Thank you folks. I would admit the layout and examples are very nice. I could bring things up on my laptop very quickly without reading much into it.
I looked at the system test example as well. The ZK setup in source and target clusters etc. I assume linked-in has the similar config. Each DC/kafka cluster has its own ZK cluster. The mirroring consumer from another DC points to the source ZK cluster. Sharad Hadoop Committer and Head of Technology Platforms@InMobi