Method and system for maintaining connections in a network

• US 20020107966A1
• Filed: 02/06/2001
• Published: 08/08/2002
• Est. Priority Date: 02/06/2001
• Status: Abandoned Application

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Sassi, Abdessattar, Kwong, Stella, Baudot, Jacques, Brandt, Marc, Wong, Isaac, Roger, Denis
• Application Number:
  US09/777,609
• Publication Number:
  US 20020107966A1
• Time in Patent Office: Days
• US Class Current: 709/227
• 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

Abstract

The present invention provides a method for hosting a series of active connections between Internet Protocol end-points and a system which hosts at least two processes, each process of the system including a similar instruction set constituting a service application and each process having an IP address, wherein at least one process may adopt an active state where a plurality of connections are used for sending and receiving data while at least one other process may adopt a stand-by state where a plurality of connections are not used for sending and receiving data, the method including:

replicating data from the at least one active process to the at least one stand-by process, the replicated data including status data of the connections of the active process, so that the stand-by process maintains its connections updated with said replicated data, and the replicated data further including status data of the instruction set constituting the service application in the at least one active process, so that the instruction set constituting the service application in the at least one stand-by process remains updated with said replicated data, and

deactivating the IP address of the active process and activating the IP address of the stand-by process in case the active process becomes unavailable.

Claims

1. A method for hosting network connections in a fault tolerant platform having a process in an active state, a process in a standby state and switchover capabilities for promoting a process in the standby state to an active state, the method including:

replicating status data of a network connection of the active process from an active process to a stand-by process;

maintaining for the standby process a corresponding standby network connection updated with said replicated data; and

during promotion of the standby process to an active state, deactivating the network connection in the active system without closing the connection on the network, transferring the network address to the standby process and activating the corresponding standby connection with that network address, whereby the promoted standby process does not need to reopen the connection on the network.

2. The method of claim 1, the step of activating the network address of the stand-by process is carried out before the standby connection is activated.

3. The method of claim 1 or of claim 2, including the step of monitoring the connections of the active process and initiating a replication of the status data in response to identifying an idle state of the connection.

4. The method of claim 3, wherein the step of replicating status data of the connection is carried out while allowing the active process to use said connection.

5. A method as claimed in any preceding claim comprising maintaining multiple pairs of active and standby processes each having a different network address.

6. A method as claimed in any preceding claim wherein the network address is an IP address.

7. A fault tolerant platform having a process in an active state, a process in a standby state and switchover means for promoting a process in the standby state to an active state, the platform including:

a first connection manager for retrieving status data from a connection associated with an active process;

a replication manager for replicating status data of a network connection associated with an active process to a stand-by process;

a second connection manager for maintaining for the standby process a corresponding standby network connection updated with said replicated data; and

wherein the switchover means is arranged, as a part of promotion of a standby process to an active state, to deactivate the network connection in the active system without closing the connection on the network, transfer the network address to the standby process and activate the corresponding standby connection with that network address, whereby the promoted standby process does not need to reopen the connection on the network.

8. A platform as claimed in claim 7, wherein the replication manager is in the form of a separate software module.

9. A platform as claimed in claim 7 or claim 8, wherein the first and/or second connection manager is in the form of a separate software module.

10. A platform as claimed in any one of claims 7 to 9, wherein each process hosts an application software layer forming said set of instructions, an operating system software layer, and a software layer which is able to apply a protocol of transmission control, and wherein the system hosts a process able to replicate the status data of the active connections, which process is at least in part carried out by the application layer of the active process.

11. The system of anyone of claims 7 to 10, comprising maintaining multiple pairs of active and standby processes each having a different network address.

12. A platform as claimed in any of claims 7 to 11 wherein the network addresses are IP addresses.

13. A fault tolerant platform having means to support a process in an active state, means to support a process in a standby state and switchover capabilities for promoting a process in the standby state to an active state, wherein network connections may assume a first state in which they are closed on the network each time an associated process closes them or dies and a second state in which they are not closed on the network when an associated process closes them or dies, the platform including an application programming interface that allows connections to be switched under program control between the first state and the second state, and that allows retrieval of connection state information and setting of connection state information, the connection state information being such as to enable a standby network connection that is maintained updated with said state information replicated from an active process to be used by a promoted standby process without a connection needing to be reopened on the network, by transferring a network address to said standby connection.