Patent ID: 6078930
Filing Date: 2000-06-20
Classification: G06F,Y10S

Abstract:
A method for determining a safe recovery time value after a failure of a first node in a computer system, wherein said first node is one of a plurality of nodes that has access to a database, wherein a plurality of logical clocks are associated with said plurality of nodes, the method comprising the steps of:prior to said failure, said first node maintaining a first logical clock of said plurality of logical clocks to assign time values to changes made to said database by said first node;after said failure, reading a most recent log timestamp value from a log file associated with said first node;determining, based on said most recent log timestamp value, a recovery timestamp value that is at least as recent as any time value recorded in said database by said first node prior to said failure; andrecovering said first node using said recovery timestamp value.