Preventing multiple round trips when writing to target widths
Systems and methods for storing encoded data slices in a dispersed storage network (DSN) involve receiving a write data object request, determining a source name for the data object, identifying a source name range corresponding to the source name, and identifying a storage pattern associated with the source name range. Based on the source name range, a set of DS units can be identified as can affinity DS units that correspond to the storage pattern. The data object is encoded to produce affinity encoded data slices and other encoded data slices which are output to the affinity DS units and other DS units respectively. A determination is made whether a favorable number of affinity encoded data slices were properly received. If so, rollback requests are issued with regards to the other encoded data slices. If not, commit requests are issued with regards to the other encoded data slices.
1. A method of storing a data object in a dispersed storage network, the dispersed storage network including a plurality of dispersed storage (DS) units, the method comprising:
receiving a write data object request;
determining a source name for the data object;
identifying a source name range corresponding to the source name;
identifying a storage pattern associated with the source name range;
identifying a set of DS units of the plurality of DS units corresponding to the source name;
identifying affinity DS units of the set of DS units that correspond to the storage pattern;
encoding the data object to produce encoded affinity data slices;
encoding the data object to produce other encoded data slices;
outputting the encoded affinity data slices to the affinity DS units;
outputting the other encoded data slices to other DS units of the set of DS units;
determining if the encoded affinity data slices were properly received by the affinity DS units; and
issuing at least one rollback request regarding the other encoded data slices stored on the other DS units.
2. The method of claim 1 , wherein the data object includes a data name.
3. The method of claim 2 , wherein the source name is based on the data name.
4. The method of claim 1 , wherein the step of identifying the storage pattern associated with the source name range includes identifying the storage pattern from a list of storage patterns associated with the source name range.
5. The method of claim 1 , wherein the data object is a data segment.
6. The method of claim 1 , wherein the step of further comprising the step of determining if the encoded affinity data slices were properly received by the affinity DS units comprises determining at least one affinity data slice was not properly received.
7. The method of claim 6 , further comprising issuing at least one commit request regarding the other encoded data slices stored on the other DS units.
8. A dispersed storage processing unit for storing a data object in a dispersed storage network, the dispersed storage network including a plurality of dispersed storage (DS) units, the dispersed storage processing unit comprising:
a memory; and
a computer processor;
where the memory includes instructions for causing the computer processor to:
receive a write data object request;
determine a source name for the data object;
identify a source name range corresponding to the source name;
identify a storage pattern associated with the source name range;
identify a set of DS units of the plurality of DS units corresponding to the source name;
identify affinity DS units of the set of DS units that correspond to the storage pattern;
encode the data object to produce encoded affinity data slices;
encode the data object to produce other encoded data slices;
output the encoded affinity data slices to the affinity DS units;
output the other encoded data slices to other DS units of the set of DS units;
determine if the encoded affinity data slices were properly received by the affinity DS units; and
issue at least one rollback request regarding the other encoded data slices stored on the other DS units.
9. The dispersed storage processing unit of claim 8 , wherein the data object includes a data name.
10. The dispersed storage processing unit of claim 9 , wherein the source name is based on the data name.
11. The dispersed storage processing unit of claim 8 , wherein the memory includes instructions for further causing the computer processor to identify the storage pattern from a list of storage patterns associated with the source name range.
12. The dispersed storage processing unit of claim 8 , wherein the data object is a data segment.
13. The dispersed storage processing unit of claim 8 , wherein the memory includes instructions for further causing the computer processor to determine at least one encoded affinity data slice was not properly received.
14. The dispersed storage processing unit of claim 13 , wherein the memory includes instructions for further causing the computer processor to issue at least one commit request regarding the other encoded data slices stored on the other DS units.
15. A dispersed storage network comprising:
a plurality of dispersed storage (DS) units;
a dispersed storage processing unit for storing a data object in the dispersed storage network including:
a memory; and
a computer processor;
where the memory includes instructions for causing the computer processor to:
receive a write data object request;
determine a source name for the data object;
identify a source name range corresponding to the source name;
identify a storage pattern associated with the source name range;
identify a set of DS units of the plurality of DS units corresponding to the source name;
identify affinity DS units of the set of DS units that correspond to the storage pattern;
encode the data object to produce encoded affinity data slices;
encoding the data object to produce other encoded data slices;
output the encoded affinity data slices to the affinity DS units;
output the other encoded data slices to other DS units of the set of DS units;
determine if the encoded affinity data slices were properly received by the affinity DS units; and
issue at least one rollback request regarding the other encoded data slices stored on the other DS units.
16. The dispersed storage network of claim 15 , wherein the data object includes a data name.
17. The dispersed storage network of claim 16 , wherein the source name is based on the data name.
18. The dispersed storage network of claim 15 , wherein the memory includes instructions for further causing the computer processor to identify the storage pattern from a list of storage patterns associated with the source name range.
19. The dispersed storage network of claim 15 , wherein the memory includes instructions for further causing the computer processor to determine at least one encoded affinity data slice was not properly received.
20. The dispersed storage network of claim 15 , wherein the memory includes instructions for further causing the computer processor to issue at least one commit request regarding the other encoded data slices stored on the other DS units.