Patent ID: 7035922

Claim:
A method for monitoring replication latency in a computer system comprising a plurality of servers connected by a plurality of data links, and wherein the servers periodically replicate object updates with one another and maintain an update sequence number that is increased upon update to the server's replica of a database, the method comprising: first maintaining, by each of the plurality of servers, a timestamp that is posted upon each update to the server's database; second maintaining, by two or more of the plurality of servers, a replica partner vector table that includes for each other server from which the server replicates, the update sequence number of such other server at a time of a most recent replication from such other server or the timestamp of the last successful replication attempt with such other server; transmitting a copy of the replica partner vector table of a local server to a remote server; comparing, by the remote server, the update sequence numbers and timestamps in the replica partner vector table received from the local server to the update sequence numbers and timestamps in the replica partner vector table of the remote server; updating, by the remote server, the replica partner vector table received from the local server; transmitting, by the remote server, a copy of the updated replica partner vector table and object updates to the local server; improving, by the local server, upon receiving the updated replica partner vector from the remote server, update sequence numbers or timestamps in the partner vector table of the local server; calculating, by the local server, a difference between the timestamp for each server in the replica partner vector and a current time; comparing, by the local server, the difference to a maximum allowable latency time period; and generating, by the local server, an alert if the difference is greater than the maximum allowable latency time.