Session establishing device, session establishing method, and recording medium

A session establishing method of a session establishing device comprising:

• upon receipt of a session start request from a terminal unit, determining, using a processor of the session establishing device, whether there is in a storage any session whose establishment-finished information indicates not-yet-established by referring to establishment-finished information stored in the storage, the establishment-finished information indicating whether a session has already been established or not;
• when there is a session indicating not-yet-established in the storage, determining, using the processor, whether the session is in the process of establishment by referring to under-establishment information stored in the storage, the under-establishment information indicating whether a session is in the process of establishment or not;
• when the under-establishment information corresponding to the session indicates not in the process of establishment, assigning, using the processor, the session to the terminal unit which issued the session start request;
• when the session has been assigned to the terminal unit which issued the session start request, registering, using the processor, session identifying information identifying the session and terminal identifying information identifying the terminal unit in a manner associated with the session and changing, using the processor, content of the under-establishment information corresponding to the session to in the process of establishment;
• and
• upon receipt of a session execute request from a terminal unit, determining, using the processor, whether there is in the storage any session having session identifying information identical to session identifying information included in the session execute request, and, when there is a session having the same session identifying information, establishing, using the processor, a session with the terminal unit which issued the session execute request by using the session identifying information.

A computer-readable recording medium having stored therein a session establishing program of a session establishing device including a processor, the program causing the processor to execute a process comprising:

• storing establishment-finished information indicating whether a session has already been established or not and under-establishment information indicating whether a session is in the process of establishment or not, in a storage in a manner associated with each other with respect to each session used by a terminal unit;
• upon receipt of a session start request from a terminal unit, determining whether there is in the storage any session whose establishment-finished information indicates not-yet-established, and, when there is a session indicating not-yet-established, determining whether under-establishment information corresponding to the session indicates not in the process of establishment;
• when the under-establishment information corresponding to the session indicates not in the process of establishment, assigning the session to the terminal unit which issued the session start request;
• when the session has been assigned to the terminal unit which issued the session start request, registering session identifying information identifying the session and terminal identifying information identifying the terminal unit in a manner associated with the session and changing content of the under-establishment information corresponding to the session to in the process of establishment;
• and
• upon receipt of a session execute request from a terminal unit, determining whether there is any session having session identifying information identical to session identifying information included in the session execute request in the storage, and, when there is a session having the same session identifying information, establishing a session with the terminal unit which issued the session execute request by using the session identifying information.