Systems and methods are provided for improving latency during message processing in a network environment via the use of SIP server architecture. The SIP server can be comprised of an engine tier and a state tier distributed on a cluster network. The engine tier can send and receive messages and execute various processes. The state tier can maintain in-memory state data associated with various SIP sessions. The state tier can store various long lived data objects and the engine tier can contain short lived data objects. The state data can be maintained in partitions comprised of state replicas. When processing messages, the engine can pull state data objects from the state tier, use the objects and push them back to the state tier after processing is complete. If one state replica is unavailable, such as during garbage collection, the engine can retrieve the objects from another replica in the partition.