Recovery procedure for a dynamically reconfigured quorum group of processors in a distributed computing system

A system for recovering a current state of a quorum group of processors dynamically reconfigured while at least one processor of said quorum group of processors was unavailable, said system comprising:

• means for obtaining, for said at least one processor, said current state of said dynamically reconfigured quorum group of processors from one or more processors of said quorum group of processors;
• and
• wherein each processor of said quorum group of processors includes an incarnation number and a list of member processors which resulted from a commit process;
• wherein said commit process resulted in said incarnation number and required participation by a majority of processors of said quorum group of processors;
• and wherein said means for obtaining comprises means for checking said one or more processors of said quorum group of processors for incarnation numbers and lists of member processors which resulted from the commit processes.

A distributed processing system comprising:

• a group of processors, said group of processors being adapted to allow recovering of a current state for at least one processor thereof which was unavailable during a dynamic reconfiguration of said group of processors, said group of processors being adapted to:
• obtain, for said at least one processor, said current state of said dynamically reconfigured quorum group of processors from one or more processors of said quorum group of processors;
• and
• wherein each processor of the quorum group of processors includes an incarnation number and a list of member processors which resulted from a commit process;
• wherein said commit process resulted in said incarnation number and required participation by a majority of processors of said quorum group of processors;
• and wherein the group of processors is adapted to allow the at least one processor to check the one or more processors for incarnation numbers and lists of member processors which resulted from the commit processes.

At least one program storage device readable by a machine, tangibly embodying at least one program of instructions executable by the machine to perform a method for recovering a current state of a quorum group of processors dynamically reconfigured while at least one processor of said quorum group of processors was unavailable, comprising:

• obtaining, for said at least one processor, said current state of said dynamically reconfigured quorum group of processors from one or more processors of said quorum group of processors;
• and
• wherein each processor of said quorum group of processors includes an incarnation number and a list of member processors which resulted from a commit process;
• wherein said commit process resulted in said incarnation number and required participation by a majority of processors of said quorum group of processors;
• and wherein said obtaining comprises checking said one or more processors of said quorum group of processors for incarnation numbers and lists of member processors which resulted from the commit processes.