Why Are the Results Inconsistent After the MATCH AGAINST Statement Is Executed, Respectively, on the Primary Node and Read Replicas?

MATCH AGAINST is used to search for MySQL full-text indexes. For each row in a table, MATCH() returns a relevance value, that is, a similarity measure between the search string (given as the argument to the AGAINST() function) and the text in that row in the columns named in the MATCH() list.

The primary node and read replicas use different methods to obtain the stat_n_rows value. The primary node uses the persistent method and read replicas use the transient method. The use of stat_n_rows in the MATCH AGAINST relevance score calculation causes inconsistent results between the primary node and the read replicas.