Mechanism for communication in a distributed database

A computer program product for providing communication integrity within a distributed database computer system, the computer program product comprising:

• one or more computer-readable storage media and program instructions stored on the one or more computer-readable storage media, the program instructions comprising:
• program instructions to transmit, by a first node of a plurality of nodes, a change notification to a second node of the plurality of nodes, wherein the second node is a neighbor of the first node, and wherein the change notification indicates that the first node has changed from a first version to a second version;
• program instructions to receive, by the first node of the plurality of nodes, at least one change confirmation from the second node, the change confirmation confirming acknowledgment of the change notification by the second node and by a third node of the plurality of nodes, wherein the third node of the plurality of nodes is not a neighbor of the first node of the plurality of nodes;
• program instructions to, in response to receiving the at least one change confirmation, program instructions to determine, by the first node of the plurality of nodes, that all nodes of the plurality of nodes have acknowledged the change notification;
• and
• program instructions to update, by the first node of the plurality of nodes, a version table of the first node to show that the second node and the third node know that the first node has changed from the first version to the second version, wherein the version table of the first node shows the first node's knowledge about what the second node knows about the version of the first node and a version of the third node, and about what the third node knows about the version of the first node and a version of the second node.

A computer system for providing communication integrity within a distributed database computer system, the computer system comprising:

• one or more computer processors, one or more computer-readable storage media, and program instructions stored on the computer-readable storage media for execution by at least one of the one of the one or more processors, the program instructions comprising:
• program instructions to transmit, by a first node of a plurality of nodes, a change notification to a second node of the plurality of nodes, wherein the second node is a neighbor of the first node, and wherein the change notification indicates that the first node has changed from a first version to a second version;
• program instructions to receive, by the first node of the plurality of nodes, at least one change confirmation from the second node, the change confirmation confirming acknowledgment of the change notification by the second node and by a third node of the plurality of nodes, wherein the third node of the plurality of nodes is not a neighbor of the first node of the plurality of nodes;
• program instructions to, in response to receiving the at least one change confirmation, program instructions to determine, by the first node of the plurality of nodes, that all nodes of the plurality of nodes have acknowledged the change notification;
• and
• updating, by the first node of the plurality of nodes, a version table of the first node to show that the second node and the third node know that the first node has changed from the first version to the second version, wherein the version table of the first node shows the first node's knowledge about what the second node knows about the version of the first node and a version of the third node, and about what the third node knows about the version of the first node and a version of the second node.