HIGHLY RELIABLE CROSS-SESSION WEB APPLICATION INSTRUMENTATION

A reliable caching mechanism is provided for client-side caching of data that captures user interaction with a remote service, where users interact with the remote service through a computing device. Such instrumentation items are cached in a client-side offline queue. Within the client-side queue, the gathered instrumentation items survive between user sessions with the remote service. Because the client-side does not lose the instrumentation items that were gathered in a session when the session ends, those instrumentation items do not all need to be transferred to the server-side at or prior to the termination of the session in which the instrumentation items are collected. Instead, the instrumentation items may be sent to the server-side at times that will have less impact on the user experience, such as when the computing device is otherwise idle.