Unable to delete Deployment Client from Deployment server after upgrading to 9.2.1

Applicability

Description

After upgrading Splunk to 9.2.1, by trying to delete the client's record from the deployment server, an error message pops up stating :
 

This functionality is deprecated
The record of the client will be removed. Next time it phones it will be listed again.

And there is no mention of this feature being deprecated in the docs:
Deprecated features
Known issues
Fixed issues

Investigation

There are no errors messages in any of the internal logs that reflect my attempts at deleting records.

Running this command
 

 `curl -k -u admin:<password> --request DELETE https://localhost:8089/services/deployment/server/clients/<client_guid>` 

returns this response:
 

<?xml version="1.0" encoding="UTF-8"?>
<response>
<messages>
<msg type="ERROR">This functionality has been deprecated</msg>
</messages>
</response>

 

Attempting to remove the record from the Forwarder Management UI results in the same error being shown:

 
We have analyzed the HAR file as well and spotted the same response content, PFA:

 

Resolution

In the Splunk version 9.2.1, this feature was limited to clearing or resetting the client's information from the DeploymentServer in the case that the Deployment Client was entirely removed.

If the deployment client was still operational and phoning in, it would eventually come back into the UI and therefore known by the deployment server.

On 9.2.x, the deployment server now uses search behavior to know about clients with a saved search called DeploymentServerClientsBasic from SplunkDeploymentServerConfig app  , so as long as the deployment client is no longer phoning home, the deployment server should eventually "forget" about the deployment client.

DeploymentServerClientsBasic saved search  has "earliest=$reloadTime$" as the time range so if a deployment client is no longer phoning in to Deployment server, the deployment client can be removed from the forwarder management table by  using the command :

$SPLUNK_HOME/bin/splunk reload deploy-server

or applying a  Splunk restart with the Splunk command

 $SPLUNK_HOME/bin/splunk restart

This has not yet been updated in the deprecated features, for which there is an internal ticket opened to fix it. The documents will reflect the same shortly.