The precedence of configuration files would take place. So in your case, placing the deploymentclient.conf in your TestApp/local from system/local is fine.
What you have encountered is a known issue (SPL-41174) where
the phoneHomeIntervalInSecs setting is actually being honored despite splunkd_access.log's "POST /services/broker/phonehome/connection_....." message displaying every 60 seconds. This was seen under 4.2 +
Workaround:
The deploymentclient.conf should have the phoneHomeIntervalInSecs setting in both stanzas: [deployment-client] and [target-broker:deploymentServer]
Splunk will need to be restarted on the client host.
eg.
[deployment-client]
phoneHomeIntervalInSecs = 1800
[target-broker:deploymentServer]
targetUri= mydeploymentserver.acme.com:8089
phoneHomeIntervalInSecs = 1800
Additionally you can always confirm the deployment client's phoneHomeIntervalInSecs is being properly set by temporarily enabling DEBUG logging on the deployment server and reviewing splunkd.log for "phoneHome" entries.
On the deployment server via SplunkWeb, can navigate to Manager > System Settings > System Logging > in the query box enter in: deployment *
For each of the 2 entries below, drill down and reset the logging level from the default WARN to DEBUG and Save
1) DeploymentServer
2) DeploymentServerAdminHandler
The logging change will occur dynamically. So there is no need to restart Splunk.
Note: if you restart Splunk, these log levels will revert back to their default.
Let's reload what is memory on the deployment server via:
$SPLUNK_HOME/bin/splunk reload deploy-server
Now on the deployment server via Search, query for the last 60 minutes
index=_internal source=*splunkd.log phonehome
This should display all the DEBUG entries in splunkd.log relating to phonehome and you should see 3 entries from the deployment client along the lines of:
DEBUG DeploymentServer - Recvd phonehome from: ip=.....
DEBUG DeploymentServer - Token matched:....
DEBUG DeploymentServer - Replying back to client[ip=.....
Check the timelines of a set of these to see if they repeat every X seconds based on your specified phoneHomeIntervalInSecs setting.
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