Enable batch delivery over WebSockets

docs/reference/config.md

@@ -224,7 +224,7 @@ nav_order: 2
 |Key|Description|Type|Default Value|
 |---|-----------|----|-------------|
 |batchSize|The maximum number of records to read from the DB before performing an aggregation run|[`BytesSize`](https://pkg.go.dev/github.com/docker/go-units#BytesSize)|`200`
-|batchTimeout|How long to wait for new events to arrive before performing aggregation on a page of events|[`time.Duration`](https://pkg.go.dev/time#Duration)|`250ms`
+|batchTimeout|How long to wait for new events to arrive before performing aggregation on a page of events|[`time.Duration`](https://pkg.go.dev/time#Duration)|`0ms`
 |firstEvent|The first event the aggregator should process, if no previous offest is stored in the DB. Valid options are `oldest` or `newest`|`string`|`oldest`
 |pollTimeout|The time to wait without a notification of new events, before trying a select on the table|[`time.Duration`](https://pkg.go.dev/time#Duration)|`30s`
 |rewindQueryLimit|Safety limit on the maximum number of records to search when performing queries to search for rewinds|`int`|`1000`
@@ -249,7 +249,7 @@ nav_order: 2
 
 |Key|Description|Type|Default Value|
 |---|-----------|----|-------------|
-|batchTimeout|A short time to wait for new events to arrive before re-polling for new events|[`time.Duration`](https://pkg.go.dev/time#Duration)|`250ms`
+|batchTimeout|A short time to wait for new events to arrive before re-polling for new events|[`time.Duration`](https://pkg.go.dev/time#Duration)|`0ms`
 |bufferLength|The number of events + attachments an individual dispatcher should hold in memory ready for delivery to the subscription|`int`|`5`
 |pollTimeout|The time to wait without a notification of new events, before trying a select on the table|[`time.Duration`](https://pkg.go.dev/time#Duration)|`30s`
 
@@ -1387,7 +1387,8 @@ nav_order: 2
 
 |Key|Description|Type|Default Value|
 |---|-----------|----|-------------|
-|batchSize|Default read ahead to enable for subscriptions that do not explicitly configure readahead|`int`|`0`
+|batchSize|Default read ahead to enable for subscriptions that do not explicitly configure readahead|`int`|`50`
+|batchTimeout|Default batch timeout|`int`|`50ms`
 
 ## subscription.retry
 

docs/reference/types/wsack.md

@@ -37,7 +37,7 @@ nav_order: 24
 
 | Field Name | Description | Type |
 |------------|-------------|------|
-| `type` | WSActionBase.type | `FFEnum`:<br/>`"start"`<br/>`"ack"`<br/>`"protocol_error"` |
+| `type` | WSActionBase.type | `FFEnum`:<br/>`"start"`<br/>`"ack"`<br/>`"protocol_error"`<br/>`"event_batch"` |
 | `id` | WSAck.id | [`UUID`](simpletypes#uuid) |
 | `subscription` | WSAck.subscription | [`SubscriptionRef`](#subscriptionref) |
 

docs/reference/types/wserror.md

@@ -33,6 +33,6 @@ nav_order: 25
 
 | Field Name | Description | Type |
 |------------|-------------|------|
-| `type` | WSAck.type | `FFEnum`:<br/>`"start"`<br/>`"ack"`<br/>`"protocol_error"` |
+| `type` | WSAck.type | `FFEnum`:<br/>`"start"`<br/>`"ack"`<br/>`"protocol_error"`<br/>`"event_batch"` |
 | `error` | WSAck.error | `string` |
 

docs/reference/types/wsstart.md

@@ -42,7 +42,7 @@ nav_order: 23
 
 | Field Name | Description | Type |
 |------------|-------------|------|
-| `type` | WSActionBase.type | `FFEnum`:<br/>`"start"`<br/>`"ack"`<br/>`"protocol_error"` |
+| `type` | WSActionBase.type | `FFEnum`:<br/>`"start"`<br/>`"ack"`<br/>`"protocol_error"`<br/>`"event_batch"` |
 | `autoack` | WSStart.autoack | `bool` |
 | `namespace` | WSStart.namespace | `string` |
 | `name` | WSStart.name | `string` |

internal/coreconfig/coreconfig.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Kaleido, Inc.
+// Copyright © 2024 Kaleido, Inc.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -327,8 +327,10 @@ var (
 	OrgDescription = ffc("org.description")
 	// OrchestratorStartupAttempts is how many time to attempt to connect to core infrastructure on startup
 	OrchestratorStartupAttempts = ffc("orchestrator.startupAttempts")
-	// SubscriptionDefaultsReadAhead default read ahead to enable for subscriptions that do not explicitly configure readahead
-	SubscriptionDefaultsReadAhead = ffc("subscription.defaults.batchSize")
+	// SubscriptionDefaultsBatchSize default read ahead to enable for subscriptions that do not explicitly configure readahead
+	SubscriptionDefaultsBatchSize = ffc("subscription.defaults.batchSize")
+	// SubscriptionDefaultsBatchTimeout default batch timeout
+	SubscriptionDefaultsBatchTimeout = ffc("subscription.defaults.batchTimeout")
 	// SubscriptionMax maximum number of pre-defined subscriptions that can exist (note for high fan-out consider connecting a dedicated pub/sub broker to the dispatcher)
 	SubscriptionMax = ffc("subscription.max")
 	// SubscriptionsRetryInitialDelay is the initial retry delay
@@ -404,7 +406,7 @@ func setDefaults() {
 	viper.SetDefault(string(DownloadRetryFactor), 2.0)
 	viper.SetDefault(string(EventAggregatorFirstEvent), core.SubOptsFirstEventOldest)
 	viper.SetDefault(string(EventAggregatorBatchSize), 200)
-	viper.SetDefault(string(EventAggregatorBatchTimeout), "250ms")
+	viper.SetDefault(string(EventAggregatorBatchTimeout), "0ms")
 	viper.SetDefault(string(EventAggregatorPollTimeout), "30s")
 	viper.SetDefault(string(EventAggregatorRewindTimeout), "50ms")
 	viper.SetDefault(string(EventAggregatorRewindQueueLength), 10)
@@ -414,7 +416,7 @@ func setDefaults() {
 	viper.SetDefault(string(EventAggregatorRetryMaxDelay), "30s")
 	viper.SetDefault(string(EventDBEventsBufferSize), 100)
 	viper.SetDefault(string(EventDispatcherBufferLength), 5)
-	viper.SetDefault(string(EventDispatcherBatchTimeout), "250ms")
+	viper.SetDefault(string(EventDispatcherBatchTimeout), "0ms")
 	viper.SetDefault(string(EventDispatcherPollTimeout), "30s")
 	viper.SetDefault(string(EventTransportsEnabled), []string{"websockets", "webhooks"})
 	viper.SetDefault(string(EventTransportsDefault), "websockets")
@@ -451,7 +453,8 @@ func setDefaults() {
 	viper.SetDefault(string(PrivateMessagingBatchSize), 200)
 	viper.SetDefault(string(PrivateMessagingBatchTimeout), "1s")
 	viper.SetDefault(string(PrivateMessagingBatchPayloadLimit), "800Kb")
-	viper.SetDefault(string(SubscriptionDefaultsReadAhead), 0)
+	viper.SetDefault(string(SubscriptionDefaultsBatchSize), 50)
+	viper.SetDefault(string(SubscriptionDefaultsBatchTimeout), "50ms")
 	viper.SetDefault(string(SubscriptionMax), 500)
 	viper.SetDefault(string(SubscriptionsRetryInitialDelay), "250ms")
 	viper.SetDefault(string(SubscriptionsRetryMaxDelay), "30s")

internal/coremsgs/en_config_descriptions.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Kaleido, Inc.
+// Copyright © 2024 Kaleido, Inc.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -383,8 +383,9 @@ var (
 	ConfigPluginSharedstorageIpfsGatewayURL      = ffc("config.plugins.sharedstorage[].ipfs.gateway.url", "The URL for the IPFS Gateway", urlStringType)
 	ConfigPluginSharedstorageIpfsGatewayProxyURL = ffc("config.plugins.sharedstorage[].ipfs.gateway.proxy.url", "Optional HTTP proxy server to use when connecting to the IPFS Gateway", urlStringType)
 
-	ConfigSubscriptionMax               = ffc("config.subscription.max", "The maximum number of pre-defined subscriptions that can exist (note for high fan-out consider connecting a dedicated pub/sub broker to the dispatcher)", i18n.IntType)
-	ConfigSubscriptionDefaultsBatchSize = ffc("config.subscription.defaults.batchSize", "Default read ahead to enable for subscriptions that do not explicitly configure readahead", i18n.IntType)
+	ConfigSubscriptionMax                  = ffc("config.subscription.max", "The maximum number of pre-defined subscriptions that can exist (note for high fan-out consider connecting a dedicated pub/sub broker to the dispatcher)", i18n.IntType)
+	ConfigSubscriptionDefaultsBatchSize    = ffc("config.subscription.defaults.batchSize", "Default read ahead to enable for subscriptions that do not explicitly configure readahead", i18n.IntType)
+	ConfigSubscriptionDefaultsBatchTimeout = ffc("config.subscription.defaults.batchTimeout", "Default batch timeout", i18n.IntType)
 
 	ConfigTokensName     = ffc("config.tokens[].name", "A name to identify this token plugin", i18n.StringType)
 	ConfigTokensPlugin   = ffc("config.tokens[].plugin", "The type of the token plugin to use", i18n.StringType)

internal/events/event_dispatcher.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Kaleido, Inc.
+// Copyright © 2024 Kaleido, Inc.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -65,25 +65,21 @@ type eventDispatcher struct {
 	elected       bool
 	eventPoller   *eventPoller
 	inflight      map[fftypes.UUID]*core.Event
-	eventDelivery chan *core.EventDelivery
+	eventDelivery chan []*core.EventDelivery
 	mux           sync.Mutex
 	namespace     string
 	readAhead     int
 	batch         bool
-	batchTimeout  time.Duration
 	subscription  *subscription
 	txHelper      txcommon.Helper
 }
 
 func newEventDispatcher(ctx context.Context, enricher *eventEnricher, ei events.Plugin, di database.Plugin, dm data.Manager, bm broadcast.Manager, pm privatemessaging.Manager, connID string, sub *subscription, en *eventNotifier, txHelper txcommon.Helper) *eventDispatcher {
 	ctx, cancelCtx := context.WithCancel(ctx)
-	readAhead := config.GetUint(coreconfig.SubscriptionDefaultsReadAhead)
+	readAhead := uint(0)
 	if sub.definition.Options.ReadAhead != nil {
 		readAhead = uint(*sub.definition.Options.ReadAhead)
 	}
-	if readAhead > maxReadAhead {
-		readAhead = maxReadAhead
-	}
 
 	batchTimeout := defaultBatchTimeout
 	if sub.definition.Options.BatchTimeout != nil && *sub.definition.Options.BatchTimeout != "" {
@@ -108,13 +104,12 @@ func newEventDispatcher(ctx context.Context, enricher *eventEnricher, ei events.
 		subscription:  sub,
 		namespace:     sub.definition.Namespace,
 		inflight:      make(map[fftypes.UUID]*core.Event),
-		eventDelivery: make(chan *core.EventDelivery, readAhead+1),
+		eventDelivery: make(chan []*core.EventDelivery, readAhead+1),
 		readAhead:     int(readAhead),
 		acksNacks:     make(chan ackNack),
 		closed:        make(chan struct{}),
 		txHelper:      txHelper,
 		batch:         batch,
-		batchTimeout:  batchTimeout,
 	}
 
 	pollerConf := &eventPollerConf{
@@ -138,6 +133,20 @@ func newEventDispatcher(ctx context.Context, enricher *eventEnricher, ei events.
 		firstEvent:       sub.definition.Options.FirstEvent,
 	}
 
+	// Users can tune the batch related settings.
+	// This is always true in batch:true cases, and optionally you can use the batchTimeout setting
+	// to tweak how we optimize ourselves for readahead / latency detection without batching
+	// (most likely users with this requirement would be best to just move to batch:true).
+	if batchTimeout > 0 {
+		pollerConf.eventBatchTimeout = batchTimeout
+		if batchTimeout > pollerConf.eventPollTimeout {
+			pollerConf.eventPollTimeout = batchTimeout
+		}
+	}
+	if batch || pollerConf.eventBatchSize < int(readAhead) {
+		pollerConf.eventBatchSize = ed.readAhead
+	}
+
 	ed.eventPoller = newEventPoller(ctx, di, en, pollerConf)
 	return ed
 }
@@ -165,11 +174,8 @@ func (ed *eventDispatcher) electAndStart() {
 	ed.elected = true
 	ed.eventPoller.start()
 
-	if ed.batch {
-		go ed.deliverBatchedEvents()
-	} else {
-		go ed.deliverEvents()
-	}
+	go ed.deliverEvents()
+
 	// Wait until the event poller closes
 	<-ed.eventPoller.closed
 }
@@ -326,7 +332,15 @@ func (ed *eventDispatcher) bufferedDelivery(events []core.LocallySequenced) (boo
 			ed.mux.Unlock()
 
 			dispatched++
-			ed.eventDelivery <- event
+			if !ed.batch {
+				// dispatch individually
+				ed.eventDelivery <- []*core.EventDelivery{event}
+			}
+		}
+
+		if ed.batch && len(dispatchable) > 0 {
+			// Dispatch the whole batch now marked in-flight
+			ed.eventDelivery <- dispatchable
 		}
 
 		if inflightCount == 0 {
@@ -384,88 +398,48 @@ func (ed *eventDispatcher) handleAckOffsetUpdate(ack ackNack) {
 	}
 }
 
-func (ed *eventDispatcher) deliverBatchedEvents() {
-	withData := ed.subscription.definition.Options.WithData != nil && *ed.subscription.definition.Options.WithData
-
-	var events []*core.CombinedEventDataDelivery
-	var batchTimeoutContext context.Context
-	var batchTimeoutCancel func()
-	for {
-		var timeoutContext context.Context
-		var timedOut bool
-		if batchTimeoutContext != nil {
-			timeoutContext = batchTimeoutContext
-		} else {
-			timeoutContext = ed.ctx
-		}
-		select {
-		case event, ok := <-ed.eventDelivery:
-			if !ok {
-				if batchTimeoutCancel != nil {
-					batchTimeoutCancel()
-				}
-				return
-			}
-
-			if events == nil {
-				events = []*core.CombinedEventDataDelivery{}
-				batchTimeoutContext, batchTimeoutCancel = context.WithTimeout(ed.ctx, ed.batchTimeout)
-			}
-
-			log.L(ed.ctx).Debugf("Dispatching %s event in a batch: %.10d/%s [%s]: ref=%s/%s", ed.transport.Name(), event.Sequence, event.ID, event.Type, event.Namespace, event.Reference)
-
-			var data []*core.Data
-			var err error
-			if withData && event.Message != nil {
-				data, _, err = ed.data.GetMessageDataCached(ed.ctx, event.Message)
-			}
-
-			events = append(events, &core.CombinedEventDataDelivery{Event: event, Data: data})
-
-			if err != nil {
-				ed.deliveryResponse(&core.EventDeliveryResponse{ID: event.ID, Rejected: true})
-			}
-
-		case <-timeoutContext.Done():
-			timedOut = true
-		case <-ed.ctx.Done():
-			if batchTimeoutCancel != nil {
-				batchTimeoutCancel()
-			}
-			return
-		}
-
-		if len(events) == ed.readAhead || (timedOut && len(events) > 0) {
-			_ = ed.transport.BatchDeliveryRequest(ed.ctx, ed.connID, ed.subscription.definition, events)
-			// If err handle all the delivery responses for all the events??
-			events = nil
-		}
-	}
-}
-
 // TODO issue here, we can't just call DeliveryRequest with one thing.
 func (ed *eventDispatcher) deliverEvents() {
 	withData := ed.subscription.definition.Options.WithData != nil && *ed.subscription.definition.Options.WithData
 	for {
 		select {
-		case event, ok := <-ed.eventDelivery:
+		case events, ok := <-ed.eventDelivery:
 			if !ok {
 				return
 			}
 
-			log.L(ed.ctx).Debugf("Dispatching %s event: %.10d/%s [%s]: ref=%s/%s", ed.transport.Name(), event.Sequence, event.ID, event.Type, event.Namespace, event.Reference)
-			var data []*core.Data
+			// As soon as we hit an error, we need to trigger into nack mode
 			var err error
-			if withData && event.Message != nil {
-				data, _, err = ed.data.GetMessageDataCached(ed.ctx, event.Message)
+			eventsWithData := make([]*core.CombinedEventDataDelivery, len(events))
+			for i := 0; i < len(events) && err == nil; i++ {
+				e := &core.CombinedEventDataDelivery{
+					Event: events[i],
+				}
+				eventsWithData[i] = e
+				log.L(ed.ctx).Debugf("Dispatching %s event: %.10d/%s [%s]: ref=%s/%s", ed.transport.Name(), e.Event.Sequence, e.Event.ID, e.Event.Type, e.Event.Namespace, e.Event.Reference)
+				if withData && e.Event.Message != nil {
+					e.Data, _, err = ed.data.GetMessageDataCached(ed.ctx, e.Event.Message)
+				}
+				// Individual events (in reality there is only ever i==0 for this case)
+				if err == nil && !ed.batch {
+					err = ed.transport.DeliveryRequest(ed.ctx, ed.connID, ed.subscription.definition, e.Event, e.Data)
+				}
+				if err != nil {
+					ed.deliveryResponse(&core.EventDeliveryResponse{ID: e.Event.ID, Rejected: true})
+				}
 			}
 
-			if err == nil {
-				err = ed.transport.DeliveryRequest(ed.ctx, ed.connID, ed.subscription.definition, event, data)
-			}
-			if err != nil {
-				ed.deliveryResponse(&core.EventDeliveryResponse{ID: event.ID, Rejected: true})
+			// In batch mode we do one dispatch of the whole set as one
+			if err == nil && ed.batch {
+				err = ed.transport.BatchDeliveryRequest(ed.ctx, ed.connID, ed.subscription.definition, eventsWithData)
+				if err != nil {
+					// nack everything on behalf of the failed delivery
+					for _, e := range events {
+						ed.deliveryResponse(&core.EventDeliveryResponse{ID: e.Event.ID, Rejected: true})
+					}
+				}
 			}
+
 		case <-ed.ctx.Done():
 			return
 		}