Investigate removing PartitionHandlingInterceptor ------------------------------------------------- Key: ISPN-7956 URL: https://issues.jboss.org/browse/ISPN-7956 Project: Infinispan Issue Type: Task Components: Core Affects Versions: 9.1.0.Beta1 Reporter: Dan Berindei Assignee: Dan Berindei Fix For: 9.4.0.Final When all the owners of a key leave the cluster, the distribution interceptor doesn't know how to handle that key. Instead, it has to signal that to the {{PartitionHandlingInterceptor}} somehow, and PHI decides whether to return a {{null}} value or throw an {{AvailabilityException}}. Single-key read commands and write commands are handled by throwing an {{AllOwnersLostException}} (initially an {{RpcException}}) from the distribution interceptor and catching it in {{PartitionHandlingInterceptor}}. If partitioning handling is disabled, the {{AllOwnersLostException}} is instead caught by {{StateTransferInterceptor}}, which returns the {{null}} value (for read commands) or waits for a new topology and retries (for write commands). For multi-key read commands the distribution interceptor can't throw an exception, because that would lose the values that were retrieved successfully. For {{GetAllCommand}} we could get away with storing the values in the context, but that wouldn't work for functional commands because they transform the values on the remote node. ISPN-7884 removing the values with missing owners from the result collection, but that means values that are simply missing have to be treated differently, and {{StateTransferInterceptor}} has to iterate through the list of results again in order to remove them. It should be simpler to move all the availability checks to the distribution interceptor, and remove the {{PartitionHandlingInterceptor}}. DI already calls some {{PartitionHandlingManager}} methods directly, in order to keep track of partially committed transactions.