30.4.4.23 The ps_trace_thread() Procedure

Dumps all Performance Schema data for an instrumented thread to a .dot formatted graph file (for the DOT graph description language). Each result set returned from the procedure should be used for a complete graph.

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 7.1.9.1, “System Variable Privileges”.

Parameters

• in_thread_id INT: The thread to trace.

• in_outfile VARCHAR(255): The name to use for the .dot output file.

• in_max_runtime DECIMAL(20,2): The maximum number of seconds (which can be fractional) to collect data. Use NULL to collect data for the default of 60 seconds.

• in_interval DECIMAL(20,2): The number of seconds (which can be fractional) to sleep between data collections. Use NULL to sleep for the default of 1 second.

• in_start_fresh BOOLEAN: Whether to reset all Performance Schema data before tracing.

• in_auto_setup BOOLEAN: Whether to disable all other threads and enable all instruments and consumers. This also resets the settings at the end of the run.

• in_debug BOOLEAN: Whether to include file:lineno information in the graph.

Example

mysql> CALL sys.ps_trace_thread(25, CONCAT('/tmp/stack-', REPLACE(NOW(), ' ', '-'), '.dot'), NULL, NULL, TRUE, TRUE, TRUE);
+-------------------+
| summary           |
+-------------------+
| Disabled 1 thread |
+-------------------+
1 row in set (0.00 sec)

+---------------------------------------------+
| Info                                        |
+---------------------------------------------+
| Data collection starting for THREAD_ID = 25 |
+---------------------------------------------+
1 row in set (0.03 sec)

+-----------------------------------------------------------+
| Info                                                      |
+-----------------------------------------------------------+
| Stack trace written to /tmp/stack-2014-02-16-21:18:41.dot |
+-----------------------------------------------------------+
1 row in set (60.07 sec)

+-------------------------------------------------------------------+
| Convert to PDF                                                    |
+-------------------------------------------------------------------+
| dot -Tpdf -o /tmp/stack_25.pdf /tmp/stack-2014-02-16-21:18:41.dot |
+-------------------------------------------------------------------+
1 row in set (60.07 sec)

+-------------------------------------------------------------------+
| Convert to PNG                                                    |
+-------------------------------------------------------------------+
| dot -Tpng -o /tmp/stack_25.png /tmp/stack-2014-02-16-21:18:41.dot |
+-------------------------------------------------------------------+
1 row in set (60.07 sec)

+------------------+
| summary          |
+------------------+
| Enabled 1 thread |
+------------------+
1 row in set (60.32 sec)