From 42d7def171cd6cf07a86fe61cbfc80b3a0a0b631 Mon Sep 17 00:00:00 2001
From: Sameer Kumar Subudhi <sameer.subudhi@lightcurve.io>
Date: Wed, 10 Jan 2024 12:38:09 +0530
Subject: [PATCH] :bug: Kickstart event subscription if the
 eventSubscriptionClient is renewed

---
 services/blockchain-connector/config.js        |  2 +-
 .../blockchain-connector/shared/sdk/client.js  | 18 +++++++++++++-----
 .../blockchain-connector/shared/sdk/events.js  |  5 +++++
 3 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/services/blockchain-connector/config.js b/services/blockchain-connector/config.js
index cc725ebbbd..ad8864446f 100644
--- a/services/blockchain-connector/config.js
+++ b/services/blockchain-connector/config.js
@@ -127,7 +127,7 @@ config.apiClient = {
 
 // Every n milliseconds, verify if client connection is alive
 config.clientConnVerifyInterval =
-	Number(process.env.CLIENT_CONNECTION_VERIFY_INTERVAL) || 60 * 1000; // in millisecs
+	Number(process.env.CLIENT_CONNECTION_VERIFY_INTERVAL) || 30 * 1000; // in millisecs
 
 // Backdoor config to restart the connector if the stall issue pops up - disabled by default
 const exitDelay = Number(process.env.CONNECTOR_EXIT_DELAY_IN_HOURS); // in hours
diff --git a/services/blockchain-connector/shared/sdk/client.js b/services/blockchain-connector/shared/sdk/client.js
index 480755100e..61e6e3be1c 100644
--- a/services/blockchain-connector/shared/sdk/client.js
+++ b/services/blockchain-connector/shared/sdk/client.js
@@ -56,15 +56,15 @@ const clientInstantiationStats = {
 };
 let requestCount = 0;
 
+const checkIsClientAlive = client => client && client._channel && client._channel.isAlive;
+
 const getApiClientStats = () => ({
 	...clientInstantiationStats,
-	currentPoolSize: clientPool.length,
+	activePoolSize: clientPool.filter(client => checkIsClientAlive(client)).length,
 	expectedPoolSize: MAX_CLIENT_POOL_SIZE,
 	numEndpointInvocations: requestCount,
 });
 
-const checkIsClientAlive = client => client && client._channel && client._channel.isAlive;
-
 const pingListener = apiClient => {
 	if (!isObject(apiClient)) {
 		logger.warn(`apiClient is ${JSON.stringify(apiClient)}. Cannot register a pingListener.`);
@@ -125,7 +125,13 @@ const initClientPool = async poolSize => {
 	// Set the intervals only at application init
 	if (clientPool.length === 0) {
 		setInterval(() => {
-			logger.info(`API client instantiation stats: ${JSON.stringify(getApiClientStats())}`);
+			const stats = getApiClientStats();
+			logger.info(`API client instantiation stats: ${JSON.stringify(stats)}`);
+			if (stats.activePoolSize < stats.expectedPoolSize) {
+				logger.warn(
+					'activePoolSize should catch up with the expectedPoolSize, once the node is under less stress.',
+				);
+			}
 		}, 5 * 60 * 1000);
 
 		setInterval(() => {
@@ -133,12 +139,14 @@ const initClientPool = async poolSize => {
 				if (isObject(apiClient)) return;
 
 				// Re-instantiate when null
-				clientPool[index] = await instantiateNewClient()
+				const newApiClient = await instantiateNewClient()
 					.then(client => {
 						client.poolIndex = index;
 						return client;
 					})
 					.catch(() => null);
+				clientPool[index] = newApiClient;
+				if (newApiClient) Signals.get('newApiClient').dispatch(newApiClient.poolIndex);
 			});
 		}, WS_SERVER_PING_INTERVAL);
 	}
diff --git a/services/blockchain-connector/shared/sdk/events.js b/services/blockchain-connector/shared/sdk/events.js
index 6b7982f9ff..6e8b025b6a 100644
--- a/services/blockchain-connector/shared/sdk/events.js
+++ b/services/blockchain-connector/shared/sdk/events.js
@@ -160,6 +160,9 @@ const ensureAPIClientLiveness = () => {
 						logger.debug(
 							`Dispatched 'resetApiClient' signal for the event subscription API client ${apiClient.poolIndex}.`,
 						);
+					} else {
+						logger.debug('Triggered subscribeToAllRegisteredEvents from ensureAPIClientLiveness.');
+						await subscribeToAllRegisteredEvents();
 					}
 				}
 			} catch (_) {
@@ -174,11 +177,13 @@ const ensureAPIClientLiveness = () => {
 };
 
 const nodeIsSyncedListener = () => {
+	logger.debug('Node is now synced with the network.');
 	isNodeSynced = true;
 	ensureAPIClientLiveness();
 };
 
 const genesisBlockDownloadedListener = () => {
+	logger.debug('Genesis block is now downloaded.');
 	isGenesisBlockDownloaded = true;
 	ensureAPIClientLiveness();
 };