To find out more about these lookup tables, I recommend to read the in-view help (accessible using the "Learn More" button) for the Deployment Topology view as well as the $SPLUNK_HOME/etc/apps/sos/lookups/splunk_servers_cache.csv.spec file.
Note that this maintenance of the lookup table only involves adding or updating records - S.o.S will not automatically remove entries of hosts that are no longer reachable.
If you decommissioned search peers, you'll need to edit the $SPLUNK_HOME/etc/apps/sos/lookups/splunk_servers_cache.csv lookup file to manually remove the entries corresponding to those instances.
How this file $SPLUNKHOME/etc/apps/sos/lookups/splunkforwarders_cache.csv gets populated.
I see some incorrect hosts in that file
Can i delete the file and regenerate it.
How to regenerate this file ???