README.md in fluent-plugin-dedup-0.2.0 vs README.md in fluent-plugin-dedup-0.3.0

@@ -19,18 +19,24 @@
 
     <match some.thing>
       type dedup
       key  unique_id # required
       file /tmp/dedup_state.json # optional. If set, saves the state to the file.
+      cache_per_tag 10 # optional. If set, recent logs up to this number is cached.
+      cache_ttl 600 # optional. If set, cache entries is expired in this TTL.
     </match>
 
     <match dedup.some.thing>
       type stdout
     </match>
 
 All logs that are processed by this plugin will have tag prefix `dedup`.
 
 If the optional `file` parameter is set, it dumps the state during shutdown and loads on start, so that it can still dedup after reload.
+
+If the optional `cache_per_tag` is set, it caches N recently appeared logs (only caches `unique_id` in this example) and compared to new logs.
+
+If the optional `cache_ttl` is set, it evicts cache entries in a specific amount of time.
 
 ## Testing
 
     bundle install
     bundle exec rake test