Abstract: A computer-implemented distributed file-system in a distributed data network in which metadata related to the files and directories of the file-system is distributed. A unique and non-reusable inode number is assigned to each file/directory of the file-system. A key-value store built up in rows is created for the distributed metadata. Each of the rows has a composite row key and a row value (key-value pair) where the composite row key for each file/directory includes the inode number of the parent directory, and a name of the file/directory. For files below the maximum file size, the entire file or portion thereof is encoded in the corresponding row value of the key-value pair. In this case, the corresponding composite row key holds the inode number of the file itself and an offset information of the data of the file in the row value. Files above maximum file size are stored in a large-scale storage.

Abstract: A method and high availability cluster configuration for capture of data packets propagating in an external network into the cluster through a wired-tap connection between the cluster and at least one router of the external network. Captured packets are supplied with popularity tags and striped over high-access-rate non-transitory storage media belonging to a capture pool of serving nodes that are specially provisioned and selected by the master node. The captured packets are either devolved or demoted to low-access-rate non-transitory storage media of at least two serving nodes not including any backup master based on popularity metrics contained their tags. The demotion, devolution as well as determination of popularity metrics and setting of a popularity threshold are managed by a distributed management protocol.

Abstract: A computer-implemented distributed file-system in a distributed data network in which metadata related to the files and directories of the file-system is distributed. A unique and non-reusable inode number is assigned to each file/directory of the file-system. A key-value store built up in rows is created for the distributed metadata. Each of the rows has a composite row key and a row value (key-value pair) where the composite row key for each file/directory includes the inode number of the parent directory, and a name of the file/directory. For files below the maximum file size, the entire file or portion thereof is encoded in the corresponding row value of the key-value pair. In this case, the corresponding composite row key holds the inode number of the file itself and an offset information of the data of the file in the row value. Files above maximum file size are stored in a large-scale storage.

Abstract: Method and high availability clusters that support synchronous state replication to provide for failover between nodes, and more precisely, between the master candidate machines at the corresponding nodes. There are at least two master candidates (m=2) in the high availability cluster and the election of the current master is performed by a quorum-based majority vote among quorum machines, whose number n is at least three and odd (n?3 and n is odd). The current master is issued a current time-limited lease to be measured off by the current master's local clock. In setting the duration or period of the lease, a relative clock skew is used to bound the duration to an upper bound, thus ensuring resistance to split brain situations during failover events.

Abstract: A high availability cluster and method of storage medium management in such high availability cluster. A number k of nodes belonging to the cluster, where k?2 and includes a master node, are provisioned with high-access-rate and low-access-rate storage media. A file is written to the high-access-rate medium of a serving node selected from among k?1 nodes excluding the master node. The file is also written to low-access-rate medium of each of k?2 nodes excluding the master node and the serving node. A distributed storage medium management protocol supervises file migration from the low-access-rate medium of a back-up node to the high-access-rate medium of the back-up node upon disruption of file availability on the serving node. File rebalancing relies on parameters including popularity, write- and read-requests, capacity, processing load or cost.

Abstract: A method and high availability cluster configuration for capture of data packets propagating in an external network into the cluster through a wired-tap connection between the cluster and at least one router of the external network. Captured packets are supplied with popularity tags and striped over high-access-rate non-transitory storage media belonging to a capture pool of serving nodes that are specially provisioned and selected by the master node. The captured packets are either devolved or demoted to low-access-rate non-transitory storage media of at least two serving nodes not including any backup master based on popularity metrics contained their tags. The demotion, devolution as well as determination of popularity metrics and setting of a popularity threshold are managed by a distributed management protocol.

Abstract: Method and high availability clusters that support synchronous state replication to provide for failover between nodes, and more precisely, between the master candidate machines at the corresponding nodes. There are at least two master candidates (m=2) in the high availability cluster and the election of the current master is performed by a quorum-based majority vote among quorum machines, whose number n is at least three and odd (n?3 and n is odd). The current master is issued a current time-limited lease to be measured off by the current master's local clock. In setting the duration or period of the lease, a relative clock skew is used to bound the duration to an upper bound, thus ensuring resistance to split brain situations during failover events.

Abstract: Method and high availability clusters that support synchronous state replication to provide for failover between nodes, and more precisely, between the master candidate machines at the corresponding nodes. There are at least two master candidates (m=2) in the high availability cluster and the election of the current master is performed by a quorum-based majority vote among quorum machines, whose number n is at least three and odd (n?3 and n is odd). The current master is issued a current time-limited lease to be measured off by the current master's local clock. In setting the duration or period of the lease, a relative clock skew is used to bound the duration to an upper bound, thus ensuring resistance to split brain situations during failover events.

Abstract: A high availability cluster and method of storage medium management in such high availability cluster. A number k of nodes belonging to the cluster, where k?2 and includes a master node, are provisioned with high-access-rate and low-access-rate storage media. A file is written to the high-access-rate medium of a serving node selected from among k-1 nodes excluding the master node. The file is also written to low-access-rate medium of each of k-2 nodes excluding the master node and the serving node. A distributed storage medium management protocol supervises file migration from the, low-access-rate medium of a back-up node to the high-access-rate medium of the back-up node upon disruption of file availability on the serving node. File rebalancing relies on parameters including popularity, write- and read-requests, capacity, processing load or cost.

Abstract: Method and high availability clusters that support synchronous state replication to provide for failover between nodes, and more precisely, between the master candidate machines at the corresponding nodes. There are at least two master candidates (m=2) in the high availability cluster and the election of the current master is performed by a quorum-based majority vote among quorum machines, whose number n is at least three and odd (n?3 and n is odd). The current master is issued a current time-limited lease to be measured off by the current master's local clock. In setting the duration or period of the lease, a relative clock skew is used to bound the duration to an upper bound, thus ensuring resistance to split brain situations during failover events.

Abstract: A computer-implemented method and a distributed file system in a distributed data network in which file metadata related to data files is distributed. A unique and non-reusable mode number is assigned to each data file that belongs to the data files and a directory of that data file. A key-value store built up in rows is created for the distributed file metadata. Each of the rows has a composite row key and a row value (key-value pair) where the composite row key for each data file includes the mode number and a name of the data file. When present in the directory, the data file is treated differently depending on size. For data files below the maximum file size the entire file or portion thereof is encoded in the corresponding row value of the key-value pair. Data files above maximum file size are stored in large-scale storage.