SYNCHRONIZATION CACHE SEEDING

• US 20160063083A1
• Filed: 08/29/2014
• Published: 03/03/2016
• Est. Priority Date: 08/29/2014
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Mu, Yuedong, Ngan, Ching-Yuk Paul, Sundararajan, Manoj V.
• Granted Patent: US 10,496,676 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/20 using active fault-masking, e.g. by switching out faulty elements or by switching in spare elements
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: G06F 2201/82 Solving problems relating to consistency ensuring consistency in mirrored systems G06F11/2064
• CPC Class Codes: H04L 47/828 Allocation of resources per group of connections, e.g. per group of users
• CPC Class Codes: H04L 65/40 Support for services or applications
• CPC Class Codes: H04L 67/1078 Resource delivery mechanisms
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching

Abstract

Synchronization metadata is read from non-volatile storage. The synchronization metadata comprises indications of one or more synchronization targets. A synchronization target is a node of a clustered storage system. A synchronization cache is populated with the synchronization metadata. After populating the synchronization cache with at least a portion of the synchronization metadata, a connection to a network is established. After the connection to the network is established, a connection to a first of the one or more synchronization targets is established.

Claims

1. A method comprising:

reading synchronization metadata from non-volatile storage, wherein the synchronization metadata comprises indications of one or more synchronization targets, wherein a synchronization target is a node of a clustered storage system;

populating a synchronization cache with the synchronization metadata;

after populating the synchronization cache with at least a portion of the synchronization metadata, establishing a connection to a network; and

after establishing the connection to the network, establishing a connection to a first of the one or more synchronization targets.

2. The method of claim 1, further comprising:

loading metadata from the non-volatile storage, wherein the metadata comprises a reference to the location of the synchronization metadata in the non-volatile storage; and

resolving the reference to the location of the synchronization metadata in the non-volatile storage.

3. The method of claim 1 further comprising:

determining that the connection to the network is established;

wherein said establishing the connection to the first of the one or more synchronization targets is in response to said determining that the connection to the network is established.

4. The method of claim 1 further comprising:

receiving an indication to begin a boot process; and

in response to receiving an indication to begin the boot process, initiating the boot process;

wherein said establishing a connection to a first of the one or more synchronization targets occurs within thirty seconds of the initiation of the boot process.

5. The method of claim 1 further comprising:

receiving an indication of an input/output operation, wherein the input/output operation modifies data;

determining that the indication of the input/output operation references data stored in the clustered storage system;

determining that the stored data is part of a consistency group based, at least in part, on the synchronization metadata;

determining that the input/output operation modifies the data stored in the clustered storage system;

determining that modifications to the consistency group are replicated to a consistency group endpoint located on the first of the one or more synchronization targets; and

in response to said determining that the input/output operation modifies the data stored in the clustered storage system and said determining that modifications to the consistency group are replicated to a consistency group endpoint located on the first of the one or more synchronization targets, replicating the input/output operation to the first of the one or more synchronization targets.

6. The method of claim 5 further comprising:

receiving, from the first of the one or more synchronization targets, an acknowledgement indicating that replication of the input/output operation is complete; and

in response to said receiving the acknowledgement indicating that replication of the input/output operation is complete, sending, to a client associated with the input/output operation, an acknowledgement that the input/output operation was performed.

7. The method of claim 1, wherein said reading the synchronization metadata from the non-volatile storage comprises reading the synchronization metadata from sequential locations in the non-volatile storage.

8. A non-transitory machine readable medium having stored thereon instructions for establishing connections to synchronization targets, comprising machine executable code which, when executed by at least one machine, causes the at least one machine to:

read synchronization metadata from non-volatile storage, wherein the synchronization metadata comprises indications of one or more synchronization targets, wherein a synchronization target is a node of a clustered storage system;

populate a synchronization cache with at least a portion of the synchronization metadata;

establish a connection to a network after the synchronization cache is populated with at least the portion of the synchronization metadata; and

establish a connection to a first of the one or more synchronization targets after a connection to the network is established.

9. The non-transitory machine readable medium of claim 8, further comprising machine executable code which, when executed by the at least one machine, causes the at least one machine to:

load metadata from the non-volatile storage, wherein the metadata comprises a reference to the location of the synchronization metadata in the non-volatile storage; and

resolving the reference to the location of the synchronization metadata in the non-volatile storage.

10. The non-transitory machine readable medium of claim 8 further comprising machine executable code which, when executed by the at least one machine, causes the at least one machine to:

determine that the connection to the network is established;

wherein establishment of a connection to the first of the one or more synchronization targets is in response to a determination that a connection to the network is established.

11. The non-transitory machine readable medium of claim 8 further comprising machine executable code which, when executed by the at least one machine, causes the at least one machine to:

receive an indication to begin a boot process; and

in response to reception of an indication to begin the boot process, initiating the boot process;

wherein establishment of a connection to the first of the one or more synchronization targets occurs within thirty seconds of the initiation of the boot process.

12. The non-transitory machine readable medium of claim 8 further comprising machine executable code which, when executed by the at least one machine, causes the at least one machine to:

receive an indication of an input/output operation, wherein the input/output operation modifies data;

determine that the indication of the input/output operation references data stored in the clustered storage system;

determine that the stored data is part of a consistency group based, at least in part, on the synchronization metadata;

determine that the input/output operation modifies the data stored in the clustered storage system;

determine that modifications to the consistency group are replicated to a consistency group endpoint located on the first of the one or more synchronization targets; and

in response to a determination that the input/output operation modifies the data stored in the clustered storage system and a determination that modifications to the consistency group are replicated to a consistency group endpoint located on the first of the one or more synchronization targets, replicate the input/output operation to the first of the one or more synchronization targets.

13. The non-transitory machine readable medium of claim 12 further comprising machine executable code which, when executed by the at least one machine, causes the at least one machine to:

receive, from the first of the one or more synchronization targets, an acknowledgement that indicates that replication of the input/output operation is complete; and

in response to reception of an acknowledgement indicating that replication of the input/output operation is complete, send, to a client associated with the input/output operation, an acknowledgement that the input/output operation was performed.

14. The non-transitory machine readable medium of claim 8, wherein the machine executable code which, when executed by the at least one machine, causes the at least one machine to read the synchronization metadata from the non-volatile storage comprises machine executable code which, when executed by the at least one machine, causes the at least one machine to read the synchronization metadata from sequential locations in the non-volatile storage.

15. An apparatus comprising:

a processor;

a network interface; and

a machine readable storage medium having program code stored therein that is executable by the processor to cause the apparatus to;

prior to establishment of a connection to a network and after initiation of a boot process, begin to load metadata usable to connect, via the network, to a first node of a clustered storage system;

identify the first node of a clustered storage system based, at least in part, on the metadata, wherein the metadata indicates that the first node of the clustered storage system comprises a consistency group endpoint; and

subsequent to establishment of a connection to the network and prior to completion of the boot process, establish a connection to the first node of the clustered storage system.

16. The apparatus of claim 15, wherein said program code further comprises program code executable by the processor to cause the apparatus to:

establish, via the network interface, a connection to the network;

wherein said program code being executable by the processor to cause the apparatus to establish a connection to the first node of the clustered storage system comprises program code that is executable by the processor to cause the apparatus to establish a connection to the first node of the clustered storage system in response to establishment of a connection to the network.

17. The apparatus of claim 15, wherein said program code further comprises program code executable by the processor to cause the apparatus to:

determine that the first node of the clustered storage system does not comprise the consistency group endpoint;

responsive to a determination that the first node of the clustered storage system does not comprise the consistency group endpoint, determine that a second node of the clustered storage system comprises the consistency group endpoint; and

responsive to a determination that the second node of the clustered storage system comprises the consistency group endpoint, update the metadata to indicate that the second node of the clustered storage system comprises the consistency group endpoint.

18. The apparatus of claim 17, wherein said program code further comprises program code executable by the processor to cause the apparatus to, subsequent to an update of the metadata, store the updated metadata to non-volatile storage.

19. The apparatus of claim 18, wherein said program code being executable by the processor to cause the apparatus to store the updated metadata in non-volatile storage further comprises program code executable by the processor to cause the apparatus to write the updated metadata to sequential locations in the non-volatile storage.

20. The apparatus of claim 18, wherein said program code further comprises program code executable by the processor to cause the apparatus to:

prior to completion of the boot process,

receive an input/output operation that modifies data stored on at least one storage device associated with the apparatus;

determine that the data stored on the at least one storage device is associated with a consistency group based, at least in part, on the metadata;

determine that the consistency group endpoint is associated with the consistency group based, at least in part, on the metadata; and

send an indication of the input/output operation to the first node of the clustered storage system.