now loopback reconects to db

loopback/server/connectors/vn-mysql.js

@@ -246,3 +246,98 @@ exports.initialize = function initialize(dataSource, callback) {
             dataSource.connector.connect(callback);
     }
 };
+
+MySQL.prototype.connect = function(callback) {
+    const self = this;
+    const options = generateOptions(this.settings);
+
+    if (this.client) {
+        if (callback) {
+            process.nextTick(function() {
+                callback(null, self.client);
+            });
+        }
+    } else
+        this.client = connectionHandler(options, callback);
+
+    function connectionHandler(options, callback) {
+        const client = mysql.createPool(options);
+        client.getConnection(function(err, connection) {
+            const conn = connection;
+            if (!err) {
+                if (self.debug)
+                    debug('MySQL connection is established: ' + self.settings || {});
+
+                connection.release();
+            } else {
+                if (err.code == 'ECONNREFUSED' || err.code == 'PROTOCOL_CONNECTION_LOST') { // PROTOCOL_CONNECTION_LOST
+                    console.error(`MySQL connection lost (${err.code}). Retrying..`);
+
+                    return setTimeout(() =>
+                        connectionHandler(options, callback), 5000);
+                }
+                if (self.debug || !callback)
+                    console.error('MySQL connection is failed: ' + self.settings || {}, err);
+            }
+            callback && callback(err, conn);
+        });
+
+        return client;
+    }
+};
+
+function generateOptions(settings) {
+    const s = settings || {};
+    if (s.collation) {
+        // Charset should be first 'chunk' of collation.
+        s.charset = s.collation.substr(0, s.collation.indexOf('_'));
+    } else {
+        s.collation = 'utf8_general_ci';
+        s.charset = 'utf8';
+    }
+
+    s.supportBigNumbers = (s.supportBigNumbers || false);
+    s.timezone = (s.timezone || 'local');
+
+    if (isNaN(s.connectionLimit))
+        s.connectionLimit = 10;
+
+    let options;
+    if (s.url) {
+        // use url to override other settings if url provided
+        options = s.url;
+    } else {
+        options = {
+            host: s.host || s.hostname || 'localhost',
+            port: s.port || 3306,
+            user: s.username || s.user,
+            password: s.password,
+            timezone: s.timezone,
+            socketPath: s.socketPath,
+            charset: s.collation.toUpperCase(), // Correct by docs despite seeming odd.
+            supportBigNumbers: s.supportBigNumbers,
+            connectionLimit: s.connectionLimit,
+        };
+
+        // Don't configure the DB if the pool can be used for multiple DBs
+        if (!s.createDatabase)
+            options.database = s.database;
+
+        // Take other options for mysql driver
+        // See https://github.com/strongloop/loopback-connector-mysql/issues/46
+        for (const p in s) {
+            if (p === 'database' && s.createDatabase)
+                continue;
+
+            if (options[p] === undefined)
+                options[p] = s[p];
+        }
+        // Legacy UTC Date Processing fallback - SHOULD BE TRANSITIONAL
+        if (s.legacyUtcDateProcessing === undefined)
+            s.legacyUtcDateProcessing = true;
+
+        if (s.legacyUtcDateProcessing)
+            options.timezone = 'Z';
+    }
+    return options;
+}