Abstract: Embodiments relate to supporting transaction data committed to a stable storage. Committed data in the cluster is stored in the persistent cache layer and replicated and stored in the cache layer of one or more secondary nodes. One copy is designated as a master copy and all other copies are designated as replica, with an exclusive write lock assigned to the master and a shared write lock extended to the replica. An acknowledgement of receiving the data is communicated following confirmation that the data has been replicated to each node designated to receive the replica. Managers and a director are provided to support management of the master copy and the replicas within the file system, including invalidation of replicas, fault tolerance associated with failure of a node holding a master copy, recovery from a failed node, recovered of the file system from a power failure, and transferring master and replica copies within the file system.

Abstract: Embodiments of the present invention relate to dynamic feedback-based throughput control for storage systems. In one embodiment, a method of and computer program product for storage throughput control are provided. A plurality of I/O requests is received at a rate controller. The rate controller comprises a plurality of token buckets. A token bucket is selected from the plurality of token buckets based on a service class of each of the plurality of I/O requests. The plurality of I/O requests is sent from the rate controller to a storage system at a control rate. Throughput of the storage system is observed. The control rate is dynamically adjusted based on the variance between the observed throughput of the storage system and the first rate. Adjusting the control rate includes determining a minimum throughput reservation for each service class, and allocating throughput capacity to each service class proportional to its throughput reservation.

Abstract: Embodiments of the invention relate to supporting transaction data committed to a stable storage. Committed data in the cluster is stored in the persistent cache layer and replicated and stored in the cache layer of one or more secondary nodes. One copy is designated as a master copy and all other copies are designated as replica, with an exclusive write lock assigned to the master and a shared write lock extended to the replica. An acknowledgement of receiving the data is communicated following confirmation that the data has been replicated to each node designated to receive the replica. Managers and a director are provided to support management of the master copy and the replicas within the file system, including invalidation of replicas, fault tolerance associated with failure of a node holding a master copy, recovery from a failed node, recovered of the file system from a power failure, and transferring master and replica copies within the file system.

Abstract: Embodiments of the present invention relate to dynamic feedback-based throughput control for storage systems. In one embodiment, a method of and computer program product for storage throughput control are provided. A plurality of I/O requests is received at a rate controller. The rate controller comprises a plurality of token buckets. A token bucket is selected from the plurality of token buckets based on a service class of each of the plurality of I/O requests. The plurality of I/O requests is sent from the rate controller to a storage system at a control rate. Throughput of the storage system is observed. The control rate is dynamically adjusted based on the variance between the observed throughput of the storage system and the first rate. Adjusting the control rate includes determining a minimum throughput reservation for each service class, and allocating throughput capacity to each service class proportional to its throughput reservation.

Abstract: Embodiments of the present invention relate to dynamic feedback-based throughput control for storage systems. In one embodiment, a method of and computer program product for storage throughput control are provided. A plurality of I/O requests is received at a rate controller. The plurality of I/O requests is sent from the rate controller to a storage system at a first rate. Throughput of the storage system is observed. The first rate is dynamically adjusted based on the variance between the observed throughput of the storage system and the first rate.

Abstract: Maintaining high availability of objects for both read and write transactions. Secondary copies of cached objects are created and maintained on disks of a secondary caching node and in remote data storage. In response to an update request, the secondary copies of cached objects are updated. Secondary cached objects are synchronously invalidated in response to the update request, and the update is asynchronously propagated to a secondary caching node.

Abstract: Embodiments of the present invention relate to dynamic feedback-based throughput control for storage systems. In one embodiment, a method of and computer program product for storage throughput control are provided. A plurality of I/O requests is received at a rate controller. The plurality of I/O requests is sent from the rate controller to a storage system at a first rate. Throughput of the storage system is observed. The first rate is dynamically adjusted based on the variance between the observed throughput of the storage system and the first rate.

Abstract: Embodiments relate to supporting transaction data committed to a stable storage. Committed data in the cluster is stored in the persistent cache layer and replicated and stored in the cache layer of one or more secondary nodes. One copy is designated as a master copy and all other copies are designated as replica, with an exclusive write lock assigned to the master and a shared write lock extended to the replica. An acknowledgement of receiving the data is communicated following confirmation that the data has been replicated to each node designated to receive the replica. Managers and a director are provided to support management of the master copy and the replicas within the file system, including invalidation of replicas, fault tolerance associated with failure of a node holding a master copy, recovery from a failed node, recovered of the file system from a power failure, and transferring master and replica copies within the file system.

Abstract: Aspects of the invention are provided for rate control and management of service requests. A token bucket is employed in conjunction with a capacity sharing scheme to manage processing of service requests. Each token represents the capacity reserved for a particular source of requests. Excess tokens may be shed, with the excess tokens representing available excess capacity. Similarly, a projected time at which the service request(s) may be released may be computed in the event the bucket does not contain the required quantity of tokens to process the request.

Abstract: Embodiments of the present invention relate to dynamic feedback-based throughput control for storage systems. In one embodiment, a method of and computer program product for storage throughput control are provided. A plurality of I/O requests is received at a rate controller. The plurality of I/O requests is sent from the rate controller to a storage system at a first rate. Throughput of the storage system is observed. The first rate is dynamically adjusted based on the variance between the observed throughput of the storage system and the first rate.

Abstract: Embodiments of the invention relate to supporting transaction data committed to a stable storage. Committed data in the cluster is stored in the persistent cache layer and replicated and stored in the cache layer of one or more secondary nodes. One copy is designated as a master copy and all other copies are designated as replica, with an exclusive write lock assigned to the master and a shared write lock extended to the replica. An acknowledgement of receiving the data is communicated following confirmation that the data has been replicated to each node designated to receive the replica. Managers and a director are provided to support management of the master copy and the replicas within the file system, including invalidation of replicas, fault tolerance associated with failure of a node holding a master copy, recovery from a failed node, recovered of the file system from a power failure, and transferring master and replica copies within the file system.

Abstract: Embodiments of the present invention relate to dynamic feedback-based throughput control for storage systems. In one embodiment, a method of and computer program product for storage throughput control are provided. A plurality of I/O requests is received at a rate controller. The plurality of I/O requests is sent from the rate controller to a storage system at a first rate. Throughput of the storage system is observed. The first rate is dynamically adjusted based on the variance between the observed throughput of the storage system and the first rate.

Abstract: Aspects of the invention are provided for rate control and management of service requests. A token bucket is employed in conjunction with a capacity sharing scheme to manage processing of service requests. Each token represents the capacity reserved for a particular source of requests. Excess tokens may be shed, with the excess tokens representing available excess capacity. Similarly, a projected time at which the service request(s) may be released may be computed in the event the bucket does not contain the required quantity of tokens to process the request.

Abstract: Embodiments of the invention relate to optimizing the storage of data in a multi-cache level environment. In one aspect, data is classified into primary and secondary cache sections. Data is differentiated based on an inherent sharing characteristic of the data within a system comprising virtual machines. The data is then placed into the classified sections of the cache storage layer and/or persistent data, reflective of how the data is shared among virtual disk images access by virtual machines.

Abstract: Embodiments of the invention relate to supporting transaction data committed to a stable storage. Committed data in the cluster is stored in the persistent cache layer and replicated and stored in the cache layer of one or more secondary nodes. One copy is designated as a master copy and all other copies are designated as replica, with an exclusive write lock assigned to the master and a shared write lock extended to the replica. An acknowledgement of receiving the data is communicated following confirmation that the data has been replicated to each node designated to receive the replica. Managers and a director are provided to support management of the master copy and the replicas within the file system, including invalidation of replicas, fault tolerance associated with failure of a node holding a master copy, recovery from a failed node, recovered of the file system from a power failure, and transferring master and replica copies within the file system.

Abstract: Embodiments of the invention relate to supporting transaction data committed to a stable storage. Committed data in the cluster is stored in the persistent cache layer and replicated and stored in the cache layer of one or more secondary nodes. One copy is designated as a master copy and all other copies are designated as replica, with an exclusive write lock assigned to the master and a shared write lock extended to the replica. An acknowledgement of receiving the data is communicated following confirmation that the data has been replicated to each node designated to receive the replica. Managers and a director are provided to support management of the master copy and the replicas within the file system, including invalidation of replicas, fault tolerance associated with failure of a node holding a master copy, recovery from a failed node, recovered of the file system from a power failure, and transferring master and replica copies within the file system.

Abstract: Maintaining high availability of objects for both read and write transactions. Secondary copies of cached objects are created and maintained on disks of a secondary caching node and in remote data storage. In response to an update request, the secondary copies of cached objects are updated. Secondary cached objects are synchronously invalidated in response to the update request, and the update is asynchronously propagated to a secondary caching node.