Abstract: The frequency at which a multisystem log stream is compressed by a system of a multisystem environment is adjusted in real-time. The rate at which the multisystem log stream is compressed by the system is ascertained. That rate is relative to how frequently the multisystem log stream is compressed by other systems of the multisystem environment. The frequency with which the system compresses the multisystem log stream is then adjusted in real-time. Thus, the frequency at which one system of the multisystem environment compresses the log stream is relative to the frequency at which other systems of the multisystem environment are compressing the log stream.

Abstract: The frequency at which a multisystem log stream is compressed by a system of a multisystem environment is adjusted in real-time. The rate at which the multisystem log stream is compressed by the system is ascertained. That rate is relative to how frequently the multisystem log stream is compressed by other systems of the multisystem environment. The frequency with which the system compresses the multisystem log stream is then adjusted in real-time. Thus, the frequency at which one system of the multisystem environment compresses the log stream is relative to the frequency at which other systems of the multisystem environment are compressing the log stream.

Abstract: Managing a log stream of a computer system. An entry of a log stream, desired to be removed from the log stream, but not eligible for removal, is logically deleted. Logical deletion keeps the entry on the log stream and indicates that the entry can be removed from the log stream when it is eligible. When the entry is eligible, it is removed. If a desired entry remains at the tail of the log stream for a given period of time, thus not all owing the removal of one or more undesired entries, the desired entry is rewritten to the head of the log stream and deleted from the tail. Thereafter, other logically deleted entries eligible for deletion are removed from the log stream.

Abstract: The frequency at which a multisystem log stream is compressed by a system of a multisystem environment is adjusted in real-time. The rate at which the multisystem log stream is compressed by the system is ascertained. That rate is relative to how frequently the multisystem log stream is compressed by other systems of the multisystem environment. The frequency with which the system compresses the multisystem log stream is then adjusted in real-time. Thus, the frequency at which one system of the multisystem environment compresses the log stream is relative to the frequency at which other systems of the multisystem environment are compressing the log stream.

Abstract: Six instructions for the manipulation of discontinuous memory locations in a computer memory are described. They are: Compare and Load (CL), Compare and Swap (CS), Double Compare and Swap (DCS), Compare and Swap and Store (CSST), Compare and Swap and Double Store (CSDST), and Compare and Swap and Triple Store (CSTST). In each instruction a processor associates a programming-specified blocking symbol with a lock not accessible to software. The lock is used by any of these instructions only during its single instance of instruction execution, and the lock is made available (unlocked) at the end of each instance to then enable another blocking-symbol instruction instance to use the lock, thereby serializing concurrent multiple processor requests for accessing the same resource. Programming associates resources in a system with the unique blocking symbols. Each instance of these instructions executes an operand earlier prepared from a data value taken from the resource..

Abstract: A multisystem log stream of a multisystem environment is compressed. The oldest record needed for each system that can write or delete entries from the multisystem log stream is tracked, and that information is used in compression of the log stream. The block ids associated with those oldest records are maintained within a vector, and when the vector is updated, a determination is made as to whether the entry in the vector that it replaced previously contained the lowest block id in the vector. If so, all the records having block ids lower than the new lowest block id in the vector are deleted.

Abstract: Managing a log stream of a computer system. An entry of a log stream, desired to be removed from the log stream, but not eligible for removal, is logically deleted. Logical deletion keeps the entry on the log stream and indicates that the entry can be removed from the log stream when it is eligible. When the entry is eligible, it is removed. If a desired entry remains at the tail of the log stream for a given period of time, thus not allowing the removal of one or more undesired entries, the desired entry is rewritten to the head of the log stream and deleted from the tail. Thereafter, other logically deleted entries eligible for deletion are removed from the log stream.

Abstract: One system of a multisystem environment takes over log entries owned by another system of the environment. When a system owning entries on a primary log stream is inactive (or a sync point manager on the system is inactive), another system of the multisystem environment writes the log entries corresponding to the inactive system to other locations. The entries within the other locations are not owned by any system. Thus, the resource managers associated with those log entries are eligible for restarting on any system of the multisystem environment. However, all resource managers involved in a common set of transactions are to restart on the same system. The other resource managers can restart on another system. When one of the resource managers restarts on a system, the system takes back ownership of the entries associated with the common set of transactions.

Abstract: One system of a multisystem environment takes over log entries owned by another system of the environment. When a system owning entries on a primary log stream is inactive (or a sync point manager on the system is inactive), another system of the multisystem environment writes the log entries corresponding to the inactive system to other locations. The entries within the other locations are not owned by any system. Thus, the resource managers associated with those log entries are eligible for restarting on any system of the multisystem environment. However, all resource managers involved in a common set of transactions are to restart on the same system. The other resource managers can restart on another system. When one of the resource managers restarts on a system, the system takes back ownership of the entries associated with the common set of transactions.

Abstract: A multisystem log stream of a multisystem environment is compressed. The oldest record needed for each system that can write or delete entries from the multisystem log stream is tracked, and that information is used in compression of the log stream. The block ids associated with those oldest records are maintained within a vector, and when the vector is updated, a determination is made as to whether the entry in the vector that it replaced previously contained the lowest block id in the vector. If so, all the records having block ids lower than the new lowest block id in the vector are deleted.

Abstract: Managing a log stream of a computer system. An entry of a log stream, desired to be removed from the log stream, but not eligible for removal, is logically deleted. Logical deletion keeps the entry on the log stream and indicates that the entry can be removed from the log stream when it is eligible. When the entry is eligible, it is removed. If a desired entry remains at the tail of the log stream for a given period of time, thus not allowing the removal of one or more undesired entries, the desired entry is rewritten to the head of the log stream and deleted from the tail. Thereafter, other logically deleted entries eligible for deletion are removed from the log stream.

Abstract: When a log stream has a determined amount of reusable space, the log stream is compressed in order to free up the reusable space. Compression of the log stream includes rewriting one or more active entries located at one or more positions of the log stream to one or more other locations, either within the same log stream or on another log stream. Thereafter, the rewritten entries are deleted from their previous positions within the log stream. Additionally, one or more logically deleted entries of the log stream is removed from the log stream. The resulting log stream is a compressed log stream.

Abstract: When a log stream has a determined amount of reusable space, the log stream is compressed in order to free up the reusable space. Compression of the log stream includes rewriting one or more active entries located at one or more positions of the log stream to one or more other locations, either within the same log stream or on another log stream. Thereafter, the rewritten entries are deleted from their previous positions within the log stream. Additionally, one or more logically deleted entries of the log stream is removed from the log stream. The resulting log stream is a compressed log stream.

Abstract: Provides a processor CLE (CPU lock element) for each processor in a protected storage in a multi-processor computer system. Each CLE contains a blocking symbol field (called herein a PLT, program lock token, field), a lock field H, and a wait field W which is used to chain plural CLEs currently having the same blocking symbol. When the lock field H is set to a lock held state, it indicates the associated processor has exclusive rights to access a data resource unit associated with the blocking symbol in the CLE entry. When the wait field in a lock entry contains a pointer to another lock entry and the H field in the lock entry indicates a not held state, the associated processor is waiting for the resource and cannot further execute its PLO instance until it later gets set to the lock state, which is done by the processor of the prior CLE in the chain when it completes execution of its PLO instance. Each PLO instruction also has operand fields, and a function code (FC).

Abstract: PLO (perform locked operation) instructions containing blocking symbols are executed on each of multiple processors in a computer system to control coherence in data structures which may be changed by any of multiple processors in a computer system. The blocking symbol is extracted from a PLO instruction instance when invoked by its executing processor. Then the processor hashes the blocking symbol using hardware-microcode (H-M) to generate the location of a lock field in protected storage. The PLO instruction's blocking symbol is associated with a computer resource unit by software providing the PLO instruction, and the blocking symbol then associates the resource with a protected lock through the hashing operation on the blocking symbol. A processor must obtain the lock for a blocking symbol before the executing PLO instruction instance is allowed to make access and change the resource unit associated with the blocking symbol.

Abstract: Work units are identified, managed and reported on as a group or enclave. The dispatching priorities of the work units are separated from the address spaces executing the work units. Instead, the dispatching priorities are tied to the priority of the enclave allowing work units to be executed within an address space at a priority independent from the address space. Additionally, resources used by the work units are accumulated and allocated to the requestor of the work.