archaius-core/src/main/java/com/netflix/config/AbstractPollingScheduler.java
protected Runnable getPollingRunnable(final PolledConfigurationSource source, final Configuration config) {
        return new Runnable() {
            public void run() {
                log.debug("Polling started");
                PollResult result = null;
                try {
                    result = source.poll(false, getNextCheckPoint(checkPoint));
                    checkPoint = result.getCheckPoint();
                    fireEvent(EventType.POLL_SUCCESS, result, null);
                } catch (Throwable e) {
                    log.error("Error getting result from polling source", e);
                    fireEvent(EventType.POLL_FAILURE, null, e);
                    return;
                }
                try {
                    populateProperties(result, config);
                } catch (Throwable e) {
                    log.error("Error occured applying properties", e);
                }                 
            }
            
        };   
    }
protected Runnable getPollingRunnable(final PolledConfigurationSource source, final Configuration config) {
        return new Runnable() {
            public void run() {
                log.debug("Polling started");
                PollResult result = null;
                try {
                    result = source.poll(false, getNextCheckPoint(checkPoint));
                    checkPoint = result.getCheckPoint();
                    fireEvent(EventType.POLL_SUCCESS, result, null);
                } catch (Throwable e) {
                    log.error("Error getting result from polling source", e);
                    fireEvent(EventType.POLL_FAILURE, null, e);
                    return;
                }
                try {
                    populateProperties(result, config);
                } catch (Throwable e) {
                    log.error("Error occured applying properties", e);
                }                 
            }
            
        };   
    }
Gets the runnable to be scheduled. The implementation does the following
<li>Gets the next check point
<li>call source.poll(fase, checkpoint)
<li>fire event for poll listeners
<li>If success, update the configuration with the polled result

@return Runnable to be scheduled in {@link #schedule(Runnable)}