Description (see also attached document)

Storage systems used by HEP require remote management. The availability of a common API reduces the complexity of client-side software. Currently, the SRM v2.2 API is widely used, which provides many advanced features.

There are several problems with relying on SRM v2.2 for management:

• Not all HEP storage is manageable through SRM.
• Not all Storage Element implementations provide the complete implementation of SRM specification.
• Not all of SRM v2.2 specification has proved useful.

Within the commercial sphere, different approaches to managing storage have appeared. Perhaps two of the most successful are Amazon's Simple Storage Service (S3) and DropBox. Both services use proprietary communication for managing storage, with S3 inspiring open-source projects that emulate the interface.

In addition to such proprietary interfaces, standards exist that provide comparable levels of functionality. CDMI is an emerging standard interface for managing storage. In addition, WebDAV provides many of the functionality of SRM, with Microsoft's SkyDrive providing it as the interface to their storage service.

The document attached breaks down the SRM protocol into basic functional blocks. These descriptions of functionality provide a reference when comparing the functionality of different protocols. It concludes with recommendations with regard to adoption of storage protocols with WLCG community.

Comments

-- WahidBhimji - 02-Mar-2012