Identifying and correcting an undesired condition of a dispersed storage network access request

• US 9,300,477 B2
• Filed: 07/15/2014
• Issued: 03/29/2016
• Est. Priority Date: 06/22/2010
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Cleversafe Incorporated (International Business Machines Corporation)
• Inventors: Resch, Jason K., Dhuse, Greg, Baptist, Andrew
• Primary Examiner(s): KHAJURIA, SHRIPAL K
• Application Number:
  US14/331,526
• Publication Number:
  US 20140331087A1
• Time in Patent Office: 623 Days
• Field of Search: 709/225
• US Class Current: 1/1
• CPC Class Codes: G06F 11/0727 in a storage system, e.g. in a DASD or network based storage system drivers for digital recording or reproducing units G06F3/06; circuits for error detection or correction within digital recording or reproducing units G11B20/18; 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], H04L67/1097
• CPC Class Codes: G06F 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G06F 11/141 for bus or memory accesses
• CPC Class Codes: G06F 11/167 Error detection by comparing the memory output
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• CPC Class Codes: G06F 16/137 Hash-based content-based indexing of textual data G06F16/31
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity
• CPC Class Codes: H04L 2209/043 of tables, e.g. lookup, substitution or mapping
• CPC Class Codes: H04L 2209/30 Compression, e.g. Merkle-Damgard construction
• CPC Class Codes: H04L 2209/34 Encoding or coding, e.g. Huffman coding or error correction
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/06 for supporting key management in a packet data network cryptographic mechanisms or cryptographic arrangements for key management H04L9/08
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 67/1097 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 Class Codes: H04L 9/3242 involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC
• CPC Class Codes: H04L 9/3247 : involving digital signatures
• CPC Class Codes: H04L 9/3263 : involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823
• CPC Class Codes: H04L 9/3271 : using challenge-response
• CPC Class Codes: H04W 12/041 : Key generation or derivation
• CPC Class Codes: H04W 12/0431 : Key distribution or pre-distribution; Key agreement
• CPC Class Codes: H04W 12/10 : Integrity
• CPC Class Codes: H04W 12/35 : Protecting application or service provisioning, e.g. securing SIM application provisioning

Abstract

A method begins by a processing module sending a transaction verification request to the set of dispersed storage (DS) units, wherein the transaction verification request includes a transaction number that corresponds to a particular dispersed storage network (DSN) access request. The method continues with the processing module receiving transaction verification responses from at least some of the set of DS units to produce received transaction verification responses. The method continues with the processing module identifying an undesired condition with processing the DSN access request and initiating a corrective remedy for the undesired condition when a DS unit of the set of DS units does not provide a desired transaction verification response.

Claims

1. A method for execution by a computer, the method comprises:

generating, by the computer, a transaction number for a write operation;

sending, by the computer, a set of write requests and a set of transaction verification requests to a set of storage units for the write operation, wherein a transaction verification request of the set of transaction verification requests includes the transaction number of the write operation; and

when verification responses from at least a decode threshold number of storage units are consistent;

generating, by the computer, a second transaction number for a write commit operation that corresponds to the write operation;

sending, by the computer, a set of write commit requests and a second set of transaction verification requests to the set of storage units for the write operation, wherein a transaction verification request of the second set of transaction verification requests includes the second transaction number of the write commit operation; and

receiving, by the computer, commit verification responses from at least some of the storage units.

2. The method of claim 1 further comprises:

when verification responses from less than the decode threshold number of storage units includes are consistent, sending a set of rollback commands to the storage units to rollback from the write operation to a previously successful write operation.

3. The method of claim 1 further comprises:

verifying that the verification responses from at least a decode threshold number of storage units are consistent by determining that the verification responses from the at least the decode threshold number of storage units include the transaction number.

4. The method of claim 1 further comprises:

when commit verification responses from at least the decode threshold number of storage units are consistent;

generating a third transaction number for a write finalize operation that corresponds to the write operation; and

sending a set of write finalize requests and a third set of transaction verification requests to the set of storage units for the write operation, wherein a transaction verification request of the third set of transaction verification requests includes the third transaction number of the write commit operation.

5. The method of claim 1 further comprises:

when commit verification responses from less than the decode threshold number of storage units includes are consistent, sending a set of undo commands to the storage units to undo the write operation.

6. A computer readable storage device comprises:

a first memory section that includes operational instructions that, when executed by a computing device, causes the computing device to;

generate a transaction number for a write operation; and

send a set of write requests and a set of transaction verification requests to a set of storage units for the write operation, wherein a transaction verification request of the set of transaction verification requests includes the transaction number of the write operation; and

a second memory section that includes operational instructions that, when executed by the computing device, causes the computing device to;

when verification responses from at least a decode threshold number of storage units are consistent;

generate a second transaction number for a write commit operation that corresponds to the write operation;

send a set of write commit requests and a second set of transaction verification requests to the set of storage units for the write operation, wherein a transaction verification request of the second set of transaction verification requests includes the second transaction number of the write commit operation; and

receive commit verification responses from at least some of the storage units.

7. The computer readable storage device of claim 6, wherein the second memory section further includes operational instructions that, when executed by the computing device, causes the computing device to:

when verification responses from less than the decode threshold number of storage units includes are consistent, send a set of rollback commands to the storage units to rollback from the write operation to a previously successful write operation.

8. The computer readable storage device of claim 6, wherein the second memory section further includes operational instructions that, when executed by the computing device, causes the computing device to:

verify that the verification responses from at least a decode threshold number of storage units are consistent by determining that the verification responses from the at least the decode threshold number of storage units include the transaction number.

9. The computer readable storage device of claim 6 further comprises:

a third memory section that includes operational instructions that, when executed by the computing device, causes the computing device to;

when commit verification responses from at least the decode threshold number of storage units are consistent;

generate a third transaction number for a write finalize operation that corresponds to the write operation; and

send a set of write finalize requests and a third set of transaction verification requests to the set of storage units for the write operation, wherein a transaction verification request of the third set of transaction verification requests includes the third transaction number of the write commit operation.

10. The computer readable storage device of claim 6, wherein the second memory section further includes operational instructions that, when executed by the computing device, causes the computing device to:

when commit verification responses from less than the decode threshold number of storage units includes are consistent, send a set of undo commands to the storage units to undo the write operation.

11. A computer comprises:

an interface;

a memory; and

a processing module operably coupled to the interface and the memory, wherein the processing module is operable to;

generate a transaction number for a write operation;

send a set of write requests and a set of transaction verification requests to a set of storage units for the write operation, wherein a transaction verification request of the set of transaction verification requests includes the transaction number of the write operation;

when verification responses from at least a decode threshold number of storage units are consistent;

generate a second transaction number for a write commit operation that corresponds to the write operation;

send a set of write commit requests and a second set of transaction verification requests to the set of storage units for the write operation, wherein a transaction verification request of the second set of transaction verification requests includes the second transaction number of the write commit operation; and

receive commit verification responses from at least some of the storage units.

12. The computer of claim 11, wherein the processing module is further operable to:

when verification responses from less than the decode threshold number of storage units includes are consistent, send a set of rollback commands to the storage units to rollback from the write operation to a previously successful write operation.

13. The computer of claim 11, wherein the processing module is further operable to:

verify that the verification responses from at least a decode threshold number of storage units are consistent by determining that the verification responses from the at least the decode threshold number of storage units include the transaction number.

14. The computer of claim 11, wherein the processing module is further operable to:

when commit verification responses from at least the decode threshold number of storage units are consistent;

generate a third transaction number for a write finalize operation that corresponds to the write operation; and

send a set of write finalize requests and a third set of transaction verification requests to the set of storage units for the write operation, wherein a transaction verification request of the third set of transaction verification requests includes the third transaction number of the write commit operation.

15. The computer of claim 11, wherein the processing module is further operable to:

when commit verification responses from less than the decode threshold number of storage units includes are consistent, send a set of undo commands to the storage units to undo the write operation.