# US 2014/0156596 A1 · Replication control using eventually consistent meta-data > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0156596 A1 - Document ID: US20140156596A1 - Status: Published application - Kind: A1 - Application number: 13/693,393 - Filed: 2012-12-04 - Published: 2014-06-05 - Earliest claimed: 2012-12-04 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Venkat K. Chandra; Prasad G. Parulekar; Sunil Sarin; Krishnan Seetharaman; David L. Shepard; Lewrence Stabile - Web page: https://patentgrep.com/patent/US20140156596A1 ## CPC - G06F 16/27: Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract The present invention provides a method, system and computer program product for replication control using eventually consistent meta-data. In an embodiment of the invention, a method for replication control using eventually consistent meta-data is provided. The method includes replicating data in a replication data processing system of nodes coupled to one another over a computer communications network. The method also includes replicating meta-data representing the state of the replication data processing system into a data structure of eventually consistent meta-data. Finally, the method includes managing the replication of the data according to the replicated meta-data. ## Claims ### Claim at position 1 1-9. (canceled) ### Claim 10 A replicated data processing system configured for replication control using eventually consistent meta-data, the system comprising a plurality of replication nodes, each of which comprising: a host computing device with memory and at least one processor; a database of replicated data coupled to the host computing device; a replication flow machine executing in the memory of the host computing device, the flow machine replicating the data in the database responsive to data modifications in coupled nodes of the replicated data processing system; and, a replication controller configured for eventual consistency, the controller comprising program code enabled upon execution in the memory of the host computing device to replicate state information for the replication data processing system into a data structure of eventually consistent meta-data, and to manage the replication flow machine according to the replicated meta-data. ### Claim 11 (depends on 9) The system of claim 9, wherein the data structure of eventually consistent meta-data is organized into rows of a table for each replicated system, the rows in the table representing a state of all replication nodes in the system. ### Claim 12 (depends on 11) The system of claim 11, wherein the table comprises different time stamps for each of the nodes. ### Claim 13 (depends on 12) The system of claim 12, wherein the state information in one of the nodes is replicated by receiving a replicated form of stored state information from another of the nodes and for each row in the stored state information, overwriting the row with a corresponding row from the received replicated form of the stored state information when a time stamp of the corresponding row is more recent than a time stamp for the row to be overwritten. ### Claim 14 (depends on 9) The system of claim 9, wherein the replication controller processes the replicated meta-data in the data structure to detect violations of integrity constraints in the meta-data. ### Claim 15 (depends on 14) The system of claim 14, wherein the replication controller manages the replication flow machine according to the replicated meta-data by directing a suspension of the replication of the data responsive to detecting an integrity constraint violation in the meta-data. ### Claim 16 (depends on 14) The system of claim 14, wherein the replication controller manages the replication flow machine according to the replicated meta-data by transmitting an alert to an administrator responsive to detecting an integrity constraint violation in the meta-data. ### Claim 17 (depends on 14) The system of claim 14, wherein the replication controller manages the replication flow machine according to the replicated meta-data by invoking an external administrative program responsive to detecting an integrity constraint violation in the meta-data. ### Claim 18 (depends on 14) The system of claim 14, wherein the constraints include a prohibition against multiple nodes of the system acting in a master role, where a node in a master role acts as if the node in the master role is the only node permitted to modify the replicated data. ### Claim 19 A computer program product for replication control using eventually consistent meta-data, the computer program product comprising: a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising: computer readable program code for replicating data in a replication data processing system of nodes coupled to one another over a computer communications network; computer readable program code for replicating state information for the replication data processing system into a data structure of eventually consistent meta-data; and, computer readable program code for managing the replication of the data according to the replicated meta-data. ### Claim 20 (depends on 19) The computer program product of claim 19, wherein the data structure of eventually consistent meta-data is organized into rows of a table, the rows representing a state of all replication nodes in the system. ### Claim 21 (depends on 20) The computer program product of claim 20, wherein each of the rows has an associated timestamp representing a time of last modification. ### Claim 22 (depends on 21) The computer program product of claim 21, wherein the meta-data in one of the nodes is replicated by receiving a replicated form of stored meta-data from another of the nodes and for each row in the stored meta-data, overwriting the row with a corresponding row from the received replicated form of the stored meta-data when a time stamp of the corresponding row is more recent than a time stamp for the row to be overwritten. ### Claim 23 (depends on 19) The computer program product of claim 19, further comprising computer readable program code for processing the meta-data in the data structure to detect violations of integrity constraints in the meta-data. ### Claim 24 (depends on 23) The computer program product of claim 23, wherein the replication of the data is managed according to the replicated meta-data by directing a suspension of the replication of the data responsive to detecting an integrity constraint violation in the meta-data. ### Claim 25 (depends on 23) The computer program product of claim 23, wherein the replication of the data is managed according to the replicated meta-data by transmitting an alert to an administrator responsive to detecting an integrity constraint violation in the meta-data. ### Claim 26 (depends on 23) The computer program product of claim 23, wherein the replication of the data is managed by invoking an external administrative computer program responsive to detecting an integrity constraint violation in the meta-data. ### Claim 27 (depends on 23) The computer program product of claim 23, wherein the integrity constraints include a prohibition against multiple nodes of the system acting in a master role, where a node in a master role acts as if the node in the master role is the only node permitted to modify the replicated data.