tiup cluster scale-in
The tiup cluster scale-in
command is used to scale in the cluster, which takes the services of the specified nodes offline, removes the specified nodes from the cluster, and deletes the remaining files from those nodes.
Particular handling of components' offline process
Because the TiKV, TiFlash, and TiDB Binlog components are taken offline asynchronously (which requires TiUP to remove the node through API first) and the stopping process takes a long time (which requires TiUP to continuously check whether the node is successfully taken offline), the TiKV, TiFlash, and TiDB Binlog components are handled particularly as follows:
For TiKV, TiFlash and, TiDB Binlog components:
TiUP Cluster takes the node offline through API and directly exits without waiting for the process to be completed.
To check the status of the nodes being scaled in, you need to execute the
tiup cluster display
command and wait for the status to becomeTombstone
.To clean up the nodes in the
Tombstone
status, you need to execute thetiup cluster prune
command. Thetiup cluster prune
command performs the following operations:- Stops the services of the nodes that have been taken offline.
- Cleans up the data files of the nodes that have been taken offline.
- Updates the cluster topology and removes the nodes that have been taken offline.
For other components:
- When taking the PD components offline, TiUP Cluster quickly deletes the specified nodes from the cluster through API, stops the service of the specified PD nodes, and then deletes the related data files from the nodes.
- When taking other components down, TiUP Cluster directly stops the node services and deletes the related data files from the specified nodes.
Syntax
tiup cluster scale-in <cluster-name> [flags]
<cluster-name>
is the name of the cluster to scale in. If you forget the cluster name, you can check it using the tiup cluster list
command.
Options
-N, --node
- Specifies the nodes to take down. Multiple nodes are separated by commas.
- Data type:
STRING
- There is no default value. This option is mandatory and the value must be not null.
--force
- Controls whether to forcibly remove the specified nodes from the cluster. Sometimes, the host of the node to take offline might be down, which makes it impossible to connect to the node via SSH for operations, so you can forcibly remove the node from the cluster using the
-force
option. - Data type:
BOOLEAN
- This option is disabled by default with the
false
value. To enable this option, add this option to the command, and either pass thetrue
value or do not pass any value.
--transfer-timeout
- When a PD or TiKV node is to be removed, the Region leader on the node will be transferred to another node first. Because the transferring process takes some time, you can set the maximum waiting time (in seconds) by configuring
--transfer-timeout
. After the timeout, thetiup cluster scale-in
command skips waiting and starts the scaling-in directly. - Data type:
UINT
- The option is enabled by default with
300
seconds (the default value) passed in.
-h, --help
- Prints the help information.
- Data type:
BOOLEAN
- This option is disabled by default with the
false
value. To enable this option, add this option to the command, and either pass thetrue
value or do not pass any value.
Output
Shows the logs of the scaling-in process.