Add network ready event - Closes #4090

elements/lisk-p2p/src/p2p.ts

@@ -117,6 +117,7 @@ export {
 export const EVENT_NEW_INBOUND_PEER = 'newInboundPeer';
 export const EVENT_FAILED_TO_ADD_INBOUND_PEER = 'failedToAddInboundPeer';
 export const EVENT_NEW_PEER = 'newPeer';
+export const EVENT_NETWORK_READY = 'networkReady';
 
 export const DEFAULT_NODE_HOST_IP = '0.0.0.0';
 export const DEFAULT_DISCOVERY_INTERVAL = 30000;
@@ -156,6 +157,7 @@ export class P2P extends EventEmitter {
 	private readonly _sanitizedPeerLists: PeerLists;
 	private readonly _httpServer: http.Server;
 	private _isActive: boolean;
+	private _hasConnected: boolean;
 	private readonly _peerBook: PeerBook;
 	private readonly _bannedPeers: Set<string>;
 	private readonly _populatorInterval: number;
@@ -214,6 +216,7 @@ export class P2P extends EventEmitter {
 		);
 		this._config = config;
 		this._isActive = false;
+		this._hasConnected = false;
 		this._peerBook = new PeerBook({
 			secret: config.secret ? config.secret : DEFAULT_RANDOM_SECRET,
 		});
@@ -260,6 +263,9 @@ export class P2P extends EventEmitter {
 
 			// Re-emit the message to allow it to bubble up the class hierarchy.
 			this.emit(EVENT_CONNECT_OUTBOUND, peerInfo);
+			if (this._isNetworkReady()) {
+				this.emit(EVENT_NETWORK_READY);
+			}
 		};
 
 		this._handleOutboundPeerConnectAbort = (peerInfo: P2PPeerInfo) => {
@@ -777,6 +783,16 @@ export class P2P extends EventEmitter {
 		}
 	}
 
+	private _isNetworkReady(): boolean {
+		if (!this._hasConnected && this._peerPool.getConnectedPeers().length > 0) {
+			this._hasConnected = true;
+
+			return true;
+		}
+
+		return false;
+	}
+
 	private _pickRandomPeers(count: number): ReadonlyArray<P2PPeerInfo> {
 		const peerList: ReadonlyArray<P2PPeerInfo> = this._peerBook.getAllPeers(); // Peers whose values has been updated at least once.
 
@@ -865,6 +881,7 @@ export class P2P extends EventEmitter {
 			throw new Error('Cannot stop the node because it is not active');
 		}
 		this._isActive = false;
+		this._hasConnected = false;
 		this._stopPopulator();
 		this._peerPool.removeAllPeers();
 		await this._stopPeerServer();

elements/lisk-p2p/src/peer_pool.ts

@@ -316,16 +316,14 @@ export class PeerPool extends EventEmitter {
 		);
 		const selectedPeers = this._peerSelectForRequest({
 			peers: getUniquePeersbyIp(listOfPeerInfo),
-			nodeInfo: this._nodeInfo,
-			peerLimit: 1,
-			requestPacket: packet,
 		});
 
 		if (selectedPeers.length <= 0) {
 			throw new RequestFailError(
 				'Request failed due to no peers found in peer selection',
 			);
 		}
+
 		const selectedPeerId = constructPeerIdFromPeerInfo(selectedPeers[0]);
 
 		return this.requestFromPeer(packet, selectedPeerId);

elements/lisk-p2p/src/peer_selection.ts

@@ -23,14 +23,6 @@ import {
 } from './p2p_types';
 
 /* tslint:disable: readonly-keyword*/
-interface Histogram {
-	[key: number]: number;
-}
-interface HistogramValues {
-	height: number;
-	histogram: Histogram;
-	max: number;
-}
 
 export const getUniquePeersbyIp = (
 	peerList: ReadonlyArray<P2PDiscoveredPeerInfo>,
@@ -55,60 +47,18 @@ export const getUniquePeersbyIp = (
 export const selectPeersForRequest = (
 	input: P2PPeerSelectionForRequestInput,
 ): ReadonlyArray<P2PDiscoveredPeerInfo> => {
-	const { peers, nodeInfo } = input;
+	const { peers } = input;
 	const peerLimit = input.peerLimit;
-	const nodeHeight = nodeInfo ? nodeInfo.height : 0;
-	const filteredPeers = peers.filter(
-		// Remove unreachable peers or heights below last block height
-		(peer: P2PDiscoveredPeerInfo) => peer.height >= nodeHeight,
-	);
 
-	if (filteredPeers.length === 0) {
+	if (peers.length === 0) {
 		return [];
 	}
 
-	// Order peers by descending height
-	const sortedPeers = filteredPeers.sort((a, b) => b.height - a.height);
-
-	const aggregation = 2;
-
-	const calculatedHistogramValues = sortedPeers.reduce(
-		(histogramValues: HistogramValues, peer: P2PDiscoveredPeerInfo) => {
-			const val = Math.floor(peer.height / aggregation) * aggregation;
-			histogramValues.histogram[val] =
-				(histogramValues.histogram[val] ? histogramValues.histogram[val] : 0) +
-				1;
-			if (histogramValues.histogram[val] > histogramValues.max) {
-				histogramValues.max = histogramValues.histogram[val];
-				histogramValues.height = val;
-			}
-
-			return histogramValues;
-		},
-		{ height: 0, histogram: {}, max: -1 },
-	);
-
-	// Perform histogram cut of peers too far from histogram maximum
-	const processedPeers = sortedPeers.filter(
-		peer =>
-			peer &&
-			Math.abs(calculatedHistogramValues.height - peer.height) <
-				aggregation + 1,
-	);
-
 	if (peerLimit === undefined) {
-		return processedPeers;
-	}
-
-	if (peerLimit === 1) {
-		const goodPeer: ReadonlyArray<P2PDiscoveredPeerInfo> = [
-			processedPeers[Math.floor(Math.random() * processedPeers.length)],
-		];
-
-		return goodPeer;
+		return shuffle(peers);
 	}
 
-	return shuffle(processedPeers).slice(0, peerLimit);
+	return shuffle(peers).slice(0, peerLimit);
 };
 
 export const selectPeersForSend = (

elements/lisk-p2p/test/unit/peer_selection.ts

@@ -54,7 +54,7 @@ describe('peer selector', () => {
 			it('returned array should contain good peers according to algorithm', () => {
 				return expect(selectPeersForRequest({ peers: peerList, nodeInfo }))
 					.and.be.an('array')
-					.and.of.length(3);
+					.and.of.length(5);
 			});
 
 			it('return empty peer list for no peers as an argument', () => {
@@ -82,7 +82,7 @@ describe('peer selector', () => {
 			it('should return an array having all good peers', () => {
 				return expect(selectPeersForRequest({ peers: peerList, nodeInfo }))
 					.and.be.an('array')
-					.and.of.length(3);
+					.and.of.length(5);
 			});
 
 			it('should return an array of equal length equal to requested number of peers', () => {
@@ -102,7 +102,7 @@ describe('peer selector', () => {
 				peer => peer.height < nodeInfo.height,
 			);
 
-			it('should return an array with 0 good peers', () => {
+			it('should return an array with 1 good peer', () => {
 				return expect(
 					selectPeersForRequest({
 						peers: lowHeightPeers,
@@ -111,7 +111,7 @@ describe('peer selector', () => {
 					}),
 				)
 					.and.be.an('array')
-					.and.of.length(0);
+					.and.of.length(1);
 			});
 		});
 	});

framework/src/modules/chain/chain.js

@@ -160,11 +160,14 @@ module.exports = class Chain {
 			this._subscribeToEvents();
 
 			this.channel.subscribe('network:bootstrap', async () => {
-				this._startLoader();
 				this._calculateConsensus();
 				await this._startForging();
 			});
 
+			this.channel.subscribe('network:ready', async () => {
+				this._startLoader();
+			});
+
 			// Avoid receiving blocks/transactions from the network during snapshotting process
 			if (!this.options.loading.rebuildUpToRound) {
 				this.channel.subscribe('network:event', ({ data: { event, data } }) => {

framework/src/modules/network/index.js

@@ -49,7 +49,7 @@ module.exports = class NetworkModule extends BaseModule {
 	}
 
 	get events() {
-		return ['bootstrap', 'event'];
+		return ['bootstrap', 'event', 'ready'];
 	}
 
 	get actions() {

framework/src/modules/network/network.js

@@ -17,6 +17,7 @@
 const { getRandomBytes } = require('@liskhq/lisk-cryptography');
 const {
 	P2P,
+	EVENT_NETWORK_READY,
 	EVENT_NEW_INBOUND_PEER,
 	EVENT_CLOSE_INBOUND,
 	EVENT_CLOSE_OUTBOUND,
@@ -171,6 +172,10 @@ module.exports = class Network {
 		});
 
 		// ---- START: Bind event handlers ----
+		this.p2p.on(EVENT_NETWORK_READY, () => {
+			this.logger.debug('Node connected to the network');
+			this.channel.publish('network:ready');
+		});
 
 		this.p2p.on(EVENT_CLOSE_OUTBOUND, closePacket => {
 			this.logger.debug(