Asymmetric data mirroring

Patent metadata

Field	Value
Publication number	US-9344502-B2
Application number	US-201414334715-A
Country	US
Kind code	B2
Filing date	Jul 18, 2014
Priority date	Aug 27, 2002
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

Methods, systems, and products mirror data between local memory and remote storage. A write command is sent from a server to a remote storage device, and a timer is established. A current time of the timer is compared to a maximum time period. If the maximum time period expires without receipt of an acknowledgment to the write command, then a write error is assumed to exist to the remote storage device.

First claim

The invention claimed is:

1. A method, comprising:
sending, by a server, an electronic request to store data to a local storage device and to mirror the data to a remote storage device;
counting, by the server, a time of latency;
monitoring, by the server, for receipt of an acknowledgment sent from the remote storage device;
submitting, by the server, additional requests to the remote storage device while monitoring for the acknowledgment sent from the remote storage device;
determining, by the server, an expiration of the time of latency without the receipt of the acknowledgment sent from the remote storage device; and
resubmitting, by the server, the additional requests to the remote storage device in response to the expiration of the time of latency.

2. The method of claim 1 , further comprising determining the time of latency using a ping command.

3. The method of claim 1 , further comprising retrieving the time of latency from a memory coupled to the server.

4. The method of claim 1 , further comprising erasing a block of memory in response to the expiration of the time of latency.

5. The method of claim 1 , further comprising caching the data to the local storage device.

6. The method of claim 1 , further comprising initializing a timer that counts the time of latency.

7. The method of claim 6 , further comprising re-establishing the timer in response to resubmission of the additional requests.

8. A system, comprising:
a processor; and
a memory storing instructions that when executed cause the processor to perform operations, the operations comprising:
sending a request to store data to a local storage device and to mirror the data to a remote storage device;
counting a time of latency;
monitoring for receipt of an acknowledgment sent from the remote storage device;
submitting additional requests to the remote storage device while monitoring for the acknowledgment sent from the remote storage device;
expiring the time of latency without the receipt of the acknowledgment sent from the remote storage device; and
resubmitting the additional requests to the remote storage device in response to an expiration of the time of latency.

9. The system of claim 8 , wherein the operations further comprise determining the time of latency using a ping command.

10. The system of claim 8 , wherein the operations further comprise retrieving the time of latency from the memory.

11. The system of claim 8 , wherein the operations further comprise erasing a block of memory in response to the expiration of the time of latency.

12. The system of claim 8 , wherein the operations further comprise caching the data to the local storage device.

13. The system of claim 8 , wherein the operations further comprise initializing a timer that counts the time of latency.

14. The system of claim 13 , wherein the operations further comprise re-establishing the timer in response to resubmission of the additional requests.

15. A memory device storing instructions that when executed cause a processor to perform operations, the operations comprising:
sending a request to store data to a local storage device and to mirror the data to a remote storage device;
counting a time of latency;
monitoring for receipt of an acknowledgment sent from the remote storage device;
submitting additional requests to the remote storage device while monitoring for the acknowledgment sent from the remote storage device;
expiring the time of latency without the receipt of the acknowledgment sent from the remote storage device; and
resubmitting the additional requests to the remote storage device in response to an expiration of the time of latency.

16. The memory device of claim 15 , wherein the operations further comprise determining the time of latency using a ping command.

17. The memory device of claim 15 , wherein the operations further comprise retrieving the time of latency from the memory.

18. The memory device of claim 15 , wherein the operations further comprise erasing a block of memory in response to the expiration of the time of latency.

19. The memory device of claim 15 , wherein the operations further comprise caching the data to the local storage device.

20. The memory device of claim 15 , wherein the operations further comprise initializing a timer that counts the time of latency.

Assignees

• At & T Ip Ii Lp

Inventors

• Gardner James A
• Freeman Darrell G

Classifications

• G06F11/1443 Primary

  Transmit or communication errors · CPC title

• H04L67/2842

  Electricity · mapped topic

• H04L67/1097 Primary

  for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS] · CPC title

• G06F11/2064

  while ensuring consistency · CPC title

• G06F11/2071

  using a plurality of controllers · CPC title