Change min ratelimit calculation to per period

So when you have a short flush period it will go faster

Also initialize the rate-limit to "Inf" or no limit, so we start out
fast and slow down once we know what the queue is like.

Signed-off-by: Bryan Boreham <[email protected]>

Author: bboreham

pkg/ingester/flush.go

@@ -20,8 +20,8 @@ const (
 	// Backoff for retrying 'immediate' flushes. Only counts for queue
 	// position, not wallclock time.
 	flushBackoff = 1 * time.Second
-	// Slowest per-second we will rate-limit flush calls to the chunk store
-	minFlushRate = 10
+	// Lower bound on flushes per check period for rate-limiter
+	minFlushes = 100
 )
 
 // Flush triggers a flush of all the chunks and closes the flush queues.
@@ -111,8 +111,8 @@ func (i *Ingester) setFlushRate() {
 	const fudge = 1.05 // aim to finish a little bit before the end of the period
 	flushesPerSecond := float64(totalQueueLength) / i.cfg.FlushCheckPeriod.Seconds() * fudge
 	// Avoid going very slowly with tiny queues
-	if flushesPerSecond < minFlushRate {
-		flushesPerSecond = minFlushRate
+	if flushesPerSecond*i.cfg.FlushCheckPeriod.Seconds() < minFlushes {
+		flushesPerSecond = minFlushes / i.cfg.FlushCheckPeriod.Seconds()
 	}
 	level.Debug(util.Logger).Log("msg", "computed flush rate", "rate", flushesPerSecond)
 	i.flushRateLimiter.SetLimit(rate.Limit(flushesPerSecond))

pkg/ingester/ingester.go

@@ -203,7 +203,7 @@ func New(cfg Config, clientConfig client.Config, limits *validation.Overrides, c
 		limits:           limits,
 		chunkStore:       chunkStore,
 		flushQueues:      make([]*util.PriorityQueue, cfg.ConcurrentFlushes),
-		flushRateLimiter: rate.NewLimiter(minFlushRate, 1),
+		flushRateLimiter: rate.NewLimiter(rate.Inf, 1),
 		usersMetadata:    map[string]*userMetricsMetadata{},
 		registerer:       registerer,
 	}