Recovery and flush of endurant cache

摘要

Various embodiments are directed towards enabling data writes utilizing a node cache and a logstore stored on a stable storage device. A client device may send data to a node for writing to a parent file. The node may cache the received data prior to writing the data to the parent file. Caching the received data may comprise adding the received data to a node cache and to a logstore. In one embodiment, the node cache may include a coalescer that combines data from a plurality of data writes from the client device to the node prior to writing to the parent file. In some embodiments, the logstore may be mirrored logstore on one or more stable storage devices. The parent file may periodically be updated from the node cache data. After the parent file is updated, the node cache data and the logstore data may be purged.

主权项

1. A method for employing a node device to recover cached data in a cluster of node devices over a network, wherein the node device performs actions, comprising:
if a recovery condition for the cached data in a logstore occurs, determining recoverable cached data in the logstore that is mirrored in a node cache, wherein the node cache is maintained in a memory of the node device, and wherein the logstore is maintained on a stable storage device accessible to all node devices in the cluster of node devices; determining a parent file associated with the logstore, wherein the parent file is stored in a stable storage device; writing the recoverable cached data to the parent file in the stable storage device; and in response to determining that the recoverable cached data has been committed to the parent file in the stable storage device:
purging the recoverable cached data from the node cache;invalidating the cached data in a block in the logstore that corresponds to the recoverable cached data; anddeallocating each block in the logstore that includes the invalidated cached data, wherein each deallocated block is available for storage of subsequent cached data.