Naming service implementation in a clustered environment

• US 8,028,002 B2
• Filed: 05/27/2004
• Issued: 09/27/2011
• Est. Priority Date: 05/27/2004
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Petev, Petio, Pancheva, Elitsa
• Primary Examiner(s): Breene; John E
• Assistant Examiner(s): Raab; Christopher J
• Application Number:
  US10/856,053
• Publication Number:
  US 20050278332A1
• Time in Patent Office: 2,679 Days
• Field of Search: 707/803, 707/792, 711/117
• US Class Current: 707/803
• CPC Class Codes: G06F 16/10 File systems; File servers

Abstract

A method and system for providing naming operations. Contexts are created and organized hierarchically under an initial context. The hierarchy is retained in a non-persistent storage medium. The objects and contexts created as a result of various naming operations are removed from the naming system responsive to a reboot of a server. In one embodiment, the entire naming hierarchy is represented in nested hash tables with a nesting level of only two.

Claims

1. An apparatus comprising:

an application server instance including a dispatcher node in communication with at least one application server node, wherein the application server node includes at least one core service;

the application server instance including a plurality of virtual machines, wherein the dispatcher node is included within a first virtual machine of the plurality of virtual machines and the application server node is included within a second virtual machine of the plurality of virtual machines;

a non-persistent storage unit representing a memory implementation of the second virtual machine included in the application server node; and

a hierarchical memory representation of a hierarchical naming structure stored within the non-persistent storage unit, wherein the hierarchical memory representation includes a plurality of hash tables stored via two levels of nesting, wherein a first hash table from the plurality of hash tables storing a plurality of containers is stored as a first level in two levels of nesting, and wherein each container from the plurality of containers includes at least one hash table from the plurality of hash tables storing at least one object, wherein the at least one hash table is stored in the first hash table as a second level in the two levels of nesting.

2. The apparatus of claim 1 wherein the hierarchical memory representation of the hierarchical naming structure is removed from the non-persistent storage unit when the application server node is rebooted.

3. The apparatus of claim 1 wherein the hierarchical memory representation of the hierarchical naming structure comprises:

a plurality of contexts each context including a basic object linked to a container from the plurality of containers.

4. The apparatus of claim 3 wherein the container comprises:

a hash table of objects against names in the second level of the two levels of nesting.

5. The apparatus of claim 3 wherein the container comprises:

a hash table of objects against identifiers in the second level of the two levels of nesting.

6. The apparatus of claim 3 wherein the basic object comprises:

a name string;

a byte array; and

a link identifier.

7. The apparatus of claim 6 wherein the link identifier has a value equal to a container identifier of exactly one container in the hierarchical naming structure and wherein that link identifier is unique within the hierarchical naming structure.

8. A computing system comprising:

a processor; and

a memory, the memory comprising;

a plurality of virtual machines (VM) each comprising an application server node;

a non-persistent memory implementation of a VM within the application server node; and

a naming service within the application server node, the naming service to store a hierarchical memory representation of a hierarchical naming structure in the non-persistent memory implementation of the VM, wherein the hierarchical memory representation includes a plurality of hash tables stored via two levels of nesting, wherein a first hash table from the plurality of hash tables storing a plurality of containers is stored as a first level in two levels of nesting, and wherein each container from the plurality of containers includes at least one hash table from the plurality of hash tables storing at least one object, wherein the at least one hash table is stored in the first hash table as a second level in the two levels of nesting.

9. The system of claim 8 wherein the naming service comprises:

a naming cache, including a hash table of cached objects as a byte array and a name; and

a hash table of cached objects as an object instance and a name.

10. The system of claim 9 wherein the naming cache further comprises:

a cache communicator to provide communication between naming services running on different application server nodes of a cluster.

11. The system of claim 8 wherein a container from the plurality of containers comprises:

a hash table of objects against names in the second level of the two levels of nesting; and

a hash table of objects against identifiers in the second level of the two levels of nesting.

12. A method comprising:

receiving a serialized directory object;

generating a basic object from the serialized directory object;

creating a context instance by linking the basic object to a container, wherein the container represents the context instance;

storing the container in a hierarchical memory representation of a hierarchical naming structure stored within a non-persistent storage unit, wherein the hierarchical memory representation includes a plurality of hash tables stored via two levels of nesting, wherein a first hash table from the plurality of hash tables that stores the container is stored as a first level of nesting of two levels of nesting, and wherein the container includes at least one hash table from the plurality of hash tables; and

storing objects bound in the context instance represented by the container in the at least one hash table nested in the first hash table as a next second level in the two levels of nesting.

13. The method of claim 12 further comprising:

storing the context instance in a memory implementation of a virtual machine; and

removing the context instance in response to a reboot of an application server resident in the virtual machine.

14. The method of claim 12 further comprising:

storing the objects against names in the next second level of nesting of the two levels of nesting; and

storing the objects against identifiers in the second level of nesting of the two levels of nesting.

15. An apparatus comprising:

means for hierarchically organizing a plurality of contexts in a hierarchical memory representation of a hierarchical naming structure, wherein the hierarchical memory representation includes a plurality of hash tables stored via two levels of nesting, wherein a first hash table from the plurality of hash tables storing a plurality of containers is stored as a first level in two levels of nesting, and wherein each container from the plurality of containers includes at least one hash table from the plurality of hash tables storing at least one object, wherein the at least one hash table is stored in the first hash table as a second level in the two levels of nesting; and

means for non-persistently storing the hierarchical memory representation as a plurality of hash tables stored via the two levels of nesting in a non-persistent storage unit.

16. The apparatus of claim 15 further comprising:

means for linking a first object type to a container object type to form a sub-context.

17. The apparatus of claim 16 wherein the means for linking insure that no more than one object of the first object type is linked to a single object of the container object type.

18. A non-transitory computer-readable medium containing instructions that, when executed, cause a machine to:

receive a serialized directory object;

generate a basic object from the serialized directory object;

create a context instance by linking the basic object to a container, wherein the container represents the context instance;

store the container in a hierarchical memory representation of a hierarchical naming structure, wherein the hierarchical memory representation includes a plurality of hash tables stored via two levels of nesting, wherein a first hash table from the plurality of hash tables that stores the container is stored as a first level of nesting of two levels of nesting, and wherein the container includes at least one hash table from the plurality of hash tables; and

store objects bound in the context instance represented by the container in the at least one hash table nested in the first hash table as a next second level in the two levels of nesting.

19. The computer-readable medium of claim 18 wherein the instructions further cause the machine to:

store the context instance in a memory implementation of a virtual machine; and

remove the context instance in response to a reboot of an application server resident in the virtual machine.

20. The computer-readable medium of claim 18 wherein the instructions further cause the machine to:

store the objects against names in the second level of nesting of the two levels of nesting; and

store the objects against identifiers in the second level of nesting of the two levels of nesting.