public ObserverGrpc.ObserverBlockingStub getObserverStub() {
        if (closed) {
            return null;
        }
        if (Objects.nonNull(observerStub)) {
            return observerStub;
        }

        synchronized (this) {
            if (Objects.isNull(observerStub)) {
                final Tuple2<String, Integer> addressTuple = parseAddress();
                observerStub = clientBuilder.buildClient(addressTuple._1, addressTuple._2, ObserverGrpc.ObserverBlockingStub.class);
            }
        }
        return observerStub;
    }
CiliumNode represents a node in the Cilium cluster.
Usually it's aware by the Cilium Peer Service.
oap-server/server-fetcher-plugin/cilium-fetcher-plugin/src/main/java/org/apache/skywalking/oap/server/fetcher/cilium/nodes/CiliumNode.java