Browse Prior Art Database

Consistent Resource Registration

IP.com Disclosure Number: IPCOM000113622D
Original Publication Date: 1994-Sep-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 6 page(s) / 226K

Publishing Venue

IBM

Related People

Gopal, PM: AUTHOR [+3]

Abstract

Computer networks provide communications between remote resources. A resource may be a server, such as a printer, or a client, such as an application using the printer. In order for a client resource to communicate with a server resource, it must first know about the existence of the server, know the name of the server and know how to reach it. Consider an environment in which resources residing in local area networks are interconnected via a wide area network. Local area networks are referred to as access networks and wide area networks are referred to as backbone networks.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 27% of the total text.

Consistent Resource Registration

      Computer networks provide communications between remote
resources.  A resource may be a server, such as a printer, or a
client, such as an application using the printer.  In order for a
client resource to communicate with a server resource, it must first
know about the existence of the server, know the name of the server
and know how to reach it.  Consider an environment in which resources
residing in local area networks are interconnected via a wide area
network.  Local area networks are referred to as access networks and
wide area networks are referred to as backbone networks.

      A server resource informs the backbone network of its name and
location.  Subsequently, the backbone network may provide this
information to interested client resources.  The process of informing
the backbone network of a resource's name and location is called
resource registration.  The backbone network control component which
maintains the resource registration information is referred to as the
Directory Service (DS).  A resource may discover the location of
other resources by querying the DS.  The DS may be implemented as a
single, centralized database or as a distributed database.

      This invention addresses the issue of consistent resource
registration in a backbone network which may partition or heal.  A
network N has partitioned if one or more independent sub-networks are
formed from the network nodes which previously made-up network N.  A
network has healed if one or more partitions combine to form one
network.  A resource on an access network may have connectivity to
two or more backbone network partitions.  A resource registration is
consistent if, in steady state, it is registered with one and only
one DS in each backbone network partition with which it has
connectivity.  A resource must be registered with only one DS in a
partition to ensure the uniqueness of the resource.  Otherwise, if a
client resource queries a server resource which is multiply
registered, the client may obtain conflicting information.
Furthermore, a resource must be registered in each backbone partition
so that it may be discovered by other resources.  When a network
partitions, a resource which is accessible in both partitions must be
registered with one and only one DS in each partition.  When two or
more network partitions heal, the resource registration must be made
consistent again.  During transient phases of network partitioning or
healing, resources may be registered in more than one DS for a given
partition, or not registered with any DS in any partition.
Consistent resource registration is achievable when the network has
reached a steady state.

      The following example illustrates the need for consistent
resource registration.  Assume that the backbone network partitions
into two networks, N1 and N2, as shown in Fig. 1.

      Assume resource A has connectivity to N1 and N2, but DS1...