Esempio n. 1
0
func TriggerBatchProcessing(c appengine.Context, article ArticleId) error {
	// Instead of submitting a task to match incoming bids, resulting in one task per bid,
	// we collect bids for up to two seconds and batch-process them afterwards.
	semaphoreKey := "semaphore-" + string(article)
	if semaphore, err := memcache.Increment(c, semaphoreKey, 1, 0); err != nil {
		return err
	} else if semaphore >= 2 {
		c.Infof("Batch processing already triggered for article %v", article)
		memcache.IncrementExisting(c, semaphoreKey, -1)
		return nil
	} else {
		time.Sleep(1 * time.Second)
		c.Infof("Starting batch processing...")
		memcache.IncrementExisting(c, semaphoreKey, -1)
		time_before := time.Now()
		matchingErr := MatchIncomingBids(c, article)
		time_after := time.Now()
		duration := time_after.Sub(time_before)
		if duration > 1000*time.Millisecond {
			c.Errorf("Batch processing finished after %v. Limit exceeded!", duration)
		} else if duration > 500*time.Millisecond {
			c.Warningf("Batch processing finished after %v. Limit in danger.", duration)
		} else {
			c.Infof("Batch processing finished after %v.", duration)
		}
		return matchingErr
	}
}
Esempio n. 2
0
func IncrExisting(c TransactionContext, key string, delta int64) (newValue uint64, err error) {
	k, err := Keyify(key)
	if err != nil {
		return
	}
	if newValue, err = memcache.IncrementExisting(c, k, delta); err != nil {
		err = errors.Errorf("Error doing IncrementExisting %#v: %v", k, err)
		return
	}
	return
}