Sometimes as mentioned in
CASSANDRA-8472 streams will hang. We have streaming_socket_timeout_in_ms which can retry after a timeout. It would be good to make a default non-zero value. We don't want to paper over problems, but streams sometimes hang and you don't want long running streaming operations to just fail - as in repairs or bootstraps.
streaming_socket_timeout_in_ms should be based on the tcp idle timeout so it shouldn't be a problem to set it to on the order of minutes. Also the socket should only be open during the actual streaming and not during operations such as merkle tree generation. We can set it to a conservative value and people can set it more aggressively as needed. Disabling as a default, in my opinion, is too conservative.