Double check the port you have set
If you are running and receiving the following:
# /opt/gravwell/bin/gravwell_singlefile -block-size=1024
-i=test-dat.txt --timestamp-override=DPKG -timezone-override=America/New_York
-clear-conns= 192.168.200.2:9404, 192.168.200.3:9404, 192.168.200.4:9404
-tag-name=test -ingest-secret=<secret> -verbose
2020/04/21 11:55:32 Failed to wait for hot connection: Connection timeout
A common gotcha is the port number. In the above 9404 is the wrong port, 4023 is the cleartext ingest port which should resolve the issue.
Take a look at https://docs.gravwell.io/docs/#!configuration/networking.md for more information.
Still having trouble? Reach out to firstname.lastname@example.org anytime!