Jason, In 0.8, each message can optionally have a key. The key is retained as part of the message and will be stored in the broker. One can design a partition function to route the message based on the key. The default partitioner ignores the key and selects a partition at random.
Thanks, Jun On Mon, Jan 7, 2013 at 8:49 AM, Jason Huang <jason.hu...@icare.com> wrote: > Hello, > > I did some search on the web but couldn't find any documentation for > 0.8 so I am trying to ask here: > > KeyedMessage is introduced in 0.8.0: > class KeyedMessage[K, V](val topic: String, val key: K, val message: V) > > Does the parameter "key" = "partition key"? > > If I build a KeyedMessage with a specific key string, then the message > will be stored to this partition, right? > > If I build a KeyedMessage without a key, then the message will be > distributed to a random partition belonging to this topic? Or will it > always use a certain default partition? > > thanks, > > Jason >
