/admin/add/ranks

URL: http://GPUDB_IP_ADDRESS:GPUDB_PORT/admin/add/ranks

Add one or more ranks to an existing Kinetica cluster. The new ranks will not contain any data initially (other than replicated tables) and will not be assigned any shards. To rebalance data and shards across the cluster, use /admin/rebalance.

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

For example, if attempting to add three new ranks (two ranks on host 172.123.45.67 and one rank on host 172.123.45.68) to a Kinetica cluster with additional configuration parameters:

  • input parameter hosts would be an array including 172.123.45.67 in the first two indices (signifying two ranks being added to host 172.123.45.67) and 172.123.45.68 in the last index (signifying one rank being added to host 172.123.45.67)
  • input parameter config_params would be an array of maps, with each map corresponding to the ranks being added in input parameter hosts. The key of each map would be the configuration parameter name and the value would be the parameter's value, e.g. '{"rank.gpu":"1"}'

This endpoint's processing includes copying all replicated table data to the new rank(s) and therefore could take a long time. The API call may time out if run directly. It is recommended to run this endpoint asynchronously via /create/job.

Input Parameter Description

NameTypeDescription
hostsarray of stringsArray of host IP addresses (matching a hostN.address from the gpudb.conf file), or host identifiers (e.g. 'host0' from the gpudb.conf file), on which to add ranks to the cluster. The hosts must already be in the cluster. If needed beforehand, to add a new host to the cluster use /admin/add/host. Include the same entry as many times as there are ranks to add to the cluster, e.g., if two ranks on host 172.123.45.67 should be added, input parameter hosts could look like '["172.123.45.67", "172.123.45.67"]'. All ranks will be added simultaneously, i.e. they're not added in the order of this array. Each entry in this array corresponds to the entry at the same index in the input parameter config_params.
config_paramsarray of maps of string to stringsArray of maps containing configuration parameters to apply to the new ranks found in input parameter hosts. For example, '{"rank.gpu":"2", "tier.ram.rank.limit":"10000000000"}'. Currently, the available parameters are rank-specific parameters in the Network, Hardware, Text Search, and RAM Tiered Storage sections in the gpudb.conf file, with the key exception of the 'rankN.host' settings in the Network section that will be determined by input parameter hosts instead. Though many of these configuration parameters typically are affixed with 'rankN' in the gpudb.conf file (where N is the rank number), the 'N' should be omitted in input parameter config_params as the new rank number(s) are not allocated until the ranks have been added to the cluster. Each entry in this array corresponds to the entry at the same index in the input parameter hosts. This array must either be completely empty or have the same number of elements as the input parameter hosts. An empty input parameter config_params array will result in the new ranks being set with default parameters.
optionsmap of string to strings

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

Supported Parameters (keys)Parameter Description
dry_run

If true, only validation checks will be performed. No ranks are added. The default value is false. The supported values are:

  • true
  • false

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:

NameTypeDescription
statusString'OK' or 'ERROR'
messageStringEmpty if success or an error message
data_typeString'admin_add_ranks_request' or 'none' in case of an error
dataStringEmpty string
data_strJSON or String

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

NameTypeDescription
added_ranksarray of stringsThe number assigned to each added rank, formatted as 'rankN', in the same order as the ranks in input parameter hosts and input parameter config_params.
infomap of string to stringsAdditional information.

Empty string in case of an error.