Jens Jensen, STFC/RAL Bear with me for a moment View of the past –Achievements –Lessons learned Present –SRM 2 deployment Future –Todo –Really high level stuff
Jens Jensen, STFC/RAL Who we are… GridPP storage community As defined by mailing list, has ~55 members –Covers every UK site –Also in.ie,.nl,.ca,.pl,.it,.de However, not all are equally active… –But thats OK –Isnt it?
Jens Jensen, STFC/RAL Support Developers Dev support Depl. support GridPP supprot community supprot (local) users
Jens Jensen, STFC/RAL Support Developers Dev support Depl. support GridPP supprot community supprot (local) users 1 person…
Jens Jensen, STFC/RAL Support Developers Dev support Depl. support GridPP supprot community supprot users Maybe reality is a little more complicated
Jens Jensen, STFC/RAL Your name appeared among the beneficiaries who will receive a part- payment of US$2.8 million and has been approved already for months. You are requested to get back to me for more direction and instruction on how to receive your fund. We want to hear from you before we can make the transfer Open for questions, goes to Greig and Jens Almost all spam Promising to solve our financial problems They tell us: Storage, size matters email@example.com
Jens Jensen, STFC/RAL Status 2/3 of sites running DPM –Experimentally on Lustre –(Cambridge, UCL) 1/3 of sites running dCache Tier 1 running CASTOR –(and dCache) Bristol (Jon) running StoRM
Jens Jensen, STFC/RAL Status Finished CCRC 08 Should have SRM2 deployed –At least for Atlas (sites) Need space token descrs Problems with space manager in dCache –And CMS (sites) More static token descrs initially –Information system secondary (tokens static) Still reqd for accounting Many people worked hard to make it a success
Jens Jensen, STFC/RAL Experiences Went well, mostly SRM2 used at RAL –Few odd bugs and issues –E.g. -0.00P free –Negative file sizes (gridftp 32 bit issue?) Took time to get space token (descr) agreed Who speaks for expts? Using spaces at T2s –OK for DPMers Needs firewall open Endpoint published Spaces set up –Harder for dCache Problems with space mgr But running on same port
Jens Jensen, STFC/RAL Lessons No way to get through to everyone –Needs some effort at sites (to do what we need) –Workshop at NeSC was a success Storage is more difficult than you'd think –Particularly the occasional peaks –Implementation specific optimisations –Locating the problem – complex implementations Need to manage risks more carefully –GridPP2: surprising number of risks happened!
Jens Jensen, STFC/RAL risks Risks...(dating back to Dec06-Feb07, needs revision)
Jens Jensen, STFC/RAL Special Achievements Beyond the call of duty Recognised internationally Or special benefits to users
Jens Jensen, STFC/RAL Information Systems Information collected globally Used for accounting Users locate resources
Jens Jensen, STFC/RAL Information Systems Much work done on information system backends in GridPP –GIP plugin easier –DPM (Graeme, then Greig) –dCache debug (owned by SARA then DESY) –CASTOR Disk servers – Tier 1 CASTOR, LSF, tape robot – RAL Storage Oracle databases – RAL DB group
Jens Jensen, STFC/RAL Special Achievements Accounting –Space available and used –Resource overview and selection –(or non-selection) Numerous subtle issues with space What is used? Available? Can info be relied on for selection? Subtle implementation issues Long propeller head discussions
Jens Jensen, STFC/RAL SRM/SRB interoperation using gLite Pretend SRB is a Classic SE Classic SE still supported by gLite FTS FTS SRB Disk storage SRM GridFTP SRM selects pool node… Disk storage GridFTP Disk storage GridFTP LFC
Jens Jensen, STFC/RAL Achievements – standards SRM 2.2 is now an OGF standard –Collaboration between SRM developers –…and WLCG –New challenges ahead GLUE –Contributed to GLUE SE schema –1.3, also some for 2.0
Jens Jensen, STFC/RAL What Keeps the Unreasonable (Wo)Man Awake at Night? CUS – Campaign for Usable Storage Fabric Staff...!! Coordination
Jens Jensen, STFC/RAL What is Usable Storage Users: we want usable storage Deployment: storage is usable if its being used Not necessarily… Identified (currently) 13 areas –Somewhat overlapping –But that is normal
Jens Jensen, STFC/RAL What is Usable Storage Robust –Doesnt fall over Measure uptime (for some definition of uptime) Good performance Requests per second, concurrent users –Can be tested – DESY did this for dCache Can be tested! (Dave Newbold for CASTOR, ScotGrid for DPM and dCache) –(Also tests the SRM itself)
Jens Jensen, STFC/RAL What is Usable Storage Good Overall Data Performance Tests the data movers and networks –Experiments are good at this –Also 3 rd party transfers, and to tape –Optimisations Ensures resource availability –Concurrent users (other experiments, same expt) Ancient available/used metrics –Load balancing, dynamic alloc.
Jens Jensen, STFC/RAL What is Usable Storage Monitored. Accountable. –See when something goes wrong Reliable accounting data Minimise downtime Maintainable –Ease upgrade, installation and configuration Minimise downtime Tested (prior to release)
Jens Jensen, STFC/RAL What is Usable Storage Standards compliant and interoperable –Provides SRM 2.2 / GLUE 1.3 / GridFTP –Extensive test suite available Secure –Access control, secure implementations Supported –Upstream: developers Publishing metadata in current schema Usable by applications (interfaces)
Jens Jensen, STFC/RAL Challenges Services Capabilities Scale, Performance Economy, Sustainability Middleware State of the Art Users Challenges
Jens Jensen, STFC/RAL Conclusion Lots of things achieved Lots of stuff to do –Somehow always harder than expected –Doesnt asymptotically tend to zero –Plus there are regular peaks so it doesnt even converge Storage is important! should not be underestimated Good community to go forward into GridPP3
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