Package io.grpc

Interface LoadBalancer.SubchannelStateListener

    • Method Detail

      • onSubchannelState

        void onSubchannelState​(ConnectivityStateInfo newState)
        Handles a state change on a Subchannel.

        The initial state of a Subchannel is IDLE. You won't get a notification for the initial IDLE state.

        If the new state is not SHUTDOWN, this method should create a new picker and call Helper.updateBalancingState(). Failing to do so may result in unnecessary delays of RPCs. Please refer to PickResult.withSubchannel()'s javadoc for more information.

        SHUTDOWN can only happen in two cases. One is that LoadBalancer called LoadBalancer.Subchannel.shutdown() earlier, thus it should have already discarded this Subchannel. The other is that Channel is doing a forced shutdown or has already terminated, thus there won't be further requests to LoadBalancer. Therefore, the LoadBalancer usually don't need to react to a SHUTDOWN state.

        Parameters:
        newState - the new state
        Since:
        1.22.0