A New Milestone for Grid Interoperation: SRM-SRB Interface ...SRM-SRB Interface Software Version 1.0...

Enabling Grids for E-sciencE

www.eu-egee.org

EGEE-II INFSO-RI-031688

A New Milestone for Grid Interoperation: SRM-SRB Interface Development

WeiLong, UengAcademia SINICA Grid Computingwlueng@twgrid.org

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Outline

• Overview• Architecture• Progress• Future Plan• Conclusions

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Overview

SRM

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Why SRM?

• SRM is an unique interface for accessing diffident backend storages for diffident middleware.

• Easy to develop applications to adapt different backend storages.

• Provide space and file management on the storage system.

• SRM is the web service interface and the implementation usually depends on the backend storage technology.

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Why SRM?

• Storage Elements (SE) can use different type of technologies– CASTOR, dCache, DPM, BeStMan,...,etc.– DRM (Disk Resource Manager)/TRM (Tape Resource

Manager) /HRM (Hierarchical Resource Manager)

• Grid middleware needs to access files with an uniform interface– Manage storage resources– Not a file transfer protocol

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SRM features

• Provides space management• Provides an uniform access interface• Manages DRM/Tape/HRM• Does not transfer files itself.• Manage the life time of file

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What is SRB ?

• Developed by San Diego Supercomputer Center• A distributed file management system (Data Grid), based on a

client-server architecture.• Allows users to access files seamlessly across a distributed

environment, based upon their attributes rather than just their names or physical locations.

• It replicates, syncs, archives, and connects heterogeneous resources in a logical and abstracted manner.

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SRB Physical Structure

Oracle Client SRB ServerOracle RDBMS

SRB Vault@ location B

SRB Vault@ location B

SRB Vault@ location D

SRB Server

Storage Space

Storage Driver

SRB Server

Storage Space

Storage Driver

SRB Server

Storage Space

Storage Driver

User@

location X

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SRM-SRB Architecture Overview

Core

SRB+DSI

Auxiliary Filecatalog

Gridftp/management API

SRM API

File transfer (gridftp)

Web Service

Data server management

Users/applications

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Information in Auxiliary Filecatalog

• AMGA server, it stores partial filecatalog, resource and SRB host information…– Users Information– Resources Information– Files Information– Space Metadata– Resource States– …

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Architecture Overview (cont.)

Web Service

Core

Data server management

Non MES+DSI

MES Server(GSI enabled)

SRB storage space

Non MESNon MES

Auxiliary filecatalog(AMGA)

Put a file (SURL)

SURL->PathDefault space is available? If yes, some files need to be uploaded

Non MES(+DSI)

Non MES(+DSI)

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Architecture Overview (cont.)

Web Service

Core

Data server management

Non MES+DSI

MES Server(GSI enabled)

SRB storage space

Non MES(+DSI)

Non MES(+DSI)

Auxiliary Filecatalog(AMGA)

Return TURL

Transfer to TURLYes, default space is ready and this file has been set to pinned.

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Architecture Overview (cont.)

Web Service

Core

Data server management

Storage space

MES Server(+GSI enabled)

Storage space

Non MES(+DSI)

Non MES(+DSI)

Auxiliary Filecatalog(AMGA)

Upl

oad

a fil

e(gr

idftp

)

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Architecture Overview (cont.)

Web Service

Core

Data server management

Storage space

MES Server(GSI enabled)

Storage space

Non MES(+DSI)Non MES

(+DSI)

Auxiliary Filecatalog(AMGA)

put file done

SURL -> Path

Set this file has been uploaded and unpinned

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Architecture Overview (cont.)

Web Service

Core

Data server management

Storage space

MES Server(GSI enabled)

Storage space

Non MES(+DSI)Non MES

(+DSI)

Auxiliary filecatalog(AMGA)

The Status of PutDone

Return the Status of PutDone

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Support Flexible File/Space Types

• SRM system has a caching mechanism and has to take care of SRM issues like file lifetime, space management,…,etc.– Volatile space– Durable space– Permanent space

• In our implementation– Use AMGA as auxiliary catalog and record all space

usage, space type, and some file metadata inside.

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Checking Disk Status

• How to get the disk usage of the space?– Need to know the free and used space on SRB server– SRB does not provide the mechanism to monitor resource

usage– We need to know the usage

Space management

• In our implementation– InfoServer:

Deployed on non-MCAT enabled SRB server– SRBInfoServer:

Deployed on MCAT-enabled SRB server

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Checking Disk Status(Cont.)

Web Service

Core

Data server management

Storage space

MES Server(GSI enabled)

Storage space

Non MES(+DSI)Non MES

(+DSI)

• Auxiliary Filecatalog• (AMGA)

SRBInfoServer

InfoServerInfoServer

Update all resource information

Query SRBInfoServer

Query InfoServerQuery InfoServer

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Checking Disk Status(Cont.)

Web Service

Core

Data server management

Storage space

MES Server(GSI enabled)

Storage space

Non MES(+DSI)Non MES

(+DSI)

• Auxiliary Filecatalog• (AMGA)

SRBInfoServer

InfoServerInfoServer

Update status of each resource

Resource info

Logical Resource info

Resource infoResource info

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Progress

• Space Management Functions– srmReserveSpace– srmReleaseSpace– srmUpdateSpace– srmGetSpaceMetaData– srmChangeSpaceForFiles– srmGetSpaceTokens

• Permission Functions– srmSetPermission– srmCheckPermission– srmGetPermission

• Directory Functions. – srmMkdir– srmRmdir– srmRm– srmLs– srmMv

• Data Transfer Functions– srmPrepareToGet– srmBringOnline– srmPrepareToPut– srmCopy– srmStatusOfCopyRequest– srmReleaseFiles– srmPutDone– srmAbortRequest – srmSuspendRequest– srmResumeRequest – srmGetRequestSummary – srmGetRequestTokens

• Discovery Functions– srmGetTransferProtocols – srmPing

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Future Plan

• Internal space management functions– Use a thread to recycle expired space

• More async operation– Space functions

srmReserveSpace, srmStatusOfReserveSpaceRequest srmUpdateSpace, srmStatusOfUpdateSpaceRequest srmChangeSpaceForFiles, srmStatusOfChangeSpaceForFilesRequest

– Transfer functions srmBringOnline, srmStatusOfBringOnlineRequest srmPrepareToGet, srmStatusOfGetRequest srmPrepareToPut, srmStatusOfPutRequest srmAbortRequest, srmAbortFiles,srmResumeRequest, srmSuspendRequest,

srmGetRequestSummary, srmGetRequestToken• Implement IRODS-DSI• Transfer to SRM-IRODS Interface

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Conclusions

• ASGC (Academia Sinica Grid Computing) launches the SRM-SRB Interface Software Version 1.0

• Implement the SRM functions for SRB based on SRM v2.2

• Built on a GridFTP server, an AMGA Server developed for SRB, to make an SRB look like a Classic Storage Element.

• Allowed the gLite tools to transfer files between SRMs and SRBs

• Next, the interoperation between SRB and DPM, dCache, Castor, etc. would be realized.

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Further Information

• For more information on SRM-SRB Interface, please see – http://www2.twgrid.org/SRM-SRB/– email: srm-srb-dev@lists.grid.sinica.edu.tw.

• SRM Working Group: http://sdm.lbl.gov/srm-wg/• SRB: http://srb.diceresearch.org• EGEE: http://www.eu-egee.org/• ASGC: http://www.twgrid.org

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Thank you