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Andrew OverviewWalter WongComputing Services

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Andrew YesterdayBuilding the next generation campus computing environmentFunded by IBM in 1982Early large scale distributed system

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AFSAUISAMSWorkstation Configuration

Significant Contributions

Wor

ksta

tion

conf

igAFS

AUIS

AMS

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AFSScalable Distributed FilesystemClient Side CachingGlobal NamespaceServer IndependenceUnderstandable ACLsVolumes

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AUISAndrew User Interface SoftwareObjected orientated, customizable, multi-media environment

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AMSAndrew Messaging SystemBuilt on AUISAuthenticatedShared folders (bboards)

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Workstation ManagementOperating system and configurations remain consistentSynchronization of existing files on AFS for central maintenanceRemoval of files that “don’t belong”

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Andrew/Unix Workstations

Original Andrew

Information

Backup

Mail/News

Printing

Clients ServicesInfrastructure

AFS Fileservers

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Transition to ProductionDefault campus environment in 1988Rapid GrowthSoftware Release ManagementDelegation and Distribution of AdministrationPersonal Computers

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Rapid GrowthNeed for monitoring and reporting Stable servicesReduce incremental administrative costs through automation and tools Otherwise, no time for development

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Identify all software componentsControlled test environmentsRollback supportImplemented under Unix with Depot & EMT http://andrew2.andrew.cmu.edu/depot http://andrew2.andrew.cmu.edu/emt

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Distributed AdministrationProvide a default configurationProvide an infrastructure for customizationat multiple levelsAllow one to control whatthey want - ignore whatthey do not want

Vendor

Central

Departmental

Workgroup

Personal

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Personal ComputersMore affordable than workstationsDifficult to port AFS and other applicationsMissing key features in the operating systems

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Architectural ProblemsAFS is complicated, but necessarily soSystem built on AFS inherit its complexity, often unnecessarilyAFS has not been ported to many platforms (Mac, DOS, Windows 3.x)Performance problems in AFS are inherited by other servicesAFS is not good over slow linksAFS is going to be replaced with the DFS.… Or maybe not...

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Personal Computers

Andrew Plus

Clients ServicesInfrastructure

Andrew/Unix Workstations

Information

Backup

Mail/News

Printing

Andrew/Unix Workstations AFS

Fileservers

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Andrew IIInitiated in 1992 to cope with DCE/DFSNo single system or single delivery dateMultiple projects with common goals

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Andrew II

Filesystems

OtherWorkstations

AndrewWorkstations

Information BackupMail/NewsPrinting

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Andrew II GoalsStandards based or in wide spread useAvoid unnecessary filesystem dependenciesSimple independent scaleable servicesPC and Mac integrationDisconnected operation

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Andrew II StrategiesLimit operating system modificationsLayer local changes on vendor solutionsSeek vendor solutions when ever possibleSeek vendor and external use of local solutionsIntegrate external solutionsAdapt local environment when market forces dictate change

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Major Andrew II ProjectsMessaging - CyrusInformation Services - Polaris, Infoserver, Userweb

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Project CyrusInspired by ancient Persian Royal Postal System System linked an Empire 1500 miles broad (delivery time from end to end: 3 weeks)Postal System was integral to ordered organization of societyDurable, enterprise communications -- lasted for over 1500 years

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Project Cyrus GoalsScalable Enterprise Wide Mail SystemAccess Control ListsQuota per User/MailboxServer IndependenceMessage Service Integration:Mail, Netnews, local bulletin boards, internet mailing lists, wire services, etc.

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Project Cyrus StatusImplemented high quality IMAP server http://andrew2.andrew.cmu.edu/cyrusWork progressing with ACAP for server independenceIMAP proxy as interim measureWaiting for client vendors to catch upSASL LibrarySMTP AUTH

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PolarisWeb based help serviceDynamic Browse Space Can be designed and built by

documentation staff or by developers as they release help pages

Full-text searchingAUIS, man, and HTML supporthttp://polaris.andrew.cmu.edu/

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InfoserverCMU Online Information SystemWeb based Depot managedFull-text searching http://www.cmu.edu

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User/Course Web ServiceDistributed filesystem manages quota Immediate publishing No release managementFull-text searchinghttp://www.andrew.cmu.edu

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Major Current InitiativesFull NT integrationDirectory ServicesSecurity Services

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OrpheusNT provides a ‘real’ operating system on PCsMicrosoft considers interoperability as a method of conquestChallenge is fully integrating NT environment with existing infrastructure

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Directory ServicesProvide the integration missing when filesystem is removedLDAP basedIntegration with Microsoft Active Directory

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Security ServicesIntegration/co-existence of public and secret key systemsUnsolved public key infrastructure issues

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Andrew Today and BeyondEducational environments differ in interesting waysRapid changesInnovative Integration with focused development

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Security Greater (recognized) internal threats Conflicting goals of collaboration vs. privacy

Less rigid hierarchy A person may be staff, student and faculty

Nomadic behavior A person may use multiple machines, some

they do not have administrative control over Some machines may be shared among

many diverse individuals

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Rapid ChangesLocal solutions can not keep up with the featuresOn going support of legacy systems is expensivePorting local solutions to new environments is expensiveOther groups and individuals on campus adopt commercial systems

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Seek vendor solutionsCooperate with vendorsSeek public solutionsCooperate to enhance public solutionsCooperate to develop new technologies and get those technologies on standards tracksDo it ourselves

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Scalability ModelsMonolithic Have a single highly

redundant system Simplifies

administration Single point of

failure

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Scalability ModelsDistributed - server dependent Multiple servers provide

redundancy, better performance

Burden on users to know about the servers

Higher administrative cost in managing multiple machines

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Scalability ModelsDistributed – server independent Actual server(s) hidden

by a layer of indirection Additional client/server

support

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Integration ProblemsScale The market is still primarily producing work

group solutions Can’t scale to a single computing community

of over 10,000 users and over 6,000 networked machines

Interoperability Many solutions do not work together Many solutions do not exist across

architectures

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Focusing DevelopmentFocus on key areas and do proof of concept development (and maybe deployment)Force issues in standards bodies (IETF, etc.)Leverage development efforts with vendors to influence directions

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Unique Users

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ReferencesHttp://andrew2.andrew.cmu.eduKhanna, Raman, ed. “Managing Distributed Systems” and “System Management Strategies” in Distributed Computing: Implementation and Management Strategies. Prentice Hall. 1994.Khanna, Raman, ed. “Personal Computer Integration in the Andrew System” in Integrating Personal Computers in a Distributed Client-Server Environment. Prentice Hall, 1995.