README.md in message_bus-2.1.2 vs README.md in message_bus-2.1.3

@@ -17,10 +17,11 @@
 
 ## Want to help?
 
 If you are looking to contribute to this project here are some ideas
 
+- MAKE THIS README BETTER!
 - Build backends for other providers (zeromq, rabbitmq, disque) - currently we support pg and redis.
 - Improve and properly document admin dashboard (add opt-in stats, better diagnostics into queues)
 - Improve general documentation (Add examples, refine existing examples)
 - Make MessageBus a nice website
 - Add optional transports for websocket and shared web workers
@@ -56,10 +57,13 @@
 Server to Server messaging
 
 ```ruby
 message_id = MessageBus.publish "/channel", "message"
 
+# last id in a channel
+id = MessageBus.last_id("/channel")
+
 # in another process / spot
 
 MessageBus.subscribe "/channel" do |msg|
   # block called in a background thread when message is received
 end
@@ -140,17 +144,17 @@
 
 **NOTE**: do not set proxy_buffering off globally, it may have unintended consequences.
 
 If you wish to disable chunked encoding run:
 
-```
+```ruby
 MessageBus.enableChunkedEncoding = false; // in your JavaScript
 ```
 
 Or
 
-```
+```ruby
 MessageBus.configure(chunked_encoding_enabled: false) // in Ruby
 ```
 
 Long Polling requires no special setup, as soon as new data arrives on the channel the server delivers the data and closes the connection.
 
@@ -279,9 +283,27 @@
 
 ```ruby
 MessageBus.configure(backend: :redis, url: "redis://:p4ssw0rd@10.0.1.1:6380/15")
 ```
 The redis client message_bus uses is [redis-rb](https://github.com/redis/redis-rb), so you can visit it's repo to see what options you can configure.
+
+#### Data Retention
+
+Out of the box Redis keeps track of 2000 messages in the global backlog and 1000 messages in a per-channel backlog. Per-channel backlogs get cleared automatically after 7 days of inactivity.
+
+This is configurable via accessors on the ReliablePubSub instance.
+
+```ruby
+# only store 100 messages per channel
+MessageBus.reliabe_pub_sub.max_backlog_size = 100
+
+# only store 100 global messages
+MessageBus.reliabe_pub_sub.max_global_backlog_size = 100
+
+# flush per-channel backlog after 100 seconds of inactivity
+MessageBus.reliabe_pub_sub.max_backlog_age = 100
+
+```
 
 ### PostgreSQL
 
 message_bus also supports PostgreSQL as the backend: