Abstract: Embodiments of the present disclosure relate to an apparatus comprising a memory and at least one processor. The at least one processor is configured to monitor one or more processing threads of a storage device. Each of the one or more processing threads includes two or more cache states. The at least one processor also updates one or more data structures to indicate a subject cache state of each of the one or more processing threads and detect an event that disrupts at least one of the one or more processing threads. Further, the processor determines a cache state of the at least one of the one or more processing threads contemporaneous to the disruption event using the one or more data structures and performs a recovery process for the disrupted at least one of the one or more processing threads.

Abstract: A storage system includes at least two independent storage engines interconnected by a fabric, each storage engine having two compute nodes. A shared global memory is implemented using cache slots of each of the compute nodes. Memory access operations to the slots of shared global memory are managed by a fabric adapter to guarantee that the operations are atomic. To enable local cache operations to be managed independent of the fabric adapter, a cache metadata data structure includes a global flag bit for each cache slot, that is used to designate the cache slot as globally available or temporarily reserved for local IO processing. The cache metadata data structure also includes a mutex (Peterson lock) for each cache slot to enforce a mutual exclusion concurrency control policy on the cache slot between the two compute nodes of the storage engine when the cache slot is used for local IO processing.

Abstract: Embodiments of the present disclosure relate to an apparatus comprising a memory and at least one processor. The at least one processor is configured to monitor one or more processing threads of a storage device. Each of the one or more processing threads includes two or more cache states. The at least one processor also updates one or more data structures to indicate a subject cache state of each of the one or more processing threads and detect an event that disrupts at least one of the one or more processing threads. Further, the processor determines a cache state of the at least one of the one or more processing threads contemporaneous to the disruption event using the one or more data structures and performs a recovery process for the disrupted at least one of the one or more processing threads.