diff --git a/src/core/ext/filters/client_channel/lb_policy/xds/xds.cc b/src/core/ext/filters/client_channel/lb_policy/xds/xds.cc index 38f8072e8d3..59923ab8610 100644 --- a/src/core/ext/filters/client_channel/lb_policy/xds/xds.cc +++ b/src/core/ext/filters/client_channel/lb_policy/xds/xds.cc @@ -1321,11 +1321,10 @@ void XdsLb::ProcessChannelArgsLocked(const grpc_channel_args& args) { void XdsLb::UpdateLocked(const grpc_channel_args& args) { ProcessChannelArgsLocked(args); - // If fallback is configured and the RR policy already exists, update - // it with the new fallback addresses. - if (lb_fallback_timeout_ms_ > 0 && rr_policy_ != nullptr) { - CreateOrUpdateRoundRobinPolicyLocked(); - } + // Note: We have disabled fallback mode in the code, so we don't need to + // handle fallback address changes. + // TODO(vpowar): Handle the fallback_address changes when we add support for + // fallback in xDS. // Start watching the LB channel connectivity for connection, if not // already doing so. if (!watching_lb_channel_) { @@ -1393,11 +1392,10 @@ void XdsLb::OnFallbackTimerLocked(void* arg, grpc_error* error) { if (xdslb_policy->serverlist_ == nullptr && !xdslb_policy->shutting_down_ && error == GRPC_ERROR_NONE) { if (grpc_lb_xds_trace.enabled()) { - gpr_log(GPR_INFO, "[xdslb %p] Falling back to use backends from resolver", + gpr_log(GPR_INFO, + "[xdslb %p] Fallback timer fired. Not using fallback backends", xdslb_policy); } - GPR_ASSERT(xdslb_policy->fallback_backend_addresses_ != nullptr); - xdslb_policy->CreateOrUpdateRoundRobinPolicyLocked(); } xdslb_policy->Unref(DEBUG_LOCATION, "on_fallback_timer"); } @@ -1641,19 +1639,12 @@ void XdsLb::CreateRoundRobinPolicyLocked(const Args& args) { grpc_channel_args* XdsLb::CreateRoundRobinPolicyArgsLocked() { grpc_lb_addresses* addresses; bool is_backend_from_grpclb_load_balancer = false; - if (serverlist_ != nullptr) { - GPR_ASSERT(serverlist_->num_servers > 0); - addresses = ProcessServerlist(serverlist_); - is_backend_from_grpclb_load_balancer = true; - } else { - // If CreateOrUpdateRoundRobinPolicyLocked() is invoked when we haven't - // received any serverlist from the balancer, we use the fallback backends - // returned by the resolver. Note that the fallback backend list may be - // empty, in which case the new round_robin policy will keep the requested - // picks pending. - GPR_ASSERT(fallback_backend_addresses_ != nullptr); - addresses = grpc_lb_addresses_copy(fallback_backend_addresses_); - } + // This should never be invoked if we do not have serverlist_, as fallback + // mode is disabled for xDS plugin. + GPR_ASSERT(serverlist_ != nullptr); + GPR_ASSERT(serverlist_->num_servers > 0); + addresses = ProcessServerlist(serverlist_); + is_backend_from_grpclb_load_balancer = true; GPR_ASSERT(addresses != nullptr); // Replace the LB addresses in the channel args that we pass down to // the subchannel.