A method, apparatus, system, and signal-bearing medium that in an embodiment determine the active partitions of an application and assign the active partitions among servers via a routing table. The routing table is sent to a client, who uses the routing table to send requests and/or messages to the active partitions. In an embodiment, the routing table includes identifiers of the active partitions and the associated partitions. If one of the servers fails or if the partitions have a loading imbalance, the partitions are reassigned via the routing table.