EGEE is a project funded by the European Union under contract IST-2003-508833

EGEE is a project funded by the European Union under contract IST-2003-508833

Data ManagementData Access From WN

Paolo Badino ([email protected])

Ricardo Rocha ([email protected])

JRA1 all-hands meeting, 29-June-2004

www.eu-egee.org

JRA1 all-hands meeting, 29-June-2004 - 2

glite I/O

• Goals Provides a library for accessing files stored on a remote a SE in a

transparent way

• Release Plan First version foreseen for PM03 Two weeks late…

JRA1 all-hands meeting, 29-June-2004 - 3

Guiding Principles

• Based on existing libraries Aiod, gfal, rfio, dcap Stable

Quickly deployable

• POSIX-like I/O API Remote open, read, write Minimum impact on existent code

• Extensible Plug-ins and callouts to support additional protocols and

authorization models

JRA1 all-hands meeting, 29-June-2004 - 4

API

• POSIX-like I/O APIglite_handle glite_open(char * name, int32 flags, int32 mode)int32 glite_read(glite_handle fh, void * buf, size_t count)int32 glite_write(glite_handle fh, void *buf, size_t count)int32 glite_lseek(glite_handle fh, int64 offset, int32 whence)int32 glite_close(glite_handle fh)int64 glite_size(glite_handle fh)

• Support both GUID and LFNname = “guid:2cd59291-7ae7-4778-af6d-b1f423719441”name = “lfn:egee/foo12345”

JRA1 all-hands meeting, 29-June-2004 - 6

Flow

glite-io client

rfio

glite-io daemon

FAS

SRM

Authorizationcallout

Protocol Plug-in

Name Resolutioncallout

GUID

GUID

GUID ACL

SURL

TURL

TURL

RCGUID

SURL

LFN

FC

LFN

GUID

AlienIOclient aiod gfal

LFN

HANDLE

HANDLE

HANDLE

HANDLE

SE

JRA1 all-hands meeting, 29-June-2004 - 7

Open Issues

• Is Read-Only access ok for now?

• Writes (later): updating is not a problem, synchronization with other replicas is. Depends on semantics of file update policy – single master, multi-master with reconciliation, etc.

• Creation of a new file through this interface? We think not..Problems:glite_open (name, O_WRONLY | O_CREAT, mode) Is name a GUID/LFN? Should the file name already be registered or should it be inserted

into the File Catalog later? When should the file be inserted in Replica Catalog? During open or

close?

JRA1 all-hands meeting, 29-June-2004 - 8

File Access Service

File Access Service (FAS)

Authz Framework

CLIENT

SITE POLICY VO POLICY

GUID USER (RWX) GROUP (RWX) OTHER (RWX)

ACL PRINCIPAL (RWX)

Storage Element

VOMS CERTIFICATEGROUPS / ROLES

Transfer FILE request

GET PERMISSIONS

SRMUser Mapping

File TransferServiceXFER

BufferUse protocol X

JRA1 all-hands meeting, 29-June-2004 - 9

Security Implementation

• Authentication GSI / Proxy Certificates

• Authorization VOMS – Attribute Certificates Authz Framework

• XACML compatible• End of summer (alpha / beta before that)

• Toolkits Java – Java CoG C++ – gSOAP with GSI plugin

• Delegation JRA3 magic