The Common Execution Architecture and Grid Computing Guy Rixon Presentation to RadioNet workshop Oxford, December 2006

Pattern: in-grid processing Application with UI Data processing Data processing Data selection Good bandwidth Limited bandwidth Archive Libraries of applications

Implementation: CEA app servers AstroGrid app-server CEC Application with UI Data-selection service “Wrapped” application; no UI AstroGrid Registry Publish app details as well as service details Look up app details Data

Three ways to wrap an app > astrogrid-cea-server > astrogrid-cea-commandline > astrogrid-cea-http Java wrapper class (optional) wrapper shell-script Your app in Java Your app as executable Your app on the web

Wrapping a CL application (1) Data centre > astrogrid-cea-commandline > app-description.xml > registry-template.xml > apache-tomcat > astrogrid-registry > environment entry > environment entry > environment entry > environment entry

Wrapping a CL application (2) > astrogrid-cea-commandline > astrogrid-registry > app-description.xml > registry-template.xml > environment entry app registration service registration + > environment entry > environment entry > environment entry > astrogrid-registry app registration service registration + Arrows indicate data flow

Running a CL application (1) > Astro Runtime UI of choice > astrogrid-registry 1: Look up application 2: Find service offering application Arrows show command flow UI form for app 3:create UI

Running a CL app (2) > Astro Runtime UI of choice > astrogrid-cea-commandline Arrows show command flow > “tool” document

Running a CL app (3) > astrogrid-cea-commandline URL to data Arrows indicate data flow Data > Input > Input > Input > Output > Output > Output Parameter value Parameter value Parameter value AstroGrid FileStore AstroGrid FileManager AstroGrid FileStore AstroGrid FileManager AstroGrid FileStore AstroGrid FileManager AstroGrid FileStore AstroGrid FileManager URL to data Data Local “sandbox”; app runs in sub-process with local files

Dude, where's my Grid? Hmm...too much local execution. Can we put it on the Grid?

CEA scaled up to a Grid (future) > astrogrid-cea-commandline URL to data Data AstroGrid FileStore AstroGrid FileManager AstroGrid FileStore AstroGrid FileManager AstroGrid FileStore AstroGrid FileManager AstroGrid FileStore AstroGrid FileManager URL to data Data Grid “sandbox”; app runs in sub- process with local files > Input > Input > Input > Output > Output > Output Parameter value Parameter value Parameter value Grid adaptor A Grid Delegation to a Grid Assignment to a compute element

Workshop exercises ● Objective: use ParselTounge within wrapped application within CEA app-server ● Intermediate step: wrap a simpler, example application ● Do one of two starter exercises before doing the ParselTounge exercise

Example 1: trivial Python app ● Simple one-page app – Calculates observed angular diameter at cosmological distances ● Learning exercise – same technique as wrapping bigger Python programmes ● workshop/examples/angularDiameter/

Example 2: tcopy from STILTS ● Wraps one function from Starlink's STILTS package: copying a table with format conversion ● Real app; potentially useful. (But STILTS is already wrapped and available.) ● workshop/examples/stilts/

app-description.xml ● XML file, using schema ● Declares aspects of app to app-server: – Formal name (identities app in registry) – Parameters, including for each ● Name ● Description ● Data-type ● Presentation on app's command line – Grouping of parameters into interfaces ● Example: Full application-description ● > app-description.xml