Add execution metadata to scheduled tasks actuator endpoint

[enesify]

Hi,

It would be nice that Spring Boot Actuator exposes endpoints for extra information about scheduled tasks(crons) in addition to runnable, expression, fixedDelay, fixedRate and custom endpoints like these:

• Last Execution Time

• Last Execution Status

• Next Execution Time

• Ability to change expression

• Ability to run a scheduled task manually

I think these endpoints would be helpful for developers and for 3rd party monitoring tools (e.g. Spring Boot Admin)

Thanks.

[wilkinsona]

Thanks for the suggestions.

Last execution time, last execution status, and next execution time are not made available by Spring Framework's task infrastructure. I can see the value in them being available via the endpoint though. @jhoeller what do you think about exposing these in Framework for consumption by the Actuator?

I'm less sure about providing write operations for tasks. It isn't possible to set the expression on a cron task at the moment or to request immediate execution of a scheduled task so our hands are tied on both of those anyway without some changes to Spring Framework.

[scottylaw]

I'm not sure how to solve the issue with checking execution times or changing the cron expression but I also wanted to be able to run my scheduled tasks ad-hoc via the Spring Boot Admin dashboard and came up with the following. There is probably a better way to do this without having to pass in the fully qualified class name but since this is displayed on the Scheduled Tasks tab it has worked for us.

@Component
@EndpointJmxExtension(endpoint = ScheduledTasksEndpoint.class)
public class ScheduledTasksEndpointExtension {

    private final Logger logger = LoggerFactory.getLogger(ScheduledTasksEndpointExtension.class);
    private final AutowireCapableBeanFactory beanFactory;

    @Autowired
    public ScheduledTasksEndpointExtension(AutowireCapableBeanFactory beanFactory) {
        this.beanFactory = beanFactory;
    }

    @WriteOperation
    public ResponseEntity runTask(@Selector String taskName) {
        try {
            String clazzName = taskName.substring(0,taskName.lastIndexOf("."));
            Class<?> clazz = Class.forName(clazzName);
            Object object = clazz.newInstance();
            Method method = object.getClass().getDeclaredMethod(taskName.substring(taskName.lastIndexOf(".") + 1));
            beanFactory.autowireBean(object);
            method.invoke(object);
            return ResponseEntity.ok().build();
        } catch (InstantiationException | ClassNotFoundException | NoSuchMethodException | IllegalAccessException | InvocationTargetException ex) {
            logger.error("Error running {}",taskName,ex);
            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(ex.getMessage());
        }
    }

}

[wilkinsona]

Looking more closely, I don't think there's anything in Framework for last execution time, last execution status, and next execution time that could be exposed. If a fixed delay task is current running, the next execution time is unknown so it's not particularly surprising that it doesn't track it.

@enesify Can you please provide a bit more information about what properties of Spring Framework's scheduled tasks you wanted to be exposed?

[spring-projects-issues]

If you would like us to look at this issue, please provide the requested information. If the information is not provided within the next 7 days this issue will be closed.

[scottylaw]

@enesify you could expose this data with a custom actuator endpoint like what I showed above if you also set up a custom aspect with an Around and AfterThrowing advice. I'm thinking you would inject this ScheduleAspect bean into your custom actuator endpoint and then you'll need to add the read operations for each piece of data you wish to consume. Below is an example that only handles a single cron expression, logic would need to be added to handle the other types of schedules. Also note that the ScheduledTask object show below is a custom object that I created, it isn't the one from Spring Framework.

@Component
@Aspect
public class ScheduleAspect {

    private static final String ERROR_STATUS = "ERROR";
    private static final Map<String, ScheduledTask> taskMap = new HashMap<>();

    @Around("@annotation(schedule)")
    public Object around(ProceedingJoinPoint proceedingJoinPoint, Scheduled schedule) throws Throwable {
        ScheduledTask scheduledTask;
        String signature = proceedingJoinPoint.getSignature().toLongString();
        if (!taskMap.containsKey(signature)) {
            scheduledTask = new ScheduledTask();
            taskMap.put(signature,scheduledTask);
        } else {
            scheduledTask = taskMap.get(signature);
        }
        scheduledTask.setLastExecutionTime(LocalDateTime.now());
        Object proceed = proceedingJoinPoint.proceed();
        scheduledTask.setNextExecutionTime(getNextExecutionTime(schedule));
        return proceed;
    }

    @AfterThrowing(value = "@annotation(schedule)",throwing = "ex")
    public void afterThrowing(JoinPoint joinPoint, Exception ex, Scheduled schedule) {
        String signature = joinPoint.getSignature().toLongString();
        if (taskMap.containsKey(signature)) {
            ScheduledTask scheduledTask = taskMap.get(signature);
            scheduledTask.setLastExecutionStatus(ERROR_STATUS);
            scheduledTask.setLastExecutionException(ex);
            scheduledTask.setNextExecutionTime(getNextExecutionTime(schedule));
        }
    }

    private LocalDateTime getNextExecutionTime(Scheduled schedule) {
        CronSequenceGenerator cronSequenceGenerator = new CronSequenceGenerator(schedule.cron());
        java.util.Date nextRunDate = cronSequenceGenerator.next(Date.from(Instant.now()));
        return nextRunDate.toInstant().atZone(ZoneId.systemDefault()).toLocalDateTime();
    }
}