Information processing system, switching device, and method for controlling information processing system

A switching device that is provided an information processing system including a plurality of switching device groups of a plurality of switching devices that include a switching device as a root node and switching devices as leaf nodes which are connected to an information processing apparatus, the plurality of switching devices being connected in a tree topology, the switching device among the plurality of switching devices comprising:

• a controller that, when a failure that occurs in a communication path directly connected without another switching device to the root node side of the switching device is detected, writes identification information indicating the communication path from which the failure is detected to a flow table which stores the identification information and output destination port information indicating a communication path of an output destination of a packet so as to be associated with each other, thereby switching a plurality of communication paths;
• and
• a processor configured to, when a failure that occurs in a communication path directly connected without the another switching device to the leaf node side of the switching device is detected, notify the another switching device connected to the switching device of a position where the failure occurs,
• the flow table stores, as rule information, the identification information and the output destination port information so as to be associated with header information after masking which is obtained by applying a mask corresponding to the number of output destination port information items to a predetermined position of header information of an input packet, the mask being determined according to the number of a communication path to a destination of the packet,
• the switching device controls the input packet based on the rule information which is selected based on the header information after masking, and
• the controller rewrites the flow table based on the notification from the another switching device connected to the switching device to switch the plurality of communication paths.

A method of controlling an information processing system including a plurality of switching device groups of a plurality of switching devices that include a switching device as a root node and switching devices as leaf nodes which are connected to an information processing apparatus, the plurality of switching devices being connected in a tree topology, the method comprising:

• by a first switching device among the plurality of switching devices,
• when a failure that occurs in a communication path directly connected without another switching device to the root node side of the first switching device is detected, writing identification information indicating the communication path, from which the failure is detected, to a flow table which stores the identification information and output destination port information indicating a communication path of an output destination of a packet so as to be associated with each other, thereby switching a plurality of communication paths;
• and
• when a failure that occurs in a communication path directly connected without the another switching device to the leaf node side of the first switching device is detected, notifying the another switching device connected to the first switching device of a position where the failure occurs,
• the flow table stores, as rule information, the identification information and the output destination port information so as to be associated with header information after masking which is obtained by applying a mask corresponding to the number of output destination port information items to a predetermined position of header information of an input packet, the mask being determined according to the number of a communication path to a destination of the packet,
• controlling the input packet based on the rule information which is selected based on the header information after masking, and
• rewriting the flow table based on the notification from the another switching device connected to the switching device to switch the plurality of communication paths.