CASTOR SRM v 1 1 experience Presentation at

CASTOR SRM v 1. 1 experience Presentation at SRM meeting 01/09/2004, Berkeley Olof Bärring, CERN-IT 01/09/2004 CASTOR SRM v 1. 1 experience

Outline • CASTOR SRM v 1. 1 implementation • Interoperability tests • Problems found – SRM specification – GSI • SRM @ GGF: GSM WG – Input to the definition of SRM-Basic • Conclusions and outlook 01/09/2004 CASTOR SRM v 1. 1 experience 2

CASTOR SRM v 1. 1 • Implements the vital operations – get, put, get. Request. Status, set. File. Status, get. Protocols • No-ops: – pin, un. Pin, get. Est. Get. Time, get. Est. Put. Time • Implemented but optionally disabled (requested by LCG) – advisory. Delete • CASTOR GSI (CGSI) plug-in for g. SOAP – Also used in GFAL • Evolution @ CERN: – First prototype in summer 2003 – First production version deployed in December 2003 • Other sites having deployed the CASTOR SRM – CNAF (INFN/Bologna) – PIC (Barcelona) 01/09/2004 CASTOR SRM v 1. 1 experience 3

CASTOR SRM v 1. 1 Grid services SRM request repository GSI SRM gridftp CASTOR disk cache stager CASTOR name space RFIO CASTOR tape archive Tape queue Volume Manager 01/09/2004 Local clients Tape mover CASTOR SRM v 1. 1 experience 4

Deployment castorgrid. cern. ch DNS loadbalancing Test/dev node gridftp 01 gridftp 02 gridftp 03 gridftp 04 gridftp 05 gridftp 06 srm gridftp srm gridftp RFIO&co CASTOR (stager, nameserver, . . . ) 01/09/2004 CASTOR SRM v 1. 1 experience 5

Interoperability tests • CASTOR SRM has been running interoperability tests with various clients, notably – GFAL (Jean-Philippe) – EDG replica manager (Peter) – FNAL/d. Cache SRM (Timur) 01/09/2004 CASTOR SRM v 1. 1 experience 6

Problems found • The interoperability problems can be classified as: – Due to problems with the SRM specification – Due to assumptions in SRM or SOAP implementations – Due to GSI incompatibilities • The debugging of GSI incompatibilities is by far the most difficult and time consuming 01/09/2004 CASTOR SRM v 1. 1 experience 7

Problems with SRM spec (1) • Lack of enumeration – All enumeration-like types are strings – Client needs to find a common denominator (e. g. cast all strings in capital letters) • Request and file state lifecycles – Concise for ‘put’ or ‘get’ – Draft proposal submitted by Timur for ‘copy’. Not yet adopted by CASTOR SRM implementation. – Undefined for ‘mk. Permanent’, ‘pin’, ‘unpin’ (probably irrelevant for the latter two)? • Request history – What an SRM should with requests that have reached the “Done” or “Failed” status 01/09/2004 CASTOR SRM v 1. 1 experience 8

Problems with SRM spec (2) • Immutability of request identifier – Request id is a 32 bit word – Unspecified if an SRM can reuse request ids for finished (“Done” or “Failed”) requests • SURL (Site URL) semantics – Is it an URL or URI? – If URL, does it support relative and absolute paths? – If URI name space is virtually flat for an arbitrary client • Pin lifetime – Pin lifetime is defined to be subject for site policy – No way to query the remaining pin lifetime for a particular file – Current definition appears useless for any practical purpose 01/09/2004 CASTOR SRM v 1. 1 experience 9

Problems with SRM spec (3) • Exception handling and error propagation – Unspecified if a multi-file request should fail when a subset of the files got an error – Unspecified if and when an SRM can do retries – Only one error message, global for all files in a multi-file request, is available for reporting – Format and contents of error message undefined • advisory. Delete != delete – It may be vital to know what the effect is • No effect at all (if so, what happens if SURL is reused for a new file? ) • Only remove disk resident copy (if so, when? ) • Remove HSM file (if so, when? ) • Directory creation on the fly for ‘put’ requests – If a ‘put’ requests specifies a SURL corresponding to a path for which one or several sub-directory levels do not exist, should it create the missing dirs on the fly (provided the client has the appropriate permissions)? 01/09/2004 CASTOR SRM v 1. 1 experience 10

Problems due to SRM or SOAP implementation details • SRM WSDL discovery – FNAL client put severe constraints on the wsdl publication • Bug in g. SOAP v 2. 3 WSDL importer • Various bugs in CASTOR SRM found but not reported here 01/09/2004 CASTOR SRM v 1. 1 experience 11

GSI problems (1) • CASTOR (GSI) – EDG RC (Java Trust. Manager) – Trust. Manager does not use GSI default of SSL handshake + credential delegation, but just a SSL handshake – Trust. Manager client would not work with SSL 3. 0, which is forced by GSI – Solution: EDG RC uses Co. G (Globus Java Security Implementation) instead • CASTOR (GSI) – FNAL d. Cache (Java Co. G) – FNAL client only used a limited number of algorithms for encryption that were not matching those provided by standard GSI – Limited Proxy certificate • GSI error reporting not working properly 01/09/2004 CASTOR SRM v 1. 1 experience 12

GSI problems (2) • Administration and deployment issues – EDG globus patch for supporting for dynamic pool accounts requires GRIDMAPDIR environment to be declared, even if default location was used for the security files – configuration problems (right Root CA not trusted) – CERN CA changed the Certificate naming scheme (number added at the end of DN). New certificates were not automatically propagated (to, for instance, FNAL). • The effort for debugging GSI problems will scale with the number of SRM implementations – Establishing a ‘SRM reference implementation’ for certifying new servers and clients would help 01/09/2004 CASTOR SRM v 1. 1 experience 13

Conclusions and outlook • CASTOR SRM v 1. 1 is in production since a couple of months at CERN and some other CASTOR Tier 1 sites • SRM interoperability does not come for free – Definition not concise enough, room for too much site specific interpretation – Is GSI interoperability an illusion and, if so, will it continue to be so? • We have currently no plans for a CASTOR SRM v 2. 1 implementation. Would rather like to tighten up SRM v 1. 1 in the context of the GGF GSM WG and the SRM-Basic definition 01/09/2004 CASTOR SRM v 1. 1 experience 14