Method TestRingHash_HeaderHashing

balancer/ringhash/ringhash_e2e_test.go:732–772

Tests that ring hash policy that hashes using a header value can send RPCs to specific backends based on their hash.

(t *testing.T)

// Tests that ring hash policy that hashes using a header value can send RPCs
// to specific backends based on their hash.
func (s) TestRingHash_HeaderHashing(t *testing.T) {
	backends := backendAddrs(startTestServiceBackends(t, 4))

	xdsServer, nodeID, xdsResolver := setupManagementServerAndResolver(t)

	const clusterName = "cluster"
	endpoints := endpointResource(t, clusterName, backends)
	cluster := e2e.ClusterResourceWithOptions(e2e.ClusterOptions{
		ClusterName: clusterName,
		ServiceName: clusterName,
		Policy:      e2e.LoadBalancingPolicyRingHash,
	})
	route := headerHashRoute("new_route", virtualHostName, clusterName, "address_hash")
	listener := e2e.DefaultClientListener(virtualHostName, route.Name)

	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
	defer cancel()

	if err := xdsServer.Update(ctx, xdsUpdateOpts(nodeID, endpoints, cluster, route, listener)); err != nil {
		t.Fatalf("Failed to update xDS resources: %v", err)
	}

	conn, err := grpc.NewClient("xds:///test.server", grpc.WithResolvers(xdsResolver), grpc.WithTransportCredentials(insecure.NewCredentials()))
	if err != nil {
		t.Fatalf("Failed to create client: %s", err)
	}
	defer conn.Close()
	client := testgrpc.NewTestServiceClient(conn)

	// Note each type of RPC contains a header value that will always be hashed
	// to a specific backend as the header value matches the value used to
	// create the entry in the ring.
	for _, backend := range backends {
		ctx := metadata.NewOutgoingContext(ctx, metadata.Pairs("address_hash", backend+"_0"))
		numRPCs := 10
		reqPerBackend := checkRPCSendOK(ctx, t, client, numRPCs)
		if reqPerBackend[backend] != numRPCs {
			t.Errorf("Got RPC routed to addresses %v, want all RPCs routed to %v", reqPerBackend, backend)
		}
	}
}

// Tests that ring hash policy that hashes using a header value and regex
// rewrite to aggregate RPCs to 1 backend.