libarcdata is a library for data access. It provides a uniform interface to several types of grid storage and catalogs using various protocols. See the DataPoint inheritance diagram for a list of currently supported protocols. The interface can be used to read, write, list, transfer and delete data to and from storage systems and catalogs.
The library uses ARC's dynamic plugin mechanism to load plugins for specific protocols only when required at runtime. These plugins are called Data Manager Components (DMCs). The DataHandle class should be used to automatically load the required DMC at runtime. To create a new DMC for a protocol which is not yet supported see the instruction and examples in the DataPoint class documentation. This documentation also gives a complete overview of the interface.
The following protocols are currently supported in standard distributions of ARC (except XRootd, which is not yet distributed).
ARC (arc://) - Protocol to access the Chelonia storage system developed by ARC.
File (file://) - Regular local file system.
GridFTP (gsiftp://) - GridFTP is essentially the FTP protocol with GSI security. Regular FTP can also be used.
HTTP(S/G) (http://) - Hypertext Transfer Protocol. HTTP over SSL (HTTPS) and HTTP over GSI (HTTPG) are also supported.
LDAP (ldap://) - Lightweight Directory Access Protocol. LDAP is used in grids mainly to store information about grid services or resources rather than to store data itself.
LFC (lfc://) - The LCG File Catalog (LFC) is a replica catalog developed by CERN. It consists of a hierarchical namespace of grid files and each filename can be associated with one or more physical locations.
RLS (rls://) - The Replica Location Service (RLS) is a replica catalog developed by Globus. It maps filenames in a flat namespace to one or more physical locations, and can also store meta-information on each file.
SRM (srm://) - The Storage Resource Manager (SRM) protocol allows access to data distributed across physical storage through a unified namespace and management interface.
XRootd (root://) - Protocol for data access across large scale storage clusters. More information can be found at http://xrootd.slac.stanford.edu/
1.6.3