The document provides an overview of various remote procedure call (RPC) systems including Sun RPC, DCE RPC, DCOM, CORBA, and Java RMI. It summarizes the key aspects of each system such as how interfaces are defined, how clients locate and invoke remote objects, how data is marshaled and transported, and improvements made in newer systems over older ones.

1. RPC Case Studies Paul Krzyzanowski [email_address] [email_address] Distributed Systems Except as otherwise noted, the content of this presentation is licensed under the Creative Commons Attribution 2.5 License.

2. Overview of RPC Systems Sun RPC DCE RPC DCOM CORBA Java RMI XML RPC, SOAP/.NET, AJAX, REST

3. Sun RPC

5. RPC IDL Interface definition program number Interface definition version 1 version 2

6. RPC IDL program GETNAME { version GET_VERS { long GET_ID(string<50>) = 1; string GET_ADDR(long) = 2; } = 1; /* version */ } = 0x31223456; name.x

11. DCE RPC

17. DCE service lookup client cell dir server Request service lookup from cell directory server Return server machine name service? server

18. DCE service lookup client cell dir server Connect to endpoint mapper service and get port binding from this local name server local dir server SERVER service? port dced

19. DCE service lookup client cell dir server Connect to service and request remote procedure execution local dir server SERVER RPC server dced

22. The next generation of RPCs Support for object oriented languages

23. Microsoft DCOM

32. CORBA

35. CORBA logical view object implementation client ORB Generated stub code Generated skeleton code

37. IDL example Module StudentObject { struct StudentInfo { string name; int id; float gpa; }; exception Unknown {}; interface Student { StudentInfo getinfo(in string name) raises(Unknown); void putinfo(in StudentInfo data); }; };

49. Java RMI

61. Java RMI infrastructure client application registry stub skeleton remote interface remote object implementation bind lookup remote reference f(args) f(args) return/exc. return/exception marshal stream

63. The third generation of RPCs Web services and Riding the XML Bandwagon

65. XML RPC

67. XML-RPC example <methodCall> <methodName> sample.sumAndDifference </methodName> <params> <param><value><int> 5 </int></value></param> <param><value><int> 3 </int></value></param> </params> </methodCall>

70. SOAP

74. WSDL structure: port types <definitions name=&quot;MobilePhoneService“ target=…> <portType name=&quot;MobilePhoneService_port&quot;> <operation name=&quot;getListOfModels&quot;> <operation name=&quot;getPrice&quot;> <Input message=&quot;PhoneModel&quot;/> <output message=&quot;PhoneModelPrice&quot;/> <output message=&quot;ListOfPhoneModels&quot;/> 2. service definition 1. type definitions 3. messaging spec

75. WSDL part 3: messaging spec <binding name=&quot;MobilePhoneService_Binding“ type=&quot;MobilePhoneService_port&quot;> <soap:binding style=&quot;rpc“ transport=&quot;http://schemas.xmlsoap.org/soap/http“ /> <operation name=&quot; getPrice &quot;> <soap:operation soapAction=&quot; urn:MobilePhoneService &quot;/> <input> <soap:body encodingStyle= &quot;http://schemas.xmlsoap.org/soap/encoding/“ namespace=&quot;urn:MobilePhoneService&quot; use=&quot;encoded&quot;/> </input> <output> <soap:body encodingStyle= &quot;http://schemas.xmlsoap.org/soap/encoding/“ namespace=&quot;urn:MobilePhoneService&quot; use=&quot;encoded&quot; /> </output> </operation> </binding>

76. Microsoft .NET Remoting

88. Web Service invocation ASP.NET HTTP request Method/parameters Encoded in XML Process ASP Unmarshal msg Invoke procedure .NET object Method 1 Method n Web Server

89. Web Service invocation ASP.NET HTTP request Method/parameters Encoded in XML Process ASP Unmarshal msg Return data Marshal return data Encoded response .NET object Method 1 Method n Web Server

90. Away from RPC… More Web Services

102. Summary

109. The end.