/admin/remove/ranks

URL: http://<db.host>:<db.port>/admin/remove/ranks

Remove one or more ranks from an existing Kinetica cluster. All data will be rebalanced to other ranks before the rank(s) is removed unless the rebalance_sharded_data or rebalance_unsharded_data parameters are set to false in the input parameter options, in which case the corresponding sharded data and/or unsharded data (a.k.a. randomly-sharded) will be deleted.

The database must be offline for this operation, see /admin/offline

This endpoint's processing time depends on the amount of data in the system, thus the API call may time out if run directly. It is recommended to run this endpoint asynchronously via /create/job.

NOTE: This endpoint should be used for on-premise deployments only.

Input Parameter Description

Name

Type

Description

ranks

array of strings

Each array value designates one or more ranks to remove from the cluster. Values can be formatted as 'rankN' for a specific rank, 'hostN' (from the gpudb.conf file) to remove all ranks on that host, or the host IP address (hostN.address from the gpub.conf file) which also removes all ranks on that host. Rank 0 (the head rank) cannot be removed (but can be moved to another host using /admin/switchover). At least one worker rank must be left in the cluster after the operation.

options

map of string to strings

Optional parameters. The default value is an empty map ( {} ).

Supported Parameters (keys)

Parameter Description

rebalance_sharded_data

If true, sharded data will be rebalanced approximately equally across the cluster. Note that for clusters with large amounts of sharded data, this data transfer could be time consuming and result in delayed query responses. The default value is true. The supported values are:

true
false

rebalance_unsharded_data

If true, unsharded data (a.k.a. randomly-sharded) will be rebalanced approximately equally across the cluster. Note that for clusters with large amounts of unsharded data, this data transfer could be time consuming and result in delayed query responses. The default value is true. The supported values are:

true
false

aggressiveness

Influences how much data is moved at a time during rebalance. A higher aggressiveness will complete the rebalance faster. A lower aggressiveness will take longer but allow for better interleaving between the rebalance and other queries. Valid values are constants from 1 (lowest) to 10 (highest). The default value is '10'.

Output Parameter Description

The GPUdb server embeds the endpoint response inside a standard response structure which contains status information and the actual response to the query. Here is a description of the various fields of the wrapper:

Name

Type

Description

status

String

'OK' or 'ERROR'

message

String

Empty if success or an error message

data_type

String

'admin_remove_ranks_response' or 'none' in case of an error

data

String

Empty string

data_str

JSON or String

This embedded JSON represents the result of the /admin/remove/ranks endpoint:

Name	Type	Description
removed_ranks	array of strings	The number assigned to each rank removed from the cluster. This array will be empty if the operation fails.
info	map of string to strings	Additional information.

Empty string in case of an error.