[scaleout1]

Here is a pdf going briefly into kafka comparison and design motivation http://goo.gl/J9XdsG . During my time at twitter I remember when Twitter switch from Kafka to distributedlog. They have an internal layer that adapts Kafka API to distributedlog, I am not sure if they have open sourced that

[gshx]

Very nice, now that we have some good competition in this space - kafka, ddl and wormhole. If only Fb can open src wormhole, there will be some good related systems software to choose from and contribute to.