MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6
Creates a report of the current server status for diagnostic purposes.
This procedure disables binary logging during its execution by
manipulating the session value of the
sql_log_bin system variable.
That is a restricted operation, so the procedure requires
privileges sufficient to set restricted session variables. See
Section 5.1.8.1, “System Variable Privileges”.
Data collected for diagnostics()
includes this information:
Information from the metrics
view (see Section 26.4.3.21, “The metrics View”)
Information from other relevant sys
schema views, such as the one that detemines queries in
the 95th percentile
Information from the ndbinfo schema, if
the MySQL server is part of NDB Cluster
Replication status (both source and replica)
Some of the sys schema views are calculated as initial (optional), overall, and delta values:
The initial view is the content of the view at the start
of the diagnostics()
procedure. This output is the same as the start values
used for the delta view. The initial view is included if
the diagnostics.include_raw
configuration option is ON.
The overall view is the content of the view at the end of
the diagnostics() procedure.
This output is the same as the end values used for the
delta view. The overall view is always included.
The delta view is the difference from the beginning to the
end of procedure execution. The minimum and maximum values
are the minimum and maximum values from the end view,
respectively. They do not necessarily reflect the minimum
and maximum values in the monitored period. Except for the
metrics view, the delta is
calculated only between the first and last outputs.
in_max_runtime INT UNSIGNED: The
maximum data collection time in seconds. Use
NULL to collect data for the default
of 60 seconds. Otherwise, use a value greater than 0.
in_interval INT UNSIGNED: The sleep
time between data collections in seconds. Use
NULL to sleep for the default of 30
seconds. Otherwise, use a value greater than 0.
in_auto_config ENUM('current', 'medium',
'full'): The Performance Schema configuration
to use. Permitted values are:
current: Use the current
instrument and consumer settings.
medium: Enable some instruments
and consumers.
full: Enable all instruments and
consumers.
The more instruments and consumers enabled, the more
impact on MySQL server performance. Be careful with
the medium setting and especially
the full setting, which has a large
performance impact.
Use of the medium or
full setting requires the
SUPER privilege.
If a setting other than current is
chosen, the current settings are restored at the end of
the procedure.
diagnostics() operation can be
modified using the following configuration options or their
corresponding user-defined variables (see
Section 26.4.2.1, “The sys_config Table”):
debug, @sys.debug
If this option is ON, produce
debugging output. The default is OFF.
diagnostics.allow_i_s_tables,
@sys.diagnostics.allow_i_s_tables
If this option is ON, the
diagnostics() procedure is
permitted to perform table scans on the Information
Schema TABLES table. This
can be expensive if there are many tables. The default
is OFF.
diagnostics.include_raw,
@sys.diagnostics.include_raw
If this option is ON, the
diagnostics() procedure
output includes the raw output from querying the
metrics view. The default
is OFF.
statement_truncate_len,
@sys.statement_truncate_len
The maximum length of statements returned by the
format_statement()
function. Longer statements are truncated to this
length. The default is 64.
Create a diagnostics report that starts an iteration every 30 seconds and runs for at most 120 seconds using the current Performance Schema settings:
mysql> CALL sys.diagnostics(120, 30, 'current');
To capture the output from the
diagnostics() procedure in a file as it
runs, use the mysql client tee
and
filenamenotee commands (see
Section 4.5.1.2, “mysql Client Commands”):
mysql>tee diag.out;mysql>CALL sys.diagnostics(120, 30, 'current');mysql>notee;