Systems and methods for providing nonlinear journaling
In one embodiment, systems and methods are provided for nonlinear journaling. In one embodiment, groups of data designated for storage in a data storage unit are journaled into persistent storage. In one embodiment, the journal data is recorded nonlinearly. In one embodiment, a linked data structure records data and data descriptors in persistent storage.
1. A system for journaling data to be written to a data storage node, comprising:
a processor coupled to a memory;
persistent memory configured to store journal data; and
a journal module configured to store, in the persistent memory:
a plurality of transaction descriptors, the plurality of transaction descriptors including a first transaction descriptor and a second transaction descriptor, wherein the first transaction descriptor comprises a link to the second transaction descriptor, wherein the plurality of transaction descriptors are stored such that each transaction descriptor may be removed from the plurality of transaction descriptors in an order that is different than an order in which the transaction descriptor was stored, wherein each of the plurality of transaction descriptors includes information identifying a transaction state of an associated transaction;
a plurality of block descriptors, wherein the first transaction descriptor comprises a link to a first block descriptor, the first block descriptor comprises a link to a second block descriptor, the second transaction descriptor comprises a link to a third block descriptor, and the third block descriptor comprises a link to a fourth block descriptor, wherein the plurality of block descriptors are stored such that each block descriptor may be removed from the plurality of block descriptors in an order that is different than an order in which the block descriptor was stored; and
a plurality of journal blocks, wherein each journal block of the plurality of journal blocks comprises data to be written to the data storage node;
wherein each of the plurality of block descriptors comprises a link to at least one of the plurality of journal blocks and at least one respective address in the data storage node to which the at least one journal block is to be written.
2. The system of claim 1 , wherein each transaction is a global transaction that is distributed among two or more data storage nodes, such that each global transaction is associated with a request to write data to the data storage node and a request to write different data to at least one other data storage node.
3. The system of claim 1 , wherein said journal blocks are one of the following sizes: 512 bytes and 8196 bytes.
4. The system of claim 1 , wherein at least one of the plurality of block descriptors further comprises a link to at least one other block descriptor of said plurality of block descriptors.
5. The system of claim 1 , wherein at least one of the plurality of transaction descriptors further comprises a link to at least one other transaction descriptor of said plurality of transaction descriptors.
6. The system of claim 1 , wherein each of the plurality of transaction descriptors comprises information identifying a transaction state and one or more data storage nodes participating in the associated transaction.
7. The system of claim 1 , wherein each of said links comprises an address in persistent memory associated with the data storage node.
8. A computer-implemented method of journaling data to be written to a data storage node, the computer-implemented method comprising:
storing in persistent memory a plurality of transaction descriptors, the plurality of transaction descriptors including a first transaction descriptor and a second transaction descriptor, wherein the first transaction descriptor comprises a link to the second transaction descriptor, wherein each of the plurality of transaction descriptors includes information identifying a transaction state of an associated transaction, wherein the plurality of transaction descriptors are stored such that each transaction descriptor may be removed from the plurality of transaction descriptors in an order that is different than an order in which the transaction descriptor was stored;
storing in persistent memory a plurality of block descriptors, wherein the first transaction descriptor comprises a link to a first block descriptor, the first block descriptor comprises a link to a second block descriptor, the second transaction descriptor comprises a link to a third block descriptor, and the third block descriptor comprises a link to a fourth block descriptor, wherein the plurality of block descriptors are stored such that each block descriptor may be removed from the plurality of block descriptors in an order that is different than an order in which the block descriptor was stored; and
storing in persistent memory a plurality of journal blocks, wherein each journal block of the plurality of journal blocks comprises data to be written to the data storage node, wherein each of the plurality of block descriptors comprises a link to at least one of the plurality of journal blocks and at least one respective address in the data storage node to which the at least one journal block is to be written.
9. The computer implemented method of claim 8 , wherein each of said links comprises an address in persistent memory associated with the data storage node.