We have our failure detection defined like below.

<FD_SOCK external_port="7804" />
<FD timeout="3000" max_tries="3" />
<VERIFY_SUSPECT timeout="3000" />

Please note that we have used FD instead of FD_ALL in AWS. We will be changing it to FD_ALL later after detailed testing.

In my local, this is working perfect. As soon as I kill my node, I was able to see that view change was happening immediately with FD_SOCK.

We were not mentioning the external_port in the FD_SOCK but later I thought it may be an issue with the port and defined it as 7804 and added the same port to the security group that allows to access this port among all the nodes. So no issue with the port.

Can you please let us know if we need any additional configurations to make FD_SOCK works well in AWS.

Thanks,
Sibin