Information processing system, license server, communication relay device, non-transitory readable recording medium and data restoration method

An information processing system comprises: an image processing device; an application server that provides with an application service for cooperation with the image processing device; a communication relay device that relays communications between the image processing device and the application server; a license server managing the communication relay server; and a backup server. The communication relay device includes: a relay information generating part that generates relay information to relay the communications; a storage part in which the relay information is stored; a communication relaying part that relays the communications based on the relay information; a backup part that sends the relay information to the backup server; an identification information transmission part that reads identification information and sends the read identification information to the license server; and a setting applying part that obtains the relay information from the backup server and stores the obtained relay information in the storage part.