ComponentUtil.setFessConfig(new FessConfig.SimpleImpl() {
            private static final long serialVersionUID = 1L;

            @Override
            public String getSchedulerTargetName() {
                return "";
            }
        });
        final String hostname = systemHelper.getHostname();
        final long pid = ProcessHandle.current().pid();

            @Override
            public boolean isSchedulerTarget(final String target) {
                return true;
            }

            @Override
            public String getSchedulerTargetName() {
                return Constants.DEFAULT_JOB_TARGET;
            }
        };
        ComponentUtil.setFessConfig(fessConfig);

        // JobManager that finds our job

     * to ensure uniqueness across multiple JVMs on the same host.
     *
     * @return The instance ID.
     */
    public String getInstanceId() {
        final String targetName = ComponentUtil.getFessConfig().getSchedulerTargetName();
        final String hostname = getHostname();
        final long pid = ProcessHandle.current().pid();
        if (StringUtil.isNotBlank(targetName)) {
            return targetName + "@" + hostname + ":" + pid;

        final String hostname = ComponentUtil.getSystemHelper().getHostname();
        final String targetName = ComponentUtil.getFessConfig().getSchedulerTargetName();

        final String body = toJson(Map.of( //
                "type", TYPE_HEARTBEAT, //
                "instanceId", instanceId, //
                "hostname", hostname, //

        thumbnailQueueBhv.selectList(cb -> {
            if (StringUtil.isBlank(fessConfig.getSchedulerTargetName())) {
                cb.query().setTarget_Equal(Constants.DEFAULT_JOB_TARGET);
            } else {
                cb.query().setTarget_InScope(Lists.newArrayList(Constants.DEFAULT_JOB_TARGET, fessConfig.getSchedulerTargetName()));
            }
            cb.query().addOrderBy_CreatedTime_Asc();