1. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware SRM 2.1 issues j.jensen@rl.ac.uk hepsysman Oxford 5 Dec 2005

2. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware Reminder – SRM Storage Resource Manager Control protocol. What it does: –Ask to make file ready for upload/download –Basic metadata (size, checksum,…) –Many components optional Web service (over GSI HTTP) A Storage Element with an SRM interface is often called an SRM

3. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware Reminder – SRM What it doesnt: –Data transfer Except it can do third party transfer –Access control & permissions Some have tried to implement it

4. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware Reminder: baseline Give us SRM 2.1, they said. 1.Pin/unpin 2.Space reservation 3.Volatile and permanent space (space?) 4.Directory stuff 5.VOMS & permissions 6.Abort, suspend/resume requests 7.getProtocols()

5. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware interoblems SRM 2.1 is really SRM 2.1.1 Two versions: 2.1.1 and 2.1.1-modified 2.1.1 has a more soapy array handling Most are now implementing 2.1.1-modified –DPM has switched, as of 1.4.1 Publishing? –Both 1.1 and 2.1 are called SRM ? ?

6. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware interoblems Much of the API is optional –Some things are genuinely optional –Clients dont use full API so why implement all Extra features –Access control Interop is more than using same WSDL –API is quite complex (much more than 1.1) –Semantics, my dear, semantics

7. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware interoblems SRM2 Client srmCopy put cycle The Chocolate and Vanilla and Strawberry problem

8. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware interoblems Not all sites will upgrade at the same time Some sites will continue to publish 1.1 Even DPM has two different daemons –So they compete for 8443 –Must be able to upload via one interface and download via the other

9. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware What should lost Aeneas do? Colourful solution Each flavour can talk to any other flavour

10. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware What should lost Aeneas do? Common client can talk to all flavours

11. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware Use get/put for file transfer SRM2 Client srmGetsrmPut GridFTP 3 rd party xfer for now…

12. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware Then Wait SRMs will interoperate SRMs are converging –Needs testing though They will use 2.1.1-modified They will be able to use srmCopy between SRMs PessimistOptimist

13. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware Implementations dCache –Provides 1.1 since forever –2.1 (FNAL) expected mid January –We wont meet storage goals if 2.1 is delayed –Upgrade from 1.5.{2,3} via 1.6.6

14. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware Implementations DPM –Provides 1.1 and 2.1 since, uhh, quite a while –Now uses 2.1.1-modified –Can publish both interfaces at same time But not on the same web service port

15. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware Other Implementations Not supported for Tier 2 deployment CASTOR2 SRM –Developed at RAL –Deployed at CERN (other CASTOR sites later) StoRM –Developed at INFN –Not tested in UK yet –Thin layer, depends on underlying filesystem

16. Jens G Jensen CCLRC/RAL hepsysman 2005Storage Middleware Testing 2.1 clients developed with DPM RAL developing more elaborate testing framework GOC deploying SE monitoring –Easily adapted to 2.1s