Add DualClusterClient for live testing phase of backend/frontend split

index.js

@@ -19,6 +19,7 @@ try {
 }
 var Config = require("./lib/config");
 var Logger = require("./lib/logger");
+const Switches = require("./lib/switches");
 require("source-map-support").install();
 
 Config.load("config.yaml");
@@ -61,5 +62,16 @@ function handleLine(line) {
                 Logger.syslog.log("Deleted old channel tables");
             }
         });
+    } else if (line.indexOf("/switch") === 0) {
+        var args = line.split(" ");
+        args.shift();
+        if (args.length === 1) {
+            Logger.syslog.log("Switch " + args[0] + " is " +
+                    (Switches.isActive(args[0]) ? "ON" : "OFF"));
+        } else if (args.length === 2) {
+            Switches.setActive(args[0], args[1].toLowerCase() === "on" ? true : false);
+            Logger.syslog.log("Switch " + args[0] + " is now " +
+                    (Switches.isActive(args[0]) ? "ON" : "OFF"));
+        }
     }
 }

src/backend/backendmodule.js

@@ -1,4 +1,6 @@
 import { RedisClusterClient } from '../io/cluster/redisclusterclient';
+import { DualClusterClient } from '../io/cluster/dualclusterclient';
+import NullClusterClient from '../io/cluster/nullclusterclient';
 import { FrontendPool } from 'cytube-common/lib/redis/frontendpool';
 import RedisClientProvider from 'cytube-common/lib/redis/redisclientprovider';
 import { loadFromToml } from 'cytube-common/lib/configuration/configloader';
@@ -6,6 +8,9 @@ import path from 'path';
 import { BackendConfiguration } from './backendconfiguration';
 import logger from 'cytube-common/lib/logger';
 import redisAdapter from 'socket.io-redis';
+import LegacyConfig from '../config';
+import IOConfiguration from '../configuration/ioconfig';
+import * as Switches from '../switches';
 
 const BACKEND_CONFIG_PATH = path.resolve(__dirname, '..', '..', 'backend.toml');
 
@@ -67,7 +72,19 @@ class BackendModule {
             this.redisClusterClient = new RedisClusterClient(this.getFrontendPool());
         }
 
-        return this.redisClusterClient;
+        if (Switches.isActive(Switches.DUAL_BACKEND) && !this.nullClusterClient) {
+            this.nullClusterClient = new NullClusterClient(
+                    IOConfiguration.fromOldConfig(LegacyConfig));
+        }
+
+        if (Switches.isActive(Switches.DUAL_BACKEND)) {
+            this.clusterClient = new DualClusterClient(this.nullClusterClient,
+                    this.redisClusterClient);
+        } else {
+            this.clusterClient = this.redisClusterClient;
+        }
+
+        return this.clusterClient;
     }
 }
 

src/io/cluster/dualclusterclient.js

@@ -0,0 +1,27 @@
+import logger from 'cytube-common/lib/logger';
+import * as Switches from '../../switches';
+
+class DualClusterClient {
+    constructor(authoritativeClient, altClient) {
+        this.authoritativeClient = authoritativeClient;
+        this.altClient = altClient;
+    }
+
+    getSocketConfig(channel) {
+        return this.authoritativeClient.getSocketConfig(channel).then(result => {
+            if (!Switches.isActive(Switches.DUAL_BACKEND)) {
+                return result;
+            }
+
+            return this.altClient.getSocketConfig(channel).then(altResult => {
+                result.alt = altResult.servers;
+                return result;
+            }).catch(error => {
+                logger.warn(`Error loading alt servers: ${error}`);
+                return result;
+            });
+        })
+    }
+}
+
+export { DualClusterClient };

src/io/cluster/redisclusterclient.js

@@ -1,3 +1,8 @@
+import Promise from 'bluebird';
+
+const ONE_SECOND = 1000;
+const ERR_TIMEOUT = 'Timed out when retrieving server information';
+
 class RedisClusterClient {
     constructor(frontendPool) {
         this.frontendPool = frontendPool;
@@ -10,7 +15,7 @@ class RedisClusterClient {
             }
 
             return { servers: result };
-        });
+        }).timeout(ONE_SECOND, ERR_TIMEOUT);
     }
 }
 

src/server.js

@@ -48,6 +48,8 @@ import WebConfiguration from './configuration/webconfig';
 import NullClusterClient from './io/cluster/nullclusterclient';
 import session from './session';
 import { LegacyModule } from './legacymodule';
+import * as Switches from './switches';
+console.log(Switches);
 
 var Server = function () {
     var self = this;
@@ -62,6 +64,9 @@ var Server = function () {
     // backend init
     var initModule;
     if (Config.get("new-backend")) {
+        if (Config.get("dual-backend")) {
+            Switches.setActive(Switches.DUAL_BACKEND, true);
+        }
         const BackendModule = require('./backend/backendmodule').BackendModule;
         initModule = new BackendModule();
     } else {

src/switches.js

@@ -0,0 +1,11 @@
+const switches = {};
+
+export function isActive(switchName) {
+    return switches.hasOwnProperty(switchName) && switches[switchName] === true;
+}
+
+export function setActive(switchName, active) {
+    switches[switchName] = active;
+}
+
+export const DUAL_BACKEND = 'DUAL_BACKEND';