Reducing contention and messaging traffic in a distributed shared caching for clustered file systems

• US 8,788,547 B2
• Filed: 01/03/2013
• Issued: 07/22/2014
• Est. Priority Date: 08/25/2008
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Aronovich, Lior, Toaff, Yair, Paz, Gil, Asher, Ron
• Primary Examiner(s): Casanova, Jorge A
• Application Number:
  US13/733,194
• Publication Number:
  US 20130191330A1
• Time in Patent Office: 565 Days
• Field of Search: 707/826
• US Class Current: 707/826
• 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 12/0828 with concurrent directory accessing, i.e. handling multiple concurrent coherency transactions
• CPC Class Codes: G06F 12/084 with a shared cache
• CPC Class Codes: G06F 16/11 File system administration, e.g. details of archiving or snapshots file system backup G06F11/14
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• CPC Class Codes: G06F 16/16 File or folder operations, e.g. details of user interfaces specifically adapted to file systems
• CPC Class Codes: G06F 16/172 Caching, prefetching or hoarding of files
• CPC Class Codes: G06F 16/182 Distributed file systems
• CPC Class Codes: G06F 16/183 Provision of network file services by network file servers, e.g. by using NFS, CIFS network file access protocols H04L67/1097
• CPC Class Codes: G06F 16/1865 Transactional file systems
• CPC Class Codes: G06F 16/24552 Database cache management
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 2212/604 Details relating to cache allocation

Abstract

Systems. Methods, and Computer Program Products are provided managing global cache coherency and reducing contention and messaging traffic in a distributed shared caching for a clustered file systems (CFS). The CFS manages access to data segment space of the data segments shared between a cluster of nodes by using the file access component. A CFS disk space is partitioned into regions and disk objects are partitioned into groups. Each of the regions and the groups are assigned to a CFS agent residing on each one of the cluster of nodes.

Claims

1. A method for managing global cache coherency and reducing contention and messaging traffic in a distributed shared caching for clustered file systems (CFS), the CFS having a file access component that includes a cache and a distributed shared memory (DSM) module in a computing environment, the method comprising:

managing the access permissions to data segment space of the data segments shared between a cluster of nodes by using the file access component;

partitioning CFS disk space into a plurality of regions and disk objects into a plurality of groups;

assigning each of the plurality of regions and the plurality of groups to a CFS agent residing on each one of the cluster of nodes;

modifying, by a CFS agent, those of the plurality of regions and the plurality of objects assigned to the CFS agent; and

modifying, at an increased frequency, by the CFS agent, those of the plurality of regions and the plurality of objects assigned to the CFS agent as compared to those of the plurality of regions and the plurality of objects that are not assigned to the CFS agent.

2. The method of claim 1, further including managing the access permissions to data segment space of the data segments by the DSM module.

3. The method of claim 1, further including providing, in the CFS, the cache of data segment slots on each of the cluster of nodes, wherein the distributed shared memory (DSM) module has no internal memory for the data segments on each of the cluster of nodes and the cache acts as an external memory.

4. The method of claim 1, further including applying the partitioning to at least one of a file system metadata space and objects and a file system user data space and objects.

5. The method of claim 1, further including integrating a distributed shared memory with caching for both CFS user data and CFS metadata for alleviating the contention on frequently accessed data segments and reducing messaging traffic for coordination of access to shared storage.

6. A system for managing global cache coherency and reducing contention and messaging traffic in a distributed shared caching for a clustered file systems (CFS), the system comprising:

a cluster of nodes, the CFS including the cluster of nodes forming a computer cluster, data segments shared between the cluster of nodes, wherein the CFS resides on the cluster of nodes for accessing space of data segments that are shared between the cluster of nodes, a distributed shared memory (DSM) module, with no internal memory for the data segments on each of the cluster of nodes within a node of the cluster of nodes; and

a file access component included in the CFS, wherein the file access component includes a cache and the DSM module, a plurality of storage devices in communication with the CFS, the cache of data segment slots on each of the cluster of nodes, wherein the cache, acting as an external memory, are included in the CFS, a remote cache memory within each of the cluster of nodes, a cache associated with the node, a CFS agent associated with the CFS, and a processor device having a memory coupled to the processor device for controlling the CFS, wherein the processor device is assigned to the node and the node is in communication with the plurality of storage devices, wherein the processor device;

manages the access permissions to data segment space of the data segments shared between the cluster of nodes by using the file access component;

partitions CFS disk space of the CFS into a plurality of regions and disk objects into a plurality of groups; and

assigns each of the plurality of regions and the plurality of groups to the CFS agent residing on each one of the cluster of nodes, wherein;

the CFS agent modifies those of the plurality of regions and the plurality of objects assigned to the CFS agent, and

the CFS agent modifies, at an increased frequency, those of the plurality of regions and the plurality of objects assigned to the CFS agent as compared to those of the plurality of regions and the plurality of objects that are not assigned to the CFS agent.

7. The system of claim 6, wherein the processor device manages the access permissions to data segment space of the data segments by the DSM module.

8. The system of claim 6, wherein the processor device provides, in the CFS, the cache of data segment slots on each of the cluster of nodes, wherein the distributed shared memory (DSM) module has no internal memory for the data segments on each of the cluster of nodes and the cache is acting as an external memory in the CFS.

9. The system of claim 6, wherein the processor device applies the partitioning to at least one of a file system metadata space and objects and a file system user data space and objects.

10. The system of claim 6, wherein the processor device integrates a distributed shared memory with caching for both CFS user data and CFS metadata for alleviating the contention on frequently accessed data segments and reducing messaging traffic for coordination of access to shared storage.

11. A computer program product for managing global cache coherency and reducing contention and messaging traffic in a distributed shared caching for a clustered file systems (CFS), the CFS having a file access component that includes a cache and a distributed shared memory (DSM) module using a processor device, the CFS having a file access component that includes a cache and a distributed shared memory (DSM) module, and the computer program product comprising a non-transitory computer-readable storage medium having computer-readable program code portions stored therein, the computer-readable program code portions comprising:

a first executable portion that manages the access permissions to data segment space of the data segments shared between the cluster of nodes by using the file access component;

a second executable portion that partitions CFS disk space of the CFS into a plurality of regions and disk objects into a plurality of groups;

a third executable portion that assigns each of the plurality of regions and the plurality of groups to a CFS agent residing on each one of the cluster of nodes; and

a fourth executable portion that modifies, by a CFS agent, those of the plurality of regions and the plurality of objects assigned to the CFS agent, and modifies, at an increased frequency, by the CFS agent, those of the plurality of regions and the plurality of objects assigned to the CFS agent as compared to those of the plurality of regions and the plurality of objects that are not assigned to the CFS agent.

12. The computer program product of claim 11, further including a fourth executable portion that manages the access permissions to data segment space of the data segments by the DSM module.

13. The computer program product of claim 11, further including a fourth executable portion that provides, in the CFS, the cache of data segment slots on each of the cluster of nodes, wherein the distributed shared memory (DSM) module has no internal memory for the data segments on each of the cluster of nodes and the cache is acting as an external memory in the CFS.

14. The computer program product of claim 11, further including a fourth executable portion that applies the partitioning to at least one of a file system metadata space and objects and a file system user data space and objects.

15. The computer program product of claim 11, further including a fourth executable portion that integrates a distributed shared memory with caching for both CFS user data and CFS metadata for alleviating the contention on frequently accessed data segments and reducing messaging traffic for coordination of access to shared storage.