Cluster families for cluster selection and cooperative replication

• US 9,250,825 B2
• Filed: 07/31/2014
• Issued: 02/02/2016
• Est. Priority Date: 12/11/2009
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Bish, Thomas W., Nohta, Takeshi, Swingler, Joseph M., Twito, Rufus-John Y.
• Primary Examiner(s): NGUYEN, THAN VINH
• Application Number:
  US14/448,110
• Publication Number:
  US 20140344540A1
• Time in Patent Office: 551 Days
• Field of Search: 711/162, 711/148
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/2082 Data synchronisation
• CPC Class Codes: G06F 12/0802 Addressing of a memory level in which the access to the desired data or data block requires associative addressing means, e.g. caches
• CPC Class Codes: G06F 12/0815 Cache consistency protocols
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 2212/1016 Performance improvement
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0683 Plurality of storage devices
• CPC Class Codes: G06F 3/0686 Libraries, e.g. tape libraries, jukebox
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

Cluster families for cluster selection and cooperative replication are created. The clusters are grouped into family members of a cluster family base on their relationships and roles. Members of the cluster family determine which family member is in the best position to obtain replicated information and become cumulatively consistent within their cluster family. Once the cluster family becomes cumulatively consistent, the data is shared within the cluster family so that all copies within the cluster family are consistent. Each family member in the family replicates 1/Nth volumes and N represents a total number of cluster family members in the family.

Claims

1. A method for cooperative replication of multiple clusters, the method comprising:

arranging at least one subset of the multiple clusters into family members of a cluster family;

negotiating between cluster family members to determine which cluster family member is in the best position to obtain at least one outside data object from at least one cluster outside of the cluster family;

selecting one family member of the cluster family to obtain the outside data object; and

sharing the outside data objects among the cluster family so that each cluster within the cluster family is consistent with respect to outside data objects,

wherein each family member in the cluster family replicates 1/Nth volumes and N represents a total number of cluster family members in the cluster family.

2. The method of claim 1, further comprising creating a relationship among cluster families based on at least one of a cluster relationship and role.

3. The method of claim 1, wherein the family member with a consistent source maintains a volume in cache in order to make the volume readily available to other family members for peer replication.

4. The method of claim 3, wherein the at least one cluster outside of the cluster family does not cache the volume when the family member maintains the volume in the cache.

5. The method of claim 1, further comprising cooperatively serializing all replication into the cluster family.

6. The method of claim 1, wherein a first family member to replicate 1/Nth volumes informs the at least one cluster outside of the cluster family that the first family member will maintain the volumes for the cluster family members.

7. The method of claim 1, further comprising a plurality of cluster families wherein at least one family member from each cluster family replicates a volume.

8. The method of claim 1, further comprising a domain comprising a plurality of clusters from the multiple clusters that cooperate to make sure at least one family member from each cluster family replicates a volume and the remaining clusters surrender replication requirements.

9. A system for cooperative replication of multiple clusters, the system comprising:

a network;

a plurality of sites in communication over the network, each site comprising at least one host and a storage system comprising a plurality of clusters, each cluster comprising at least one tape drive configured to access volumes stored on magnetic tape, at least one tape volume cache, and a cluster manager configured to execute computer readable programs using a processor and a memory, wherein the software readable programs comprising;

a creation module configured to setup and arrange a group of clusters into family members of a cluster family; and

a cooperative replication module configured to select a family member to cooperatively replicate data from at least one cluster outside of the cluster family into the cluster family and achieve cumulative family consistency,

wherein each family member in the cluster family replicates 1/Nth volumes and N represents a total number of cluster family members in the cluster family.

10. The system of claim 9, further comprising creating a relationship among cluster families based on at least one of a cluster relationship and role.

11. The system of claim 9, wherein the family member with a consistent source maintains a volume in cache in order to make the volume readily available to other family members for peer replication.

12. The system of claim 11, wherein the at least one cluster outside of the cluster family does not cache the volume when the family member maintains the volume in the cache.

13. The system of claim 9, further comprising cooperatively serializing all replication into the cluster family.

14. The system of claim 9, wherein a first family member to replicate 1/Nth volumes informs the at least one cluster outside of the cluster family that the first family member will maintain the volumes for the cluster family members.

15. The system of claim 9, further comprising a plurality of cluster families wherein at least one family member from each family replicates a volume.

16. The system of claim 9, further comprising a domain comprising the plurality of clusters wherein the clusters cooperate to make sure at least one family member from each cluster family replicates a volume and the remaining clusters surrender replication requirements.

17. A computer program product comprising a non-transitory computer readable medium including a computer readable program, wherein the computer readable program when executed on a computer causes the computer to:

group a plurality of clusters into family members of a cluster family;

determine which family member is in the best position to obtain outside data objects from a source, the source included in at least one cluster outside of the cluster family;

select one or more family members of the cluster family to obtain the outside data objects;

cooperatively replicate the outside data objects into the cluster family; and

share the outside data objects within the cluster family so that all copies of the outside data objects within the cluster family are consistent,

wherein each family member in the cluster family replicates 1/Nth volumes and N represents a total number of cluster family members in the cluster family.

18. The computer program product of claim 17, further comprising creating a relationship among cluster families based on at least one of a cluster relationship and role.

19. The computer program product of claim 17, wherein the family member with a consistent source maintains a volume in cache in order to make the volume readily available to other family members for peer replication.

20. The computer program product of claim 19, wherein the at least one cluster outside of the cluster family does not cache the volume when the family member maintains the volume in the cache.