MySQL 8.4 Release Notes
If a replication source server does not write a statement to its binary log, the statement is not replicated. If the server does log the statement, the statement is sent to all replicas and each replica determines whether to execute it or ignore it.
On the source, you can control which databases to log changes for
by using the --binlog-do-db and
--binlog-ignore-db options to
control binary logging. For a description of the rules that
servers use in evaluating these options, see
Section 19.2.5.1, “Evaluation of Database-Level Replication and Binary Logging Options”. You should not use
these options to control which databases and tables are
replicated. Instead, use filtering on the replica to control the
events that are executed on the replica.
On the replica side, decisions about whether to execute or ignore
statements received from the source are made according to the
--replicate-* options that the replica was
started with. (See Section 19.1.6, “Replication and Binary Logging Options and Variables”.) The
filters governed by these options can also be set dynamically
using the CHANGE REPLICATION FILTER statement.
The rules governing such filters are the same whether they are
created on startup using --replicate-* options or
while the replica server is running by CHANGE REPLICATION
FILTER. Note that replication filters cannot be used on
Group Replication-specific channels on a MySQL server instance
that is configured for Group Replication, because filtering
transactions on some servers would make the group unable to reach
agreement on a consistent state.
In the simplest case, when there are no
--replicate-* options, the replica executes all
statements that it receives from the source. Otherwise, the result
depends on the particular options given.
Database-level options
(--replicate-do-db,
--replicate-ignore-db) are checked
first; see Section 19.2.5.1, “Evaluation of Database-Level Replication and Binary Logging Options”, for a
description of this process. If no database-level options are
used, option checking proceeds to any table-level options that may
be in use (see Section 19.2.5.2, “Evaluation of Table-Level Replication Options”,
for a discussion of these). If one or more database-level options
are used but none are matched, the statement is not replicated.
For statements affecting databases only (that is,
CREATE DATABASE,
DROP DATABASE, and
ALTER DATABASE), database-level
options always take precedence over any
--replicate-wild-do-table options.
In other words, for such statements,
--replicate-wild-do-table options
are checked if and only if there are no database-level options
that apply.
To make it easier to determine what effect a given set of options
has, it is recommended that you avoid mixing do-*
and ignore-* options, or options containing
wildcards with options which do not.
If any --replicate-rewrite-db
options were specified, they are applied before the
--replicate-* filtering rules are tested.
Note
All replication filtering options follow the same rules for case
sensitivity that apply to names of databases and tables
elsewhere in the MySQL server, including the effects of the
lower_case_table_names system
variable.
Filtering rules are applied before performing any privilege checks; if a transaction is filtered out, no privilege check is performed for that transaction, and thus no error can be raised by it. See Section 19.5.1.29, “Replica Errors During Replication”, for more information.