Method for a non-disruptive host connection switch after detection of an error condition or during a host outage or failure

• US 5,727,142 A
• Filed: 05/03/1996
• Issued: 03/10/1998
• Est. Priority Date: 05/03/1996
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Chen, Shawfu
• Primary Examiner(s): Beausoliel, Jr., Robert W.
• Assistant Examiner(s): LE, DIEU MINH T
• Application Number:
  US08/642,543
• Time in Patent Office: 676 Days
• Field of Search: 395/181, 395/182.09, 395/182.1, 395/182.11, 395/182.13, 395/182.14
• US Class Current: 714/2
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/162 involving adaptations of sockets based mechanisms secure socket layer H04L63/168
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04L 69/326 in the transport layer [OSI layer 4] H04L69/16 takes precedence
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A method for a non-disruptive TCP connection switch is introduced that allows the re-establishment of communications between a remote host and a new host when the host originally in processing communication with the remote host takes an outage. The present invention particularly relates to loosely coupled environments connecting to a TCP/IP network. The method involves three important steps of initialization, during which all hosts and remote hosts are identified by a communication box; failure detection step during which a host outage is detected by the communication box; and re-registration step during which the communication box provides and re-establishes processing connection between the remote host and a new host replacing the initial failing host.

Claims

1. In a loosely coupled environment using TCP/IP communication protocol and having a plurality of hosts connected to a plurality of remote hosts through a communication box, with at least one remote host being in processing communication with at least one host, a method of restoring said processing communication after a failure, without a need for re-initiating communication protocols for re-establishing processing communication and without losing any processing information, the steps comprising:

performing an initialization step to identify all hosts and all remote hosts present in said loosely coupled environment;

offloading all TCP/IP communication protocol information relating to said hosts and said remote hosts in an offload frontend box located in said communication box, so that after an error is detected, another host can replace said failing one;

said offload frontend box performing data flow control, error detection, recovery and routing of messages from one node to another node;

maintaining all processing information needed to restore an application running on any host or remote host in processing communication with one another, so that said application can be restored in same exact location on said replacing host as immediately before said failure occurred; and

performing a re-registration step during which a working host is located to replace said failing host after said new replacing host announces its availability for said replacement;

said processing information only being passed to said replacement host or replacement remote host after said re-registration step has been completed and in a manner so that said replacement is invisible to any user;

said replacing host signalling said communication box of its availability before said data is transferred from said communication box to said second host; and

replacing said host signalling said communication box after said replacing host receives all processing information from said communication box.