Table of Contents
This guide contains information of interest to developers working with DRS. It provides reference information for application developers, including APIs, architecture, procedures for using the APIs and code samples.
Features new in release GT 4.0.1:
- Improved implementation of the Data Replication Service: a WS-Resource, called the Replicator, which accepts a request from a client to locate, transfer, and register new replicas of data files in the Grid environment.
- A set of command-line tools to create (
globus-replication-create), start (globus-replication-start), stop (globus-replication-stop), suspend (globus-replication-suspend), resume (globus-replication-resume) replication requests, and find item status (globus-replication-finditems). - WSDL-defined SOAP operations to create, start, stop, suspsend, and resume a replication request, along with operations to get the status of individual replicas in the request. For details, click here to view a listing of the WSDL-defined interface from the Globus CVS repository.
- APIs to allows users to implement custom replica source selection algorithms.
Other Supported Features
- Supports secure transport, secure conversation, and secure message communication as provided by GT 4.0.
Deprecated Features
- Database-backed State Persistence: State is now maintained in memory and lasts only for the lifetime of the WS-Resource or as dictated by the service container. This change simplifies setup of the DRS. We intend to reintroduce other persistence model(s) after we have collected additional user feedback on the DRS.
Protocol changes since GT version 3.2:
- None
API changes since GT version 3.2:
- None
Exception changes since GT version 3.2:
- None
Schema changes since GT version 3.2:
- None
DRS depends on the following GT components:
- Java WS Core
- WS Authentication and Authorization
- Delegation Service
- RFT
- RLS
DRS depends on the following 3rd party software:
- None
The service configuration files such as the JNDI configuration file,jndi-config.xml,
and the Web service deployment descriptor, server-config.wsdd, located in the
$GLOBUS_LOCATION/etc/globus_wsrf_replicator directory, contain sensitive information
such as database username and password. It is important to ensure that these files are readable
only by the system administrator that is responsible for the container. During deployment, the
permissions on these files are adjusted automatically, however, you should verify the permissions
to ensure that they have been correctly set for your specific platform.
Creating a Replicator requires that the user supply a delegated credential to the DRS
during the initial creation request. The service retrieves the delegated credential from the
Delegation Service and stores it on the file system. As part of the DRS configuration (see
installation and configuration instructions), the user selects a directory to use for storage of
delegated credentials. The default setting is for the DRS to store the file in the system's
designated temporary directory (e.g., /tmp on many platforms). The service sets the
permissions on the temporary file such that it can only be accessed by the user account used to
run the container.
For a review of the DRS architecture and design please see Wide Area Data Replication for Scientific Collaboration.
The semantics and syntax of the APIs for this component can be found in the public interface guide.