Abstract:
A cache manager maintains coherency of cached objects used by applications in a computing system. The cache manager maintains a cache memory of objects as they are accessed by an application. The cache manager tracks cached objects on a per-application basis using a cache database, storing for each object metadata comprising the generation number of the application using the cached object, and the file generation number of the file from which the object was read. The cache manager determines whether cached objects are valid and can be used by the application, or are stale and must be reloaded, by using these generation numbers when an application attempts to use a file or object. In this fashion, cache coherency is maintained even in a distributed environment without the centralized cache management bottlenecks of prior approaches and without the need to eagerly purge the cache of stale versions of objects.
Abstract:
Systems and methods for managing records stored in a storage cache are provided. A cache index is created and maintained to track where records are stored in buckets in the storage cache. The cache index maps the memory locations of the cached records to the buckets in the cache storage and can be quickly traversed by a metadata manager to determine whether a requested record can be retrieved from the cache storage. Bucket addresses stored in the cache index include a generation number of the bucket that is used to determine whether the cached record is stale. The generation number allows a bucket manager to evict buckets in the cache without having to update the bucket addresses stored in the cache index. In an alternative embodiment, non-contiguous portions of computing system working memory are used to cache data instead of a dedicated storage cache.
Abstract:
A cache manager maintains coherency of cached objects used by applications in a computing system. The cache manager maintains a cache memory of objects as they are accessed by an application. The cache manager tracks cached objects on a per-application basis using a cache database, storing for each object metadata comprising the generation number of the application using the cached object, and the file generation number of the file from which the object was read. The cache manager determines whether cached objects are valid and can be used by the application, or are stale and must be reloaded, by using these generation numbers when an application attempts to use a file or object. In this fashion, cache coherency is maintained even in a distributed environment without the centralized cache management bottlenecks of prior approaches and without the need to eagerly purge the cache of stale versions of objects.
Abstract:
Systems and methods for managing records stored in a storage cache are provided. A cache index is created and maintained to track where records are stored in buckets in the storage cache. The cache index maps the memory locations of the cached records to the buckets in the cache storage and can be quickly traversed by a metadata manager to determine whether a requested record can be retrieved from the cache storage. Bucket addresses stored in the cache index include a generation number of the bucket that is used to determine whether the cached record is stale. The generation number allows a bucket manager to evict buckets in the cache without having to update the bucket addresses stored in the cache index. In an alternative embodiment, non-contiguous portions of computing system working memory are used to cache data instead of a dedicated storage cache.
Abstract:
Systems and methods for managing records stored in a storage cache are provided. A cache index is created and maintained to track where records are stored in buckets in the storage cache. The cache index maps the memory locations of the cached records to the buckets in the cache storage and can be quickly traversed by a metadata manager to determine whether a requested record can be retrieved from the cache storage. Bucket addresses stored in the cache index include a generation number of the bucket that is used to determine whether the cached record is stale. The generation number allows a bucket manager to evict buckets in the cache without having to update the bucket addresses stored in the cache index. Further, the bucket manager is tiered thus allowing efficient use of differing filter functions and even different types of memories as may be desired in a given implementation.
Abstract:
When a virtual machine sends a write command to a host operating system, a cache system stores the record included in the write command and later sends the write command to a storage system. Systems and methods store an indication of when the write command was received along with the received records in the cache. The cache system determines an order of the records from the indication. In some instances, records received at the same time are serialized and/or assigned record numbers. The simultaneously received records can be assigned a batch number. According to the determined order, the records are retrieved from the cache memory and included in write commands sent to the storage system. In some instances, checkpoints can be stored to prevent records from being re-sent to the storage system following a failure.
Abstract:
Systems and methods for managing records stored in a storage cache are provided. A cache index is created and maintained to track where records are stored in buckets in the storage cache. The cache index maps the memory locations of the cached records to the buckets in the cache storage and can be quickly traversed by a metadata manager to determine whether a requested record can be retrieved from the cache storage. Bucket addresses stored in the cache index include a generation number of the bucket that is used to determine whether the cached record is stale. The generation number allows a bucket manager to evict buckets in the cache without having to update the bucket addresses stored in the cache index. Further, the bucket manager is tiered thus allowing efficient use of differing filter functions and even different types of memories as may be desired in a given implementation.
Abstract:
When a virtual machine sends a write command to a host operating system, a cache system stores the record included in the write command and later sends the write command to a storage system. Systems and methods store an indication of when the write command was received along with the received records in the cache. The cache system determines an order of the records from the indication. In some instances, records received at the same time are serialized and/or assigned record numbers. The simultaneously received records can be assigned a batch number. According to the determined order, the records are retrieved from the cache memory and included in write commands sent to the storage system. In some instances, checkpoints can be stored to prevent records from being re-sent to the storage system following a failure.
Abstract:
Systems and methods for managing records stored in a storage cache are provided. A cache index is created and maintained to track where records are stored in buckets in the storage cache. The cache index maps the memory locations of the cached records to the buckets in the cache storage and can be quickly traversed by a metadata manager to determine whether a requested record can be retrieved from the cache storage. Bucket addresses stored in the cache index include a generation number of the bucket that is used to determine whether the cached record is stale. The generation number allows a bucket manager to evict buckets in the cache without having to update the bucket addresses stored in the cache index. Further, the cache index can be expanded to accommodate very small records, such as those generated by legacy systems.
Abstract:
Systems and methods for managing records stored in a storage cache are provided. A cache index is created and maintained to track where records are stored in buckets in the storage cache. The cache index maps the memory locations of the cached records to the buckets in the cache storage and can be quickly traversed by a metadata manager to determine whether a requested record can be retrieved from the cache storage. Bucket addresses stored in the cache index include a generation number of the bucket that is used to determine whether the cached record is stale. The generation number allows a bucket manager to evict buckets in the cache without having to update the bucket addresses stored in the cache index. Further, the cache index can be expanded to accommodate very small records, such as those generated by legacy systems.