Performance Schema Miscellaneous Tables The name associated with the thread instrumentation code in the server. For example,  thread/sql/ one_connection  corresponds to the thread function in the code responsible for handling a user connection, and  thread/sql/main  stands for the  main()  function of the server. The thread type, either  FOREGROUND  or  BACKGROUND . User connection threads are foreground threads. Threads associated with internal server activity are background threads. Examples are internal  InnoDB threads, “binlog dump”  threads sending information to replicas, and replication I/O and SQL threads. For a foreground thread (associated with a user connection), this is the connection identifier. This is the same value displayed in the  ID  column of the  INFORMATION_SCHEMA PROCESSLIST  table, displayed in the  Id  column of  SHOW PROCESSLIST  output, and returned by the  CONNECTION_ID()  function within the thread. For a background thread (not associated with a user connection),  PROCESSLIST_ID  is  NULL , so the values are not unique. The user associated with a foreground thread,  NULL  for a background thread. The host name of the client associated with a foreground thread,  NULL  for a background thread. Unlike the  HOST  column of the  INFORMATION_SCHEMA PROCESSLIST  table or the  Host  column of SHOW PROCESSLIST  output, the  PROCESSLIST_HOST  column does not include the port number for TCP/IP connections. To obtain this information from the Performance Schema, enable the socket instrumentation (which is not enabled by default) and examine the  socket_instances  table: 5090 • PROCESSLIST_HOST • PROCESSLIST_USER • PROCESSLIST_ID • TYPE mysql>  SELECT NAME, ENABLED, TIMED FROM performance_schema.setup_instruments WHERE NAME LIKE ’wait/io/socket%’; +----------------------------------------+---------+-------+ | NAME | ENABLED | TIMED | +----------------------------------------+---------+-------+ | wait/io/socket/sql/server_tcpip_socket | NO | NO | | wait/io/socket/sql/server_unix_socket | NO | NO | | wait/io/socket/sql/client_connection | NO | NO | +----------------------------------------+---------+-------+ 3 rows in set (0.01 sec) mysql>  UPDATE performance_schema.setup_instruments SET ENABLED=’YES’ WHERE NAME LIKE ’wait/io/socket%’; Query OK, 3 rows affected (0.00 sec) Rows matched: 3 Changed: 3 Warnings: 0 mysql>  SELECT * FROM performance_schema.socket_instances\G *************************** 1. row *************************** EVENT_NAME: wait/io/socket/sql/client_connection OBJECT_INSTANCE_BEGIN: 140612577298432 THREAD_ID: 31 SOCKET_ID: 53 IP: ::ffff:127.0.0.1 PORT: 55642 STATE: ACTIVE ...