@Override public void prepare() throws ServiceNotProvidedException, ModuleStartException {
        score.set(-1);
        ses = Executors.newSingleThreadScheduledExecutor();
        healthQueryService = new HealthQueryService(score, details);
        this.registerServiceImplementation(HealthQueryService.class, healthQueryService);
    }
HealthCheckerProvider fetches health check metrics from telemetry module, then calculates health score and generates
details explains the score. External service or users can query health status by HealthCheckerService.
oap-server/server-health-checker/src/main/java/org/apache/skywalking/oap/server/health/checker/provider/HealthCheckerProvider.java