| 摘要 |
A append-only data storage system that stores sets of data blocks in extents that are located in storage devices. When an extent becomes full, the system changes the extent from an open state, wherein data can be appended to the extent, to a closed state, wherein data cannot be appended to the extent. This change involves performing a synchronization operation by: obtaining a list of data blocks in the extent from each storage device that has a copy of the extent; forming a union of the lists; looking up data blocks from the union in a database that maps data blocks to storage devices and extents to determine which data blocks belong in the extent; and if a copy of the extent is missing data blocks that belong in the extent, performing a remedial action before changing the extent from the open state to the closed state. |
| 主权项 |
1. A computer-implemented method, comprising:
operating a data storage system that is append-only and stores sets of data blocks in extents that are replicated across multiple storage devices in the data storage system; and when an extent becomes full during operation of the data storage system, changing the extent from an open state, wherein data can be appended to the extent, to a closed state, wherein data cannot be appended to the extent; wherein changing the extent from the open state to the closed state includes performing a synchronization operation to ensure that the multiple copies of the extent contain the same data blocks by,
obtaining a list of data blocks in the extent from each storage device that has a copy of the extent,forming a union of the obtained lists,looking up data blocks from the union in a database that maps data blocks to storage devices and extents to determine which data blocks belong in the extent, andif a copy of the extent is missing one or more data blocks that belong in the extent, performing a remedial action before changing the extent from the open state to the closed state. |
