GridNexus © 2009 Clayton S. Ferner 1 GridNexus UNCW GUI for Workflow Management Clayton Ferner

GridNexus © 2009 Clayton S. Ferner 2 Outline Basics  Getting Started  Simple workflows  A little bit about JXPL  Libraries  Composites  Ports  User Library  Splitting Relations Examples  Prog  Cond  Defun  Recursion  Iteration Services  Web Services  Grid Services

GridNexus © 2009 Clayton S. Ferner 3 What is GridNexus GridNexus is a GUI that allows the user to create/edit/run workflows Based on Ptolemy II Ptolemy provides the GUI and workflow features. We have extended it to provide the functionality we want (JXPL and GridServices) Release 2.0 download available

GridNexus © 2009 Clayton S. Ferner 4 Getting Started Download from Follow instructions for installation Run GridNexus Choose File->New - >Workflow

GridNexus © 2009 Clayton S. Ferner 5 Getting Started The main frame on the right is the palette for building workflows The upper left frame provides the library of modules The lower left frame is a thumbnail of the entire workflow

GridNexus © 2009 Clayton S. Ferner 6 The Basics Sources produce data without needing input Sinks consume data but may have side effects (such as displaying results) All workflows must start with sources and end with sinks

GridNexus © 2009 Clayton S. Ferner 7 Simple Example 1 Click and drag the “Const” source to the workflow. Click and drag the “JxplDisplay” sink to the workflow

GridNexus © 2009 Clayton S. Ferner 8 Simple Example 1 Double-click on the Const module Change its value to 10 Click commit The new value is shown on the icon

GridNexus © 2009 Clayton S. Ferner 9 Simple Example 1 Input ports are on the left-hand side and output ports are on the right-hand side of each module Click and drag from the output port of the Const module to the JxplDisplay

GridNexus © 2009 Clayton S. Ferner 10 Simple Example 1 A link (or relation) is created between the two modules The output of Const is consumed by the JxplDisplay

GridNexus © 2009 Clayton S. Ferner 11 Simple Example 1 Click on the run button ( ) The JxplDisplay evaluates the input and produces a display window to show the results.

GridNexus © 2009 Clayton S. Ferner 12 Simple Example 2 Transformers are modules that take input, transform it, and produce new output This example computes the express: (23 + 6) ∙ -2

GridNexus © 2009 Clayton S. Ferner 13 Simple Example 2 The Multiplication module takes the result of the addition (its first input) and multiplies that by -2 (its second input) The result is consumed by JxplDisplay

GridNexus © 2009 Clayton S. Ferner 14 What's Going On? The workflow is not actually performing the operations. Instead it is creating a script (JXPL) that, when executed, produces the result The JxplDisplay is evaluating the script and displaying the results

GridNexus © 2009 Clayton S. Ferner 15 What's Going On? Double-click on the JxplDisplay and deselect the “Evaluate Jxpl” as well as the “Output in Text” parameters The “Evaluate Jxpl” parameter tells JxplDisplay whether or not to evaluate the script that is generated

GridNexus © 2009 Clayton S. Ferner 16 What's Going On? Now when we run it, we see the actual script that is produced by the workflow The script is written in XML using a language developed at UNCW called JXPL

GridNexus © 2009 Clayton S. Ferner 17 A Little Bit about JXPL JXPL is based on LISP The corresponding LISP to the JXPL on the right looks like: (* (+ 23 6) -2) <jxpl:list xmlns:jxpl="

GridNexus © 2009 Clayton S. Ferner 18 A Little Bit about JXPL Why?  XML is used to transport data between web/grid services  XML opening/closing tags LISP opening/closing parentheses  Everything is either an atom or a list (functions, Data Structures) <jxpl:list xmlns:jxpl="

GridNexus © 2009 Clayton S. Ferner 19 A Little Bit about JXPL The transformer library is LISP-centric More on JXPL later See

GridNexus © 2009 Clayton S. Ferner 20 What's Going On? The “Output in Text” parameter tells JxplDisplay to translate the resulting Jxpl into something more pleasant to view versus

GridNexus © 2009 Clayton S. Ferner 21 Transformer Library

GridNexus © 2009 Clayton S. Ferner 22 Sources Const – Integers and Decimals Decimal – Integers and Decimals Symbol – Variables (use quotes 1 ) Rational – Fractions (use quotes 1 ) 1 Quotes are needed to prevent Ptolemy from evaluating the expressions before the JXPL evaluator gets a chance to see them.

GridNexus © 2009 Clayton S. Ferner 23 Examples Choose File->Open and select the Examples folder There are many examples that don't need explanation. Just give 'em a try! Others will be discussed later

GridNexus © 2009 Clayton S. Ferner 24 Composites A composite is a means to abstract a workflow into a single module From the “utilities” folder, drag the “Composite actor” to the workflow Right-click->Look Inside

GridNexus © 2009 Clayton S. Ferner 25 Composites This opens a new window in which we create the workflow that defines the new module First we need ports  Single ports take or produce single values  Multi ports take or produce multiple values

GridNexus © 2009 Clayton S. Ferner 26 Composites Toolbar icons  Single input port  Single output port  Multi input port  Multi output port Notice how the ports show up on the composite actor module

GridNexus © 2009 Clayton S. Ferner 27 Composites Right-click on a port and choose “Customize Name” Enter name for the Icon Selecting “Show name” causes the label to show up on the composite module

GridNexus © 2009 Clayton S. Ferner 28 Composites To make a relation from a port, hold down the shift key and click and drag Since a multiport can produce more than one value, we need to specify a width for the relation involving a multiport

GridNexus © 2009 Clayton S. Ferner 29 Composites For a multiport, double-click on the relation (the link from the multiport) and choose Add The name should be “width” with a default of zero

GridNexus © 2009 Clayton S. Ferner 30 Composites Close the composite window We can name the composite by right- clicking and choosing “Customize Name” Now we are ready to use it

GridNexus © 2009 Clayton S. Ferner 31 User Library To save a module in the user library, right- click on it and choose Save Actor in Library The user library is stored in.GridNexus/user\ library.xml in your home directory

GridNexus © 2009 Clayton S. Ferner 32 User Library Actually, it isn't saved. It opens the user library with the new module You still have to choose File->Save to save the user library.

GridNexus © 2009 Clayton S. Ferner 33 User Library Alternatively, you can save an entire workflow in the library Choose Graph->Save in Library. The workflow is saved in the library as a new composite named with the filename

GridNexus © 2009 Clayton S. Ferner 34 Splitting Relations Sometime, you want the results of a module to be used as input to more than one other modules SetQ module assigns a value to a symbol The symbol X is input to both SetQ and Addition modules file: examples/setq.xml

GridNexus © 2009 Clayton S. Ferner 35 Splitting Relations To create a new splitter, click the button Link the output of Symbol to the splitter Hold down the shift key and click and drag the splitter to the input port of SetQ. file: examples/setq.xml

GridNexus © 2009 Clayton S. Ferner 36 Splitting Relations Repeat for Addition (Sometimes, the use of a splitter can complicate the workflow due to crossing relations. It is not necessary to split the output from Symbol “x”. Alternatively, we can simply make a duplicate Symbol “x”.) file: examples/setq.xml

GridNexus © 2009 Clayton S. Ferner 37 The Prog The Prog (short for Program) module allows one to execute separate workflows where it is not desirable to have a relationship between them (i.e. synchro- nization rather than data dependency) file: examples/prog.xml

GridNexus © 2009 Clayton S. Ferner 38 The Prog The Prog primitive evaluates each of its inputs in turn It returns the results of the last one evaluated (in this case this case it returns 2x). file: examples/prog.xml

GridNexus © 2009 Clayton S. Ferner 39 Multi Ports One difficulty with multi ports is the order in which its inputs are evaluated is not evident from the GUI Which of the sub- workflows is executed first? Are you sure? file: examples/prog.xml

GridNexus © 2009 Clayton S. Ferner 40 Multi Ports If one deletes the SetQ -> Prog relation, then puts it back, the result is that Prog will evaluation the Multiplication before the SetQ – Not good! Multi Ports are best for commutative operations like Addition, but not like Prog. However, the alternative to using a multi port for Prog is to have a fixed number of single ports. When it doubt, delete all relations to a multi port and redo them

GridNexus © 2009 Clayton S. Ferner 41 Cond Cond is the branching mechanism in LISP A Cond List Element takes a boolean expression and the results if the boolean is true file: examples/cond.xml

GridNexus © 2009 Clayton S. Ferner 42 Cond The Cond finds the first Cond List Element whose boolean is true and returns its result Be careful of the order in which the Elements are linked to the multi- input port file: examples/cond.xml

GridNexus © 2009 Clayton S. Ferner 43 Cond An “else” clause should the last List Element with a boolean of “true” The last List Element will be returned if all others are false file: examples/cond.xml

GridNexus © 2009 Clayton S. Ferner 44 Defun Defun defines a new primitive (function) It takes a symbol as the function name, a set of symbols as parameters, and a workflow as the body file: examples/defun.xml

GridNexus © 2009 Clayton S. Ferner 45 Defun Once it is defined, we can call it using the Primitive module file: examples/defun.xml

GridNexus © 2009 Clayton S. Ferner 46 Recursion Of course, we have to do factorial! This workflow first defines factorial (using a composite to keep the workflow clean) then uses it to compute 10!. file: examples/factorial.xml

GridNexus © 2009 Clayton S. Ferner 47 Recursion Inside Factorial:  If N <= 1 return 1  Else return N(N-1)! file: examples/factorial.xml

GridNexus © 2009 Clayton S. Ferner 48 Recursion Inside N(N-1)!:  Notice the recursive call to factorial  Remember that this generates a script that will be executed later file: examples/factorial.xml

GridNexus © 2009 Clayton S. Ferner 49 Iteration Arguments:  loop variable  initial value  step size (loop variable += step size)  termination boolean (true => terminate)  loop body file: examples/do.xml

GridNexus © 2009 Clayton S. Ferner 50 Web Services The WS Client module can serve as a general purpose client for a Web Service given the WSDL Double-click on the module and enter the URL of the WSDL

GridNexus © 2009 Clayton S. Ferner 51 Web Services The icon is set with the name of the service Ports are added for the methods of the service Only the method with input will be called file: examples/wsclient.xml

GridNexus © 2009 Clayton S. Ferner 52 Proxy You will need a proxy before you can work with a Grid Three options: 1. Download your certificate and private key to the local machine and use grid-proxy-init (not secure if the local machine is shared or a lab computer) 2. Log into a server, obtain a proxy, and download the proxy (secure, but requires extra steps) 3. Use MyProxyLogon (preferred)

GridNexus © 2009 Clayton S. Ferner 53 MyProxyLogon Choose Start->All Programs-> GridNexus->Utils->Proxy- >MyProxyLogon The first time (only) you aquire a proxy, select the “Write trust roots to …”

GridNexus © 2009 Clayton S. Ferner 54 Grid Services First, you need the jars of the Grid Service. E.g.: edu_uncw_math_mathservice.jar edu_uncw_math_mathservice_stubs.jar These are found in $GLOBUS_LOCATION/lib on the server Put in $GRIDNEXUS_HOME/lib (Linux) or C:\Program Files\GridNexus2.xx\lib (Windows) You will need to restart GridNexus so that it will reset the classpath

GridNexus © 2009 Clayton S. Ferner 55 Grid Services The WSRF Client module can serve as a general purpose client for a Grid Service given the following:  URL of the Factory  Class name of the Addressing Locator class

GridNexus © 2009 Clayton S. Ferner 56 Grid Services The class name of the Addressing Locator class can be found from the stubs jar From this example it would be: edu.uncw.math.service.M athServiceAddressingLoc ator $ jar tf edu_uncw_math_mathservice_stubs.jar... edu/uncw/math/Create.class edu/uncw/math/GetValue.class edu/uncw/math/MathPortType.class edu/uncw/math/MathResourceProperties.class edu/uncw/math/bindings/MathPortTypeSOAPBindingStub.class edu/uncw/math/service/MathService.class edu/uncw/math/service/MathServiceAddressing.class edu/uncw/math/service/MathServiceAddressingLocator.class edu/uncw/math/service/MathServiceLocator.class

GridNexus © 2009 Clayton S. Ferner 57 Grid Services The icon is set with the name of the service Ports are added for the methods of the service An EndpointReference (epr) can be provided, which will override the Factory URL

GridNexus © 2009 Clayton S. Ferner 58 Grid Services In order to call a method that takes no parameters, pass a value of “void” (including double quotes) For example, the “create” method takes no parameters The “create” method creates a service instance and returns the epr file: examples/wsrf_client/ MathService2Create.xml

GridNexus © 2009 Clayton S. Ferner 59 Grid Services What does this workflow do?

GridNexus © 2009 Clayton S. Ferner 60 Grid Services The destroy method also does not take a parameter After the destroy, the service instance no longer exists and the epr file is no longer of use file: examples/wsrf_client/ MathService2Destroy.xml

GridNexus © 2009 Clayton S. Ferner 61 User Library Don't forget to save these actors in the user library now that they are configured Just click and drag these to the palette and they're ready for use

GridNexus © 2009 Clayton S. Ferner 62 GridExec (GRAM Client) The GridExec module will run an application on a service using GRAM The Factory Contact is the URL of the server If a Simple command is given, GridExec will construct a JDD file to run it /bin/echo hello world ${GLOBUS_USER_HOME}/stdout ${GLOBUS_USER_HOME}/stderr

GridNexus © 2009 Clayton S. Ferner 63 GridExec (GRAM Client) One can also provide the JDD in a file Choose File->New- >TextEditor to create the JDD file Save as text and not XML /bin/echo hello world /${GLOBUS_USER_HOME}/stdout /${GLOBUS_USER_HOME}/stderr

GridNexus © 2009 Clayton S. Ferner 64 GridExec (GRAM Client) The Factory Type indicates a scheduler, such as LSF, SGE, Condor, PBS, etc. (default is Fork).

GridNexus © 2009 Clayton S. Ferner 65 GridExec (GRAM Client) The Input and Output Files can be used to perform file staging This only works if you can gridFTP files from the server to your local machine (ie. does not work on Windows) file:///home/cferner/stdout gsiftp://gridprof1.bear.uncw.edu/home/ cferner/stdout

GridNexus © 2009 Clayton S. Ferner 66 File Transfer via GridFTP The first argument is the source and the second is the destination Note that, unlike globus-url-copy, the user’s home directory is NOT specified This is because ${GLOBUS_USER_HOME} is the implied directory Furthermore, both machines are remote

GridNexus © 2009 Clayton S. Ferner 67 File Transfer via SFTP To transfer files with sftp, the local machine and server must be setup to use public/private key authentication (see installation guide for details)

GridNexus © 2009 Clayton S. Ferner 68 File Transfer via SFTP Note that Windows directories should use forward slash (/) instead of backslash (\) You can use backslash, but you will need double backslashes (\\) for every backslash.

GridNexus © 2009 Clayton S. Ferner 69 File Transfer via SFTP With sftp, one can accomplish file staging (albeit manual)

GridNexus © 2009 Clayton S. Ferner 70 GridNexus UNCW GUI for Workflow Management Clayton Ferner