Computer cluster with second-node instance of application having access to state snapshot of first-node instance of application

A computer cluster comprising:

• storage media;
• a first computer having a first instance of an application program installed, said application program having instructions, said first computer including,
• volatile memory;
• processing means
• for executing instructions of said first instance of said application program so as to modify data stored in said volatile memory,
• for creating a snapshot of said data while said first instance of said application program is running, said snapshot being stored in said volatile memory, and
• for, while said first instance of said application continues to modify said data so that it diverges from said snapshot, transferring said snapshot from said volatile memory to said storage media, and
• a second computer having a second instance of said application program installed, said second computer including means for accessing said storage media so that said second instance of said application can access said snapshot as stored on said storage media.