Cache management in RDMA distributed key/value stores based on atomic operations

• US 10,037,302 B2
• Filed: 11/30/2015
• Issued: 07/31/2018
• Est. Priority Date: 10/16/2015
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hack, Michel H., Ren, Yufei, Wang, Yandong, Zhang, Li
• Primary Examiner(s): Naji, Younes
• Application Number:
  US14/953,488
• Publication Number:
  US 20170109317A1
• Time in Patent Office: 974 Days
• Field of Search: None
• CPC Class Codes: G06F 12/0813 with a network or matrix configuration
• CPC Class Codes: G06F 15/167 using a common memory, e.g. mailbox
• CPC Class Codes: G06F 17/00 Digital computing or data processing equipment or methods, specially adapted for specific functions information retrieval, database structures or file system structures therefor G06F16/00
• CPC Class Codes: G06F 2212/154 Networked environment
• CPC Class Codes: H04L 67/5681 Pre-fetching or pre-delivering data based on network characteristics

Abstract

A cache management system performs cache management in a Remote Direct Memory Access (RDMA) key value data store. The cache management system receives a request from at least one client configured to access a data item stored in a data location of a remote server, and determines a popularity of the data item based on a frequency at which the data location is accessed by the at least one client. The system is further configured to determine a lease period of the data item based on the frequency and assigning the lease period to the data location.

Claims

1. A method of performing cache management in a Remote Direct Memory Access (RDMA) key value data store, the method comprising:

receiving a request from at least one client configured to access a data item stored in a data location of a remote server;

determining a popularity of the data item based on a frequency at which the data location is accessed by the at least one client; and

calculating a lease period of the item based on the frequency and assigning the lease period to the data location, and maintaining accessibility of the data location to the at least one client for a duration of the lease period,

wherein determining the popularity of the data item further comprises using a RDMA remote pointer to perform an atomic fetch/add operation to update, by the at least one client, a frequency data location stored in the remote server with access frequency data indicating the frequency at which the data location is accessed by the at least one client without requiring the remote server to process a read request.

2. The method of claim 1, wherein the frequency is based on a frequency differential between a first frequency during a first time period and a second frequency during a second subsequent time period.

3. The method of claim 2, further comprising dynamically tuning the lease period as the frequency differential changes over time.

4. The method of claim 3, further comprising resetting the cache management system by deleting the frequency from the frequency data location in response to an error event.

5. The method of claim 4, further comprising reclaiming by the remote server the data location by deleting the data item in response to expiration of the lease period.

6. The method of claim 1, further comprising controlling access of the data location via a hardware controller, and bypassing the controller, via the at least one client, when performing the atomic fetch/add operation to update the frequency data location.