diff --git a/pkg/apiserver/controllers/v1/usagemetrics.go b/pkg/apiserver/controllers/v1/usagemetrics.go
index 8fda148ce..f77239e56 100644
--- a/pkg/apiserver/controllers/v1/usagemetrics.go
+++ b/pkg/apiserver/controllers/v1/usagemetrics.go
@@ -131,11 +131,13 @@ func (c *Controller) UsageMetrics(gctx *gin.Context) {
 	}
 
 	if _, err := c.DBClient.CreateMetric(generatedType, generatedBy, collectedAt, string(jsonPayload)); err != nil {
-		log.Errorf("Failed to store usage metrics: %s", err)
+		log.Error(err)
 		c.HandleDBErrors(gctx, err)
 		return
 	}
 
-	// empty body
+	// if CreateMetrics() returned nil, the metric was already there, we're good
+	// and don't split hair about 201 vs 200/204
+
 	gctx.Status(http.StatusCreated)
 }
diff --git a/pkg/csconfig/crowdsec_service.go b/pkg/csconfig/crowdsec_service.go
index f4103293f..c54b850f6 100644
--- a/pkg/csconfig/crowdsec_service.go
+++ b/pkg/csconfig/crowdsec_service.go
@@ -12,6 +12,11 @@ import (
 	"github.com/crowdsecurity/go-cs-lib/ptr"
 )
 
+const (
+	defaultMetricsInterval = 30 * time.Minute
+	minimumMetricsInterval = 15 * time.Minute
+)
+
 // CrowdsecServiceCfg contains the location of parsers/scenarios/... and acquisition files
 type CrowdsecServiceCfg struct {
 	Enable                    *bool             `yaml:"enable"`
@@ -143,11 +148,6 @@ func (c *Config) LoadCrowdsec() error {
 	return nil
 }
 
-const (
-	defaultMetricsInterval = 30 * time.Second
-	minimumMetricsInterval = 15 * time.Second
-)
-
 func (c *CrowdsecServiceCfg) setMetricsInterval() {
 	switch {
 	case c.MetricsInterval == nil:
diff --git a/pkg/database/flush.go b/pkg/database/flush.go
index 4828ebac9..73c9adb9d 100644
--- a/pkg/database/flush.go
+++ b/pkg/database/flush.go
@@ -7,15 +7,24 @@ import (
 	"github.com/go-co-op/gocron"
 	log "github.com/sirupsen/logrus"
 
+	"github.com/crowdsecurity/go-cs-lib/ptr"
+
 	"github.com/crowdsecurity/crowdsec/pkg/csconfig"
 	"github.com/crowdsecurity/crowdsec/pkg/database/ent/alert"
 	"github.com/crowdsecurity/crowdsec/pkg/database/ent/bouncer"
 	"github.com/crowdsecurity/crowdsec/pkg/database/ent/decision"
 	"github.com/crowdsecurity/crowdsec/pkg/database/ent/event"
 	"github.com/crowdsecurity/crowdsec/pkg/database/ent/machine"
+	"github.com/crowdsecurity/crowdsec/pkg/database/ent/metric"
 	"github.com/crowdsecurity/crowdsec/pkg/types"
 )
 
+const (
+	// how long to keep metrics in the local database
+	defaultMetricsMaxAge = 7 * 24 * time.Hour
+	flushInterval = 1 * time.Minute
+)
+
 
 func (c *Client) StartFlushScheduler(config *csconfig.FlushDBCfg) (*gocron.Scheduler, error) {
 	maxItems := 0
@@ -32,7 +41,7 @@ func (c *Client) StartFlushScheduler(config *csconfig.FlushDBCfg) (*gocron.Sched
 
 	// Init & Start cronjob every minute for alerts
 	scheduler := gocron.NewScheduler(time.UTC)
-	job, err := scheduler.Every(1).Minute().Do(c.FlushAlerts, maxAge, maxItems)
+	job, err := scheduler.Every(flushInterval).Do(c.FlushAlerts, maxAge, maxItems)
 	if err != nil {
 		return nil, fmt.Errorf("while starting FlushAlerts scheduler: %w", err)
 	}
@@ -77,19 +86,45 @@ func (c *Client) StartFlushScheduler(config *csconfig.FlushDBCfg) (*gocron.Sched
 			log.Warning("bouncers auto-delete for login/password auth is not supported (use cert or api)")
 		}
 	}
-	baJob, err := scheduler.Every(1).Minute().Do(c.FlushAgentsAndBouncers, config.AgentsGC, config.BouncersGC)
+	baJob, err := scheduler.Every(flushInterval).Do(c.FlushAgentsAndBouncers, config.AgentsGC, config.BouncersGC)
 	if err != nil {
 		return nil, fmt.Errorf("while starting FlushAgentsAndBouncers scheduler: %w", err)
 	}
 
 	baJob.SingletonMode()
-	scheduler.StartAsync()
 
-	// TODO: flush metrics here (MetricsMaxAge)
+	metricsJob, err := scheduler.Every(flushInterval).Do(c.flushMetrics, config.MetricsMaxAge)
+	if err != nil {
+		return nil, fmt.Errorf("while starting flushMetrics scheduler: %w", err)
+	}
+
+	metricsJob.SingletonMode()
+
+	scheduler.StartAsync()
 
 	return scheduler, nil
 }
 
+// flushMetrics deletes metrics older than maxAge, regardless if they have been pushed to CAPI or not
+func (c *Client) flushMetrics(maxAge *time.Duration) {
+	if maxAge == nil {
+		maxAge = ptr.Of(defaultMetricsMaxAge)
+	}
+
+	c.Log.Debugf("flushing metrics older than %s", maxAge)
+
+	deleted, err := c.Ent.Metric.Delete().Where(
+		metric.CollectedAtLTE(time.Now().UTC().Add(-*maxAge)),
+	).Exec(c.CTX)
+	if err != nil {
+		c.Log.Errorf("while flushing metrics: %s", err)
+		return
+	}
+
+	if deleted > 0 {
+		c.Log.Debugf("flushed %d metrics snapshots", deleted)
+	}
+}
 
 func (c *Client) FlushOrphans() {
 	/* While it has only been linked to some very corner-case bug : https://github.com/crowdsecurity/crowdsec/issues/778 */
diff --git a/pkg/database/metrics.go b/pkg/database/metrics.go
index 4a75f2c32..bd5254497 100644
--- a/pkg/database/metrics.go
+++ b/pkg/database/metrics.go
@@ -1,10 +1,9 @@
 package database
 
 import (
+	"fmt"
 	"time"
 
-	"github.com/pkg/errors"
-
 	"github.com/crowdsecurity/crowdsec/pkg/database/ent"
 	"github.com/crowdsecurity/crowdsec/pkg/database/ent/metric"
 )
@@ -26,9 +25,15 @@ func (c *Client) CreateMetric(generatedType metric.GeneratedType, generatedBy st
 		SetPayload(payload).
 		Save(c.CTX)
 
-	if err != nil {
+	switch {
+	case ent.IsConstraintError(err):
+		// pretty safe guess, it's the unique index
+		c.Log.Infof("storing metrics snapshot for '%s' at %s: already exists", generatedBy, collectedAt)
+		// it's polite to accept a duplicate snapshot without any error
+		return nil, nil
+	case err != nil:
 		c.Log.Warningf("CreateMetric: %s", err)
-		return nil, errors.Wrapf(InsertFail, "creating metrics set for '%s' at %s", generatedBy, collectedAt)
+		return nil, fmt.Errorf("storing metrics snapshot for '%s' at %s: %w", generatedBy, collectedAt, InsertFail)
 	}
 
 	return metric, nil