CANCEL DECOMMISSION BACKEND

Description

This statement is used to cancel the decommissioning operation of a BE node.

tip

This statement is not supported in decoupling storage and computing mode.

Syntax

CANCEL DECOMMISSION BACKEND "<be_identifier>" [, "<be_identifier>" ... ]

Where:

be_identifier
  : "<be_host>:<be_heartbeat_port>"
  | "<backend_id>"

Required Parameters

<be_host>

It can be the hostname or IP address of the BE node.

<heartbeat_port>

The heartbeat port of the BE node, the default is 9050.

<backend_id>

The ID of the BE node.

tip

<be_host>, <be_heartbeat_port>, and <backend_id> can all be obtained by querying with the SHOW BACKENDS statement.

Access Control Requirements

The user who executes this SQL must have at least the following permissions:

Privilege	Object	Notes
NODE_PRIV

Usage Notes

1. After executing this command, you can view the decommissioning status (the value of the SystemDecommissioned column is false) and the decommissioning progress (the value of the TabletNum column no longer decreases slowly) through the SHOW BACKENDS statement.
2. The cluster will slowly migrate the tablets from other nodes back to the current BE, so that the number of tablets on each BE will eventually tend to approach.

Examples

1. Safely decommission two nodes from the cluster according to the Host and HeartbeatPort of the BE.

   CANCEL DECOMMISSION BACKEND "192.168.0.1:9050", "192.168.0.2:9050";

2. Safely decommission one node from the cluster according to the ID of the BE.

   CANCEL DECOMMISSION BACKEND "10002";