About

Ranger is a high-level service discovery framework built on Zookeeper. The framework brings the following to the table:

• Support of sharding of the service provider nodes
• Support for monitoring of service provider nodes
• Provides a type-safe generic interface for integration with support for custom serializers and deserializers
• Provides simple ways to plug in custom shard and node selection
• Fault-tolerant client-side discovery with a combination of watchers and polling on watched nodes

Why?

As request rates increase, load balancers, even the very expensive ones, become bottlenecks. We needed to move beyond and be able to talk to services without having to channel all traffic through a load-balancer. There is obviously curator discovery; but as much as we love curator, we needed more features on top of it. Ranger uses the curator framework for low level ZK interactions.