Extending JICOS to nonJava Clients and Services

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Extending JICOS to non-Java Clients and Services

• Andy Pippin
• Masters Thesis Defense
• April 12th, 2005

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Agenda

• Introduction to Jicos
• Extending Jicos to non-Java clients
• Extending Jicos to non-Java services
• Administering a Jicos system

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What is Jicos?Introduction to Jicos

• Jicos is a Java-centric network computing
  service.
• Where did Jicos come from?
• SuperWeb, Javelin, CX
• What computations are suited to Jicos?
• Embarrassingly parallel computations
• Divide conquer computations
• Branch bound (e.g. traveling salesman)

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Fibonacci A Jicos hello worldIntroduction to
Jicos

• public Object execute ( Environment environment )
• if ( n lt 2 )
• return new Integer( 1 )
• else
• compute( new F( n - 1 ) )
• compute( new F( n - 2 ) )
• return( new AddInteger() )

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Benefits of JavaIntroduction to Jicos

• Platform independent
• Java classes run relatively securely
• Code mobility

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A Jicos SystemIntroduction to Jicos
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Benefits of JicosIntroduction to Jicos

• Ease of application development
• Tolerates faulty compute servers
• Supports adaptive parallelism

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Limitations of JicosIntroduction to Jicos

• Java centricity
• Clients must be written in Java
• Tasks (hosted computations) must be written in
  Java.
• The human time to start stop a Jicos system is
  proportional to the number of machines in it.

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Extending JicosIntroduction to Jicos

• Non-Java clients can use Jicos tasks
• For example, a web browser
• Jicos tasks can use non-Java services
• For example, a Matlab engine
• Administration start-up tear-down
• AdminTool framework

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Agenda

• Introduction to Jicos
• Extending Jicos to non-Java clients
• Extending Jicos to non-Java services
• Administering a Jicos system

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A Typical Jicos ClientExternal Client

• public static void main( String args )
• // get a reference to a HSP (Host Service
  Provider)
• HspAgent agent new HspAgent( args0 )
• Client2Hsp hsp agent.getClient2Hsp()
• // login
• Environment environment new Environment(
  null, null )
• hsp.login( environment )
• // compute
• int number Integer.parseInt( args1 )
• Task task new F( number )
• Integer value (Integer) hsp.compute( task
  )
• // logout
• Invoice invoice hsp.logout()

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Non-Java Clients
Oh... Okay!
???
RMI
XML
XML
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How It All WorksExternal Client
Task over RMI
!
!
XML over HTTP
???
!
Answer over RMI
Response over HTTP
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Incoming DataExternal Client

• XML
• The Collector uses XPath
• The XML Path Language (W3C)
• Typically used in XML transforms (XSLT)
• An HTTP ltFORMgt can be converted to XML

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Example Input FibonacciExternal Client

• HTTP header
• POST /ExternalRequest HTTP/1.1
• header
• header
• Content-Length 321
• /ExternalRequest_at_taskNamejicos.examples.external.
  fibonacci.Fibonacci/ExternalRequest/Fibonacci/n1
  0
• HTTP ? XML
• ltExternalRequest taskNamejicos.examples.exte
  rnal.fibonacci.Fibonaccigt
• ltFibonaccigt
• ltngt10lt/ngt
• lt/Fibonaccigt
• lt/ExternalRequestgt

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Collector/External ProcessorExternal Client

• The Collector extracts items from the input
• Task class name
• Response type
• Passes the rest of the input to the External
  Request Processor (ERP).

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Converting the XML to JavaExternal Client

• XML
• ltExternalRequest taskNamejicos.examples.exte
  rnal.fibonacci.Fibonaccigt
• ltFibonaccigt
• ltngt10lt/ngt
• lt/Fibonaccigt
• lt/ExternalRequestgt
• Fibonacci.fromXml()
• Uses XPath queries
• this.n externalRequest.getValue(
• /ExternalRequest/Fibonacci/n )

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Submitting the TaskExternal Client
Task over RMI
???
!
!
Answer over RMI
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Converting the Jicos AnswerExternal Client

• Convert the Java Result to XML
• createResult()
• Should be able to convert XML ? HTML
• Convert the XML Result for the Client
• Uses XSLT stylesheet (if available)
• Calls toHtmlString() (if appropriate)
• Just send raw XML (lt? lt )

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Sending the XML AnswerExternal Client
!
!
Response over HTTP
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Example Fibonacci ResultExternal Client

• Convert response
• this.FofN resultXml.getValue(
  /ExternalResult/Fibonacci/FofN )
• String xml Fib( this.n )
  this.FofN \r\n
• On browser
• Fib( 10 ) 89

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Sending the ResponseExternal Client

• When to send the response back?
• Short computations wait for result
• Dont send a response until there is an answer
• Browser will sit and spin
• Long computations poll
• Immediately send a response with a result id
• Check back for the answer

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Required FunctionsExternal Client

• Implement default (no-arg) constructor
• Implement XmlConverter
• fromXml() // XML ? Java
• createShared() // XML ? Shared Object
• createInput() // XML ? Input Object
• createResult() // Result ? XML
• getStyleSheet() // XSLT transformation
• toHtmlString() // (XML) Result ? HTML

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Agenda

• Introduction to Jicos
• Extending Jicos to non-Java clients
• Extending Jicos to non-Java services
• Administering a Jicos system

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Modifications to JicosExternal Services

• Jicos any Task can be performed on any Host
• However, a Task using an External (non-Java)
  Service may not be able to run on any Host
• Licensing issues
• Partitioned information
• Required a modification to Jicos
• Route Task to a proper Host

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How it All WorksExternal Services
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Class HierarchyExternal Services

• External Services class hierarchy
• TaskExternal extends Task
• HostExternal extends Host
• TaskServerExternal extends
• Service specific classes extend those classes
• TaskMatlab extends TaskExternal
• H ostMatlab extends HostExternal
• TaskServerMatlab extends TaskServerExternal
• Jicos then routes Tasks of a certain class
  towards Hosts of that class, where the task can
  access the service.

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HostExternalExternal Services

• Provides the interaction between the Task and the
  external service
• Exposes services functions
• Controls service

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Non-Java API JNIExternal Services

• Java Native Interface
• Requires a loadable library (.so/.dll/.dynlib)
• Invokes native code just like Java code
• JNI provides functions to perform object creation
  and modification (e.g. arrays)
• Java can have a segmentation fault? ?

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Task FlowExternal Services
Task
Task
MTask
Task
MTask
Task
MTask
Task
Task
MTask
Task
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Example Using MatlabExternal Services

• The HostMatlab keeps a reference to the Matlab
  engine.
• TaskMatlab uses this reference to perform a
  Matlab computation
• Exposed functions
• putVariable( name, value )
• evalString( matlabCommand )
• getVariable( name )

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Agenda

• Introduction to Jicos
• Extending Jicos to non-Java clients
• Extending Jicos to non-Java services
• Administering a Jicos system

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Starting a Jicos SystemAdminTool

• Previously
• Log in to remote machine, start a HSP
• Log in to another machine, start a TaskServer
• Log in to another machine, start a Host
• Log in to another machine, start a Host
• Log in to another machine, start a Host
• Log in to another machine, start a Host
• Log in to another machine, start a Host
• Finally, start a client.

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ChameleonAdminTool

• Starting a system now
• Administrator installs Chameleon to start up as a
  system daemon
• User starts a Console with a starting
  configuration
• Take a sip of your favorite beverage
• All requested Jicos components are started
• Done

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Example Start Configuration FileAdminTool

• lt?xml version1.0gt
• ltJicosgt
• ltMachinesgt
• ltMachine namelinux09
  addrlinux09.engr.ucsb.edu /gt
• ltGroup namecsilgt
• ltMachine namewacko
  addrwacko.cs.ucsb.edu/gt
• ltMachine namedilbert
  addr128.111.43.60/gt
• lt/Groupgt
• lt/Machinesgt
• ltHsp nameFibonacci groupcsil hosts0gt
• ltTaskServer groupcsil hosts0gt
• ltHost groupcsilgt
• ltHost groupcsilgt
• ltHost machinelinux09
  exttypematlabgt
• lt/TaskServergt
• lt/Hspgt
• lt/Jicosgt

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TuiConsoleAdminTool

• Admin framework is also interactive
• TuiConsole (Text User Interface)
• Start/stop components
• ping services
• Misc development tools (RMI registry)
• GuiConsole
• Future Work

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Summary

• Extending to non-Java clients
• ? XML?Java?Jicos?Java?XML ?
• Extending to non-Java services
• Java Native Interface
• Controlling a Jicos system (AdminTool)
• Chameleon / Console / TuiConsole

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Dedicated to my Assistant (Piglet)
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Supporting Information

• HTML ltFORMgt

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Using HTMLs ltFORMgtExternal Clients

• ltHTMLgt
• ltBODYgt
• ltFORM ACTIONhttp//localhost8181/ExternalReques
  t
• METHODpostgt
• ltINPUT TYPEhidden
• NAME/ExternalRequest_at_taskName
• VALUEjicos.examples.external.fibonacci.F
  ibonaccigt
• lt/INPUTgt
• Please enter the Fibonacci Number
• ltINPUT TYPEtext SIZE5
• NAME/ExternalRequest/Fibonacci/ngt
• lt/INPUTgt
• ltINPUT TYPEsubmitgtlt/INPUTgt
• ltINPUT TYPEresetgtlt/INPUTgt
• lt/FORMgt
• lt/HTMLgt