MySQL 5.7 Release Notes
        
          Returns YES or NO to
          indicate whether Performance Schema instrumentation for a
          given connection ID is enabled, UNKNOWN if
          the ID is unknown, or NULL if the ID is
          NULL.
- in_connection_id BIGINT UNSIGNED: The connection ID. This is a value of the type given in the- PROCESSLIST_IDcolumn of the Performance Schema- threadstable or the- Idcolumn of- SHOW PROCESSLISToutput.
mysql> SELECT sys.ps_is_thread_instrumented(43);
+-----------------------------------+
| sys.ps_is_thread_instrumented(43) |
+-----------------------------------+
| UNKNOWN                           |
+-----------------------------------+
mysql> SELECT sys.ps_is_thread_instrumented(CONNECTION_ID());
+------------------------------------------------+
| sys.ps_is_thread_instrumented(CONNECTION_ID()) |
+------------------------------------------------+
| YES                                            |
+------------------------------------------------+