ADDRESS GENERATION IN DISTRIBUTED SYSTEMS USING TREE METHOD

• US 20050149627A1
• Filed: 12/24/2003
• Published: 07/07/2005
• Est. Priority Date: 12/24/2003
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Schreter, Ivan
• Granted Patent: US 8,499,078 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: G06F 16/2246 Trees, e.g. B+trees
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 16/289 Object oriented databases
• CPC Class Codes: H04L 2101/604 Address structures or formats
• CPC Class Codes: H04L 45/48 Routing tree calculation
• CPC Class Codes: H04L 61/5069 for group communication, multicast communication or broadcast communication
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes

Abstract

Methods and apparatus, including computer program products, for managing a cluster of servers organized into nodes. A method of one aspect includes establishing a cluster; establishing a set of ultimate identifiers for nodes resulting from splitting in the cluster; and storing every new data object on a node that has a node identifier that identifies a subset of the set of ultimate identifiers, and providing for the object a universal identifier that combines (i) an object identifier that is unique on the node and (ii) a server identifier that is one of the ultimate identifiers in the subset. A method of another aspect includes generating for a new data object a universal identifier that has a node identifier part that uniquely identifies a node, a reserve part generated at least in part as a pseudo-random value, and an object identifier part that uniquely identifies the object in the node.

Claims

1-33. -33. (canceled)

34. A method for generating an identifier for a new data object to be stored in a cluster of back-end servers of the kind where the cluster is organized into nodes and every node in the cluster has a node identifier that is unique in the cluster, and where every back-end server in any node mirrors every other back-end server in the same node, the method comprising:

generating a universal identifier for a new data object, the universal identifier having a node identifier part that uniquely identifies a first node in the cluster, a reserve part, and an object identifier part that uniquely identifies the object in the first node, the reserve part being at least in part generated as a pseudo-random value.

35. The method of claim 34, wherein:

the node identifier part and the reserve part have a combined length that is a predetermined fixed length; and

the object identifier part does not uniquely identify the new data object on the cluster.

36. The method claim 34, wherein:

the reserve part is generated by the first node and given a value to maintain some locality between the new data object and certain other data objects stored on the first node.

37. The method claim 34, wherein:

the node identifier part and the reserve part are both generated as pseudo-random values.

38. The method of claim 37, wherein:

the node identifier part is modified for load balancing.

39. The method of claim 38, wherein:

the node identifiers have a structure represented as a binary tree in a front-end server, and

load balancing comprises navigating the binary tree to select a node based on the relative loads on the nodes of the cluster.

40. A computer program product, tangibly embodied on an information carrier, for generating an identifier for a new data object to be stored in a cluster of back-end servers of the kind where the cluster is organized into nodes and every node in the cluster has a node identifier that is unique in the cluster, and where every back-end server in any node mirrors every other back-end server in the same node, the product comprising instructions operable to cause data processing apparatus to:

generate a universal identifier for a new data object, the universal identifier having a node identifier part that uniquely identifies a first node in the cluster, a reserve part, and an object identifier part that uniquely identifies the object in the first node, the reserve part being at least in part generated as a pseudo-random value.

41. The product of claim 40, wherein:

the node identifier part and the reserve part have a combined length that is a predetermined fixed length; and

the object identifier part does not uniquely identify the new data object on the cluster.

42. The product claim 40, wherein:

the reserve part is generated by the first node and given a value to maintain some locality between the new data object and certain other data objects stored on the first node.

43. The product claim 40, wherein:

the node identifier part and the reserve part are both generated as pseudo-random values.

44. The product of claim 43, wherein:

the node identifier part is modified for load balancing.

45. The product of claim 44, wherein:

the node identifiers have a structure represented as a binary tree in a front-end server, and

load balancing comprises navigating the binary tree to select a node based on the relative loads on the nodes of the cluster.

46. A system for generating an identifier for a new data object to be stored in a cluster of back-end servers of the kind where the cluster is organized into nodes and every node in the cluster has a node identifier that is unique in the cluster, and where every back-end server in any node mirrors every other back-end server in the same node, the system comprising:

means for generating node identifier for a new data object that uniquely identifies a first node in the cluster for storing the new data object; and

means for generating a universal identifier for the new data object, the universal identifier having a node identifier part for the node identifier, a reserve part, and an object identifier part that uniquely identifies the object in the first node, the reserve part being at least in part generated as a pseudo-random value.

47. The system of claim 46, wherein:

the node identifier part and the reserve part have a combined length that is a predetermined fixed length; and

the object identifier part does not uniquely identify the new data object on the cluster.

48. The system of claim 46, wherein:

the reserve part is generated by the first node and given a value to maintain some locality between the new data object and certain other data objects stored on the first node.

49. The system of claim 46, wherein:

the node identifier part and the reserve part are both generated as pseudo-random values.

50. The system of claim 49, further comprising:

means for modifying the node identifier for load balancing.

51. The system of claim 50, wherein:

the node identifiers have a structure represented as a binary tree in a front-end server, and

the means for modifying the node identifier for load balancing comprises means for navigating the binary tree to select a node based on the relative loads on the nodes of the cluster.