allow fractional drain rate

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

@@ -6,9 +6,16 @@ module.exports =
 		clearInterval @interval
 		if rate == 0
 			return
+		else if rate < 1
+			# allow lower drain rates
+			# e.g. rate=0.1 will drain one client every 10 seconds
+			pollingInterval = 1000 / rate
+			rate = 1
+		else
+			pollingInterval = 1000
 		@interval = setInterval () =>
 			@reconnectNClients(io, rate)
-		, 1000
+		, pollingInterval
 
 	RECONNECTED_CLIENTS: {}
 	reconnectNClients: (io, N) ->

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

@@ -15,7 +15,7 @@ module.exports = HttpApiController =
 	startDrain: (req, res, next) ->
 		io = req.app.get("io")
 		rate = req.query.rate or "4"
-		rate = parseInt(rate, 10)
+		rate = parseFloat(rate) || 0
 		logger.log {rate}, "setting client drain rate"
 		DrainManager.startDrain io, rate
 		res.send 204