DB Connect ERROR : "Cannot communicate with task server, please check your settings"

Applicability

Description

- Splunk is running in the Windows OS
- The critical DB Alerts and Dashboards are not working.
- The below error is getting triggered in Splunk DB connect and due to this the connections in DBX are not showing. 

"Cannot communicate with task server, please check your settings" 

Investigation

- DB Connect relies on the functionality of the kvstore. Mainly for managing inputs which have transitioned from modinputs to kvstore inputs. 
- Since DB connect is not working, reviewed the status of KV store and observed that the KV store is not in Ready state.
- As the KV store is failed, reviewed the server certificate validity using the following command and observed that it is expired :

/opt/splunk/bin splunk cmd openssl x509 -enddate -noout -in D:\Splunk\etc\auth\server.pem

- Tried to renew the server certificate using the following procedure:

1) Stop the Splunk service.
2) Rename server.pem (D:\Splunk\etc\auth) to server.pembkp.
3) Start the Splunk service.

- However the certificate renewal failed with the above steps. 

Resolution

The below steps were followed to renew the certificate in the Windows environment : 

i. Go to Start menu
ii. Executed the command "certlm.msc"
iii. After the certlm prompt is launched, click on Personal > Certificates
iv. Delete everything that will be named SplunkServerDefaultCert
v. Renamed the existing server.pem and moved it to another location.
vi. Then restart the server, upon which a new server.pem will be generated. 
vii. Verify the validity of the certificate, confirming it has been successfully renewed with a new validity period.

Once the expired server cert was renewe,  the KV store went back to Ready status and DB Connect started to function as expected.