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Access Grid Workshop – APAC ‘05 Network Services Susanne Lefvert lefvert@mcs.anl.gov University of Chicago
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Access Grid Workshop – APAC ‘05 Outline Introduction Limitations of Current Architecture Enhanced Architecture Network Services Example: Debug Service Exercises
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Access Grid Workshop – APAC ‘05 Introduction Network Enable users to seamlessly participate in AG meetings. Middleware Stream processing
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Access Grid Workshop – APAC ‘05 Heterogeneous Environment Devices –VIC, RAT, Quicktime, Realplayer, H.323 clients… Formats –Different encodings, sample rate … Network –Available multicast, bandwidth … Preferences –Surgery: Want high resolution video –Presentation: Want lower resolution video
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Access Grid Workshop – APAC ‘05 Class Diagram VenueClient AGNodeService AGServiceManager AGService AGServiceManager
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Access Grid Workshop – APAC ‘05 Capability Role –CONSUMER –PRODUCER Type –AUDIO –VIDEO –TEXT Not Sufficient
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Access Grid Workshop – APAC ‘05 Sequence Diagram Mismatch can not be resolved
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Access Grid Workshop – APAC ‘05 Limitations of Current Architecture 1.Service capability description limited 2.User preferences do not exist 3.No resolution to capability mismatch
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Access Grid Workshop – APAC ‘05 Enhanced Capabilities Schema including: 1.Service capability Device (sample rate, sample size, sample format…) Encoding (name, quality, bit rate, size…) RTP (payload type, profile…) 2.Node capability Available bandwidth, multicast, firewall… 3.User preferences Preferred quality, bandwidth…
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Access Grid Workshop – APAC ‘05 VenueClient AGNodeService AGServiceManager AGService AGServiceManager Capability Service Capability Node Capability User Preferences
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Access Grid Workshop – APAC ‘05 Sequence Diagram
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Access Grid Workshop – APAC ‘05 Network Service y = Transform(x) xy xy
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Access Grid Workshop – APAC ‘05 Matcher Venue Stream Capabilities Node Capabilities Mismatch 1. Network Service Node Capabilities Stream Capabilities Match 2.
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Access Grid Workshop – APAC ‘05 Network Service Registers with a venue or a venue server Includes input and output capabilities Provides a Transform() method Has an interface for remote configuration Emits heartbeats
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Access Grid Workshop – APAC ‘05 Example: Video Selector GOAL: Reduce bandwidth EXAMPLE: Connect from home
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Access Grid Workshop – APAC ‘05 Multicas t Video Selector Example: Video Selector
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Access Grid Workshop – APAC ‘05 Example: Transcoder GOAL: Enable more devices EXAMPLE: H.323 client
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Access Grid Workshop – APAC ‘05 Multicas t Audio Transcoder Multicas t Linear16pcmu Example: Transcoder
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Access Grid Workshop – APAC ‘05 Implementation Details 1.Add new capabilities (ServiceCapability) to your node services. 2.Create a network service matching the new capabilities of the node services. 3.Connect the network service to the venue 4.Connect your node services to the venue
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Access Grid Workshop – APAC ‘05 Network Service Base Class Initiates the AG environment Hides SOAP details Includes logging Communicates with venues Includes the Transform() method
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Access Grid Workshop – APAC ‘05 Service Capabilities Describe input and output Same as node service capabilities Used during capability negotiation and network service matching
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Access Grid Workshop – APAC ‘05 Example: Video Selector class SelectorNetworkService(AGNetworkService): def __init__(self, name): AGNetworkService.__init__(self, name, 'Selector', '1.0') # Create capabilities inconfig = {"Encoding":"H261"} inCap = ServiceCapability(name, 'consumer', 'video', inconfig) outconfig = {"Encoding":"H261", "StreamSelection":"On"} outCap = ServiceCapability(name, 'producer', 'video', outconfig) self.inCapabilities = [inCap.ToXML()] self.outCapabilities = [outCap.ToXML()] # Manage processes self.processManager = ProcessManager() # Start the soap interface self.Start(self) def StopTransform(self, streamList): # Stop video selector self.processManager.TerminateAllProcesses()
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Access Grid Workshop – APAC ‘05 Example: Video Selector def Transform(self, streamList): # Start video selector newStreams = [] for s in streamList: cap = s.capability cap.xml = self.outCapabilities[0] # Create new stream description location = MulticastNetworkLocation("224.2.2.2", 8000) ns = StreamDescription("Video Selector Stream", location, cap) newStreams.append(ns) # Create process arguments fromaddr = s.location.host fromport = s.location.port toaddr = ns.location.host toport = ns.location.port executable = os.path.join(os.getcwd(), "Selector.py") options = [executable, fromaddr, fromport, toaddr, toport, 1] # Start process self.processManager.StartProcess(sys.executable, options) return newStreams
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Access Grid Workshop – APAC ‘05 Example: Video Selector Consumer Service def __SetCapabilities(self): oldCap1 = Capability( Capability.CONSUMER, "video" ) # Create new capabilities to include in old capability format val = "Off" for c in self.configuration: if c.name == "video selection": val = c.value config = {"StreamSelection": val, "Encoding":"H261"} nsc1 = ServiceCapability('Video Consumer Selector', oldCap1.role, oldCap1.type, config) oldCap1.xml = nsc1.ToXML() self.capabilities = [oldCap1]
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Access Grid Workshop – APAC ‘05 Exercises Exercise 6 – Network Services: Testing the video selector service Running a debug network service Creating a custom SOAP interface for configuration Creating a client for connecting to the custom SOAP interface http://www.mcs.anl.gov/fl/research/accessgrid/documentation/tutorial/AGTk_2.4
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Access Grid Workshop – APAC ‘05 Exercises 1: Video Selector 1.Install the modified node services with new capabilities. 2.Enter the venue the video selector is connected to 3.Switch between video selection on and off
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Access Grid Workshop – APAC ‘05 Exercises 2: Debug Service 1.Install the two modified node services with new service capabilities 2.Modify the Debug Network Service 3.Connect the network service to a venue and enter with the two node services to trigger matching.
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Access Grid Workshop – APAC ‘05 Exercises 3: SOAP Interface 1.Add a SOAP interface to the debug service 2.Create a client that can communicate remotely with the debug network service SOAP interface.
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