1. An article of manufacture including code executed in a primary system in communication with a secondary system to perform operations, the operations comprising: recording application events at the primary system, wherein each event indicates one of a plurality of processes in the primary system executing an instruction for the application; transferring the recorded events to a buffer; transferring the recorded events from the buffer to the secondary system, wherein the secondary system implements processes indicated in the recorded events to execute the instructions indicated in the events; detecting an error at the primary system; determining a primary order in which the events are executed by processes in the primary system; and determining a modified order of the execution of the events comprising a different order of executing the events than the primary order in response to detecting the error, wherein the secondary system processes execute the instructions indicated in the recorded events according to the modified order.