GT 4.2.1 Replica Location Service (RLS)


The Replica Location Service (RLS) is a standalone server (i.e., it is not deployed in a Web services container) that provides for the registration and lookup of replica information. Within the RLS, there are two types of services, a catalog service and an index service.

The Local Replica Catalog (LRC) maintains a catalog of replica information. Replica information in the RLS is maintained in the form of mappings from logical names for data items to target names. These target names may represent physical locations of data items, or an entry in the RLS may map to another level of logical naming for the data item.

In addition to the LRC, the RLS also exposes the Replica Location Index (RLI). The RLI maintains an index of logical names which indicates the LRC services(s) that have mappings for the specific logical names. The LRC generates an index of its logical names and pushes the index to one or more RLI services.

In a typical deployment, the RLS will be deployed in conjunction with one or more Storage Elements (SE). The LRC will be used to store mappings from logical names for data sets to the physical file locations as managed by the SEs. The LRC then sends an index of its contents to its associated RLI service as well as multiple remote RLI services at collaborating sites. Clients interested in a particular logical name will first query a RLI service to find the LRC services, then they will query one or more LRC services to find the target names (which may correspond to storage location URLs).

The following guides are available for this component:
Data Management Key Concepts For important general concepts. [pdf]
Admin Guide For system administrators and those installing, building and deploying GT. You should already have read Installation Guide and Quickstart. [pdf]
User's Guide Describes how end-users typically interact with this component. Be sure to also read the GT User Guide for important general information for end-users. [pdf]
Developer's Guide Reference and usage scenarios for developers. [pdf]
Other information available for this component are:
Release Notes What's new with the 4.2.1 release for this component. [pdf]
Public Interface Guide Information for all public interfaces (including APIs, commands, WSDL, etc). Please note this is a subset of information in the Developer's Guide. [pdf]
Quality Profile Information about test coverage reports, etc. [pdf]
Migrating Guide Information for migrating to this version if you were using a previous version of GT. [pdf]
All RLS Guides (PDF only)Includes all RLS guides except Public Interfaces (which is a subset of the Developer's Guide)

Glossary

L

logical name

A unique identifier for the contents of a data item.

T

target name

The address or location of a copy of a data item on a storage system.