@SneakyThrows
    @Get("/debugging/query/topology/getGlobalTopology")
    public String getGlobalTopology(@Param("startTime") String startTime,
                                    @Param("endTime") String endTime,
                                    @Param("step") String step,
                                    @Param("coldStage") Optional<Boolean> coldStage,
                                    @Param("serviceLayer") Optional<String> serviceLayer) {
        Duration duration = new Duration();
        duration.setStart(startTime);
        duration.setEnd(endTime);
        duration.setStep(Step.valueOf(step));
        coldStage.ifPresent(duration::setColdStage);
        Topology topology = topologyQuery.getGlobalTopology(duration, serviceLayer.orElse(null), true).join();
        DebuggingQueryServiceTopologyRsp result = new DebuggingQueryServiceTopologyRsp(
            topology.getNodes(), topology.getCalls(), transformTrace(topology.getDebuggingTrace()));
        return transToYAMLString(result);
    }
Only for BanyanDB, can be used to query the trace in the cold stage.
oap-server/server-query-plugin/status-query-plugin/src/main/java/org/apache/skywalking/oap/query/debug/DebuggingHTTPHandler.java