Recovery of operational state values for complex event processing based on a time window defined by an event query

A processing system to control recovery of operational state values of a complex event processing (CEP) engine that processes values of events, the processing system comprising:

• a processor;
• and
• a memory coupled to the processor and comprising computer readable program instructions that when executed by the processor causes the processor to perform operations comprising:
• determining a window size based on a property of an event query;
• retrieving events' values, from a distributed log, that are restricted to occurring within a timeframe defined based on the window size, wherein the distributed log stores events' values that have been processed by the CEP engine;
• and
• replaying the retrieved events' values to the CEP engine for processing to recover the operational state values of the CEP engine.