EU DataGrid TestBed 2 Component Review

Paul Millar(University of Glasgow)

paulm@astro.gla.ac.uk

(slides based on a presentation by Erwin Laure)

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

Outline

Middleware developments for TB 2.0

WP1 - Workload Management System

WP2 & 7 - Architecture, Visulisation tools, Data Management and Replica Management Components

WP5 - The Storage Element

WP3 - R-GMA

WP4 - LCFGng

Release plan on application testbed

Summary

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

Workload Management System

WMS architecture reviewed

To apply the “lessons” learned and addressing the problems with the first release of the software

e.g. delegate some functionalities to pluggable modules, etc.

To make easier the interoperability with other Grid frameworks

To increase the reliability of the system

To support new functionalities: User APIs (including a Java GUI) Job checkpointing Job partitioning Interactive jobs Dependencies of jobs Parallel jobs

WP 1

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

Network Monitoring Architecture

PCP

WEB RTPL

Distributed Data CollectorRaw

Iperf UDPmon GridFTPPingEr

Measure

CollectAndStorage

Visualization

MapCenter

Replica Managers & resources brokers

Network Managers

Forecaster

Processing

ArchiveInfo

Services(R-GMA)

NetworkCost

WP 7

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

Network Monitoring Architecture

PCP (Probe Coordination Protocol, dev. by WP7) schedules all active network measurements and avoids conflicts.

Standard and ad-hoc developed tools to measure network metrics

PingEr, IperfEr, UDPmon, rTPL, SNMP proxy agent …

Dedicated R-GMA infrastructure stores all network metrics and GridFTP logging.

Producers for main network metrics are available. R-GMA Archiver will to keep historical network metrics values.

WP 7

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

Visualization Tools

MapCenter TopoGrid

RTPL

WP 7

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

GetNetworkCost Suite

getNetworkCost functions assist replica managers and resource brokering

Based on various back-ends for flexibility: CGI,and Globus MDS back-ends in release 1 R-GMA back-end in release 2 Web Services back-end also under development

Based on regular TCP throughput measurement. (release 1)Parameters to be added for enhanced precision:

GridFTP logging information : the more the grid is used, the more precise are the results.

historical data stored in R-GMA Archiver other network metrics (RTT, Jitter…) forecasting methods will be also tested.

WP 7

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

Data Management

Moving to the Web Service paradigm:

GSI-enabled Web Services

Secure SOAP communication

Components:

Security : GSI-enabling Web Services fitting the EDG security framework

RLS : Replica Location Service

RMS : Replica Management Services

RMC: Replica Metadata Catalogue

Spitfire 2 : Customizable Grid RDBMS access

WP 2

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

Replica Management Services

Replica Management

Services

Optimisation

Replica Metadata

Client

Replica Location

File Transfer

EDG-ReplicaManager

RepMetatdataCatalogue

RepOptimisationServiceGridFTP

RepLocationService

WP 2

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

Replica Manager components

ERM: EDG Replica Manager client interface and API Entry point for all clients

ROS: Replication Optimization Service Replica selection based on network metrics (WP7)

RLS: Replica Location Service

Local Replica Catalog services LRC: Logical to Physical file mappings

Replica Location Index services RLI: index on Logical names

RMC: Replication Metadata Catalogue An instance of Spitfire with RDBMS backend and specialized schema

WP 2

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

Replica Selection

WP7 providing the network information that serves as the basis for the replica selection

Monitoring of network traffic between the 5 main TB sites

Calculation of expected transfer time for files between given sites.

Optimisation component of Reptor Services (WP2)

Implemented as a stand alone web service

Selection of best replicas based on network latencies

Assist the resource broker in selecting the best CE for job scheduling based on access costs of replicas

WP 2 & 7

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

Replica Location Service

RLS: A Framework for Constructing Scalable Replica Location Services

Joint collaboration between WP2 and Globus

Independent local state maintained in Local Replica Catalogues : LRCsLRCs

Unreliable collective state maintained in Replica Location Indices : RLIsRLIs

Soft state maintenance of RLI state

relaxed consistency in the RLI, full state information in LRC

Membership and partitioning information maintenance

RLS components change over time : failure, new components added

Service discovery and system policies

LRC LRC LRC

RLI RLIRLI

LRCLRC LRC LRC

RLI RLIRLI

LRC

WP 2

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

The StorageElement

TB2.0 will see the first production release of the SE control system

For this first release the three interfaces to the outside world are:

Data, gridftp will be used to transfer files over the WAN and the files will optionally be available to local nodes by NFS.

Information, Existing MDS information providers will be extended to provide the extra information in the GLUE storage schema.

Control, functions such as reservation, pinning, deletion, and transfer time estimation.

The SE control interface to a generic MSS has already been tailored for CERN and RAL and tested there.

Work is under way with IN2P3, WP10, and WP9 to adapt it to their MSS.

WP 5

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

R-GMA: Information & Monitoring

A relational implementation of GMA

Relational model is better able to describe real world systems than the hierarchical

Applied to both information and monitoring

Creates impression that you have one RDBMS per VO

Not a general distributed RDBMS system, but a way to use the relational model in a distributed environment where global consistency is not important.

Supports streaming

Producer

Consumer

Registry

Store location

Lookup

locatio

n

Execute or

stream

Producers

Announce: SQL "CREATE"

Producers

Publish: SQL "INSERT"

Consumers

Collect: SQL "SELECT"

WP 3

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

Installation & Configuration

LCFGng tailored to EDG (“EDG LCFGng”):

Component guidelines for EDG middleware developers

Produced new system management and Grid middleware components

Ported new client configuration access library to LCFGng

Non-intrusive version of the package installation subsystem (updaterpms)

Central Config DB

XMLHLDL

Pancompiler

Client node

Client node

Client node

cacheAccess

API

admins

Applications

Configuration Architecture

WP 4

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

User VOMS

service

authz

map

pre-proc

authz

LCAS

LCMAPS

pre-proc

LCAS

Coarse-grainede.g. Spitfire

service

dn

dn + attrs

Fine-grainede.g. RepMeC

Coarse-grainede.g. Gatekeeper

Fine-grainede.g. SE

Java Cauthenticate

acl acl

Authorisation via VOMS SCG

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

Release Plan on Application Testbed

Port to RH 7.3 & LCFGng February

Upgrade to Globus 2.2.3 end of February

R-GMA

RLS

Storage Element

NetworkCost Suite

ERM March & April

New Resource Broker + GLUE schema

GridFTP access to CASTOR

VOMS

Testbed 2.0: May 2003

GridPP 6th Collaboration Meeting – 30-31 Jan. 2003 – n° 1

Summary

Major new developments in all middleware areas

Addressing the key shortcomings identified:

WMS stability and scalability

Replica catalogue stability and scalability

Data management usability

Information system stability and scalability

Unified access to MSS

Providing new functionality

Upgrade underlying software