Abstract: A computer-implemented method, according to one approach, includes: receiving a request to create a new node in a clustered filesystem. In response to receiving the request, a copy of details is retrieved, the copy of details being associated with an established singleton cluster preconfigured to access the clustered filesystem. The retrieved copy of details are further applied to a new node in the clustered filesystem. Moreover, data structures of the new node are modified according to the received request. Other systems, methods, and computer program products are described in additional approaches herein.

Abstract: A computer-implemented method, according to one embodiment, includes causing a memory assessment thread to perform a first predetermined node memory contention state determination sequence for a predetermined first node. The first predetermined node memory contention state determination sequence includes recording a first timestamp, and allocating dedicated memory of the predetermined first node. The first predetermined node memory contention state determination sequence furthermore includes attempting to fill the allocated memory with content subsequent to recording the first timestamp, and recording a second timestamp after attempting to fill the allocated memory. The method further includes determining a first memory contention state of the predetermined first node based on results of performing the first predetermined node memory contention state determination sequence. The determined first memory contention state is caused to be included in a first type of message sent to a second node.

Abstract: Provided are a computer program product, system, and method for switching serialization techniques for handling concurrent write requests to a shared file. A first node serializes write requests from client nodes to write to the shared file. The first node determines whether to switch to a second node to manage write quests to the shared file based on a pattern of write requests to the shared file. The client nodes are notified to direct write requests to the shared file to the second node in response to determining to switch to the second node. The second node processes write requests to the shared file to serialize writes to the shared file after the client nodes are notified to submit the write requests to the shared file to the second node.

Abstract: A method for executing operation requests includes formatting one or more storage devices and selecting one or more labeled replicas and one or more distinguished replicas, receiving an operation request with respect to a set of data blocks, identifying a preferred replica corresponding to the received operation request, determining whether the replication-pending bits for the preferred replica are set, and executing the received operation request with respect to the corresponding distinguished replica. A method for executing a write operation request additionally includes setting replication-pending bits with respect to the labeled replica, wherein the replication-pending bits indicate an incomplete write request, writing data to both a labeled replica and a distinguished replica, and clearing the replication-pending bits with respect to the labeled replica to indicate the completion of the write operation.

Abstract: A method and a computer system for asymmetric replication of data are provided. Storage of a set of data is organized as a first copy and as a second copy in non-volatile storage. The second copy is reliable and stored so as to be readable at a speed slower than for the first copy. A read instruction regarding the set of data is received and performed preferentially via the first copy such that the asymmetric replication achieves enhanced performance speed. A request to execute a write operation is received. The write operation is executed to the first copy and to the second copy. In response to determining that the write operation to the first copy was unsuccessful, a label for the first copy is set as stale.

Abstract: A method and a computer system for asymmetric replication of data are provided. Storage of a set of data is organized as a first copy and as a second copy in non-volatile storage. The second copy is reliable and stored so as to be readable at a speed slower than for the first copy. A read instruction regarding the set of data is received and performed preferentially via the first copy such that the asymmetric replication achieves enhanced performance speed. A request to execute a write operation is received. The write operation is executed to the first copy and to the second copy. In response to determining that the write operation to the first copy was unsuccessful, a label for the first copy is set as stale.

Abstract: Provided are a computer program product, system, and method for switching serialization techniques for handling concurrent write requests to a shared file. A first node serializes write requests from client nodes to write to the shared file. The first node determines whether to switch to a second node to manage write quests to the shared file based on a pattern of write requests to the shared file. The client nodes are notified to direct write requests to the shared file to the second node in response to determining to switch to the second node. The second node processes write requests to the shared file to serialize writes to the shared file after the client nodes are notified to submit the write requests to the shared file to the second node.

Abstract: A method for executing operation requests includes formatting one or more storage devices and selecting one or more labeled replicas and one or more distinguished replicas, receiving an operation request with respect to a set of data blocks, identifying a preferred replica corresponding to the received operation request, determining whether the replication-pending bits for the preferred replica are set, and executing the received operation request with respect to the corresponding distinguished replica. A method for executing a write operation request additionally includes setting replication-pending bits with respect to the labeled replica, wherein the replication-pending bits indicate an incomplete write request, writing data to both a labeled replica and a distinguished replica, and clearing the replication-pending bits with respect to the labeled replica to indicate the completion of the write operation.

Abstract: Aspects include testing distributed file systems by selecting a file in a multiple writer environment and selecting an offset of a block in the file. Test data is generated for the block by randomly selecting a starting value from a plurality of possible starting values. A test header that includes the starting value and a test data sequence that starts with the starting value is created. A file system that is being tested writes the test header and the test data sequence to the block. Contents of the block are read by the file system that is being tested, and expected contents of the data sequence are determined based on contents of the read header. The expected contents of the data sequence are compared to the read data sequence and an error indication is output based on the expected contents not being equal to the read contents.

Abstract: Aspects include testing distributed file systems by selecting a file in a multiple writer environment and selecting an offset of a block in the file. Test data is generated for the block by randomly selecting a starting value from a plurality of possible starting values. A test header that includes the starting value and a test data sequence that starts with the starting value is created. A file system that is being tested writes the test header and the test data sequence to the block. Contents of the block are read by the file system that is being tested, and expected contents of the data sequence are determined based on contents of the read header. The expected contents of the data sequence are compared to the read data sequence and an error indication is output based on the expected contents not being equal to the read contents.

Abstract: A computer-implemented method of encryption of several units of a computerized system, wherein each of the units comprises data, includes generating distinct initialization vectors, or IVs, for the units, and storing the generated IVs; and for each unit of the several units: accessing a stored IV corresponding to the unit; and encrypting the unit according to the accessed IV and an encryption key.

Abstract: A computer-implemented method of encryption of several units of a computerized system, wherein each of the units comprises data, includes generating distinct initialization vectors, or IVs, for the units, and storing the generated IVs; and for each unit of the several units: accessing a stored IV corresponding to the unit; and encrypting the unit according to the accessed IV and an encryption key.

Abstract: Aspects include testing distributed file systems by selecting a file in a multiple writer environment and selecting an offset of a block in the file. Test data is generated for the block by randomly selecting a starting value from a plurality of possible starting values. A test header that includes the starting value and a test data sequence that starts with the starting value is created. A file system that is being tested writes the test header and the test data sequence to the block. Contents of the block are read by the file system that is being tested, and expected contents of the data sequence are determined based on contents of the read header. The expected contents of the data sequence are compared to the read data sequence and an error indication is output based on the expected contents not being equal to the read contents.

Abstract: Aspects include testing distributed file systems by selecting a file in a multiple writer environment and selecting an offset of a block in the file. Test data is generated for the block by randomly selecting a starting value from a plurality of possible starting values. A test header that includes the starting value and a test data sequence that starts with the starting value is created. A file system that is being tested writes the test header and the test data sequence to the block. Contents of the block are read by the file system that is being tested, and expected contents of the data sequence are determined based on contents of the read header. The expected contents of the data sequence are compared to the read data sequence and an error indication is output based on the expected contents not being equal to the read contents.

Abstract: A computer-implemented method of encryption of several units of a computerized system, wherein each of the units comprises data, includes generating distinct initialization vectors, or IVs, for the units, and storing the generated IVs; and for each unit of the several units: accessing a stored IV corresponding to the unit; and encrypting the unit according to the accessed IV and an encryption key.

Abstract: A computer-implemented method of encryption of several units of a computerized system, wherein each of the units comprises data, includes generating distinct initialization vectors, or IVs, for the units, and storing the generated IVs; and for each unit of the several units: accessing a stored IV corresponding to the unit; and encrypting the unit according to the accessed IV and an encryption key.

Abstract: A system to improve communication security in cluster machine processing may include interconnected computers that can jointly process data. The system may also include a shared secret key used by each of the interconnected computers to encrypt, decrypt, and/or authenticate data being sent, or received, from one of the interconnected computers to another of the interconnected computers. The system may further include a new shared secret key used by each of the interconnected computers to encrypt, decrypt, and/or authenticate data being sent, or received, from one of the interconnected computers to another of the interconnected computers. In addition, the new shared secret key may coexist with the shared secret key without adversely affecting the joint processing of data performed by the plurality of interconnected computers.

Abstract: A method is provided for establishing clusters in a distributed data processing environment having a plurality of nodes. The frequency of messages sent for the purpose of cluster formation is selected based on ranking of the nodes. Higher ranking nodes transmit such messages more frequently than lower ranking nodes. Lower ranked nodes thus are provided with an opportunity to join a cluster without first having to transmit their own messages to effectuate the joining.

Abstract: The acquisition of a lock among nodes of a divided cluster is disclosed. A method is performable by each of at least one node of the cluster. A node waits for a delay corresponding to its identifier. The node asserts intent to acquire the lock by writing its identifier to X and Y variables where another node has failed to acquire the lock. The node waits for another node to acquire the lock where the other node has written to X, and proceeds where Y remains equal to its own identifier. The node waits for another node to acquire the lock where the other node has written to a Z variable, and writes its own identifier to Z and proceeds where the other node has failed. The node writes a value to Y indicating that it is acquiring the lock, and maintains acquisition by periodically writing to Z.

Abstract: A system, method and computer readable medium are provided for configuring network interfaces grouped into nodes for monitoring functionality. According to the method, a base address and subnet mask for the network interfaces are received, and a monitoring address is automatically generated for each of the network interfaces based on the base address, the subnet mask, and the nodes. The monitoring addresses is generated such that the monitoring address for each of the network interfaces is on a different subnet than the monitoring addresses for all of the other network interfaces in the same node as that network interface. Additionally, the monitoring addresses are assigned to the network interfaces for use by the monitoring process, with each of the monitoring addresses being assigned by being added as an additional network interface address of its network interface. Also provided is a method for monitoring functionality of network interfaces and providing fault recovery.