(12) United States Patent ao) Patent No.: us 6,182,117 Bi
Christie et al. (45) Date of Patent: *Jan. 30,2001
(54) METHOD AND APPARATUS FOR WORKGROUP INFORMATION REPLICATION
(75) Inventors: David Christie, Menlo Park; Jeffrey Winner, Santa Clara, both ol CA (US)
(73) Assignee: Netscape Communications
Corporation, Mountain View, CA (US)
( * ) Notice: Under 35 U.S.C. 154(b), the term of this patent shall be extended for 0 days.
This patent is subject to a terminal disclaimer.
(21) Appl. No.: 08/873,569
(22) Filed: Jun. 12, 1997
Related U.S. Application Data
(63) Continuation of application No. 08/456,431, filed on May 31, 1995.
(51) Int. CI. G06F 15/16
(52) U.S. CI 709/205; 709/227
(58) Field of Search 395/200.01, 200.02,
395/200.08, 200.18, 600, 650, 700, 182.9; 364/514.006; 709/204, 205, 227; 714/4,
41, 56, 57
(56) References Cited
U.S. PATENT DOCUMENTS
5,740,230 * 4/1998 Vaudreuil 379/88
The present invention provides the ability to use an existing store-and-forward messaging network such as an electronic mail system to replicate data between computer sites. The replication provided by the present invention can be used with software applications, such as workgroup applications, to replicate data located on multiple sites. Workgroup replication data is sent to other sites via electronic mail ("email") messages. The present invention provides reliability features to handle errors in electronic mail transmissions. For example, the present invention provides the ability to reassemble objects at a replication site such that an object and all of its dependencies exist prior to the object's use at the site. Messages referred to as "ACK" messages are used to communicate a site's state and to provide other control information. Each site maintains latency information to determine transmission failures.
33 Claims, 12 Drawing Sheets