hai-ning wu academia sinica grid computing hnwu@twgrid

EGEE-II INFSO-RI-031688

Enabling Grids for E-sciencE

www.eu-egee.org

Data Grid Services/SRB/SRM & Practical

Hai-Ning Wu

Academia Sinica Grid Computing

[email protected]

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Outlines

• Introduction• Characteristics of data grid• Storage Resource Management (SRM)• Storage Resource Broker (SRB)

– SRB Practical

• Summary

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Data Storage in Large Scales

• Historically data has been STORED rather than MANAGED

• The amount of data grows so rapidly that traditional storage architectures are no longer suitable

• Data are distributed in multiple types of source – hard to integrate data and increase the barriers between users and storage systems

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Challenges of Data Storage

• Large scales of data• Distributed storage via network• Heterogeneous data resources• Management data with efficiency and safety• Long-term preservation

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The Solution: Data Grid

• Data virtualization– Manipulates data in high level– Hides details in low level

• Provides a uniform interface to access the distributed data storage systems

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Virtualization

• Data virtualization• Trust virtualization• Data grids are used to manage shared collections that are

distributed across multiple sites and multiple storage systems

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Data Grid - The Idea

Data Grid Data Grid

Data found

Request for D

ata

Client Users

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Data Grid - The Idea

Data found

Request for D

ata

Client Users

Details are hidden. The data grid system finds out where the data are located.

Data Grid System

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Data Grid Transparencies

• Find data without knowing the identifier– Descriptive attributes

• Access data without knowing the location– Logical name space

• Access data without knowing the type of storage– Storage repository abstraction

• Retrieve data using your preferred API– Access abstraction

• Provide transformations for any data collection– Data behavior abstraction

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Data Grid Components

• Federated client-server architecture– Servers can talk to each other independently of the client

• Infrastructure independent naming– Logical names for users, resources, files, applications

• Collective ownership of data– Collection-owned data, with infrastructure independent access control

lists• Context management

– Record state information in a metadata catalog from data grid services such as replication

• Abstractions for dealing with heterogeneity

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Data Grid Architecture

Unix Shell

Java, NTBrowsers

OAI,WSDLOGSA

HTTP

Archives - Tape,HPSS, ADSM,

UniTree, DMF, CASTOR,ADS

DatabasesDB2, Oracle, Sybase,SQLserver,Postgres,

mySQL, Informix

File SystemsUnix, NT,Mac OSX

Application

ORB

Standard Storage System Operations InterfaceStandard Database Interface

DatabasesDB2, Oracle, Sybase,

Postgres, mySQL,Informix

C, C++, Java Libraries

Logical Name Space Management

LatencyManagement

Digital ComponentTransport

MetadataTransport

Consistency & Metadata Management / Authorization-Authentication Audit

Linux I/O

DLL /Python,

Perl

Federation Management

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SRMThe Data Grid Interface for EGEE Grid

Middleware

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gLite Services

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SE

• Storage Element– The Storage Element is the service which allows a

user or an application to store data – Data Channel Protocols

File Transfer and File I/O

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SRM (Storage Resource Management)

• What is SRM?– SRM is a protocol to manage storage resources (It is NOT a file

access protocol!)– Provides an uniform interface for computing applications and

client users to heterogeneous storage elements– Does not transfer files itself– Provides space management– Manage the life time of file

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SRM & Grid

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Grid files

• Grid Files– Files in the Grid can be referred by different names:

Logical File Name (LFN) : An alias created by a user to refer to some item of data. For example, /grid/gilda/gridcamp/testFile.txt

Grid Unique IDentifier (GUID) : A non-human-readable unique identifier for an item of data. For example, 37afd0cc-c53b-4795-a873-6a9dde35a9cc

Site URL (SURL) : The location of an actual piece of data on a storage system. For example, srm://dpm01.grid.sinica.edu.tw/dpm/grid.sinica.edu.tw/home/twgrid/generated/2007-09-18/file4c4a5a6f-878d-4ef3-a73d-941ae6275383

Transport URL (TURL) : Temporary locator of a replica + access protocol: understood by a SE. For example, gsiftp://dpm01.grid.sinica.edu.tw/dpm01.grid.sinica.edu.tw:/path1/twgrid/2007-09-18/file4c4a5a6f-878d-4ef3-a73d-941ae6275383.168233.0

– While the GUIDs and LFNs identify a file irrespective of its location, the SURLs and TURLs contain information about where a physical replica is located, and how it can be accessed.

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LFC

• File Catalogue (LFC)– The mappings between LFNs, GUIDs and SURLs are kept in a

File Catalogue service, while the files themselves are stored in Storage Elements.

– The only file catalogue officially supported in WLCG/EGEE is the LCG File Catalogue (LFC).

Mapping by the “LFC” catalogue server

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I/O server

GridFTP

WNWN

WNWN

CE SE

SRMSite A

LFCUser interface

1

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Upload a file to a SE

CASE 1User needs to store data in SE (from a UI)1. Create a new LFN entry

in LFC, return a SURL.2. srmPrepateToPut

(SURL)3. Transfer the file4. srmPutDone (SURL)

4

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Upload a file to a SE

CASE 2Application needs to store data in SE (from a WN)

I/O server

GridFTP

WNWN

WNWN

CE SE

SRM

Site A

LFC1

2

3

1. Create a new LFN entry in LFC, return a SURL.

2. srmPrepateToPut (SURL)

3. Transfer the file4. srmPutDone

(SURL)

4

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I/O server

GridFTP

WNWN

WNWN

CE SE

SRMSite A

LFCUser interface

1

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Download files from a SE

CASE 3User needs to retrieve (onto the UI) data stored into SE1. Query the file catalog

to retrieve the SURL from the LFN.

2. srmPrepateToGet (SURL)

3. Transfer the file (read)4. srmReleaseFile (SURL)

4

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Download files from a SE

CASE 4Application needs to copy data locally (into the WN) and use them.

I/O server

GridFTP

WNWN

WNWN

CE SE

SRM

Site A

LFC1

2

3

1. Query the file catalog to retrieve the SURL from the LFN.

2. srmPrepateToGet (SURL)

3. Transfer the file (read)

4. srmReleaseFile (SURL)

4

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SRB

Storage Resource Broker

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Storage Resource Broker

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

client-server architecture• A uniform interface to heterogeneous data storage resources, • Based upon their attributes rather than just their names or

physical locations• Support many data storage systems• Provide various types of client interfaces on different platforms

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SRB Physical Structure

Oracle Client SRB ServerOracle RDBMS

SRB Vault@ location A

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

MCAT-Enabled Server

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SRB Pratical - inQ

• Download inQ 3.5.0 from

http://www.sdsc.edu/srb/tarfiles/inQ350.zip• Unzip inQ350.zip• Execute inQ.exe

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inQ – Login

• Name: srbusr+your number• Host: tap07.grid.sinica.edu.tw• Domain: ASGC• Port: 6833• Authorization: ENCRYPT1• Password: The same as your user name

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SRB Client Tool - inQ

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SRB Demonstrations

• Use InQ to upload, download, remove files.• Use Scommands to upload, download, remove files.

– Sinit: log in SRB system Syntax: Sinit

– Sls: list directory content Syntax: Sls

– Sput: upload a file to the SRB server Syntax: Sput filename

– Sget: download a file from the SRB server Syntax: Sget filename

– Srm: remove a file stored in SRB server Syntax: Srm filename

– Sreplicate: to replicate data to another resource Syntax: Sreplicate filename

– Sexit: log out SRB system Syntax: Sexit

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Data Grid Applications

• Digital Archiving– Long-term preservation– Heterogeneous backup

• Digital Library– Data sharing

• Scientific Computing

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SRB Use Case

• Build Data Grid Management System – Data Grid services in Academia Sinica– NDAP cross-organization data backup project

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SRB Data Grid Services in Academia Sinica (1)

• Objective– To provide Grid services for long-term preservation and

unified data access• Data Collection Status

– File size: ~ 60 TB– File count: ~ 3.5 Million

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SRB Data Grid Service in Academia Sinica(2)

Campus Backbone Network

ASCC(20TB)

IIS(8TB)

IOE(8TB)

ITH(8TB)

IHP(8TB)

IMH(8TB)

IZAS(8TB)

Tape Library(500TB)

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• Academia Sinica (AS)• National Palace Museum (NPM)• National Taiwan University (NTU)• National Museum of History (NMH)• Academia Historica (DRNH)• National Central Library (NCL)

• National Museum of Natural Science (NMNS)• Taiwan Historica (TH)

NDAP Partners For Long-term Data Preservation

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Data grid for NDAP LTP service

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Summary

• Data grids provides a new solution for large-scale storage with the following features: – Distributed data storage – Efficient and safe management of data– A uniform interface to heterogeneous systems– Flexibility to new storage technology

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SRM & SRB

• SRM– Used in gLite middleware– A uniform interface between different SEs and grid middleware

• SRB– Developed by SDSC– Support many backend storage systems– Widely used data grid software

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SRM & SRB

• SRM and SRB cannot interoperate unless they have a standard to communicate

• Constructing a bridge between SRM and SRB so that– Integrate SRB into the gLite environment– Bind resources from the two important data grid systems– This project is currently developed by ASGC

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SRM & SRB

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iRODS

• A next generation data grid system after SRB developed by SDSC

• A rule-oriented data grid system• More flexibility for data management• Current version: iRODS 1.0

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iRODS Workshop

• Time – Tue 8 April 2008• Location – 2nd Conference Room, 3F• For more information, please check on ISGC 2008

Website

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References

[1] Use Cases on Data Services, Fu-Ming Tsai

[2] Building Preservation Environments with

Data Grid Technology, R. Moore

[3] EGEE Middleware Architecture and Planning (Release 1)

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Thanks for your attentions!

hai-ning wu academia sinica grid computing hnwu@twgrid

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