Network system, control method for the same, and controller, using targeted relay processing devices
In a network system, each server is assigned to at least one relay processing devices. A plurality of switches are arranged in a network and a controller controls the switches. Specifically, the controller designs, in response to a request from a request source switch, a route of a flow from the request source switch to a destination address. Here, the controller refers to assignment information indicating an assignment relationship between servers and relay processing devices to select, as a target, any one relay processing device assigned to a server specified by the destination address, and designs the route so as to include the target. Then, the controller instructs each switch on the designed route to set the flow table such that a packet is forwarded along the designed route.
1. A network system comprising:
a plurality of servers connected to a network;
a plurality of relay processing devices connected to said network;
a plurality of switches arranged in said network; and
a controller configured to control said plurality of switches,
wherein:
each of said plurality of servers is assigned to at least one of said plurality of relay processing devices;
each of said plurality of relay processing devices performs predetermined processing with respect to a packet to a server assigned to said each relay processing device; and
each of said plurality of switches has a flow table indicating a correspondence relationship between an input source and a forwarding destination of a packet with respect to each flow and forwards a packet received from said input source to said forwarding destination by reference to said flow table,
wherein said controller comprises:
a memory unit;
a route design unit configured to design, in response to a request from a request source switch among said plurality of switches, a route of a flow from said request source switch to a destination address; and
a switch setup unit configured to instruct each switch on said designed route to set said flow table such that a packet of the flow is forwarded along said designed route,
wherein information stored in said memory unit comprises:
network configuration information which indicates a connection state between said plurality of servers, said plurality of relay processing devices and said plurality of switches; and
assignment information which indicates an assignment relationship between said plurality of servers and said plurality of relay processing devices,
wherein said route design unit refers to said assignment information to select, as a target, any one relay processing device assigned to a server specified by said destination address, and said route design unit refers to said network configuration information to design said route so as to include said target.
2. The network system according to claim 1 ,
wherein the server specified by said destination address is assigned to two or more relay processing devices among said plurality of relay processing devices, and
said route design unit selects any one of said two or more relay processing devices as said target.
3. The network system according to claim 2 , wherein the information stored in said memory unit further comprises:
load information which indicates respective loads of said plurality of relay processing devices; and
link information which indicates states of links in said network,
wherein said route design unit refers to at least one of said load information and said link information to select an optimum one of said two or more relay processing devices as said target.
4. The network system according to claim 2 , wherein at least one of said relay processing device comprises a load balancer.
5. The network system according to claim 1 , wherein the server specified by said destination address is assigned to one relay processing device among said plurality of relay processing devices, and said route design unit selects said one relay processing device as said target.
6. The network system according to claim 5 , wherein at least one of said relay processing device comprises a fire wall.
7. The network system according to claim 1 , wherein said controller further comprises an assignment management unit configured to update said assignment information in response to addition of a server or a relay processing device.
8. A controller that controls a plurality of switches arranged in a network wherein:
a plurality of servers and a plurality of relay processing devices are connected to said network;
each of said plurality of servers is assigned to at least one of said plurality of relay processing devices;
each of said plurality of relay processing devices performs predetermined processing with respect to a packet to a server assigned to said each relay processing device; and
each of said plurality of switches has a flow table indicating a correspondence relationship between an input source and a forwarding destination of a packet with respect to each flow and forwards a packet received from said input source to said forwarding destination by reference to said flow table,
said controller comprising:
a memory unit;
a route design unit configured to design, in response to a request from a request source switch among said plurality of switches, a route of a flow from said request source switch to a destination address; and
a switch setup unit configured to instruct each switch on said designed route to set said flow table such that a packet of the flow is forwarded along said designed route,
wherein information stored in said memory unit comprises:
network configuration information which indicates a connection state between said plurality of servers, said plurality of relay processing devices and said plurality of switches; and
assignment information which indicates an assignment relationship between said plurality of servers and said plurality of relay processing devices,
wherein said route design unit refers to said assignment information to select, as a target, any one relay processing device assigned to a server specified by said destination address, and said route design unit refers to said network configuration information to design said route so as to include said target.
9. A control method for a network system, wherein said network system comprises:
a plurality of servers connected to a network;
a plurality of relay processing devices connected to said network; and
a plurality of switches arranged in said network,
wherein:
each of said plurality of servers is assigned to at least one of said plurality of relay processing devices;
each of said plurality of relay processing devices performs predetermined processing with respect to a packet to a server assigned to said each relay processing device; and
each of said plurality of switches has a flow table indicating a correspondence relationship between an input source and a forwarding destination of a packet with respect to each flow and forwards a packet received from said input source to said forwarding destination by reference to said flow table,
said control method comprising:
designing, in response to a request from a request source switch among said plurality of switches, a route of a flow from said request source switch to a destination address; and
instructing each switch on said designed route to set said flow table such that a packet of the flow is forwarded along said designed route,
wherein the designing said route comprises:
reading network configuration information and assignment information from a memory device,
wherein:
said network configuration information indicates a connection state between said plurality of servers, said plurality of relay processing devices and said plurality of switches; and
said assignment information indicates an assignment relationship between said plurality of servers and said plurality of relay processing devices;
selecting, as a target, any one relay processing device assigned to a server specified by said destination address, by reference to said assignment information; and
designing said route so as to include said target, by reference to said network configuration information.
10. The control method according to claim 9 , wherein said selecting of one relay processing device as the target comprises:
determining, from said assignment information, whether a potential relay processing device is a single relay processing device associated with the server specified by said destination address; and
if so, using the potential relay processing device as the target that defines a route of flow from said request source switch to said destination address.
11. The control method according to claim 10 , further comprising:
if it is determined from said assignment information that more than one potential relay processing device is associated with the server specified by said destination address, referring to said assignment information for load information and link information associated with each potential relay processing device associated with the server; and
using at least one of the load information and link information to select an optimum relay processing device as the target.
12. The control method according to claim 11 , wherein the link information for a relay processing device comprises information of a state of a link in the network, the link state comprising at least one of a communication capacity and a congestion state.
13. The control method according to claim 9 , wherein said selecting of one relay processing device as the target comprises determining, from said assignment information, whether a potential relay processing device is a single relay processing device associated with the server specified by said destination address.
14. The controller according to claim 13 , wherein:
if it is determined from said assignment information, that a potential relay processing device is a single relay processing device associated with the server specified by said destination address, using the potential relay processing device as the target that defines a route of flow from said request source switch to said destination address; and
if it is determined from said assignment information that more than one potential relay processing device is associated with the server specified by said destination address, referring to said assignment information for load information and link information associated with each potential relay processing device associated with the server and using at least one of the load information and link information to select an optimum relay processing device as the target.
15. The controller according to claim 14 , wherein the link information for a relay processing device comprises information of a state of a link in the network, the link state comprising at least one of a communication capacity and a congestion state.
16. The network system according to claim 1 , wherein said selecting of one relay processing device as the target comprises:
determining, from said assignment information, whether a potential relay processing device is a single relay processing device associated with the server specified by said destination address; and
if so, using the potential relay processing device as the target that defines a route of flow from said request source switch to said destination address.
17. The network system according to claim 16 , wherein:
if it is determined from said assignment information that more than one potential relay processing device is associated with the server specified by said destination address, referring to said assignment information for load information and link information associated with each potential relay processing device associated with the server; and
using at least one of the load information and link information to select an optimum relay processing device as the target.
18. The network system according to claim 17 , wherein the link information for a relay processing device comprises information of a state of a link in the network, the link state comprising at least one of a communication capacity and a congestion state.
19. The network system according to claim 7 , wherein said assignment management unit is configured to update said assignment information in response to deleting a server from the network system.
20. The network system according to claim 1 , wherein said controller is configured to change said assignment relationship between said plurality of servers and said plurality of relay processing devices, as based upon determining whether a measured load of a relay processing device exceeds a predetermined threshold value.