Enabling Client Systems to Discover Services Accessible by Remote Procedure Calls (RPC) on Server Systems

Abstract

Information representing the RPC servers, on which each RPC service is currently being provided, is maintained on a directory server. A client may query the directory server and determine a specific one of the RPC servers on which to cause execution of a desired RPC service. Each RPC server may also register the service interface using which the corresponding RPC services can be accessed. As a result, the same RPC service may potentially be accessed with a different service interface on different RPC servers. Another aspect of the present invention provides a schema using which procedure interface definition (i.e., the name of the procedure, the parameters, and their attributes) can be represented. Such a feature is used to store the procedure definitions on the directory server, thereby enabling a client system to determine the procedure definition prior to sending an RPC request to execute the procedure.

What is claimed is: 
     
         1 . A method of enabling client systems to cause execution of remote procedure call (RPC) services on a plurality of RPC servers, said method comprising:
 registering on a directory server a first set of RPC servers on which a first service is accessible, wherein said first set of RPC servers is comprised in said plurality of RPC servers;   sending a query request from a first client system to said directory server, said query request specifying said first service as a desired RPC service;   receiving a query response in said first client system, wherein said query response indicates that said first set of RPC servers provide said first service; and   sending an RPC request to one of said first set of RPC servers to cause execution of said first service on said one of said first set of RPC servers.   
     
     
         2 . The method of  claim 1 , wherein said query response further indicates a service interface using which said first service can be accessed on said one of said first set of RPC servers, and wherein said RPC request is sent according to said service interface from said first client system to said one of said first set of RPC servers. 
     
     
         3 . The method of  claim 2 , wherein said service interface contains a port number at which said first service is accessible on said one of said first set of RPC servers. 
     
     
         4 . The method of  claim 2 , wherein said service interface stored on said directory server further contains access control restrictions in accessing said first service provided on each of said first set of RPC servers. 
     
     
         5 . The method of  claim 4 , wherein said service interface is represented as an object according to a schema. 
     
     
         6 . The method of  claim 1 , wherein each of said plurality of RPC servers registers with said directory server a corresponding set of services accessible on the RPC server. 
     
     
         7 . The method of  claim 6 , wherein said plurality of RPC servers perform said registration at a time of corresponding initialization. 
     
     
         8 . A method of causing execution of a service accessible by a remote procedure call (RPC), said method comprising:
 sending a directory query to a directory server requesting a RPC server on which said service is accessible;   receiving a response from said directory server indicating said RPC server on which said service is accessible; and   sending an RPC request to said RPC server to cause execution of said service.   
     
     
         9 . The method of  claim 8 , further comprising:
 requesting said directory server to specify a service interface on said RPC server using which said service is accessible; and   receiving said service interface from said directory server, wherein said RPC request is sent according to said service interface.   
     
     
         10 . The method of  claim 9 , wherein said service interface contains a port number at which said service is accessible on said RPC server. 
     
     
         11 . The method of  claim 10 , wherein said service interface further contains access control restrictions in accessing said service provided on each of said first set of RPC servers. 
     
     
         12 . A computer readable medium carrying one or more sequences of instructions for causing a system to cause execution of a service accessible by a remote procedure call (RPC), wherein execution of said one or more sequences of instructions by one or more processors contained in said system causes said system to perform the actions of:
 sending a directory query to a directory server requesting a RPC server on which said service is accessible;   receiving a response from said directory server indicating said RPC server on which said service is accessible; and   sending an RPC request to said RPC server to cause execution of said service.   
     
     
         13 . The computer readable medium of  claim 12 , further comprising one or more instructions for:
 requesting said directory server to specify a service interface on said RPC server using which said service is accessible; and   receiving said service interface from said directory server, wherein said RPC request is sent according to said service interface.   
     
     
         14 . The computer readable medium of  claim 13 , wherein said service interface contains a port number at which said service is accessible on said RPC server. 
     
     
         15 . The computer readable medium of  claim 14 , wherein said service interface further contains access control restrictions in accessing said service provided on each of said first set of RPC servers. 
     
     
         16 . The computer readable medium of  claim 15 , wherein said service contains a procedure, further comprising one or more instructions for:
 requesting said directory server to provide a procedure interface using which said procedure can be executed; and   receiving data representing said procedure interface, wherein said RPC request is sent to cause said procedure to be executed.   
     
     
         17 . The computer readable medium of  claim 16 , wherein said procedure interface contains a set of parameters, corresponding attributes, and whether each of said set of parameters is of input type, output type or both, and said data representing said procedure interface containing said set of parameters, corresponding attributes and indication of whether each of said set of parameters is of input type, output type or both. 
     
     
         18 . A computer readable medium carrying one or more sequences of instructions for causing a directory server to enable client systems to cause execution of remote procedure call (RPC) services on a plurality of RPC servers, wherein execution of said one or more sequences of instructions by one or more processors contained in said directory server causes said directory server to perform the actions of:
 storing a data representing a first set of RPC servers on which a first service is accessible, wherein said first set of RPC servers is comprised in said plurality of RPC servers;   receiving a query request from a first client system to said directory server, said query request specifying said first service as a desired RPC service; and   sending a query response to said first client system, wherein said query response indicates that said first set of RPC servers provide said first service,   whereby said first client system is enabled to send an RPC request to one of said first set of RPC servers to cause execution of said first service on said one of said first set of RPC servers.   
     
     
         19 . The computer readable medium of  claim 18 , wherein said query response further indicates a service interface using which said first service can be accessed on said one of said first set of RPC servers, and wherein said RPC request is sent according to said service interface from said first client system to said one of said first set of RPC servers. 
     
     
         20 . The computer readable medium of  claim 19 , wherein said service interface contains a port number at which said first service is accessible on said one of said first set of RPC servers. 
     
     
         21 . The computer readable medium of  claim 20 , wherein said service interface stored on said directory server further contains access control restrictions in accessing said first service provided on each of said first set of RPC servers.