The requested replication operation is disallowed on the specified channel because the command is not permitted for that channel's role or state.
MySQL error 3139 ER_SLAVE_CHANNEL_OPERATION_NOT_ALLOWED appears when you run START, STOP, RESET, or CHANGE MASTER on a replication channel that does not permit the action, often a group-replication or Multi-Source channel. Target the correct channel or use the default channel, then rerun the command to resolve.
ER_SLAVE_CHANNEL_OPERATION_NOT_ALLOWED
Error 3139 fires when a replication statement such as START SLAVE, STOP SLAVE, RESET SLAVE, or CHANGE MASTER is executed against a replication channel that does not support that operation. Channels may be reserved for Group Replication or Multi-Source tasks that need different management commands.
The message template "%s cannot be performed on channel '%s'" substitutes the attempted command and channel name, helping you identify the exact mismatch between action and channel type.
The error typically surfaces after upgrading to MySQL 5.7.8 or later, when named channels became mandatory for certain replication topologies. It also appears in MySQL 8.x when users mistakenly operate on the wrong channel or forget to switch context.
Replication interruptions block dataflow to replicas, delay failover, and risk data divergence. Resolving 3139 quickly restores healthy replication and maintains high availability and read scalability.
First confirm which channels exist and what each channel does. Then run the appropriate command on the correct channel or remove the FOR CHANNEL clause to target the default channel.
If the error appears while stopping a Group Replication channel, use STOP GROUP_REPLICATION rather than STOP SLAVE. When resetting a Multi-Source channel, issue RESET SLAVE FOR CHANNEL 'channel_name' to reset only that source.
Adopt clear naming conventions, document channel purposes, and restrict replication commands to privileged roles. Automated checks in tools like Galaxy can warn when a command targets the wrong channel.
Errors 3140 ER_SLAVE_CHANNEL_NOT_RUNNING and 3141 ER_SLAVE_CHANNEL_DOES_NOT_EXIST often accompany 3139. Verifying channel existence and status usually resolves the entire class of issues.
Group Replication channels do not accept traditional START or STOP SLAVE commands and will raise 3139.
Specifying a channel name when you meant to operate on the default channel leads to a mismatch.
Issuing CHANGE MASTER on a channel already configured for a different source triggers the error.
Trying to reset or stop a channel while its applier thread is still running causes MySQL to block the action.
The specified channel name is unknown to the server.
MySQL requires you to stop the channel before issuing the requested statement.
Multiple replication channels are active when only one is allowed for the command.
Run SHOW SLAVE STATUS or query performance_schema.replication_connection_status to display each channel and its state.
No. You must DROP the channel with RESET SLAVE ALL FOR CHANNEL 'old' and recreate it with the desired name.
No. Error 3139 was introduced in MySQL 5.7.8 when channel support became GA.
Galaxy surfaces schema context and warns when a statement references a non-default replication channel, reducing the risk of issuing an invalid command.
.avif)
.avif){kind=logo}
