摘要:
A request server automatically detects, in response to initialization of the request server, if there are previous generations of requests outstanding for the request server, and if so, immunizes itself against those requests. The request server starts one or more threads that are designed to gather messages associated with requests from previous incarnations of the server and handles those messages without affecting the requestors. While the request server is immunized from earlier generations of requests, the request server is capable of processing new requests.
摘要:
Computer system, method and program for defining first and second virtual machines and a memory shared by the first and second virtual machines. A filesystem cache resides in the shared memory. A lock structure resides in the shared memory to record which virtual machine, if any, currently has an exclusive lock for writing to the cache. The first virtual machine includes a first program function to acquire the exclusive lock when available by manipulation of the lock structure, and a second program function active after the first virtual machine acquires the exclusive lock, to write to the cache. The lock structure is directly accessible by the first program function. The cache is directly accessible by the second program function. The second virtual machine includes a third program function to acquire the exclusive lock when available by manipulation of the lock structure, and a fourth program function active after the second virtual machine acquires the exclusive lock, to write to the cache. The lock structure is directly accessible by the third program function. The cache is directly accessible by the fourth program function. Another computer system, method and program is embodied in logical partitions of a real computer, instead of virtual machines.
摘要:
A system, computer program product and method for dispatching work items in a virtual machine operating system. The virtual machine operating system defines first and second virtual machines. First and second work queues are created in a memory. The first virtual machine assigns a first work item to the first work queue and a second work item to the second work queue. The first virtual machine schedules work items from the first work queue for execution by the first virtual machine. The first and second work items originate from the first virtual machine. The first and second work queues are directly accessible by the first virtual machine. The second virtual machine assigns a third work item to the first work queue and a fourth work item to the second work queue. The second virtual machine schedules work items from the second work queue for execution by the second virtual machine. The third and fourth work items originate from the second virtual machine. The first and second work queues are directly accessible by the second virtual machine. The first virtual machine is not able to schedule work items from the second work queue, and the second virtual machine is not able to schedule work items from the first work queue. A shared work queue in shared memory is also disclosed.
摘要:
A system, method and program product for migrating a first virtual machine from a first real computer to a second real computer or from a first LPAR to a second LPAR in a same real computer. Before migration, the first virtual machine comprises an operating system and an application in a first private memory private to the first virtual machine. A communication queue of the first virtual machine resides in a shared memory shared by the first and second computers or the first and second LPARs. The operating system and application are copied from the first private memory to the shared memory. The operating system and application are copied from the shared memory to a second private memory private to the first virtual machine in the second computer or second LPAR. Then, the first virtual machine is resumed in the second computer or second LPAR.
摘要:
A method for communication between first and second computer programs having a shared memory. The first computer program has a first work dispatcher for a first work queue. The second computer program has a second work dispatcher for a second work queue. Without causing an interrupt, a message or data is written for the second program from the first program to the shared memory and the second work queue is updated with a work item indicating a message or data for the second program. In association with the updating step, it is determined if the second program is currently busy. If so, the second program is not interrupted regarding the message or data. When the second program subsequently becomes not busy, the second program receives, without an interrupt, and executes the work item to receive the message or data. If the second program was not currently busy, the second program is interrupted to process the message or data on its work queue. This imposes a minimal burden on the second program.
摘要:
A system, method and program product for migrating a first virtual machine from a first real computer to a second real computer or from a first LPAR to a second LPAR in a same real computer. Before migration, the first virtual machine comprises an operating system and an application in a first private memory private to the first virtual machine. A communication queue of the first virtual machine resides in a shared memory shared by the first and second computers or the first and second LPARs. The operating system and application are copied from the first private memory to the shared memory. The operating system and application are copied from the shared memory to a second private memory private to the first virtual machine in the second computer or second LPAR. Then, the first virtual machine is resumed in the second computer or second LPAR.
摘要:
A system, method and program product for migrating a first virtual machine from a first real computer to a second real computer or from a first LPAR to a second LPAR in a same real computer. Before migration, the first virtual machine comprises an operating system and an application in a first private memory private to the first virtual machine. A communication queue of the first virtual machine resides in a shared memory shared by the first and second computers or the first and second LPARs. The operating system and application are copied from the first private memory to the shared memory. The operating system and application are copied from the shared memory to a second private memory private to the first virtual machine in the second computer or second LPAR. Then, the first virtual machine is resumed in the second computer or second LPAR.
摘要:
Computer system, method and program for defining first and second virtual machines and a memory shared by the first and second virtual machines. A filesystem cache resides in the shared memory. A lock structure resides in the shared memory to record which virtual machine, if any, currently has an exclusive lock for writing to the cache. The first virtual machine includes a first program function to acquire the exclusive lock when available by manipulation of the lock structure, and a second program function active after the first virtual machine acquires the exclusive lock, to write to the cache. The lock structure is directly accessible by the first program function. The cache is directly accessible by the second program function. The second virtual machine includes a third program function to acquire the exclusive lock when available by manipulation of the lock structure, and a fourth program function active after the second virtual machine acquires the exclusive lock, to write to the cache. The lock structure is directly accessible by the third program function. The cache is directly accessible by the fourth program function. Another computer system, method and program is embodied in logical partitions of a real computer, instead of virtual machines.
摘要:
Management of virtual memory allocated by a virtual machine control program to a plurality of virtual machines. Each of the virtual machines has an allocation of virtual private memory divided into working memory, cache memory and swap memory. The virtual machine control program determines that it needs additional virtual memory allocation, and in response, makes respective requests to the virtual machines to convert some of their respective working memory and/or cache memory to swap memory. At another time, the virtual machine control program determines that it needs less virtual memory allocation, and in response, makes respective requests to the virtual machines to convert some of their respective swap memory to working memory and/or cache memory.
摘要:
A first piping application is defined by combining first and second stages of programming with a first sequence control program and specifying to the first sequence control program a first piping command. The second stage is a function to send data to a shared queue. The first piping command identifies the first stage, the second stage and parameters for the second stage identifying the queue and a key for the data to be sent to the queue. A second piping application is defined by combining third and fourth stages of programming with a second sequence control program, and specifying to the second sequence control program a second piping command. The third stage is a function to read the data from the queue. The second piping command identifies the fourth stage, the third stage, and parameters for the third stage identifying the queue and the key for the data to be read from the queue. A third piping application is defined by combining fifth and sixth stages of programming with the second sequence control program, and specifying to the second sequence control program a third piping command. The fifth stage is a function to read the data from the queue. The third piping command identifies the sixth stage, the fifth stage and parameters for the fifth stage identifying the queue and the key for the data to be read from the queue. The first, second and third piping applications are executed based on their respective definitions, stages and sequence control programs. The first piping command does not identify the second or third piping applications. The second piping command does not identify the first or third piping applications. The third piping command does not identify the first or second piping applications.