MySQL :: MySQL 8.4 Reference Manual :: 29.12.20.9 Socket Summary Tables (original) (raw)

29.12.20.9 Socket Summary Tables

These socket summary tables aggregate timer and byte count information for socket operations:

• socket_summary_by_event_name: Aggregate timer and byte count statistics generated by thewait/io/socket/* instruments for all socket I/O operations, per socket instrument.
• socket_summary_by_instance: Aggregate timer and byte count statistics generated by thewait/io/socket/* instruments for all socket I/O operations, per socket instance. When a connection terminates, the row insocket_summary_by_instance corresponding to it is deleted.

The socket summary tables do not aggregate waits generated byidle events while sockets are waiting for the next request from the client. For idle event aggregations, use the wait-event summary tables; seeSection 29.12.20.1, “Wait Event Summary Tables”.

Each socket summary table has one or more grouping columns to indicate how the table aggregates events. Event names refer to names of event instruments in thesetup_instruments table:

• socket_summary_by_event_name has an EVENT_NAME column. Each row summarizes events for a given event name.
• socket_summary_by_instance has an OBJECT_INSTANCE_BEGIN column. Each row summarizes events for a given object.

Each socket summary table has these summary columns containing aggregated values:

• COUNT_STAR,SUM_TIMER_WAIT,MIN_TIMER_WAIT,AVG_TIMER_WAIT,MAX_TIMER_WAIT
  These columns aggregate all operations.
• COUNT_READ,SUM_TIMER_READ,MIN_TIMER_READ,AVG_TIMER_READ,MAX_TIMER_READ,SUM_NUMBER_OF_BYTES_READ
  These columns aggregate all receive operations (RECV, RECVFROM, andRECVMSG).
• COUNT_WRITE,SUM_TIMER_WRITE,MIN_TIMER_WRITE,AVG_TIMER_WRITE,MAX_TIMER_WRITE,SUM_NUMBER_OF_BYTES_WRITE
  These columns aggregate all send operations (SEND, SENDTO, andSENDMSG).
• COUNT_MISC,SUM_TIMER_MISC,MIN_TIMER_MISC,AVG_TIMER_MISC,MAX_TIMER_MISC
  These columns aggregate all other socket operations, such as CONNECT, LISTEN,ACCEPT, CLOSE, andSHUTDOWN. There are no byte counts for these operations.

The socket_summary_by_instance table also has an EVENT_NAME column that indicates the class of the socket:client_connection,server_tcpip_socket,server_unix_socket. This column can be grouped on to isolate, for example, client activity from that of the server listening sockets.

The socket summary tables have these indexes:

• socket_summary_by_event_name:
  • Primary key on (EVENT_NAME)
• socket_summary_by_instance:
  • Primary key on (OBJECT_INSTANCE_BEGIN)
  • Index on (EVENT_NAME)

TRUNCATE TABLE is permitted for socket summary tables. Except forevents_statements_summary_by_digest, it resets the summary columns to zero rather than removing rows.