Directory synchronization of a dispersed storage network

Patent metadata

Field	Value
Publication number	US-9501341-B2
Application number	US-201414481892-A
Country	US
Kind code	B2
Filing date	Sep 9, 2014
Priority date	Mar 31, 2008
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

A method begins by independently executing a first write transaction in a dispersed storage network (DSN) to a particular write verification step of a multiple step write process, wherein the first write transaction has a first transaction identifier. The method continues by independently executing a second write transaction in the DSN to the particular write verification step, wherein the second write transaction has a second transaction identifier, and wherein subject matter of the first write transaction is related to subject matter of the second write transaction. The method continues by dependently finalizing the multiple step write process for each of the first and second write transactions utilizing the first and second transaction identifiers when each of the first and second write transactions have reached the particular write verification step.

First claim

What is claimed is:

1. A method for execution by a computing device, the method comprises:
independently executing a first write transaction in a dispersed storage network (DSN) to a particular write verification step of a multiple step write process, wherein the first write transaction has a first transaction identifier, the first write transaction includes a first set of write commands for a data segment that has been dispersed storage error encoded into a set of encoded data slices;
independently executing a second write transaction in the DSN to the particular write verification step, wherein the second write transaction has a second transaction identifier, the second write transaction includes a second set of write commands for directory information regarding the set of encoded data slices, wherein the directory information is dispersed storage error encoded into a set of encoded directory slices and wherein subject matter of the first write transaction is related to subject matter of the second write transaction; and
when each of the first and second write transactions have reached the particular write verification step, dependently finalizing the multiple step write process for each of the first and second write transactions utilizing the first and second transaction identifiers.

2. The method of claim 1 , wherein the multiple step write process further comprises:
a write initiate step that includes a set of write requests and a write threshold number of corresponding write responses;
a write commit step that includes a set of write commit requests and the write threshold number of corresponding write commit responses; and
a write finalize step that includes a set of write finalize commands, wherein the particular step is the write initiate step.

3. The method of claim 1 , wherein the multiple step write process further comprises:
a write initiate step that includes a set of write requests and a write threshold number of corresponding write responses;
a write commit step that includes a set of write commit requests and the write threshold number of corresponding write commit responses; and
a write finalize step that includes a set of write finalize commands, wherein the particular step is the write commit step.

4. The method of claim 1 , wherein the independently executing the first write transaction further comprises:
generating the first transaction identifier regarding storage of a set of encoded data slices, wherein a data segment was dispersed storage error encoded to produce the set of encoded data slices;
outputting a set of write request messages to dispersed storage (DS) units of the DSN, wherein each write request message of the set of write request messages includes the first transaction identifier and a corresponding one of the set of encoded data slices;
receiving write response messages from at least some of the DS units, wherein each of the write response messages includes a reference to the first transaction identifier; and
when at least a write threshold number of the write response messages have been received, commencing a commit step of the multiple step write process for the first write transaction.

5. The method of claim 4 , wherein the commencing the commit step for the first write transaction comprises:
outputting a plurality of data commit request messages regarding the set of encoded data slices to the DS units, wherein each of the plurality of data commit request messages includes the first transaction identifier.

6. The method of claim 1 , wherein the independently executing the second write transaction further comprises:
generating the second transaction identifier regarding storage of a set of encoded directory slices, wherein directory information is dispersed storage error encoded to produce a set of encoded directory slices;
outputting a second plurality of write request messages to DS units, wherein each of the second plurality of write request messages includes the second transaction identifier and a corresponding one of the set of encoded directory slices; and
when at least a second write threshold number of favorable second write response messages have been received from the DS units, commencing a commit step of the multiple step write process for the second write transaction.

7. The method of claim 6 , wherein the commencing the commit step for the second write transaction comprises:
outputting a plurality of directory commit request messages regarding the set of encoded directory slices to the DS units, wherein each of the plurality of directory commit request messages includes the second transaction identifier.

8. A computer comprises:
an interface;
memory; and
a processing module operably coupled to the memory and the interface, wherein the processing module is operable to:
independently execute a first write transaction in a dispersed storage network (DSN) to a particular write verification step of a multiple step write process, wherein the first write transaction has a first transaction identifier, the first write transaction including a first set of write commands for a data segment that has been dispersed storage error encoded into a set of encoded data slices;
independently execute a second write transaction in the DSN to the particular write verification step, wherein the second write transaction has a second transaction identifier, the second write transaction including a second set of write commands for directory information regarding the set of encoded data slices, wherein the directory information is dispersed storage error encoded into a set of encoded directory slices, and wherein subject matter of the first write transaction is related to subject matter of the second write transaction; and
when each of the first and second write transactions have reached the particular write verification step, dependently finalize the multiple step write process for each of the first and second write transactions utilizing the first and second transaction identifiers.

9. The computer of claim 8 , wherein the processing module is further operable to:
output, via the interface, a write initiate step that includes a set of write requests and a write threshold number of corresponding write responses;
output, via the interface, a write commit step that includes a set of write commit requests and the write threshold number of corresponding write commit responses; and
output, via the interface, a write finalize step that includes a set of write finalize commands, wherein the particular step is the write initiate step.

10. The computer of claim 8 , wherein the processing module is further operable to:
output, via the interface, a write initiate step that includes a set of write requests and a write threshold number of corresponding write responses;
output, via the interface, a write commit step that includes a set of write commit requests and the write threshold number of corresponding write commit responses; and
output, via the interface, a write finalize step that includes a set of write finalize commands, wherein the particular step is the write commit step.

11. The computer of claim 8 , wherein the processing module is further operable to:
generate the first transaction identifier regarding storage of a set of encoded data slices, wherein a data segment was dispersed storage error encoded to produce the set of encoded data slices;
output, via the interface, a set of write request messages to dispersed storage (DS) units of the DSN, wherein each write request message of the set of write request messages includes the first transaction identifier and a corresponding one of the set of encoded data slices;
receive, via th

Assignees

• Cleversafe Inc
• IBM

Inventors

• Dhuse Greg
• Baptist Andrew
• Leggette Wesley
• Volvovski Ilya
• Resch Jason K
• Cilfone Bart

Classifications

• G06F11/1064

  in cache or content addressable memories · CPC title

• G06F11/1443

  Transmit or communication errors · CPC title

• G06F12/0815

  Cache consistency protocols · CPC title

• G06F11/1471

  involving logging of persistent data for recovery · CPC title

• G06F2211/1057

  Parity-multiple bits-RAID6, i.e. RAID 6 implementations · CPC title