Chelonia - a lightweight self-healing distributed storage

This new distributed storage consists of a set of SOAP based services residing within HED. Together, the services provide a data storage system which is:

In Chelonia, data are managed in a hierarchical global namespace with files and subcollections grouped into collections. A dedicated root collection serves as a reference point for accessing the namespace. The hierarchy can then be referenced using Logical Names. The global namespace is accessed in the same manner as in local filesystems.

The capabilities of Chelonia are provided by several interconnected web services (see the figure).

The services communicate with each other through the Message Chain Components in HED. The communication channels are depicted by lines in the figure.

Chelonia has a modular architecture for file transfer protocols, currently only HTTP(S) is supported. The replicas of the files are stored on different storage nodes. A storage node here is a network-accessible computer having storage space to share, and running a Shepherd service and a supported HTTP server.

The lightweight ARC client tools provides two Command Line Interfaces (CLI) which give the basic data movement and listing capabilities. Chelonia comes also with a FUSE-module (Filesystem in Userspace) which allows users to mount the storage namespace into the local file system enabling the use of graphical browsers and simple drag-and-drop file management.

Chelonia storage can also be specified as a source of input data for jobs on an ARC-connected Grid, as well as the output location for the result files.

More material

Chelonia - on YouTube

NorduGrid homepage