diff --git a/pkg/pattern/drain/drain.go b/pkg/pattern/drain/drain.go
index 5b8535cdea179..928f4a4b12a15 100644
--- a/pkg/pattern/drain/drain.go
+++ b/pkg/pattern/drain/drain.go
@@ -255,7 +255,7 @@ func (d *Drain) treeSearch(rootNode *Node, tokens []string, simTh float64, inclu
 	}
 
 	// handle case of empty log string - return the single cluster in that group
-	if tokenCount == 0 {
+	if tokenCount < 2 {
 		return d.idToCluster.Get(curNode.clusterIDs[0])
 	}
 
diff --git a/pkg/pattern/flush.go b/pkg/pattern/flush.go
new file mode 100644
index 0000000000000..40f75de43822e
--- /dev/null
+++ b/pkg/pattern/flush.go
@@ -0,0 +1,71 @@
+package pattern
+
+import (
+	"fmt"
+
+	"github.com/go-kit/log/level"
+	"github.com/grafana/loki/v3/pkg/util"
+	"github.com/prometheus/common/model"
+)
+
+func (i *Ingester) initFlushQueues() {
+	i.flushQueuesDone.Add(i.cfg.ConcurrentFlushes)
+	for j := 0; j < i.cfg.ConcurrentFlushes; j++ {
+		i.flushQueues[j] = util.NewPriorityQueue(i.metrics.flushQueueLength)
+		// for now we don't flush only prune old samples.
+		// go i.flushLoop(j)
+	}
+}
+
+func (i *Ingester) Flush() {
+	i.flush(true)
+}
+
+func (i *Ingester) flush(mayRemoveStreams bool) {
+	i.sweepUsers(true, mayRemoveStreams)
+
+	// Close the flush queues, to unblock waiting workers.
+	for _, flushQueue := range i.flushQueues {
+		flushQueue.Close()
+	}
+
+	i.flushQueuesDone.Wait()
+	level.Debug(i.logger).Log("msg", "flush queues have drained")
+}
+
+type flushOp struct {
+	from      model.Time
+	userID    string
+	fp        model.Fingerprint
+	immediate bool
+}
+
+func (o *flushOp) Key() string {
+	return fmt.Sprintf("%s-%s-%v", o.userID, o.fp, o.immediate)
+}
+
+func (o *flushOp) Priority() int64 {
+	return -int64(o.from)
+}
+
+// sweepUsers periodically schedules series for flushing and garbage collects users with no series
+func (i *Ingester) sweepUsers(immediate, mayRemoveStreams bool) {
+	instances := i.getInstances()
+
+	for _, instance := range instances {
+		i.sweepInstance(instance, immediate, mayRemoveStreams)
+	}
+}
+
+func (i *Ingester) sweepInstance(instance *instance, _, mayRemoveStreams bool) {
+	_ = instance.streams.ForEach(func(s *stream) (bool, error) {
+		if mayRemoveStreams {
+			instance.streams.WithLock(func() {
+				if s.prune() {
+					instance.removeStream(s)
+				}
+			})
+		}
+		return true, nil
+	})
+}
diff --git a/pkg/pattern/ingester.go b/pkg/pattern/ingester.go
index f2851c5703b89..af2e842c28b83 100644
--- a/pkg/pattern/ingester.go
+++ b/pkg/pattern/ingester.go
@@ -5,10 +5,13 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"math/rand"
 	"net/http"
 	"sync"
+	"time"
 
 	"github.com/go-kit/log"
+	"github.com/go-kit/log/level"
 	"github.com/grafana/dskit/ring"
 	"github.com/grafana/dskit/services"
 	"github.com/grafana/dskit/tenant"
@@ -27,9 +30,11 @@ import (
 const readBatchSize = 1024
 
 type Config struct {
-	Enabled          bool                  `yaml:"enabled,omitempty" doc:"description=Whether the pattern ingester is enabled."`
-	LifecyclerConfig ring.LifecyclerConfig `yaml:"lifecycler,omitempty" doc:"description=Configures how the lifecycle of the pattern ingester will operate and where it will register for discovery."`
-	ClientConfig     clientpool.Config     `yaml:"client_config,omitempty" doc:"description=Configures how the pattern ingester will connect to the ingesters."`
+	Enabled           bool                  `yaml:"enabled,omitempty" doc:"description=Whether the pattern ingester is enabled."`
+	LifecyclerConfig  ring.LifecyclerConfig `yaml:"lifecycler,omitempty" doc:"description=Configures how the lifecycle of the pattern ingester will operate and where it will register for discovery."`
+	ClientConfig      clientpool.Config     `yaml:"client_config,omitempty" doc:"description=Configures how the pattern ingester will connect to the ingesters."`
+	ConcurrentFlushes int                   `yaml:"concurrent_flushes"`
+	FlushCheckPeriod  time.Duration         `yaml:"flush_check_period"`
 
 	// For testing.
 	factory ring_client.PoolFactory `yaml:"-"`
@@ -40,6 +45,8 @@ func (cfg *Config) RegisterFlags(fs *flag.FlagSet) {
 	cfg.LifecyclerConfig.RegisterFlagsWithPrefix("pattern-ingester.", fs, util_log.Logger)
 	cfg.ClientConfig.RegisterFlags(fs)
 	fs.BoolVar(&cfg.Enabled, "pattern-ingester.enabled", false, "Flag to enable or disable the usage of the pattern-ingester component.")
+	fs.IntVar(&cfg.ConcurrentFlushes, "pattern-ingester.concurrent-flushes", 32, "How many flushes can happen concurrently from each stream.")
+	fs.DurationVar(&cfg.FlushCheckPeriod, "pattern-ingester.flush-check-period", 30*time.Second, "How often should the ingester see if there are any blocks to flush. The first flush check is delayed by a random time up to 0.8x the flush check period. Additionally, there is +/- 1% jitter added to the interval.")
 }
 
 func (cfg *Config) Validate() error {
@@ -61,6 +68,15 @@ type Ingester struct {
 
 	instancesMtx sync.RWMutex
 	instances    map[string]*instance
+
+	// One queue per flush thread.  Fingerprint is used to
+	// pick a queue.
+	flushQueues     []*util.PriorityQueue
+	flushQueuesDone sync.WaitGroup
+	loopDone        sync.WaitGroup
+	loopQuit        chan struct{}
+
+	metrics *ingesterMetrics
 }
 
 func New(
@@ -69,13 +85,17 @@ func New(
 	registerer prometheus.Registerer,
 	logger log.Logger,
 ) (*Ingester, error) {
+	metrics := newIngesterMetrics(registerer, metricsNamespace)
 	registerer = prometheus.WrapRegistererWithPrefix(metricsNamespace+"_", registerer)
 
 	i := &Ingester{
-		cfg:        cfg,
-		logger:     log.With(logger, "component", "pattern-ingester"),
-		registerer: registerer,
-		instances:  make(map[string]*instance),
+		cfg:         cfg,
+		logger:      log.With(logger, "component", "pattern-ingester"),
+		registerer:  registerer,
+		metrics:     metrics,
+		instances:   make(map[string]*instance),
+		flushQueues: make([]*util.PriorityQueue, cfg.ConcurrentFlushes),
+		loopQuit:    make(chan struct{}),
 	}
 	i.Service = services.NewBasicService(i.starting, i.running, i.stopping)
 	var err error
@@ -106,18 +126,74 @@ func (i *Ingester) starting(ctx context.Context) error {
 	if err != nil {
 		return err
 	}
-	// todo: start flush queue.
+	i.initFlushQueues()
+	// start our loop
+	i.loopDone.Add(1)
+	go i.loop()
 	return nil
 }
 
 func (i *Ingester) running(ctx context.Context) error {
-	<-ctx.Done()
-	return nil
+	var serviceError error
+	select {
+	// wait until service is asked to stop
+	case <-ctx.Done():
+	// stop
+	case err := <-i.lifecyclerWatcher.Chan():
+		serviceError = fmt.Errorf("lifecycler failed: %w", err)
+	}
+
+	close(i.loopQuit)
+	i.loopDone.Wait()
+	return serviceError
 }
 
 func (i *Ingester) stopping(_ error) error {
-	// todo: stop flush queue
-	return nil
+	err := services.StopAndAwaitTerminated(context.Background(), i.lifecycler)
+	for _, flushQueue := range i.flushQueues {
+		flushQueue.Close()
+	}
+	i.flushQueuesDone.Wait()
+	return err
+}
+
+func (i *Ingester) loop() {
+	defer i.loopDone.Done()
+
+	// Delay the first flush operation by up to 0.8x the flush time period.
+	// This will ensure that multiple ingesters started at the same time do not
+	// flush at the same time. Flushing at the same time can cause concurrently
+	// writing the same chunk to object storage, which in AWS S3 leads to being
+	// rate limited.
+	jitter := time.Duration(rand.Int63n(int64(float64(i.cfg.FlushCheckPeriod.Nanoseconds()) * 0.8)))
+	initialDelay := time.NewTimer(jitter)
+	defer initialDelay.Stop()
+
+	level.Info(i.logger).Log("msg", "sleeping for initial delay before starting periodic flushing", "delay", jitter)
+
+	select {
+	case <-initialDelay.C:
+		// do nothing and continue with flush loop
+	case <-i.loopQuit:
+		// ingester stopped while waiting for initial delay
+		return
+	}
+
+	// Add +/- 20% of flush interval as jitter.
+	// The default flush check period is 30s so max jitter will be 6s.
+	j := i.cfg.FlushCheckPeriod / 5
+	flushTicker := util.NewTickerWithJitter(i.cfg.FlushCheckPeriod, j)
+	defer flushTicker.Stop()
+
+	for {
+		select {
+		case <-flushTicker.C:
+			i.sweepUsers(false, true)
+
+		case <-i.loopQuit:
+			return
+		}
+	}
 }
 
 // Watch implements grpc_health_v1.HealthCheck.
@@ -135,10 +211,6 @@ func (i *Ingester) CheckReady(ctx context.Context) error {
 	return i.lifecycler.CheckReady(ctx)
 }
 
-func (i *Ingester) Flush() {
-	// todo flush or use transfer out
-}
-
 func (i *Ingester) TransferOut(_ context.Context) error {
 	// todo may be.
 	return ring.ErrTransferDisabled
@@ -217,3 +289,14 @@ func (i *Ingester) getInstanceByID(id string) (*instance, bool) {
 	inst, ok := i.instances[id]
 	return inst, ok
 }
+
+func (i *Ingester) getInstances() []*instance {
+	i.instancesMtx.RLock()
+	defer i.instancesMtx.RUnlock()
+
+	instances := make([]*instance, 0, len(i.instances))
+	for _, instance := range i.instances {
+		instances = append(instances, instance)
+	}
+	return instances
+}
diff --git a/pkg/pattern/instance.go b/pkg/pattern/instance.go
index cf319cd2a946e..4b270a04ca391 100644
--- a/pkg/pattern/instance.go
+++ b/pkg/pattern/instance.go
@@ -154,3 +154,10 @@ func (i *instance) getLabelsFromFingerprint(fp model.Fingerprint) labels.Labels
 	}
 	return s.labels
 }
+
+// removeStream removes a stream from the instance.
+func (i *instance) removeStream(s *stream) {
+	if i.streams.Delete(s) {
+		i.index.Delete(s.labels, s.fp)
+	}
+}
diff --git a/pkg/pattern/metrics.go b/pkg/pattern/metrics.go
new file mode 100644
index 0000000000000..e4a9c146c36f6
--- /dev/null
+++ b/pkg/pattern/metrics.go
@@ -0,0 +1,21 @@
+package pattern
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+type ingesterMetrics struct {
+	flushQueueLength prometheus.Gauge
+}
+
+func newIngesterMetrics(r prometheus.Registerer, metricsNamespace string) *ingesterMetrics {
+	return &ingesterMetrics{
+		flushQueueLength: promauto.With(r).NewGauge(prometheus.GaugeOpts{
+			Namespace: metricsNamespace,
+			Subsystem: "pattern_ingester",
+			Name:      "flush_queue_length",
+			Help:      "The total number of series pending in the flush queue.",
+		}),
+	}
+}
diff --git a/pkg/pattern/stream.go b/pkg/pattern/stream.go
index 3bbe649d9aecc..8e80628e6e194 100644
--- a/pkg/pattern/stream.go
+++ b/pkg/pattern/stream.go
@@ -72,10 +72,19 @@ func (s *stream) Iterator(_ context.Context, from, through model.Time) (iter.Ite
 	iters := make([]iter.Iterator, 0, len(clusters))
 
 	for _, cluster := range clusters {
-		if cluster.Size < minClusterSize {
+		if cluster.Size < minClusterSize || cluster.String() == "" {
 			continue
 		}
 		iters = append(iters, cluster.Iterator(from, through))
 	}
 	return iter.NewMerge(iters...), nil
 }
+
+func (s *stream) prune() bool {
+	s.mtx.Lock()
+	defer s.mtx.Unlock()
+	// todo first prune all Volume Chunks.
+	// todo then prune all clusters.
+
+	return false
+}