Earliest Available Slot metrics

beacon-chain/custody/BUILD.bazel

@@ -0,0 +1,13 @@
+load("@prysm//tools/go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["metrics.go"],
+    importpath = "github.com/OffchainLabs/prysm/v7/beacon-chain/custody",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//consensus-types/primitives:go_default_library",
+        "@com_github_prometheus_client_golang//prometheus:go_default_library",
+        "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
+    ],
+)

beacon-chain/custody/metrics.go

@@ -0,0 +1,32 @@
+// Package custody provides common custody-related metrics
+package custody
+
+import (
+	"github.com/OffchainLabs/prysm/v7/consensus-types/primitives"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var (
+	// EarliestAvailableSlotP2P tracks the earliest available slot in the p2p service
+	EarliestAvailableSlotP2P = promauto.NewGauge(prometheus.GaugeOpts{
+		Name: "custody_earliest_available_slot_p2p",
+		Help: "The earliest available slot tracked by the p2p service for custody purposes",
+	})
+
+	// EarliestAvailableSlotDB tracks the earliest available slot in the database
+	EarliestAvailableSlotDB = promauto.NewGauge(prometheus.GaugeOpts{
+		Name: "custody_earliest_available_slot_db",
+		Help: "The earliest available slot tracked by the database for custody purposes",
+	})
+)
+
+// UpdateP2PMetric updates the P2P earliest available slot metric
+func UpdateP2PMetric(slot primitives.Slot) {
+	EarliestAvailableSlotP2P.Set(float64(slot))
+}
+
+// UpdateDBMetric updates the DB earliest available slot metric
+func UpdateDBMetric(slot primitives.Slot) {
+	EarliestAvailableSlotDB.Set(float64(slot))
+}

beacon-chain/db/iface/interface.go

@@ -128,6 +128,7 @@ type NoHeadAccessDatabase interface {
 	BackfillFinalizedIndex(ctx context.Context, blocks []blocks.ROBlock, finalizedChildRoot [32]byte) error
 
 	// Custody operations.
+	GetCustodyInfo(ctx context.Context) (primitives.Slot, uint64, error)
 	UpdateCustodyInfo(ctx context.Context, earliestAvailableSlot primitives.Slot, custodyGroupCount uint64) (primitives.Slot, uint64, error)
 	UpdateEarliestAvailableSlot(ctx context.Context, earliestAvailableSlot primitives.Slot) error
 	UpdateSubscribedToAllDataSubnets(ctx context.Context, subscribed bool) (bool, error)

beacon-chain/db/kv/BUILD.bazel

@@ -40,6 +40,7 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//beacon-chain/core/blocks:go_default_library",
+        "//beacon-chain/custody:go_default_library",
         "//beacon-chain/db/filters:go_default_library",
         "//beacon-chain/db/iface:go_default_library",
         "//beacon-chain/state:go_default_library",

beacon-chain/db/kv/custody.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"time"
 
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/custody"
 	"github.com/OffchainLabs/prysm/v7/config/params"
 	"github.com/OffchainLabs/prysm/v7/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v7/encoding/bytesutil"
@@ -14,6 +15,44 @@ import (
 	bolt "go.etcd.io/bbolt"
 )
 
+// GetCustodyInfo retrieves the current custody info without updating it.
+// This is a read-only operation that also updates the DB metric.
+func (s *Store) GetCustodyInfo(ctx context.Context) (primitives.Slot, uint64, error) {
+	_, span := trace.StartSpan(ctx, "BeaconDB.GetCustodyInfo")
+	defer span.End()
+
+	var storedGroupCount uint64
+	var storedEarliestAvailableSlot primitives.Slot
+
+	if err := s.db.View(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket(custodyBucket)
+		if bucket == nil {
+			return nil
+		}
+
+		// Retrieve the stored custody group count.
+		storedGroupCountBytes := bucket.Get(groupCountKey)
+		if len(storedGroupCountBytes) != 0 {
+			storedGroupCount = bytesutil.BytesToUint64BigEndian(storedGroupCountBytes)
+		}
+
+		// Retrieve the stored earliest available slot.
+		storedEarliestAvailableSlotBytes := bucket.Get(earliestAvailableSlotKey)
+		if len(storedEarliestAvailableSlotBytes) != 0 {
+			storedEarliestAvailableSlot = primitives.Slot(bytesutil.BytesToUint64BigEndian(storedEarliestAvailableSlotBytes))
+		}
+
+		return nil
+	}); err != nil {
+		return 0, 0, err
+	}
+
+	// Update the DB metric with the current value
+	custody.UpdateDBMetric(storedEarliestAvailableSlot)
+
+	return storedEarliestAvailableSlot, storedGroupCount, nil
+}
+
 // UpdateCustodyInfo atomically updates the custody group count only if it is greater than the stored one.
 // In this case, it also updates the earliest available slot with the provided value.
 // It returns the (potentially updated) custody group count and earliest available slot.
@@ -70,6 +109,10 @@ func (s *Store) UpdateCustodyInfo(ctx context.Context, earliestAvailableSlot pri
 		"groupCount":            storedGroupCount,
 	}).Debug("Custody info")
 
+	// Update the DB metric whenever we log the custody info
+	// This ensures the metric is always in sync with what we log
+	custody.UpdateDBMetric(storedEarliestAvailableSlot)
+
 	return storedEarliestAvailableSlot, storedGroupCount, nil
 }
 
@@ -143,6 +186,9 @@ func (s *Store) UpdateEarliestAvailableSlot(ctx context.Context, earliestAvailab
 
 	log.WithField("earliestAvailableSlot", storedEarliestAvailableSlot).Debug("Updated earliest available slot")
 
+	// Update DB metric after successfully updating the earliest available slot
+	custody.UpdateDBMetric(storedEarliestAvailableSlot)
+
 	return nil
 }
 

beacon-chain/p2p/BUILD.bazel

@@ -48,6 +48,7 @@ go_library(
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/time:go_default_library",
+        "//beacon-chain/custody:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/db/kv:go_default_library",
         "//beacon-chain/p2p/encoder:go_default_library",

beacon-chain/p2p/custody.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/custody"
 	"github.com/OffchainLabs/prysm/v7/config/params"
 	"github.com/OffchainLabs/prysm/v7/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v7/time/slots"
@@ -22,6 +23,9 @@ func (s *Service) EarliestAvailableSlot(ctx context.Context) (primitives.Slot, e
 		return 0, errors.Wrap(err, "wait for custody info")
 	}
 
+	// Update metric whenever the value is accessed
+	custody.UpdateP2PMetric(custodyInfo.earliestAvailableSlot)
+
 	return custodyInfo.earliestAvailableSlot, nil
 }
 
@@ -80,11 +84,15 @@ func (s *Service) UpdateCustodyInfo(earliestAvailableSlot primitives.Slot, custo
 
 		close(s.custodyInfoSet)
 
+		// Update P2P metric when initializing custody info
+		custody.UpdateP2PMetric(earliestAvailableSlot)
+
 		return earliestAvailableSlot, custodyGroupCount, nil
 	}
 
 	inMemory := s.custodyInfo
 	if custodyGroupCount <= inMemory.groupCount {
+		custody.UpdateP2PMetric(inMemory.earliestAvailableSlot)
 		return inMemory.earliestAvailableSlot, inMemory.groupCount, nil
 	}
 
@@ -97,6 +105,7 @@ func (s *Service) UpdateCustodyInfo(earliestAvailableSlot primitives.Slot, custo
 
 	if custodyGroupCount <= samplesPerSlot {
 		inMemory.groupCount = custodyGroupCount
+		custody.UpdateP2PMetric(inMemory.earliestAvailableSlot)
 		return inMemory.earliestAvailableSlot, custodyGroupCount, nil
 	}
 
@@ -107,11 +116,15 @@ func (s *Service) UpdateCustodyInfo(earliestAvailableSlot primitives.Slot, custo
 
 	if earliestAvailableSlot < fuluForkSlot {
 		inMemory.groupCount = custodyGroupCount
+		custody.UpdateP2PMetric(inMemory.earliestAvailableSlot)
 		return inMemory.earliestAvailableSlot, custodyGroupCount, nil
 	}
 
 	inMemory.earliestAvailableSlot = earliestAvailableSlot
 	inMemory.groupCount = custodyGroupCount
+
+	custody.UpdateP2PMetric(earliestAvailableSlot)
+
 	return earliestAvailableSlot, custodyGroupCount, nil
 }
 
@@ -133,6 +146,7 @@ func (s *Service) UpdateEarliestAvailableSlot(earliestAvailableSlot primitives.S
 	// Allow decrease (for backfill scenarios)
 	if earliestAvailableSlot < s.custodyInfo.earliestAvailableSlot {
 		s.custodyInfo.earliestAvailableSlot = earliestAvailableSlot
+		custody.UpdateP2PMetric(earliestAvailableSlot)
 		return nil
 	}
 
@@ -163,6 +177,7 @@ func (s *Service) UpdateEarliestAvailableSlot(earliestAvailableSlot primitives.S
 	}
 
 	s.custodyInfo.earliestAvailableSlot = earliestAvailableSlot
+	custody.UpdateP2PMetric(earliestAvailableSlot)
 	return nil
 }
 

beacon-chain/p2p/testing/BUILD.bazel

@@ -20,6 +20,7 @@ go_library(
     ],
     deps = [
         "//beacon-chain/core/peerdas:go_default_library",
+        "//beacon-chain/custody:go_default_library",
         "//beacon-chain/p2p/encoder:go_default_library",
         "//beacon-chain/p2p/peers:go_default_library",
         "//beacon-chain/p2p/peers/scorers:go_default_library",

beacon-chain/p2p/testing/p2p.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/custody"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/p2p/encoder"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/p2p/peers/scorers"
@@ -496,6 +497,8 @@ func (s *TestP2P) UpdateCustodyInfo(earliestAvailableSlot primitives.Slot, custo
 	s.earliestAvailableSlot = earliestAvailableSlot
 	s.custodyGroupCount = custodyGroupCount
 
+	custody.UpdateP2PMetric(earliestAvailableSlot)
+
 	return s.earliestAvailableSlot, s.custodyGroupCount, nil
 }
 

beacon-chain/sync/BUILD.bazel

@@ -85,6 +85,7 @@ go_library(
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
         "//beacon-chain/core/transition/interop:go_default_library",
+        "//beacon-chain/custody:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/db/filters:go_default_library",

beacon-chain/sync/custody.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/OffchainLabs/prysm/v7/async"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/custody"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/p2p"
 	"github.com/OffchainLabs/prysm/v7/cmd/beacon-chain/flags"
 	"github.com/OffchainLabs/prysm/v7/config/params"
@@ -26,6 +27,24 @@ func (s *Service) maintainCustodyInfo() {
 	})
 }
 
+// refreshCustodyMetrics refreshes both P2P and DB custody metrics with current values.
+// This is used in early return paths to ensure metrics are populated even when no update occurs.
+func (s *Service) refreshCustodyMetrics() {
+	ctx, cancel := context.WithTimeout(s.ctx, 1*time.Second)
+	defer cancel()
+
+	// Refresh P2P metric
+	if slot, err := s.cfg.p2p.EarliestAvailableSlot(ctx); err == nil {
+		custody.UpdateP2PMetric(slot)
+	}
+
+	// Refresh DB metric using read-only operation
+	if _, _, err := s.cfg.beaconDB.GetCustodyInfo(ctx); err != nil {
+		// GetCustodyInfo already updates the metric internally
+		log.WithError(err).Debug("Failed to get custody info for metrics")
+	}
+}
+
 func (s *Service) updateCustodyInfoIfNeeded() error {
 	const minimumPeerCount = 1
 
@@ -43,6 +62,8 @@ func (s *Service) updateCustodyInfoIfNeeded() error {
 
 	// If the actual custody group count is already equal to the target, skip the update.
 	if actualCustodyGrounpCount >= targetCustodyGroupCount {
+		// Refresh metrics when no update is needed (e.g., after restart)
+		s.refreshCustodyMetrics()
 		return nil
 	}
 
@@ -66,6 +87,8 @@ func (s *Service) updateCustodyInfoIfNeeded() error {
 	}
 
 	if !enoughPeers {
+		// Refresh metrics when insufficient peers (e.g., after restart)
+		s.refreshCustodyMetrics()
 		return nil
 	}
 

changelog/satushh-eas-metric-2.md

@@ -0,0 +1,3 @@
+### Added
+
+- Metric for earliest available slot.