[dbnode] Add ExcludeOrigin to skip localhost on BorrowConnections (#3066

)

src/dbnode/client/session.go

@@ -655,6 +655,10 @@ func (s *session) BorrowConnections(
 			// Error or has broken
 			return
 		}
+		if opts.ExcludeOrigin && s.origin != nil && s.origin.ID() == host.ID() {
+			// Skip origin host.
+			return
+		}
 
 		var (
 			userResult WithBorrowConnectionResult
@@ -937,7 +941,7 @@ func (s *session) setTopologyWithLock(topoMap topology.Map, queues []hostQueue,
 
 	if s.pools.multiReaderIteratorArray == nil {
 		s.pools.multiReaderIteratorArray = encoding.NewMultiReaderIteratorArrayPool([]pool.Bucket{
-			pool.Bucket{
+			{
 				Capacity: replicas,
 				Count:    s.opts.SeriesIteratorPoolSize(),
 			},

src/dbnode/client/types.go

@@ -260,6 +260,9 @@ type BorrowConnectionOptions struct {
 	// ContinueOnBorrowError allows skipping hosts that cannot borrow
 	// a connection for.
 	ContinueOnBorrowError bool
+	// ExcludeOrigin will exclude attempting to borrow a connection for
+	// the origin host (i.e. the local host).
+	ExcludeOrigin bool
 }
 
 // BorrowConnectionsResult is a result used when borrowing connections.