MySQL 5.7 Reference Manual
MySQL 5.7 Release Notes
The hosts table contains a row
for each host from which clients have connected to the MySQL
server. For each host name, the table counts the current and
total number of connections. The table size is autosized at
server startup. To set the table size explicitly, set the
performance_schema_hosts_size
system variable at server startup. To disable host statistics,
set this variable to 0.
The hosts table has the following
columns. For a description of how the Performance Schema
maintains rows in this table, including the effect of
TRUNCATE TABLE, see
Section 10.8, “Performance Schema Connection Tables”.
HOSTThe host from which the client connected. This is
NULLfor an internal thread, or for a user session that failed to authenticate.CURRENT_CONNECTIONSThe current number of connections for the host.
TOTAL_CONNECTIONSThe total number of connections for the host.