Patent attributes
Successful storing of extent operations into corresponding records of a transaction log results in acknowledgement of completion of the extent operations being indicated to one or more hosts. In response to determining that the extent operations are unrelated to each other, the extent operations are flushed in parallel from the transaction log to back-end non-volatile data storage. During the flushing, dependencies between the extent operations and other operations stored in the transaction log are maintained. Dependency chains are identified within the transaction log, and at least one tree data structure representing the dependencies between each of the extent operations and the other operations stored in the transaction log may be generated and traversed in order to select the correct operations stored in the transaction log to flush.