Identifying and correcting an undesired condition of a dispersed storage network access request
View Patent ↗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.
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.