BE-674 Lost connection to explorer-db

* using connection pools instead to PostgreSQL

Signed-off-by: nfrunza <nfrunza@gmail.com>
Change-Id: Ic2944a73cf35f4d8865cf59226c4b8a6e7c70800

Author: nfrunza

app/persistence/PersistenceFactory.js

@@ -25,7 +25,6 @@ class PersistenceFactory {
 			// Avoid to load all db Persist module
 			const PostgreSQL = require('./postgreSQL/Persist');
 			const persistence = new PostgreSQL(dbconfig);
-			await persistence.getPGService().handleDisconnect();
 			return persistence;
 		}
 		throw new ExplorerError(explorer_error.ERROR_1003, db);

app/persistence/postgreSQL/PgService.js

@@ -18,9 +18,10 @@
  * limitations under the License.
  */
 
-const { Client } = require('pg');
+// const { Client } = require('pg');
 
 const fs = require('fs');
+const Pool = require('pg-pool');
 
 const helper = require('../../common/helper');
 
@@ -65,7 +66,10 @@ class PgService {
 			 * Value this.pgconfig.ssl.key is private key
 			 */
 			const { rejectUnauthorized, requestCert } = this.pgconfig.ssl;
-			const printConfig = { rejectUnauthorized, requestCert };
+			const printConfig = {
+				rejectUnauthorized,
+				requestCert
+			};
 			logger.info('SSL to Postgresql enabled with settings: ', printConfig);
 		} else {
 			logger.info('SSL to Postgresql disabled');
@@ -78,42 +82,21 @@ class PgService {
 
 		logger.info(`connecting to Postgresql ${connectionString}`);
 
-		this.client = new Client(this.pgconfig);
+		this.client = new Pool(this.pgconfig);
+
+		console.log('DB Pool created: ');
+		logger.info('DB Pool created: ');
+
+		this.client.on('error', err => {
+			console.log('db error:', err);
+			logger.error('db error:', err);
+		});
 
 		logger.info(
 			'Please set logger.setLevel to DEBUG in ./app/helper.js to log the debugging.'
 		);
 	}
 
-	/**
-	 *
-	 *
-	 * @memberof PgService
-	 */
-	async handleDisconnect() {
-		try {
-			this.client.on('error', err => {
-				console.log('db error', err);
-				if (err.code === 'PROTOCOL_CONNECTION_LOST') {
-					this.handleDisconnect();
-				} else {
-					throw err;
-				}
-			});
-			await this.client.connect();
-		} catch (err) {
-			if (err) {
-				/*
-				 * We introduce a delay before attempting to reconnect,
-				 * To avoid a hot loop, and to allow our node script to
-				 * Process asynchronous requests in the meantime.
-				 */
-				console.log('error when connecting to db:', err);
-				setTimeout(this.handleDisconnect, 2000);
-			}
-		}
-	}
-
 	/**
 	 *
 	 *

package-lock.json

@@ -25,7 +25,6 @@
 		"ejs": "^2.5.6",
 		"enum": "^2.5.0",
 		"express": "^4.15.3",
-		"express-fileupload": "^0.4.0",
 		"fabric-ca-client": "^1.4.4",
 		"fabric-client": "^1.4.4",
 		"fabric-network": "^1.4.4",
@@ -41,7 +40,8 @@
 		"npm-run-all": "^4.1.5",
 		"passport": "^0.4.0",
 		"passport-local": "^1.0.0",
-		"pg": "^7.4.1",
+		"pg": "^7.12.1",
+		"pg-pool": "^2.0.7",
 		"prettyjson": "^1.2.1",
 		"prop-types": "^15.6.2",
 		"save": "^2.3.3",