Fault tolerant recoverable TCP/IP connection router

A fault tolerant recoverable transport connection protocol/Internet protocol (TCP/IP) connection device to provide a connection between clients and servers in a computer network, said TCP/IP connection device comprising a primary TCP/IP router and one or more backup TCP/IP routers which are connected between said clients and servers and capable of providing connection between said clients and said servers with same or different connectivity than said first TCP/IP router, said primary TCP/IP router and one of one or more said backup TCP/IP routers switching between an active state and a standby state to maintain either one of said primary TCP/IP router and one of said one or more backup TCP/IP routers in the active state for providing said connection between said clients and said servers;

• each of said primary TCP/IP router and said backup TCP/IP routers including a synchronization manager, a reach-ability manager, and a monitoring manager;
• wherein synchronization managers of said primary TCP/IP router and said one of said one or more backup TCP/IP router communicate with each other to synchronize internal tables of said primary TCP/IP router and said one of said one or more backup TCP/IP router;
• said monitoring managers of said primary TCP/IP router and said one of said one or more backup TCP/IP routers communicate with each other to monitor the state of said primary TCP/IP router and said one of said one or more backup TCP/IP router and perform the switching;
• said reach-ability managers of one of said primary TCP/IP and said one of said one or more back-up TCP/IP routers being active for collecting from said primary TCP/IP router and said one of said one or more backup TCP/IP router a reach-ability state, comparing the reach-ability states of each of said primary TCP/IP router and said one of said one or more backup TCP/IP router to determine which of said primary TCP/IP router and said one of said one or more backup TCP/IP router has optimum reach-ability to elements of a required reach-ability set;
• and, informing the monitoring manager for performing the switching in response to a TCP/IP router having an optimum reach-ability, whereby TCP/IP connectivity is maintained between said clients and said servers regardless of said connectivity configuration.

A method of recovering from a failed connection between clients and a cluster of one or more servers comprising the steps of:

• synchronizing internal tables of at least two fault tolerant recoverable transport connection protocol/Internet protocol (TCP/IP) routers connected between said clients and servers, a predetermined list of clients and servers reachable by each TCP/IP router comprising a reach-ability set, wherein when a first TCP/IP router of said at least two routers is in an active state to interconnect said clients and servers, then a second TCP/IP router of said at least two TCP/IP routers is in a standby state and capable of providing connection between said clients and said servers with same or different connectivity than said first TCP/IP router;
• monitoring a state of said at least two TCP/IP routers;
• detecting a failure of said first TCP/IP router;
• switching said second TCP/IP router from said standby state to said active state to maintain interconnection between said clients and servers;
• switching said first TCP/IP router from said active state to said standby state;
• and,
• collecting from said first TCP/IP router and said second TCP/IP router current reach-ability states;
• enabling one of said first and second TCP/IP routers in an active state to compare reach-ability states of each of said first TCP/IP router and said second TCP/IP router with a required reach-ability set;
• determining which of said first TCP/IP router and said second TCP/IP router has an optimum reach-ability;
• and
• switching a TCP/IP router from a stand-by to an active state in accordance with results of the determining step, whereby TCP/IP connectivity is maintained between said clients and said servers regardless of said connectivity configuration.

A method of managing distribution of requests in a computer network of a type wherein a fault tolerant recoverable transport connection protocol/Internet protocol (TCP/IP) router distributes requests among multiple servers, comprising the steps of:

• initializing a primary TCP/IP router in an active state and a backup TCP/IP router in a standby state, said backup TCP/IP router providing connection between said clients and said servers with same or different connectivity than said active TCP/IP router, said primary TCP/IP router and said backup TCP/IP router periodically receiving requests from the network and workload recommendations from the servers;
• constructing a primary host connection table in the primary TCP/IP router and constructing a backup host connection table in the backup TCP/IP router based on the requests from the network and the workload recommendations, said workload recommendations being a function of capacities, availability and importance level of work running on the servers, the primary host connection table being synchronized with the backup host connection table;
• distributing the requests according to the host connection table by the primary TCP/IP router in the active state;
• sensing a failure from the primary TCP/IP router by a monitoring manager of one of the primary TCP/IP router and the backup TCP/IP router;
• changing the backup TCP/IP router to the active state, in response to the failure;
• distributing the requests by the backup TCP/IP router which is changed to the active state according to the backup host connection table in response to said changing the backup TCP/IP router to the active state;
• and
• changing the primary TCP/IP router to the standby state by the monitoring manager of the backup TCP/IP router, whereby TCP/IP connectivity is maintained between said clients and said servers regardless of said connectivity configuration.

A method of switching between active and standby states of fault tolerant recoverable transport connection protocol/Internet protocol (TCP/IP) routers in a network having a primary TCP/IP router in an active state for providing a connection between clients and servers and a backup TCP/IP router in a standby state and capable of providing connection between said clients and said servers with same or different connectivity than said primary TCP/IP router comprising the steps of:

• providing a reach-ability manager at each said primary TCP/IP and back-up TCP/IP router;
• computing reach-ability set and state of said active TCP/IP router and reach-ability set and state of said standby TCP/IP router, said reach-ability manager of said back-up TCP/IP router reporting a reach-ability state to said reach-ability manager of said active TCP/IP router;
• said active TCP/IP router implementing a configurable function for comparing the reach-ability set and state of said active TCP/IP router with the reach-ability set and state of said standby TCP/IP router;
• and
• switching said primary TCP/IP router from the active state to the standby state and said backup TCP/IP router from the standby state to the active state when the reach-ability set and state of said standby TCP/IP router are better than the reach-ability set and state of said active TCP/IP router, whereby TCP/IP connectivity is maintained between said clients and said servers regardless of said connectivity configuration.