US Patent 10579502 Resuming applications using pass-through servers and trace data

Aspects include receiving, at a pass-through server executing in a replay mode, a request directed to a backend resource. The request is received from an application that is connected to the pass-through server. The pass-through server executing in the replay mode identifies a response that corresponds to the request by: forming a key that includes an identifier of the current execution phase of the application and at least a subset of the request; accessing trace data that includes a plurality of keys and corresponding responses that were previously recorded in the trace data by the pass-through server executing in a recording mode; and using the key to locate, in the trace data, the response corresponding to the request. The identified response is relayed, by the pass-through server executing in the replay mode, to the application.