DNS Query on DNS Registry got connection timed out at times.

DNS query on YARN Registry DNS got connection timed out at times.

After checking logs on registry dns, we found the cause that size of UDP Response is greater than Preallocated Byte buffer(4096)

We added failsafe case by returning input query with TC flag so that client can know they should retried using TCP protocol.

We found the problem and patched our cluster on 3.1.2 but it seems trunk still has the same problem.

I attached patch based on the trunk.

Thanks!