Enabling data integrity checking and faster application recovery in synchronous replicated datasets

• US 10,228,871 B2
• Filed: 02/22/2016
• Issued: 03/12/2019
• Est. Priority Date: 02/22/2016
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Patnaik, Pranab, Kaushik, Akhil
• Primary Examiner(s): Rojas, Midys
• Application Number:
  US15/049,410
• Publication Number:
  US 20170242599A1
• Time in Patent Office: 1,114 Days
• Field of Search: None
• CPC Class Codes: G06F 11/1662 the resynchronized component or unit being a persistent storage device re-synchronization of failed mirror storage G06F11/2082; rebuild or reconstruction of parity RAID storage G06F11/1008
• CPC Class Codes: G06F 11/2076 Synchronous techniques
• CPC Class Codes: G06F 11/2082 Data synchronisation
• CPC Class Codes: G06F 2201/82 Solving problems relating to consistency
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

One or more techniques and/or computing devices are provided for utilizing snapshots for data integrity validation and/or faster application recovery. For example, a first storage controller, hosting first storage, has a synchronous replication relationship with a second storage controller hosting second storage. A snapshot replication policy rule is defined to specify that a replication label is to be used for snapshot create requests, targeting the first storage, that are to be replicated to the second storage. A snapshot creation policy is created to issue snapshot create requests comprising the replication label. Thus a snapshot of the first storage and a replication snapshot of the second storage are created based upon a snapshot create request comprising the replication label. The snapshot and the replication snapshot may be compared for data integrity validation (e.g., determine whether the snapshots comprise the same data) and/or quickly recovering an application after a disaster.

Claims

1. A method comprising:

evaluating a snapshot create request using a snapshot replication policy rule to determine whether the snapshot create request comprises a replication label, wherein the snapshot replication policy rule is specified for a synchronous replication relationship between a first node hosting first storage and a second node hosting second storage, the snapshot replication policy rule specifying that the replication label is used to designate that snapshot create requests, targeting the first storage and having the replication label, are to be replicated to the second storage and that snapshot create requests without the replication label are excluded from being replicated to the second storage;

creating a snapshot of the first storage at the first node based upon the snapshot create request;

creating a replication snapshot of the second storage at the second node based upon the snapshot create request comprising the replication label; and

validating data integrity based upon a comparison of the snapshot and the replication snapshot.

2. The method of claim 1, comprising:

creating a second snapshot of the first storage at the first node without creating a corresponding replication snapshot of the second storage at the second node based upon receiving a second snapshot create request without the replication label.

3. The method of claim 1, comprising:

implementing the synchronous replication relationship for a storage object within the first storage, wherein an operation received by the first node from a client is acknowledged as complete based upon the operation being locally implemented upon the storage object by the first node and a replication of the operation being remotely implemented by the second nodes upon a replicated storage object of the storage object within the second storage.

4. The method of claim 3, comprising:

completing pending operations targeting the storage object before locally implementing the operation.

5. The method of claim 3, comprising:

queuing operations, targeting the storage object, into a queue while the operation is being locally implemented, wherein the operations within the queue are dequeued and implemented once the operation is locally implemented upon the storage object.

6. The method of claim 1, wherein the comparing comprises:

determining that synchronous replication, between the first node and the second node based upon the synchronous replication relationship, is not being performed correctly based upon the snapshot and the replication snapshot comprising different data.

7. The method of claim 1, wherein the comparing comprises:

verifying a dependent write order consistency of replicating operations to the second storage, wherein the dependent write order consistency corresponds to replication operations being executed upon the second storage in a same order as corresponding operations being executed upon the first storage.

8. The method of claim 1, wherein the snapshot is an application consistent snapshot associated with an application that utilizes the first storage and the replication snapshot is a replication application consistent snapshot, and the method comprising:

performing a switchover operation from the first node to the second node based upon the first node failing, wherein the replication application consistent snapshot is utilized to recover the application to utilize the second storage in place of the first storage.

9. The method of claim 8, comprising:

generating the application consistent snapshot based upon a snapshot request received from a plugin associated with the application.

10. The method of claim 9, comprising:

receiving, from a storage system replication module integrated with the application, a storage operation system application programing interface (API) command, comprising the replication label, as the snapshot request.

11. The method of claim 1, wherein the snapshot is an application consistent snapshot associated with an application that utilizes the first storage and the replication snapshot is a replication application consistent snapshot, and the method comprising:

performing a failover operation from the first node to the second node based upon a failover command to failover from the first node to the second node, wherein the replication application consistent snapshot is utilized to recover the application to utilize the second storage in place of the first storage.

12. The method of claim 11, comprising:

triggering the failover operation within a threshold amount of time from the creation of the snapshot and the replication snapshot.

13. A non-transitory machine readable medium having stored thereon instructions for performing a method comprising machine executable code which when executed by at least one machine, causes the machine to:

evaluate a snapshot create request using a snapshot replication policy rule to determine whether the snapshot create request comprises a replication label, wherein the snapshot replication policy rule is specified for a synchronous replication relationship between a first node hosting first storage, and a second node hosting second storage, the snapshot replication policy rule specifying that the replication label is used to designate that snapshot create requests, targeting the first storage and having the replication label, are to be replicated to the second storage and that snapshot create requests without the replication label are excluded from being replicated to the second storage;

create a snapshot of the first storage at the first node based upon the snapshot create request; and

create a replication snapshot of the second storage at the second node as a replication application consistent snapshot based upon the snapshot create request comprising the replication label; and

validate data integrity based upon a comparison of the snapshot and the replication snapshot.

14. The non-transitory machine readable medium of claim 13, wherein the machine executable code causes the machine to:

determine that synchronous replication, between the first node and the second node based upon the synchronous replication relationship, is not being performed correctly based upon the snapshot and the replication snapshot comprising different data.

15. The non-transitory machine readable medium of claim 13, wherein the machine executable code causes the machine to:

trigger a failover operation to failover from the first node to the second node within a threshold amount of time from the creation of the snapshot and the replication snapshot.

16. The non-transitory machine readable medium of claim 13, wherein the machine executable code causes the machine to:

verify a dependent write order consistency of replicating operations to the second storage, wherein the dependent write order consistency corresponds to replication operations being executed upon the second storage in a same order as corresponding operations being executed upon the first storage.

17. The non-transitory machine readable medium of claim 13, wherein the machine executable code causes the machine to:

implement the synchronous replication relationship for a storage object within the first storage, wherein an operation received by the first node from a client is acknowledged as complete based upon the operation being locally implemented upon the storage object by the first node and a replication of the operation being remotely implemented by the second nodes upon a replicated storage object of the storage object within the second storage.

18. A computing device comprising:

a memory containing machine readable medium comprising machine executable code having stored thereon instructions for performing a method; and

a processor coupled to the memory, the processor configured to execute the machine executable code to cause the processor to;

evaluate a snapshot create request using a snapshot replication policy rule to determine whether the snapshot create request comprises a replication label, wherein the snapshot replication policy rule is specified for a synchronous replication relationship between a first node hosting first storage and a second node hosting second storage, the snapshot replication policy rule specifying that the replication label is used to designate that snapshot create requests, targeting the first storage and having the replication label, are to be replicated to the second storage and that snapshot create requests without the replication label are excluded from being replicated to the second storage;

create a snapshot of the first storage at the first node based upon the snapshot create request; and

create a replication snapshot of the second storage at the second node based upon the snapshot create request comprising the replication label.

19. The computing device of claim 18, wherein the machine executable code causes the processor to:

validate data integrity based upon a comparison of the snapshot and the replication snapshot.

20. The computing device of claim 18, wherein the snapshot is an application consistent snapshot associated with an application that utilizes the first storage and the replication snapshot is a replication application consistent snapshot, and wherein the machine executable code causes the processor to:

perform a failover operation from the first node to the second node to failover from the first node to the second node, wherein the replication application consistent snapshot is utilized to recover the application to utilize the second storage in place of the first storage.