* @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;
        }
        return hostname + ":" + pid;
    }

        assertEquals(hostname + ":" + pid, systemHelper.getInstanceId());
    }

    @Test
    public void test_getInstanceId_withTargetName() {
        // When scheduler.target.name is set, instanceId is targetName@hostname:pid
        ComponentUtil.setFessConfig(new FessConfig.SimpleImpl() {
            private static final long serialVersionUID = 1L;

            @Override
            public String getSchedulerTargetName() {