[ROCKETMQ-238] Subsequent executions are suppressed when some key periodic tasks encounter an exception

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Feedback Received
• Affects Version/s: 4.0.0-incubating, 4.1.0-incubating
• Fix Version/s: 4.2.0
• Component/s: rocketmq-broker, rocketmq-remoting, rocketmq-store
• Assignee: Xinyu Zhou
• Reporter: Xinyu Zhou
• Created: 05/Jul/17 06:44
• Updated: 13/Dec/17 12:21
• Resolved: 13/Dec/17 12:21

Description

There are many scheduled tasks delegated to ScheduledExecutorService or Timer in broker.

When the scheduled task encounters an exception, subsequent executions are suppressed, see:

/**
     * Creates and executes a periodic action that becomes enabled first
     * after the given initial delay, and subsequently with the given
     * period; that is executions will commence after
     * {@code initialDelay} then {@code initialDelay+period}, then
     * {@code initialDelay + 2 * period}, and so on.
     * If any execution of the task
     * encounters an exception, subsequent executions are suppressed.
     * Otherwise, the task will only terminate via cancellation or
     * termination of the executor.  If any execution of this task
     * takes longer than its period, then subsequent executions
     * may start late, but will not concurrently execute.
     *
     * @param command the task to execute
     * @param initialDelay the time to delay first execution
     * @param period the period between successive executions
     * @param unit the time unit of the initialDelay and period parameters
     * @return a ScheduledFuture representing pending completion of
     *         the task, and whose {@code get()} method will throw an
     *         exception upon cancellation
     * @throws RejectedExecutionException if the task cannot be
     *         scheduled for execution
     * @throws NullPointerException if command is null
     * @throws IllegalArgumentException if period less than or equal to zero
     */
    public ScheduledFuture<?> scheduleAtFixedRate(Runnable command,
                                                  long initialDelay,
                                                  long period,
                                                  TimeUnit unit);

So catch Throwable to avoid error canceled our key scheduled tasks.