apple / foundationdb

The current ip address selection algorithm is to prefer ipv6 if any such addresses are present in the DNS lookup.

foundationdb/flow/include/flow/IConnection.h

Line 182 in 2a616b3

    
           static NetworkAddress pickOneAddress(const std::vector<NetworkAddress>& addresses) {

This fails in some environments that have ipv6 addresses returned from the DNS lookup, when the network only supports ipv4. Specifically, we have hit this issue when running backups to GCS from a ipv4-only GKE cluster.

The change to prefer ipv6 was introduced in #7733, and backported to 7.1 in #7750.

It would be nice to have a knob to revert to preferring ipv4.

cherrypicked the fix #10826 to 7.1 as well.

Configuration option to prefer ipv4 in DNS lookup