Session-return enabling stateful web applications

A computer program product comprising a non-transitory machine-readable medium storing instructions that, when executed by an application server comprising at least one programmable processor, cause the application server to perform operations comprising:

• starting a first session instance of an application in response to receiving, at an application server, a first external session identifier (ESID) at a first time, the application comprising a sequence of webpages delivered from the application server to a client caller running on a computing device, the first external session identifier having been generated externally to the application server and sent to the application server from the client caller, the first external session identifier being different from a second external session identifier for a second session instance of the application running at the computing device, and the starting comprising allocating first application server resources to the first session instance;
• terminating the first session instance, the terminating of the first session instance comprising releasing the first application server resources allocated to the first session instance, the terminating of the first session instance further comprising associating first session return state information for the first session instance with the first external session identifier and persisting the first session return state information in a session memory of the application server, the first session return state information characterizing a first state of the first session instance at termination of the first session instance, the first session return state information including user inputs on at least one webpage from the sequence of webpages that has been delivered by the application server to the client caller prior to the termination of the first session instance;
• and
• restarting, by the application server, the first session instance in response to receiving, at the application server, the first external session identifier at a second time, the second time receiving the first external session identifier being subsequent to the first time receiving the first external session identifier, the restarting comprising restoring the first session instance to the first state characterized by the first session return state information persisted in the session memory of the application server.

A system comprising an application server, the application server comprising at least one programmable processor;

• and a machine-readable medium storing instructions that, when executed by the at least one programmable processor, cause the at least one programmable processor to perform operations comprising:
• starting a first session instance of an application in response to receiving, at an application server, a first external session identifier (ESID) at a first time, the application comprising a sequence of webpages delivered from the application server to a client caller running on a computing device, the first external session identifier having been generated externally to the application server and sent to the application server from the client caller, the first external session identifier being different from a second external session identifier for a second session instance of the application running at the computing device, and the starting comprising allocating first application server resources to the first session instance;
• terminating the first session instance, the terminating of the first session instance comprising releasing the first application server resources allocated to the first session instance, the terminating of the first session instance further comprising associating first session return state information for the first session instance with the first external session identifier and persisting the first session return state information in a session memory of the application server, the first session return state information characterizing a first state of the first session instance at termination of the first session instance, the first session return state information including user inputs on at least one webpage from the sequence of webpages that has been delivered by the application server to the client caller prior to the termination of the first session instance;
• and
• restarting, by the application server, the first session instance in response to receiving, at the application server, the first external session identifier at a second time, the second time receiving the first external session identifier being subsequent to the first time receiving the first external session identifier, the restarting comprising restoring the first session instance to the first state characterized by the first session return state information persisted in the session memory of the application server.