1. dCache things
Paul Millar
… on behalf of the dCache team

2. Agility in a Changing World
Adapt to changing environment
Adapt to changing access methods
Adapt to different users

3. Flexibility through plugins
dCache has always been flexible
Very flexible configuration
Little known secret, dCache has always been extensible (adding new functionality).
Added support for loading plugins when starting
If there's something you can't configure, write a plugin!

4. gPlazma: flexible identity management
Old gPlazma wasn't flexible
Monolithic operations: either succeed or fail
Rewrote to use a plugin approach
based on PAM
Plugins can cooperate to complete a login step
Plan to add support for Federated Identity
Part of the LSDMA project
Good test of gPlazma flexibility
In good shape if WLCG moves away from X.509

5. gPlazma: flexible identity management
LSDMA
Non-HEP users:
no grid certificate /X.509
Web-based solutions are preferred (portals for metadata-based work),
LSDMA WP1 is Federated AAI,
dCache has flexible identity management system
Plugins allow adding new functionality to work with existing
Useful if WLCG moves away from pure X.509.

6. Federated storage: the idea
Client-driven
Find all replicas
Choose “best” one
Open data to best replica
Federated storage
Open data
Make request to central end-point
Find all replicas
Chooses “best” one
Reply with redirect
Follow redirect
The idea:
Access the data from wherever is “closest”
Don't be explicit: always use a “central” endpoint, which redirects client to (hopefully) the best choice
Currently for read-only (e.g., recovery)
Benefits:
Move logic to central components
Easier to keep up-to-date
Allows stateful decision
Needs a protocol with redirection support: xrootd and HTTP
NB. needs a network protocol that supports redirection: xrootd or HTTP
NB. file may have different paths in different storage systems

7. Federated storage: the implementation
xrootd-based
Experiment-driven
CMS pushing,
ATLAS are investigating
xrootd door has plugins:
Allows global-to- local path mapping
Plugin for CMS and ATLAS developed
Experiments are involved in plugins
HTTP-based
Collaboration between DESY and CERN IT- GT/DMS
Allows use of industry standard software
Can browse files
Currently in the early stages
Prototype software written
Initial performance tests are encouraging

8. dCache scientific cloud
Easy way to store, use and share data
Form new collaborations
Currently:
Users get their own area
HTTP/WebDAV for direct access to files,
Use web-browser for managing stored files, drag-and-drop support
Data is available on compute resources (via NFS)
Files are available for copying (via GridFTP)
Active collaboration with Globus Online
Longer-term:
Provide DropBox-like storage that allows scientific analysis
User sees only their own data (and what's shared)

9. Conclusion dCache is agile software
flexibility achieved through plugins
more than SRM, more than grid storage
dCache is back-bone of HEP analysis
~50% of data stored in dCache
Get involved!
If you don't have dCache, install it
If you have dCache, what else can you get it to do?

10. Image credits Skateboard: Tim Drivas (from flickr)
Horses: Verity Borthwick (from flickr)
Keyboard: Who Are You? psd (from flickr)