[glue-wg] additional nordugrid storage use cases

Balazs Konya balazs.konya at hep.lu.se
Fri Mar 14 04:35:09 CDT 2008


I've collected  requirements on storage related information our users would like 
to be able to find in glue2. Some of them i myself don't support (e.g. 
individual storage space info), nevertheless i
forward all of them.  These requirements basically ask for detailed storage 
usage information, load-like information on the storage service and introduction 
of storage activity describing a transfer process a storage service is 
participating in.

see the details below.

ps: please apologize for the last minute post (we are having a storage phone 
call in half an hour)

Use cases for storage information in glue2

1. Find out how much disk space is used by User A, Same for a group B of VO C. 
Same for tapes or other media

2. Find how much disk space is available at this moment for VO D. Same for tapes 
or other media

3. Find storages that can keep files online for at least 7 days

4. Find storages that can bring a file from tape in 10 minutes

5. Find storages that support SRM2.2

6. Find storages that have regular tape backups

7. Provide transfer progress (storage activities) and related load information.

In a complete analogy to jobs at computing elements: I can currently monitor the 
total number of grid/nongrid jobs, and each grid job status (owner, duration, 
resource consumption, submission client, everything). In the very same manner, 
I'd like to see a number of active transfers (uploads and downloads), with all 
the relevant information per transfer: file name, owner, source, destination, 
total size, progress (MB transferred), and probably some information about 
storage media (disk/tape), and whatever else I forgot.

ATLAS DDM (Distributed Data Management) suffers enormously from the lack of 
transparency of the file and dataset transfer processes, the actual load imposed 
on a storage service due to active transfer processes. General statistics such 
as number of ongoing transfers and transfer rate seen at each storage service 
would be useful to be published somewhere.

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