using cyberaide javascript to develop ajax based grid apps – a tutorial for grid app developers

Using Cyberaide JavaScript to develop Ajax based Grid Apps – A Tutorial for

Grid App Developers

Gregor von LaszewskiFugang WangJun 22, 2009

Agenda

Prerequisite to use the framework for your development

How to use the JavaScript API to interact with Grid

Authentication; job/workflow submission and status monitor; file transfer,

etc.

Mashup with other useful resources

Expand the mediator functionality while reusing the architecture

Prerequisite to use the framework for your development How to use the JavaScript API to interact with Grid


etc.



Please setup the three-tier cyberaide JavaScript framework first. A full instruction can be found at:

http://cyberaide.googlecode.com/svn/trunk/project/javascript/README.txt

The framework has Mediator service, Agent, and a web client[1]. Your app will be a web client while based on the Cyberaide JavaScript API.

[1] von Laszewski, G., Wang, F., Younge, A., He, X., Guo, Z., & Pierce, M. (2008). Cyberaide JavaScript: A JavaScript Commodity Grid Kit. Paper presented at the GCE08 at SC08, Austin, TX

Agenda



Authentication; job/workflow submission and status monitor; file

transfer, etc. Mashup with other useful resources


The usage of the Cyberaide JavaScript toolkit is shown through code snipes. The code itself is not runnable. Please setup the three-tier cyberaide JavaScript framework first as mentioned previously, and put the code snipes into your code where you want to fulfill the functionality.

An Ajax Teragrid portal example developed based on the architecture and JavaScript API

// construct authenticator object for authentication using myproxy// make sure to use the attributes keys specified here.var auth = org.cyberaide.js.jsAuthenticator(url);auth.setAttribute("host", "myproxy.teragrid.org");auth.setAttribute("port", 7512);auth.setAttribute("user", ’YOURTGUSERNAME');auth.setAttribute("password", ’YOURPASSWORD');// currently only 'myproxy' is supportedauth.setProvider("myproxy");

How to authenticate through the Cyberaidejs?

// construct cyberaidejs object by pointing to the Agent service's url// Your call through the JavaScript API will be conducted to this Web service// Refer to the installation instruction for the ‘url’.

var url = "../axis2/services/AgentService”; //If you followed each step, the url should be like this

var cyberaidejs = new org.cyberaide.js.jsUtil(url);

// authenticationcyberaidejs.authenticate(auth, authResponse);

// authResponse is the callback function handler

/* * the authenticate callback function */function authResponse(ret) { if(ret){ //authenticated successfully! //put your code here } else{ //authentication failed //put your code here }}

// define the job object//make sure to use the attributes keys specified here.var execObj = new org.cyberaide.js.jsExecutable();execObj.setAttribute("cmd", "/bin/ls");execObj.setAttribute("arg", "-l");execObj.setAttribute("rHost", 'REMOTEHOST');execObj.setAttribute("stdout", "lsoutput");execObj.setAttribute("provider", "GT4");

// construct cyberaidejs object by pointing to the agent service's urlvar cyberaidejs = new org.cyberaide.js.jsUtil(url);

How to submit a job to remote machine to execute?

// construct a remote job through the executable objectvar strProj = cyberaidejs.constructRemoteJob(execObj);

// submit the job by specifying constructed job specification, callback function.// you must be in authenticated status and in a valid session.cyberaidejs.submit(strProj, submitResponse);

// submitResponse is the callback function handler

/* * callback function of submission */function submitResponse(ret) { if(ret > 0){ //job submitted and job id returned. //your job id is 'ret', in Number format //do something here.

} else { //job submission failed. //do something here. }}

// Construct your Karajan workflow// var strProj = ...;// assign the Karajan workflow to this string and submit it.// you must be in authenticated status and in a valid session.cyberaidejs.submit(strProj, submitResponse, null);

// Construct cyberaidejs object by pointing to the agent service's urlvar cyberaidejs = new org.cyberaide.js.jsUtil(url);

// callback function could be the same as in job submission

How to submit a workflow (in Karajan format)?


// Invoke the list function//do this only after you have been authenticated and in a valid session.cyberaidejs.list(listResponse);

// listResponse is the callback function handler

How to query job/workflow list that user submitted?

/* * call back for submitted jobs listing */function listResponse(jsonRet){ if(jsonRet != null){ var jsonRetObj = eval("(" + jsonRet + ")"); var wfids = jsonRetObj.wfids; var numIds = wfids.length; //now you got the jobs list with 'numIds' items in an array wfids //do something here. }}

// the jsonRet is in JSON format {"wfids": String[]}


// and then query the status with its id// do this only after you have submitted some job/workflow cyberaidejs.statusQuery(wfid, statusQueryResponse);

// statusQueryResponse is the callback function handler

How to query job/workflow execution status?

/* * callback function of status query, to display the status info */function statusQueryResponse(jsonRet){ if(jsonRet != null){ var jsonRetObj = eval("(" + jsonRet + ")") var wfid = jsonRetObj.wfid; var status = jsonRetObj.status; //now you get the workflowid and its current status, in a 'Number' format, //representing jobs finished so far in the workflow. //do something here. }}

// the jsonRet is in JSON format {"wfid":String,"status":String}


// call the queryOutput function// do this only after you have been authenticated and in a valid session.cyberaidejs.queryOutput(wfid, queryOutputResponse);

// statusQueryResponse is the callback function handler

How to query output fileNAME of a job/workflow?

/* * display the returned output file names appropriately and add content retrieve links */function queryOutputResponse(jsonRet){ if(jsonRet != null){ var jsonRetObj = eval("(" + jsonRet + ")"); var wfid = jsonRetObj.wfid; var resultFiles = jsonRetObj.resultFiles; //the result output file names for job/workflow with id 'wfid' have been stored //into array 'resultFiles' //you can display the filenames or get the REAL output through getOutput() method. } return false;}

// the jsonRet is in JSON format {"wfid":String,"outputFiles":String[]}


// call the getOutput function// do this only after you have been authenticated and in a valid session.// wfid and filename specified job/workflow id and (one of) its output filename obtained through queryOutputcyberaidejs.getOutput(wfid, filename, getOutputResponse);

// getOutputResponse is the callback function handler

How to get a specific output from a job/workflow execution?

/* * processing the returned output */function getOutputResponse(jsonRet){ if(jsonRet != null){ var jsonRetObj = eval("(" + jsonRet + ")"); var wfid = jsonRetObj.wfid; var filename = jsonRetObj.filename; var content = jsonRetObj.content; //now you have got the output content of an output file for the job 'wfid' //your code for further processing goes herer.. }}

// the jsonRet is in JSON format {"wfid":String,"outputfilename":String,"output":String}

How to do file transfer through cyberaidejs?

// construct cyberaidejs object if not done yetvar cyberaidejs = new org.cyberaide.js.jsUtil(url);

// Invoke transfer function// source and dest are all URI per gridftp supported format, like file://PATH, gsiftp://HOST:PORT/PATH/TO/FILE// when using file:///~, it represents the user's remote home directory at where the mediator service resides,// using gsiftp://HOST:PORT/PATH/TO/FILE to point to the location at other remote resources like those from Teragrid// do this only after you have been successfully authenticated and is in valid sessioncyberaidejs.transfer(source, dest, transferResponse);

/* * the transfer callback function */function transferResponse(ret, updateloc) { if(!ret){ //Transfered successfully! //Your code goes here

} else{ //Transfer failed! //Your code goes here }}




etc.

Mashup with other useful resources Expand the mediator functionality while reusing the architecture

You can develop sophisticated Grid app/portal/scientific gateway in Ajax style

based on the JavaScript API. But you also can reuse the architecture and

mashup useful resources in either server side or client side.

Mashup in client side. You could integrate resources from other sites in your

JavaScript/DHTML code, while using the framework and API.

Mashup in server side. Due to the Cross-site restriction of JavaScript,

sometime you have to mashup resources/services in server side. You could

integrate them into the Agent service java code, or using other server side

tools to process the resources/services and access them through your client

JavaScript.




etc.



You also can expand the functionalities of the Mediator service, while using

the same architecture. In this way the expanded functionalities could be easily

accessed by a web client through the framework. The possible functionalities

could include supporting other Grid middle ware, supporting other HPC

means like CUDA, and cloud computing related technologies like VM

management & Amazon EC2. Some of these activities are being conducted or

planned to be researched in our lab.

http://cyberaide.org/projects/cyberaide/cyberaide-javascript

[email protected]

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using cyberaide javascript to develop ajax based grid apps – a tutorial for grid app developers

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