Default to using Mongo for caching

Stress testing shows that after the recent caching optimization there
seems to be no significant difference in performance when using Mongo
for caching as opposed to Redis. Redis is still supported but is now
optional.

Also removed hiredis dependency since as of node_redis 2.6 the default
parser is faster than hiredis.

README.md

@@ -16,12 +16,11 @@ systems
 
 ## Quick Start
 
-Install [Node.js](http://nodejs.org/), [Redis](http://redis.io/), and
-[MongoDB](http://www.mongodb.org/). Refer to the corresponding documentation for
-installation guides. Supported versions are:
+Install [Node.js](http://nodejs.org/) and [MongoDB](http://www.mongodb.org/).
+Refer to their corresponding documentation for installation instructions. The
+supported versions are:
 
 - Node.js: 6.x and 7.x (7.x recommended)
-- Redis: 2.4 through 3.2
 - MongoDB: 2.6 through 3.4
 
 Then install GenieACS using NPM:

config/config-sample.json

@@ -1,7 +1,5 @@
 {
   "MONGODB_CONNECTION_URL" : "mongodb://127.0.0.1/genieacs",
-  "REDIS_PORT" : "6379",
-  "REDIS_HOST" : "127.0.0.1",
   "CWMP_INTERFACE" : "0.0.0.0",
   "CWMP_PORT" : 7547,
   "CWMP_SSL" : false,

lib/config.coffee

@@ -24,7 +24,7 @@ options = {
   CONFIG_DIR : {type : 'path', default : 'config'},
   MONGODB_CONNECTION_URL : {type : 'string', default : 'mongodb://127.0.0.1/genieacs'},
   REDIS_PORT : {type : 'int', default : 6379},
-  REDIS_HOST : {type : 'string', default : '127.0.0.1'},
+  REDIS_HOST : {type : 'string', default : ''},
   REDIS_DB : {type : 'int', default : 0},
 
   CWMP_WORKER_PROCESSES : {type : 'int', default : 0},

lib/cwmp.coffee

@@ -601,7 +601,7 @@ getSession = (httpRequest, callback) ->
 
 currentSessions = new WeakMap()
 
-# When socket closes, store active sessions in redis
+# When socket closes, store active sessions in cache
 onConnection = (socket) ->
   currentSessions.set(socket, {})
   socket.on('close', () ->

package.json

@@ -19,13 +19,14 @@
     "bin": "bin"
   },
   "dependencies": {
-    "hiredis": "^0.5.0",
     "later": "^1.2.0",
     "libxmljs": "^0.18.4",
     "mongodb": "^2.2.24",
-    "redis": "^2.6.5",
     "seedrandom": "^2.4.2"
   },
+  "optionalDependencies": {
+    "redis": "^2.6.5"
+  },
   "devDependencies": {
     "coffeescript": "^1.12.4"
   },