Writing to a site cache in a distributed file system

• US 9,898,477 B1
• Filed: 09/24/2015
• Issued: 02/20/2018
• Est. Priority Date: 12/05/2014
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Inventors: Panghal, Vijay
• Primary Examiner(s): Choe, Yong
• Application Number:
  US14/864,425
• Time in Patent Office: 880 Days
• CPC Class Codes: G06F 16/172 Caching, prefetching or hoarding of files
• CPC Class Codes: G06F 16/182 Distributed file systems

Abstract

A method, article of manufacture, and apparatus for providing a site cache manager is discussed. Data objects may be read from a site cache rather than an authoritative object store. This provides performance benefits when a client reading the data has a better connection to the site cache than to the authoritative object store. The site cache manager controls the volume of stored data on the site cache to enhance performance by increasing the frequency of data object being read from or written to the site cache rather than the authoritative object store.

Claims

1. A method, the method comprising:

receiving, at a site cache, a write request from a client, the write request comprising a data object, an object identifier associated with the data object, and a location reference for an authoritative object store at the site cache;

transmitting a write intent including the object identifier to a metadata store associated with the site cache;

updating the metadata store to include the object identifier;

determining whether a transient object store associated with the site cache has exceeded a capacity threshold;

transmitting the data object and object identifier to the authoritative object store at the location reference in response to determining that the transient object store has exceeded the capacity threshold; and

writing the data object to the transient object store in response to determining that the transient object store has not exceeded the capacity threshold.

2. The method of claim 1, wherein the write request is received at a traffic processing engine of the site cache.

3. The method of claim 2, wherein the traffic processing engine transmits the write intent to a transient object store service.

4. The method of claim 3, wherein the transient object store service updates the metadata store using the write intent.

5. The method of claim 4 wherein the object store service transmits a confirmation to the traffic processing engine, the confirmation indicating the metadata store update was successful.

6. The method of claim 5, wherein the traffic processing engine writes the data object to the transient object store in response to the confirmation.

7. The method as recited in claim 1, wherein the method is performed at the site cache.

8. A system comprising a non-transitory computer readable storage medium and one or more hardware processors configured to execute instructions stored on the non-transitory computer readable storage medium for:

receiving a write request comprising a data object, an object identifier associated with the data object, and a location reference for an authoritative object store at a site cache;

transmitting a write intent including the object identifier to a metadata store associated with the site cache;

updating the metadata store to include the object identifier;

determining whether a transient object store associated with the site cache has exceeded a capacity threshold;

writing the data object to the transient object store when the transient object store has not exceeded a capacity threshold; and

transmitting the data object and object identifier to the authoritative object store at the location reference when the transient object store has exceeded the capacity threshold.

9. The system of claim 8, wherein the write request is received at a traffic processing engine.

10. The system of claim 9, wherein the traffic processing engine transmits the write intent to a transient object store service.

11. The system of claim 10, wherein the transient object store service updates the metadata store using the write intent.

12. The system of claim 11 wherein the object store service transmits a confirmation to the traffic processing engine, the confirmation indicating the metadata store update was successful.

13. The system of claim 12, wherein the traffic processing engine writes the data object to the transient object store in response to the confirmation.

14. The system of claim 8, wherein the system takes the form of a site cache that further comprises a traffic processing engine, a transient object store service, the transient object store, and the metadata store.

15. A non-transitory computer readable storage medium comprising instructions for performing the following when the instructions are executed by one or more hardware processors:

receiving, at a traffic processing engine associated with a site cache, a write request comprising a data object, an object identifier associated with the data object, and a location reference for an authoritative object store at the site cache;

transmitting, by the traffic processing engine, a write intent including the object identifier to a metadata store associated with the site cache;

updating, by a transient object store service associated with the site cache, the metadata store to include the object identifier;

writing the data object to a transient object store associated with the site cache, wherein the data object is written to the transient object store associated with the site cache when the transient object store has not exceeded a capacity threshold; and

transmitting the data object and the object identifier to the authoritative object store at the location reference when the transient object store has exceeded the capacity threshold.

16. The non-transitory computer readable storage medium as recited in claim 15, wherein the non-transitory computer readable storage medium resides at a site cache, and the traffic processing engine is configured to communicate with a client external to the site cache.