Revert "Revert "DS-631 Observation loop (#18843)""

.changeset/afraid-doors-fold.md

@@ -0,0 +1,5 @@
+---
+"chainlink": minor
+---
+
+#changed LLO's observations now run in a loop, so their cache is always warm.

core/services/llo/delegate.go

@@ -207,6 +207,9 @@ func (d *delegate) Close() error {
 		for _, oracle := range d.oracles {
 			merr = errors.Join(merr, oracle.Close())
 		}
+		if closer, ok := d.ds.(Closer); ok {
+			merr = errors.Join(merr, closer.Close())
+		}
 		merr = errors.Join(merr, d.telem.Close())
 		return merr
 	})

core/services/llo/mercurytransmitter/transmitter.go

@@ -25,7 +25,6 @@ import (
 
 	"github.com/smartcontractkit/chainlink/v2/core/config"
 	"github.com/smartcontractkit/chainlink/v2/core/services/llo/grpc"
-	"github.com/smartcontractkit/chainlink/v2/core/services/llo/observation"
 )
 
 const (
@@ -269,7 +268,6 @@ func (mt *transmitter) Transmit(
 				err = fmt.Errorf("failed to add transmission to commit channel: %w", ctx.Err())
 			}
 		}
-		observation.GetCache(digest).SetLastTransmissionSeqNr(seqNr)
 	})
 
 	if !ok {

core/services/llo/observation/cache.go

@@ -4,52 +4,34 @@ import (
 	"runtime"
 	"strconv"
 	"sync"
-	"sync/atomic"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
-	ocr2types "github.com/smartcontractkit/libocr/offchainreporting2/types"
 
 	llotypes "github.com/smartcontractkit/chainlink-common/pkg/types/llo"
 	"github.com/smartcontractkit/chainlink-data-streams/llo"
 )
 
 var (
-	registryMu = sync.Mutex{}
-	registry   = map[ocr2types.ConfigDigest]*Cache{}
-
 	promCacheHitCount = promauto.NewCounterVec(prometheus.CounterOpts{
 		Namespace: "llo",
 		Subsystem: "datasource",
 		Name:      "cache_hit_count",
 		Help:      "Number of local observation cache hits",
 	},
-		[]string{"configDigest", "streamID"},
+		[]string{"streamID"},
 	)
 	promCacheMissCount = promauto.NewCounterVec(prometheus.CounterOpts{
 		Namespace: "llo",
 		Subsystem: "datasource",
 		Name:      "cache_miss_count",
 		Help:      "Number of local observation cache misses",
 	},
-		[]string{"configDigest", "streamID", "reason"},
+		[]string{"streamID", "reason"},
 	)
 )
 
-func GetCache(configDigest ocr2types.ConfigDigest) *Cache {
-	registryMu.Lock()
-	defer registryMu.Unlock()
-
-	cache, ok := registry[configDigest]
-	if !ok {
-		cache = NewCache(configDigest, 500*time.Millisecond, time.Minute)
-		registry[configDigest] = cache
-	}
-
-	return cache
-}
-
 // Cache of stream values.
 // It maintains a cache of stream values fetched from adapters until the last
 // transmission sequence number is greater or equal the sequence number at which
@@ -58,30 +40,25 @@ func GetCache(configDigest ocr2types.ConfigDigest) *Cache {
 // The cache is cleaned up periodically to remove decommissioned stream values
 // if the provided cleanupInterval is greater than 0.
 type Cache struct {
-	mu sync.RWMutex
-
-	configDigestStr string
+	mu              sync.RWMutex
 	values          map[llotypes.StreamID]item
 	maxAge          time.Duration
 	cleanupInterval time.Duration
 
-	lastTransmissionSeqNr atomic.Uint64
-	closeChan             chan struct{}
+	closeChan chan struct{}
 }
 
 type item struct {
 	value     llo.StreamValue
-	seqNr     uint64
 	createdAt time.Time
 }
 
 // NewCache creates a new cache.
 //
 // maxAge is the maximum age of a stream value to keep in the cache.
 // cleanupInterval is the interval to clean up the cache.
-func NewCache(configDigest ocr2types.ConfigDigest, maxAge time.Duration, cleanupInterval time.Duration) *Cache {
+func NewCache(maxAge time.Duration, cleanupInterval time.Duration) *Cache {
 	c := &Cache{
-		configDigestStr: configDigest.Hex(),
 		values:          make(map[llotypes.StreamID]item),
 		maxAge:          maxAge,
 		cleanupInterval: cleanupInterval,
@@ -110,16 +87,11 @@ func NewCache(configDigest ocr2types.ConfigDigest, maxAge time.Duration, cleanup
 	return c
 }
 
-// SetLastTransmissionSeqNr sets the last transmission sequence number.
-func (c *Cache) SetLastTransmissionSeqNr(seqNr uint64) {
-	c.lastTransmissionSeqNr.Store(seqNr)
-}
-
 // Add adds a stream value to the cache.
-func (c *Cache) Add(id llotypes.StreamID, value llo.StreamValue, seqNr uint64) {
+func (c *Cache) Add(id llotypes.StreamID, value llo.StreamValue) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
-	c.values[id] = item{value: value, seqNr: seqNr, createdAt: time.Now()}
+	c.values[id] = item{value: value, createdAt: time.Now()}
 }
 
 func (c *Cache) Get(id llotypes.StreamID) (llo.StreamValue, bool) {
@@ -129,31 +101,25 @@ func (c *Cache) Get(id llotypes.StreamID) (llo.StreamValue, bool) {
 	label := strconv.FormatUint(uint64(id), 10)
 	item, ok := c.values[id]
 	if !ok {
-		promCacheMissCount.WithLabelValues(c.configDigestStr, label, "notFound").Inc()
-		return nil, false
-	}
-
-	if item.seqNr <= c.lastTransmissionSeqNr.Load() {
-		promCacheMissCount.WithLabelValues(c.configDigestStr, label, "seqNr").Inc()
+		promCacheMissCount.WithLabelValues(label, "notFound").Inc()
 		return nil, false
 	}
 
 	if time.Since(item.createdAt) >= c.maxAge {
-		promCacheMissCount.WithLabelValues(c.configDigestStr, label, "maxAge").Inc()
+		promCacheMissCount.WithLabelValues(label, "maxAge").Inc()
 		return nil, false
 	}
 
-	promCacheHitCount.WithLabelValues(c.configDigestStr, label).Inc()
+	promCacheHitCount.WithLabelValues(label).Inc()
 	return item.value, true
 }
 
 func (c *Cache) cleanup() {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
-	lastTransmissionSeqNr := c.lastTransmissionSeqNr.Load()
 	for id, item := range c.values {
-		if item.seqNr <= lastTransmissionSeqNr || time.Since(item.createdAt) >= c.maxAge {
+		if time.Since(item.createdAt) >= c.maxAge {
 			delete(c.values, id)
 		}
 	}

core/services/llo/observation/cache_test.go

@@ -10,8 +10,6 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	ocr2types "github.com/smartcontractkit/libocr/offchainreporting2/types"
-
 	llotypes "github.com/smartcontractkit/chainlink-common/pkg/types/llo"
 	"github.com/smartcontractkit/chainlink-data-streams/llo"
 )
@@ -72,7 +70,7 @@ func TestNewCache(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			cache := NewCache(ocr2types.ConfigDigest{}, tt.maxAge, tt.cleanupInterval)
+			cache := NewCache(tt.maxAge, tt.cleanupInterval)
 			require.NotNil(t, cache)
 			assert.Equal(t, tt.maxAge, cache.maxAge)
 			assert.Equal(t, tt.cleanupInterval, cache.cleanupInterval)
@@ -87,7 +85,6 @@ func TestCache_Add_Get(t *testing.T) {
 		name      string
 		streamID  llotypes.StreamID
 		value     llo.StreamValue
-		seqNr     uint64
 		maxAge    time.Duration
 		wantValue llo.StreamValue
 		wantFound bool
@@ -97,7 +94,6 @@ func TestCache_Add_Get(t *testing.T) {
 			name:      "get existing value",
 			streamID:  1,
 			value:     &mockStreamValue{value: []byte{42}},
-			seqNr:     10,
 			maxAge:    time.Second,
 			wantValue: &mockStreamValue{value: []byte{42}},
 			wantFound: true,
@@ -106,28 +102,14 @@ func TestCache_Add_Get(t *testing.T) {
 			name:      "get non-existent value",
 			streamID:  1,
 			value:     &mockStreamValue{value: []byte{42}},
-			seqNr:     10,
 			maxAge:    time.Second,
 			wantValue: nil,
 			wantFound: false,
 		},
-		{
-			name:      "get expired by sequence number",
-			streamID:  1,
-			value:     &mockStreamValue{value: []byte{42}},
-			seqNr:     5,
-			maxAge:    time.Second,
-			wantValue: nil,
-			wantFound: false,
-			beforeGet: func(cache *Cache) {
-				cache.SetLastTransmissionSeqNr(10)
-			},
-		},
 		{
 			name:      "get expired by age",
 			streamID:  1,
 			value:     &mockStreamValue{value: []byte{42}},
-			seqNr:     10,
 			maxAge:    time.Nanosecond * 100,
 			wantValue: nil,
 			wantFound: false,
@@ -139,10 +121,10 @@ func TestCache_Add_Get(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			cache := NewCache(ocr2types.ConfigDigest{}, tt.maxAge, 0)
+			cache := NewCache(tt.maxAge, 0)
 
 			if tt.wantFound {
-				cache.Add(tt.streamID, tt.value, tt.seqNr)
+				cache.Add(tt.streamID, tt.value)
 			}
 
 			if tt.beforeGet != nil {
@@ -159,11 +141,11 @@ func TestCache_Add_Get(t *testing.T) {
 }
 
 func TestCache_Cleanup(t *testing.T) {
-	cache := NewCache(ocr2types.ConfigDigest{}, time.Nanosecond*100, time.Millisecond)
+	cache := NewCache(time.Nanosecond*100, time.Millisecond)
 	streamID := llotypes.StreamID(1)
 	value := &mockStreamValue{value: []byte{42}}
 
-	cache.Add(streamID, value, 10)
+	cache.Add(streamID, value)
 	time.Sleep(time.Millisecond * 2)
 
 	gotValue, gotFound := cache.Get(streamID)
@@ -172,7 +154,7 @@ func TestCache_Cleanup(t *testing.T) {
 }
 
 func TestCache_ConcurrentAccess(t *testing.T) {
-	cache := NewCache(ocr2types.ConfigDigest{}, time.Second, 0)
+	cache := NewCache(time.Second, 0)
 	const numGoroutines = 10
 	const numOperations = uint32(1000)
 
@@ -185,7 +167,7 @@ func TestCache_ConcurrentAccess(t *testing.T) {
 			defer wg.Done()
 			for j := uint32(0); j < numOperations; j++ {
 				streamID := id*numOperations + j
-				cache.Add(streamID, &mockStreamValue{value: []byte{byte(id)}}, 1)
+				cache.Add(streamID, &mockStreamValue{value: []byte{byte(id)}})
 			}
 		}(i)
 	}
@@ -203,7 +185,7 @@ func TestCache_ConcurrentAccess(t *testing.T) {
 }
 
 func TestCache_ConcurrentReadWrite(t *testing.T) {
-	cache := NewCache(ocr2types.ConfigDigest{}, time.Second, 0)
+	cache := NewCache(time.Second, 0)
 	const numGoroutines = 10
 	const numOperations = uint32(1000)
 
@@ -216,7 +198,7 @@ func TestCache_ConcurrentReadWrite(t *testing.T) {
 			defer wg.Done()
 			for j := uint32(0); j < numOperations; j++ {
 				streamID := id*numOperations + j
-				cache.Add(streamID, &mockStreamValue{value: []byte{byte(id)}}, uint64(j))
+				cache.Add(streamID, &mockStreamValue{value: []byte{byte(id)}})
 			}
 		}(i)
 	}
@@ -236,7 +218,7 @@ func TestCache_ConcurrentReadWrite(t *testing.T) {
 }
 
 func TestCache_ConcurrentAddGet(t *testing.T) {
-	cache := NewCache(ocr2types.ConfigDigest{}, time.Second, 0)
+	cache := NewCache(time.Second, 0)
 	const numGoroutines = 10
 	const numOperations = uint32(1000)
 
@@ -249,7 +231,7 @@ func TestCache_ConcurrentAddGet(t *testing.T) {
 			defer wg.Done()
 			for j := uint32(0); j < numOperations; j++ {
 				streamID := id*numOperations + j
-				cache.Add(streamID, &mockStreamValue{value: []byte{byte(id)}}, 1)
+				cache.Add(streamID, &mockStreamValue{value: []byte{byte(id)}})
 			}
 		}(i)
 	}