MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6
This section describes startup options which are impacted by the addition of replication channels.
The following startup settings must be configured correctly to use multi-source replication.
This must be set to TABLE
. If this variable
is set to FILE
, attempting to add more
sources to a replica fails with
ER_SLAVE_NEW_CHANNEL_WRONG_REPOSITORY
.
This must be set to TABLE
. If this variable
is set to FILE
, attempting to add more
sources to a replica fails with
ER_SLAVE_NEW_CHANNEL_WRONG_REPOSITORY
.
The following startup options now affect all channels in a replication topology.
All transactions received by the replica (even from multiple sources) are written in the binary log.
When set, each channel purges its own relay log automatically.
Applier threads of all channels retry transactions.
No replication threads start on any channels.
Execution continues and errors are skipped for all channels.
The values set for the following startup options apply on each channel; since these are mysqld startup options, they are applied on every channel.
--max-relay-log-size=
size
Maximum size of the individual relay log file for each channel; after reaching this limit, the file is rotated.
--relay-log-space-limit=
size
Upper limit for the total size of all relay logs combined, for
each individual channel. For N
channels, the combined size of these logs is limited to
relay_log_space_limit *
.
N
--slave-parallel-workers=
value
Number of worker threads per channel.
Waiting time by an I/O thread for each source.
--relay-log-index=filename
Base name for each channel's relay log index file. See Section 16.2.2.4, “Replication Channel Naming Conventions”.
--relay-log=filename
Denotes the base name of each channel's relay log file. See Section 16.2.2.4, “Replication Channel Naming Conventions”.
--slave_net-timeout=N
This value is set per channel, so that each channel waits for
N
seconds to check for a broken
connection.
--slave-skip-counter=N
This value is set per channel, so that each channel skips
N
events from its source.