We can guarantee "read your writes" consistency with the help of a tweaked chaining overlay. I.e., 1) the client issues a write request to a slave 2) the slave chains the request to the master 3) when the chained write succeeds, the slave performs the write locally 4) the response is returned to the client
Another approach is to simply chain reads of any updater. This approach suffers from disconnect issues (unless the service has a long memory).
-- -- Howard Chu Chief Architect, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc OpenLDAP Core Team http://www.openldap.org/project/