Merge pull request #61 from overleaf/bg-remove-redis-cluster-from-realtime

remove redis cluster from realtime

services/real-time/app/coffee/DocumentUpdaterController.coffee

@@ -11,7 +11,7 @@ MESSAGE_SIZE_LOG_LIMIT = 1024 * 1024 # 1Mb
 module.exports = DocumentUpdaterController =
 	# DocumentUpdaterController is responsible for updates that come via Redis
 	# Pub/Sub from the document updater.
-	rclientList: RedisClientManager.createClientList(settings.redis.pubsub, settings.redis.unusedpubsub)
+	rclientList: RedisClientManager.createClientList(settings.redis.pubsub)
 
 	listenForUpdatesFromDocumentUpdater: (io) ->
 		logger.log {rclients: @rclientList.length}, "listening for applied-ops events"
@@ -21,9 +21,12 @@ module.exports = DocumentUpdaterController =
 				metrics.inc "rclient", 0.001 # global event rate metric
 				EventLogger.debugEvent(channel, message) if settings.debugEvents > 0
 				DocumentUpdaterController._processMessageFromDocumentUpdater(io, channel, message)
-			do (i) ->
-				rclient.on "message", () ->
-					metrics.inc "rclient-#{i}", 0.001 # per client event rate metric
+		# create metrics for each redis instance only when we have multiple redis clients
+		if @rclientList.length > 1
+			for rclient, i in @rclientList
+				do (i) ->
+					rclient.on "message", () ->
+						metrics.inc "rclient-#{i}", 0.001 # per client event rate metric
 		
 	_processMessageFromDocumentUpdater: (io, channel, message) ->
 		SafeJsonParse.parse message, (error, message) ->

services/real-time/app/coffee/WebsocketLoadBalancer.coffee

@@ -7,7 +7,7 @@ HealthCheckManager = require "./HealthCheckManager"
 
 module.exports = WebsocketLoadBalancer =
 	rclientPubList: RedisClientManager.createClientList(Settings.redis.pubsub)
-	rclientSubList: RedisClientManager.createClientList(Settings.redis.pubsub, Settings.redis.unusedpubsub)
+	rclientSubList: RedisClientManager.createClientList(Settings.redis.pubsub)
 
 	emitToRoom: (room_id, message, payload...) ->
 		if !room_id?