Abstract: Data is replicated from a master server to a slave server on a network by first sending a start call from a master user level to a master service level on the master server, the start call containing version information for data on the master server. The information is then sent to a slave service layer on a slave server so the slave server layer can determine whether data on the slave server is current. The slave server layer can request a delta from the master server if the slave data is not current. A delta containing the information necessary to update the slave data is sent from the master service layer to the slave service layer so the slave service layer can process the delta and send the updated information to the slave user layer.

Abstract: Data can be replicated over a network using a one or two phase method. For the one phase method, a master server containing an original copy of the data sends a version number for the current state of the data to each slave on the network so that each slave can request a delta from the master. The delta that is requested contains the data necessary to update the slave to the appropriate version of the data. For the two phase method, the master server sends a packet of information to each slave. The packet of information can be committed by the slaves if each slave is able to process the commit.

Abstract: A session replication system provides real-time data replication without unnecessarily slowing down the user experience. A system in accordance with the present invention may utilize a primary server to serve requests from a network client, as well as a secondary server to replicate the session information. When a request is received on the session, an attempt may be made to serve the request on the primary server. If the primary is unable to receive or respond to the request, the request may be served on the secondary application server or on a new primary server. If the secondary server receives the request, the secondary server may become the new primary server. If a new primary server is selected, the new primary may request the session information from the secondary server.

Abstract: A session replication system provides real-time data replication without unnecessarily slowing down the user experience. A system in accordance with the present invention may utilize a primary server to serve requests from a network client, as well as a secondary server to replicate the session information. When a request is received on the session, an attempt may be made to serve the request on the primary server. If the primary is unable to receive or respond to the request, the request may be served on the secondary server or on a new primary server. If the secondary server receives the request, the secondary server may become the new primary server. If a new primary server is selected, the new primary may request the session information from the secondary server.