As of MySQL 5.7.2, this table shows the current status of the I/O thread that handles the slave server connection to the master server.
Compared to the
changes more frequently. It contains values that change during
the connection, whereas
contains values which define how the slave connects to the
master and that remain constant during the connection.
table has these columns:
The replication channel which this row is displaying. There is always a default replication channel, and more replication channels can be added. See Section 18.2.3, “Replication Channels” for more information.
This column is reserved for future use. Added in MySQL 5.7.6.
server_uuidvalue from the master.
The I/O thread ID.
ON(thread exists and is active or idle),
OFF(thread no longer exists), or
CONNECTING(thread exists and is connecting to the master).
The set of global transaction IDs (GTIDs) corresponding to all transactions received by this slave. Empty if GTIDs are not in use. See GTID Sets for more information.
The error number and error message of the most recent error that caused the I/O thread to stop. An error number of 0 and message of the empty string mean “no error.” If the
LAST_ERROR_MESSAGEvalue is not empty, the error values also appear in the slave's error log.
A timestamp in
YYMMDD HH:MM:SSformat that shows when the most recent I/O error took place.
A timestamp in
YYMMDD HH:MM:SSformat that shows when the most recent heartbeat signal was received by a replication slave. Added in MySQL 5.7.5.
The total number of heartbeat signals that a replication slave received since the last time it was restarted or reset, or a
CHANGE MASTER TOstatement was issued. Added in MySQL 5.7.5.