Abstract: A system and method of the device may include receiving a commit statement that is part of a transaction, where the transaction is initiated by a client to be executed on the database system. In addition, the device may include validating the transaction in a pessimistic manner by placing a commit pause on data cells modified during the execution of the transaction, where the commit pause enables an atomicity of a distributed transaction commitment. The device may include returning an acknowledgment to the client that the transaction is committed, where the acknowledgment is returned upon validation of the transaction.

Abstract: In one general aspect, a method may include selecting eligible row-versions for inspection. The method may also include inspecting the selected row-versions, where the inspection results in a classification of eligible row-versions as unneeded or reliant. The method may furthermore include marking row-versions classified as unneeded as approved for immediate removal. The method may, in addition, include adding row-versions classified as reliant on cleaner structures. The method may moreover include upon detection of removal of all point-in-times (PiTs) related to a reliant row-version, deleting the reliant row-version, where the detection is performed by monitoring the cleaner structures. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

Abstract: A method and system for managing execution of database transactions are provided. The method includes receiving at least one statement that is a part of a transaction, wherein the transaction is initiated by a client to be executed on a database system; executing tasks included in each of the at least one received statement in an optimistic manner, wherein the received at least one statement is not a commit statement; and returning the client an acknowledgement that the transaction is committed, wherein the acknowledgement is returned upon validation of the transaction, wherein the transaction is validated in a pessimistic manner, and wherein the at least one received statement is a commit statement.

Abstract: A method for cleaning unneeded row-versions in a distributed database system including a plurality of nodes are provided. The method comprising: receiving, by a node of the plurality of nodes, a stream of at least Point-in-Time (PiT) creation events and PiT removal events; receiving a list of committed transaction identifiers (IDs) of committed transactions executed by the distributed database system; inspecting row-versions in the distributed database system to identify unneeded row-versions that can be safely removed, wherein the inspection is performed in part using the stream of PiT creation events and PiT removal events, and the list of committed transaction IDs; and removing the unneeded row-versions identified by the inspection.

Abstract: A method and system for managing execution of database transactions by facilitating point-in-time image (PIT). The method comprises receiving at least one statement being part of a transaction, the transaction is initiated by a client to be executed on a distributed database system; sending a single request to a sequencer server (SEQ-server) to create at least one PiT, wherein the SEQ-server provides a logical timestamp counter (LTC) value as a timestamp of the PiT; upon creation of the at least one PiT, causing execution of the at least one statement, a PiT provides a state and content of committed data in the distributed database system; upon receiving a commit statement, performing a commitment process of the transaction, the commitment process is based on a commitment timestamp (CMTS) set by the SEQ-server based on an incremented value of the LTC; and returning an acknowledgment of the transaction commitment to the client.

Abstract: A database system implementing a concurrency control protocol is provided. The database system includes a node connected through a network to a client; the node comprises: a storage for storing a plurality of data cells; one or more processors; and a memory, the memory containing instructions that, when executed by the one or more processors, configure the node to: receive at least one non-commit statement that is part of a transaction; execute locally tasks included in each of the at least one received statement in an optimistic manner allowing statements of other transactions to independently access same data cells in the database system being modified by tasks of the at least one received statement; and return the client an acknowledgment that the transaction is committed, the acknowledgment is returned upon validation of the transaction, wherein the transaction is validated in a pessimistic manner.

Abstract: A method and system for managing execution of database transactions are provided. The method includes receiving at least one statement that is a part of a transaction, wherein the transaction is initiated by a client to be executed on a database system; executing tasks included in each of the at least one received statement in an optimistic manner, wherein the received at least one statement is not a commit statement; and returning the client an acknowledgement that the transaction is committed, wherein the acknowledgement is returned upon validation of the transaction, wherein the transaction is validated in a pessimistic manner, and wherein the at least one received statement is a commit statement.

Abstract: Techniques are provided for utilizing snapshot longevity information to manage snapshots in a snapshot-enabled storage system. A snapshot management system generates a snapshot volume tree which comprises snapshots associated with a given storage volume. The snapshot management system obtains a snapshot policy associated with the given storage volume, which comprises a snapshot creation and retention schedule that specifies retention lifespans of the snapshots. The snapshot policy is evaluated to automatically determine and assign respective longevity ranking values for the snapshots within the snapshot volume tree, wherein the longevity ranking value of a given snapshot represents a retention lifespan of the given snapshot as compared to retention lifespans of other snapshots as represented by their respective longevity ranking values.

Abstract: An apparatus in an illustrative embodiment comprises at least one processing device comprising a processor coupled to a memory. The apparatus is configured to maintain a snapshot tree data structure having a plurality of volume nodes corresponding to respective ones of (i) a root volume and (ii) multiple snapshots related directly or indirectly to the root volume. The apparatus is further configured to determine a set of data descriptors for a given volume offset, to determine a set of reader volume nodes that are readers of a corresponding data item based at least in part on the set of data descriptors, to adjust one or more of the data descriptors in the set of data descriptors based at least in part on the set of reader volume nodes, and to reclaim storage space previously allocated to the data item responsive to the adjusting of the one or more data descriptors.

Abstract: An apparatus in an illustrative embodiment comprises at least one processing device comprising a processor coupled to a memory. The apparatus is configured to maintain a snapshot tree data structure having a plurality of volume nodes corresponding to respective ones of (i) a root volume and (ii) multiple snapshots related directly or indirectly to the root volume. The apparatus is further configured to determine a set of data descriptors for a given volume offset, to determine a set of reader volume nodes that are readers of a corresponding data item based at least in part on the set of data descriptors, to adjust one or more of the data descriptors in the set of data descriptors based at least in part on the set of reader volume nodes, and to reclaim storage space previously allocated to the data item responsive to the adjusting of the one or more data descriptors.

Abstract: Techniques are provided for utilizing snapshot longevity information to manage snapshots in a snapshot-enabled storage system. A snapshot management system generates a snapshot volume tree which comprises snapshots associated with a given storage volume. The snapshot management system obtains a snapshot policy associated with the given storage volume, which comprises a snapshot creation and retention schedule that specifies retention lifespans of the snapshots. The snapshot policy is evaluated to automatically determine and assign respective longevity ranking values for the snapshots within the snapshot volume tree, wherein the longevity ranking value of a given snapshot represents a retention lifespan of the given snapshot as compared to retention lifespans of other snapshots as represented by their respective longevity ranking values.

Abstract: A memory management system for a thinly provisioned memory volume in which a relatively larger virtual address range of virtual address blocks is mapped to a relatively smaller physical memory comprising physical memory blocks via a mapping table containing entries only for addresses of the physical memory blocks containing data. The memory management system comprises a snapshot provision unit to take a given snapshot of the memory volume at a given time, the snapshot comprising a mapping table and memory values of the volume, the mapping table and memory values comprising entries only for addresses of the physical memory containing data. The snapshot is managed on the same thin provisioning basis as the volume itself, and the system is particularly suitable for RAM type memory disks.

Abstract: A System, Computer program product, and computer-executable method of rebuilding a failed data storage device within a storage architecture including a plurality of protection domains including two or more data storage devices, wherein a RAID protection is generated over volumes provided from the plurality of protection domains, the System, Computer program product, and computer-executable method including receiving a notification of a failed data storage device of the data storage devices within a first protection domain of the plurality of protection domains and rebuilding the failed data storage device using reserved data storage within a first data storage device within the first protection domain.

Abstract: A Computer-executable method, system, and computer program product for managing tiers of data storage in a data storage environment using a data storage system, the Computer-executable method, system, and computer program product comprising a non-transitory computer readable medium encoded with computer-executable program code for using read signatures in replication, the code configured to enable the execution of initializing a data stack, updating a map of the data stack; and distributing the map of the data stack to a compute node.

Abstract: In one aspect, a method includes storing data in a distributed storage environment that includes data servers and configuring each data server to mark a respective bit map for each block of data changed. In another aspect, an apparatus includes electronic hardware circuitry configured to store data in a distributed storage environment that includes data servers and to configure each data server to mark a respective bit map for each block of data changed. In a further aspect, an article includes a non-transitory computer-readable medium that stores computer-executable instructions. The instructions cause a machine to store data in a distributed storage environment that includes data servers and configure each data server to mark a respective bit map for each block of data changed. In each of the aspects above each data server is configured to handle a respective portion of a logical unit.

Abstract: In one aspect, a method includes generating a plurality of protection domains of software-defined storage, generating a volume in each protection domain and exposing the volumes as devices in a storage architecture which generates a RAID protection over the exposed volumes. In another aspect, an apparatus includes electronic hardware circuitry configured to generate a plurality of protection domains of software-defined storage, generate a volume in each protection domain and expose the volumes as devices in a storage architecture which generates a RAID protection over the exposed volumes. In a further aspect, an article includes a non-transitory computer-readable medium that stores computer-executable instructions. The instructions cause a machine to generate a plurality of protection domains of software-defined storage, generate a volume in each protection domain and expose the volumes as devices in a storage architecture which generates a RAID protection over the exposed volumes.

Abstract: A method of managing a distributed storage space. The method comprises mapping a plurality of replica sets to a plurality of storage managing modules installed in a plurality of computing units, each of the plurality of storage managing modules manages access of at least one storage consumer application to replica data of at least one replica of a replica set from the plurality of replica sets, the replica data is stored in at least one drive of a respective the computing unit, allocating at least one time based credit to at least one of each storage managing module and the replica data, iteratively renewing the time based credit as long a failure of at least one of the storage managing module, and the at least one drive and the replica data is not detected plurality of storage managing.

Abstract: A CAS data storage system with one or more source CAS data storage spaces and one or more destination CAS data storage spaces, and a communication line therebetween, receives input data at the source storage space for local storage and for replication to the destination CAS storage space. CAS metadata is used in the replication procedure between the two separate CAS storage spaces. Thus, data at the source storage space is used to form an active buffer for transfer to the destination storage space, the active buffer holding a hash result of the respective data item and a storage address. The system detects whenever there is more than one data item in said active buffer sharing a same storage address and upon such detection transfers a respective hash result of only the last of the data items.

Abstract: A memory management system for a thinly provisioned memory volume in which a relatively larger virtual address range of virtual address blocks is mapped to a relatively smaller physical memory comprising physical memory blocks via a mapping table containing entries only for addresses of the physical memory blocks containing data. The memory management system comprises a snapshot provision unit to take a given snapshot of the memory volume at a given time, the snapshot comprising a mapping table and memory values of the volume, the mapping table and memory values comprising entries only for addresses of the physical memory containing data. The snapshot is managed on the same thin provisioning basis as the volume itself, and the system is particularly suitable for RAM type memory disks.

Abstract: A device for scalable block data storage and retrieval uses content addressing. Data storage devices store data blocks, and are connected over a network to computing modules. The modules comprise control modules and data modules and carry out content addressing for both storage and retrieval. The network defines separate control paths via the control modules and data paths via the data modules.