSTEM的aspect of
InnoDBthat the metric applies to.COUNT的value since the counter was enabled.
MAX_COUNT的maximum value since the counter was enabled.
MIN_COUNT的minimum value since the counter was enabled.
AVG_COUNT的average value since the counter was enabled.
COUNT_RESET的counter value since it was last reset. (The
_RESETcolumns act like the lap counter on a stopwatch: you can measure the activity during some time interval, while the cumulative figures are still available inCOUNT,MAX_COUNT, and so on.)MAX_COUNT_RESET的maximum counter value since it was last reset.
MIN_COUNT_RESET的minimum counter value since it was last reset.
AVG_COUNT_RESET的average counter value since it was last reset.
TIME_ENABLED的timestamp of the last start.
TIME_DISABLED的timestamp of the last stop.
TIME_ELAPSED的elapsed time in seconds since the counter started.
TIME_RESET的timestamp of the last reset.
STATUSWhether the counter is still running (
enabled) or stopped (disabled).TYPEWhether the item is a cumulative counter, or measures the current value of some resource.
COMMENT的counter description.
Example
mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_METRICS WHERE NAME='dml_inserts'\G *************************** 1. row *************************** NAME: dml_inserts SUBSYSTEM: dml COUNT: 3 MAX_COUNT: 3 MIN_COUNT: NULL AVG_COUNT: 0.046153846153846156 COUNT_RESET: 3 MAX_COUNT_RESET: 3 MIN_COUNT_RESET: NULL AVG_COUNT_RESET: NULL TIME_ENABLED: 2014-12-04 14:18:28 TIME_DISABLED: NULL TIME_ELAPSED: 65 TIME_RESET: NULL STATUS: enabled TYPE: status_counter COMMENT: Number of rows insertedNotes
You must have the
PROCESSprivilege to query this table.Use the
INFORMATION_SCHEMACOLUMNStable or theSHOW COLUMNSstatement to view additional information about the columns of this table, including data types and default values.Transaction counter
COUNTvalues may differ from the number of transaction events reported in Performance SchemaEVENTS_TRANSACTIONS_SUMMARYtables.InnoDBcounts only those transactions that it executes, whereas Performance Schema collects events for all non-aborted transactions initiated by the server, including empty transactions.