Exactly once data framework computer readable storage medium

Abstract

A computer readable storage medium stores instructions for managing objects in a clustered network. Several clustered servers are in communication with a file system containing at least one copy of a data object. A distributed consensus algorithm is used to select a host server. The selected host server can contain a copy of the data object, such as in local cache, providing access to the local copy to any other server in the cluster. Any change made to an item hosted by the host server can also be updated in the file system. If the host server becomes unable to host the object, a new host can be chosen using the distributed consensus algorithm. The other servers are then notified of the new host by multicast messaging.

1 . A computer readable storage medium storing instructions for managing objects on a network, the instructions comprising:
 a plurality of network servers, each network server adapted to communicate with a network data source;   a lead server in said plurality of network servers, the lead server determined by the other servers; and,   a host server in said plurality of network servers selected by said lead server using a distributed consensus algorithm, wherein the host server is assigned a data object related to a data item in the network data source by the lead server, such that any of said plurality of network servers needing to access the data item can access the data object on the host server.   
   
   
       2 . The computer readable storage medium according to  claim 1 , wherein said lead server is determined by the remaining servers in said plurality of network servers using a consensus algorithm. 
   
   
       3 . The computer readable storage medium according to  claim 1 , wherein said data item is an access point to an application. 
   
   
       4 . The computer readable storage medium according to  claim 1 , further including a second server in said plurality of servers, the second server assigned the data object and configured to provide data object access if said host server encounters a problem. 
   
   
       5 . The computer readable storage medium according to  claim 4 , wherein said second server is selected based on an algorithm. 
   
   
       6 . The computer readable storage medium according to  claim 1 , wherein said data object is configured to be accessed soley through a host server. 
   
   
       7 . The computer readable storage medium of  claim 6  wherein the data object is located in the host server local cache. 
   
   
       8 . The computer readable storage medium of  claim 6  wherein the data object is located in a file system, the host server having access to the file system. 
   
   
       9 . The computer readable storage medium according to  claim 6 , wherein the data object is located in a cache which is distributed among the plurality of network servers. 
   
   
       10 . The computer readable storage medium according to  claim 6 , wherein said data object is configured to be recovered from one of said plurality of servers if the host server fails. 
   
   
       11 . The computer readable storage medium according to  claim 6 , wherein the data is written back to the network data source when the data object is updated. 
   
   
       12 . The computer readable storage medium according to  claim 1 , wherein a new host server is selected to own the data object after a period of time. 
   
   
       13 . The computer readable storage medium according to  claim 12  wherein the new host server was a previous owner of the data object. 
   
   
       14 . The computer readable storage medium according to  claim 1 , wherein the distributed consensus algorithm includes:
 pre-selecting a host server from the plurality of servers; and   contacting the remaining servers in said plurality of servers to determine whether the remaining servers agree with the choice of the new host server.   
   
   
       15 . The computer readable storage medium according to  claim 1 , wherein a confirmation of the existence of the data object on the host server is performed. 
   
   
       16 . The computer readable storage medium of  claim 15  wherein the confirmation is performed periodically. 
   
   
       17 . The computer readable storage medium according to  claim 1 , wherein a host server is selected by the lead server for each of a plurality of data objects, each data object representing a particular data item in the network data source. 
   
   
       18 . The computer readable storage medium according to  claim 1 , wherein the host server is configured to relinquish the ownership of the data object if the lead server is unable to reach the host server within a certain amount of time. 
   
   
       19 . The computer readable storage medium according to  claim 1 , wherein the data object is stored in a cache on any server in the plurality of servers and all access to the cache goes through the host server.