commit 131b6deb5cddcc6c8ae5f9684418eee29bb43664
author Craig Tiller <ctiller@google.com> Thu Mar 31 17:05:28 2016 -0700
committer Craig Tiller <ctiller@google.com> Thu Mar 31 17:05:28 2016 -0700
tree 9e3ca72bb95b3984f5a3fbf563b32b1dbde38d67
parent a95f1b56ff5be69a3e5742d6a3f5e480cb46e275

Refine model used to enter transient failure for pick_first

src/core/ext/lb_policy/pick_first/pick_first.c

diff --git a/src/core/ext/lb_policy/pick_first/pick_first.c b/src/core/ext/lb_policy/pick_first/pick_first.c
index 8c556f4..53c14f8 100644
--- a/src/core/ext/lb_policy/pick_first/pick_first.c
+++ b/src/core/ext/lb_policy/pick_first/pick_first.c
@@ -315,11 +315,14 @@
             &p->checking_connectivity, &p->connectivity_changed);
         break;
       case GRPC_CHANNEL_TRANSIENT_FAILURE:
-        grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                    GRPC_CHANNEL_TRANSIENT_FAILURE,
-                                    "connecting_transient_failure");
         p->checking_subchannel =
             (p->checking_subchannel + 1) % p->num_subchannels;
+        if (p->checking_subchannel == 0) {
+          /* only trigger transient failure when we've tried all alternatives */
+          grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+                                      GRPC_CHANNEL_TRANSIENT_FAILURE,
+                                      "connecting_transient_failure");
+        }
         p->checking_connectivity = grpc_subchannel_check_connectivity(
             p->subchannels[p->checking_subchannel]);
         if (p->checking_connectivity == GRPC_CHANNEL_TRANSIENT_FAILURE) {