Updated query_response_time plugin
This is to update the plugin to be compatible with Percona's
query_response_time plugin, with some additions.
Some of the tests are taken from Percona server.
- Added plugins QUERY_RESPONSE_TIME_READ, QUERY_RESPONSE_TIME_WRITE and
QUERY_RESPONSE_TIME_READ_WRITE.
- Added option session_stats.
Notes:
- All modules are dependent on QUERY_RESPONSE_READ_TIME. This must always
be enabled if any of the other modules are used.
This will be auto-enabled in the near future.
- Accounting are done per statement. Stored functions are regarded
as part of the original statement.
- For stored procedures the accounting are done per statement executed
in the stored procedure. CALL will not be accounted because of this.
- FLUSH commands will not be accounted for. This is to ensure that
FLUSH QUERY_RESPONSE_TIME is not part of the statistics.
(This helps when testing with mtr and otherwise)
MDEV-31558 Add InnoDB engine information to the slow query log
The new statistics is enabled by adding the "innodb" option to
--log-slow-verbosity
Example output:
# Pages_accessed: 184 Pages_read: 95 Pages_updated: 0 Undo_rows_read: 1
# Pages_read_time: 17.0204 Engine_time: 248.1297
Page_read_time is time doing physical reads inside a storage engine.
(Writes cannot be tracked as these are usually done in the background).
Engine_time is the time spent inside the storage engine for the full duration
of the read/write/update calls. It uses the same code as 'analyze statement'
for calculating the time spent.
The engine statistics is done with a generic interface that should be
easy for any engine to use. It can also easily be extended to provide
even more statistics.
Currently only InnoDB has counters for Pages_% and Undo_% status.
Engine_time works for all engines.
Implementation details:
class ha_handler_stats holds all engine stats.
This class is included in handler and THD classes.
While a query is running, all statistics is updated in
the handler. In close_thread_tables() the statistics is
added to the THD.
handler::handler_stats is a pointer to where statistics should
be collected. This is set to point to handler::active_handler_stats
if stats are requested. If not, it is set to 0.
handler_stats has also an element, 'active' to that is 1 if stats
are requested. This is to allow engines to avoid doing any 'if's
while updating the statistics.
Cloned or partition tables have the pointer set to the base table if
status are requested.
There is a small performance impact when using --log-slow-verbosity=innodb:
- All engine calls in 'select' will be timed.
- IO calls for InnoDB reads will be timed.
- Incrementation of counters are done on local variables and accesses
are inline, so these should have very little impact.
- Statistics has to be reset for each statement for the THD and each
used handler. This is only 40 bytes, which should be neglectable.
- For partition tables we have to loop over all partitions to update
the handler_status as part of table_init(). Can be optimized in the
future to only do this is log-slow-verbosity changes. For this to work
we have to update handler_status for all opened partitions and
also for all partitions opened in the future.
Other things:
- LOG_SLOW_VERBOSITY_INNODB renamed to #define LOG_SLOW_VERBOSITY_ENGINE
- Some of the new files in the test suite comes from Percona server, which
has similar status information.
- Do not update buf_pool.stat.n_page_gets for optimistic page access
