Block server start until Cassandra is initialized

server.js

@@ -35,8 +35,6 @@ app.use(function(req, res, next) {
   }
 });
 
-console.log('PORT: ' + port);
-
 app.use(bodyParser.json({limit: '50mb'}));
 app.use(bodyParser.urlencoded({limit: '50mb', extended: true}));
 
@@ -64,6 +62,14 @@ app.use('/api/settings', graphqlHTTP({
   graphiql: true
 }));
 
-const server = http.createServer(app);
+function startServer() {
+  console.log(`PORT: ${port}`);
+  const server = http.createServer(app);
+  server.listen(port, function () {});
+}
+
+const serverStartBlocker = process.env.ENABLE_V2
+  ? require('./src/clients/cassandra/CassandraConnector').initialize()
+  : require('promise').resolve();
 
-server.listen(port, function () {});
+serverStartBlocker.then(startServer).catch(console.error);

src/clients/cassandra/CassandraConnector.js

@@ -108,7 +108,17 @@ function executeQueries(queries) {
   });
 }
 
+/**
+ * Should be called on server start to warm up the connection to
+ * Cassandra so that subsequent calls are fast.
+ * @returns {Promise}
+ */
+function intialize() {
+  return executeQuery('select sitename from fortis.sitesettings limit 1', []);
+}
+
 module.exports = {
+  initialize: trackDependency(intialize, 'Cassandra', 'initialize'),
   executeBatchMutations: trackDependency(executeBatchMutations, 'Cassandra', 'executeBatchMutations'),
   executeQueries: trackDependency(executeQueries, 'Cassandra', 'executeQueries'),
   executeQuery: trackDependency(executeQuery, 'Cassandra', 'executeQuery')