Abstract: Disclosed is a computer system for reliably running a plurality of programs performing garbage collection with less physical memory than in the past. For this purpose, there is disclosed a memory management method that releases unneeded areas in a plurality of memory areas that have been used by each of a plurality of programs stored in memory and executed on a processing unit, the processing unit acquires an index for determining the start of releasing a memory area, compares the index with a predetermined threshold, and when the index exceeds the threshold, selects one of the plurality of programs, collects unneeded areas of the memory areas used by the selected program, and releases the collected areas.

Abstract: A server management apparatus for lowering migration costs during scale-in/scale-out and workload consolidation of a cluster system(s) to thereby reduce power consumption is disclosed. The apparatus manages a physical server group which renders operative a virtual server group thereon and, when putting into practice a cluster system including a plurality of virtual servers placed in the physical server group, manages the layout state of virtual servers pursuant to the load state of the virtual server group. When executing scale-in, a virtual server operating on a physical server with the minimum number of operative virtual servers is specified as a shutdown target. When executing scale-out, a workload variation is predicted to control a scale-out destination of cluster system so that load variation-resembled cluster systems gather on the same physical server. The scale-in execution timing is delayed if the predicted load variation tends to rise and accelerated if it falls.

Abstract: A method of managing a memory in a computer system including a processor executing programs and the memory, the memory including a first area, which is managed by a garbage collector, and a second area, which is not managed by the garbage collector, the method including the steps executed by the processor of: checking a reference relation of basic point data associated with the second area by tracing references from the basic point data; when the reference relation of the basic point data has a structure including a reference to data belonging to the same class as the class of the basic point data, determining that particular data out of data constituting the structure is prohibited from being migrated to the second area; and migrating data stored in the first area out of data remaining after excluding the particular data from the data constituting the structure to the second area.

Abstract: The present invention provides a memory management method, including the steps of: securing a memory area by a program executed by a computer; storing an object in the memory area in accordance with the execution of the program; bringing the memory area into a release reservation state in accordance with the program instructing the memory area to be released; moving the object to a memory area not to be released while another object in the memory area not to be released and not to be brought into the release reservation state refers to the object in the memory area to be released including the memory area to be brought into the release reservation state; and releasing the memory area to be released.

Abstract: With regard to a plurality of data stored in a memory, relationship of data is grasped twice after a time interval therebetween. Next, increased data C1, E2, E3 which are not present in data of a first time are extracted from data of a second time, and weights “1”, “2”, “2” in accordance with data sizes are attached to the increased data. Next, the weights are successively propagated from a lower order data of a destination of reference to a higher order data of a source of reference successively. When there are a plurality of lower order data E2, E3 for a higher order D0, a weight constituted by adding the weights “2”, “2” of the plurality of lower data E2, E3 is made to be a weight “4” of the higher order data D0, and the weights of the respective data represent leak scores which causes memory leak.

Abstract: It is provided a memory management method for releasing an unnecessary area in a memory area used by a program stored in the memory and executed by the computing device. The memory management method including the step of: setting in the memory, a first memory area which is used to execute the program; setting in the memory, a second memory area which can be operated by the program; setting a utilized area in the second memory area based on an instruction from the program; storing objects including data in the utilized area of the second memory area based on an instruction from the program; determining whether the program uses the objects stored in the utilized area within the second memory area; and releasing, by the computing device, the utilized area occupied by an object that is not used by the program among the objects stored in the utilized area.

Abstract: A memory management method, which is used in a computer including a CPU and a memory to unload an area no longer necessary out of a memory area used by a program stored in the memory and executed by the CPU, comprising: generating a first processing system for executing the program in the memory; generating a second processing system in the memory when a first opportunity occurs; copying a content of a memory area of the first processing system to a memory area of the second processing system; determining an unnecessary area out of the copied memory area of the second processing system; transmitting a determination result regarding the unnecessary area to the program of the first processing system when a second opportunity occurs receiving the determination result; unloading the unnecessary area in the memory area of the first processing system.

Abstract: [Object] To increase the speed of copy processing from an online computer 101 to a standby computer 102. [Solution] When copying copy target information from the online computer 101 to the standby computer 102, a status copy processing unit 110: recognizes, as a synchronous point, a point in time when execution of a first application (AP #1), from among applications 108, is completed; extracts only information stored in a use area 401 of an OS 106 and a use area 403 of a second application (AP #2) from a storage area 400 of a memory at this synchronous point; and transfers the extracted information, as the copy target information necessary to continue the processing, from the online computer 101 to the standby computer 102. [Selected Drawing] FIG.

Abstract: Memory management by garbage collection involves a memory area that is allocated in a computer. Data is created in the memory area in accordance with a program executed by a processor of the computer, and it is checked whether or not data necessary to execute the program exists in the memory area to be released, in response to an explicit instruction to release the memory area. As a result of the check, if data necessary to execute the program does not exist in the memory area, the memory area is released. As a result of the check, if data necessary to execute the program exists in the memory area, the data is moved to a memory area different from the memory area to be released.

Abstract: Memory management by garbage collection involves a memory area that is allocated in a computer. Data is created in the memory area in accordance with a program executed by a processor of the computer, and it is checked whether or not data necessary to execute the program exists in the memory area to be released, in response to an explicit instruction to release the memory area. As a result of the check, if data necessary to execute the program does not exist in the memory area, the memory area is released. As a result of the check, if data necessary to execute the program exists in the memory area, the data is moved to a memory area different from the memory area to be released.

Abstract: A server management apparatus for lowering migration costs during scale-in/scale-out and workload consolidation of a cluster system(s) to thereby reduce power consumption is disclosed. The apparatus manages a physical server group which renders operative a virtual server group thereon and, when putting into practice a cluster system including a plurality of virtual servers placed in the physical server group, manages the layout state of virtual servers pursuant to the load state of the virtual server group. When executing scale-in, a virtual server operating on a physical server with the minimum number of operative virtual servers is specified as a shutdown target. When executing scale-out, a workload variation is predicted to control a scale-out destination of cluster system so that load variation-resembled cluster systems gather on the same physical server. The scale-in execution timing is delayed if the predicted load variation tends to rise and accelerated if it falls.

Abstract: A synchronous reference code indicative of the fact that synchronous updating was made is provided to data which is to be applied to a critical section, and the code is set when synchronous updating is made. After a sentence in the critical section is executed, it is confirmed whether or not the synchronous updating of the data was made. In a thread for synchronous reference, reference is made, it is confirmed whether or not synchronous updating was made, and then the correctness of the updating is confirmed. When the synchronous updating is not made, the execution of the critical section is completed. Thereby the simultaneous execution of the critical sections and reduction of an overhead are realized.

Abstract: In a virtual machine system built from a plurality of virtual machines, the utilization efficiency of utilized physical memory is raised. A memory management method in which a virtual machine environment, constituted by having one or several virtual machines and a hypervisor part for operating the same virtual machines, is built on a physical machine and in which: a virtual machine operates an allocation processing part and an application part, application part making a physical memory processing part allocate unallocated physical memory to a memory area and allocation processing part transmitting, when unallocated physical memory is scarce, an instruction for the release, from memory areas utilized by each application part, of memory pages for which physical memory is assigned but not used.

Abstract: A memory management method is provided to manage a memory in which areas of a garbage collected Java heap memory and a non-garbage collected external heap memory can be secured, by using a program executed by a processor in a computer. If it is judged that there is no reference to all data arranged in the external heap memory or starting point data of reference relations included in the all data, from data arranged outside the external heap memory, then the external heap memory is judged to be capable of being deallocated. As a result, it becomes possible to implement memory management in which garbage collection needing a long time program stop is not conducted and an additional API is not used.

Abstract: With regard to a plurality of data stored in a memory, relationship of data is grasped twice after a time interval therebetween. Next, increased data C1, E2, E3 which are not present in data of a first time are extracted from data of a second time, and weights “1”, “2”, “2” in accordance with data sizes are attached to the increased data. Next, the weights are successively propagated from a lower order data of a destination of reference to a higher order data of a source of reference successively. When there are a plurality of lower order data E2, E3 for a higher order D0, a weight constituted by adding the weights “2”, “2” of the plurality of lower data E2, E3 is made to be a weight “4” of the higher order data D0, and the weights of the respective data represent leak scores which causes memory leak.

Abstract: The present invention provides a memory management method, including the steps of: securing a memory area by a program executed by a computer; storing an object in the memory area in accordance with the execution of the program; bringing the memory area into a release reservation state in accordance with the program instructing the memory area to be released; moving the object to a memory area not to be released while another object in the memory area not to be released and not to be brought into the release reservation state refers to the object in the memory area to be released including the memory area to be brought into the release reservation state; and releasing the memory area to be released.

Abstract: Under program execution environment, a file size of a heap dump is reduced which is acquired so as to detect memory leaks, and so as to investigate occurrence causes of the memory leaks. In order to provide a memory leak investigating means which can be used even in a large-scaled system, the below-mentioned heap dump acquiring method is provided: When a heap dump is acquired, only such an object within objects stored in a heap memory is outputted which is adapted to the following conditions: That is, in a condition (1), an object exists among objects which are newly produced within a designated time period, and in another condition (2), an object is present on a reference path defined from a root set to the object which satisfies the above-explained condition (1).

Abstract: A pointer field compression/expansion method is provided for a computer system having a data structure reference function using a pointer. The pointers in data structure which a program refers to are classified into pointers to be frequently referred to and those not to be frequently referred to. The pointers not to be frequently referred to are determined as targets of compression and expansion to thereby reduce and suppress the overhead required for the pointer compression and expansion. Information indicating whether or not a pointer in data structure is a compression target is provided separately or such identifying information is embedded into in the pointer whereby the compressed or uncompressed format of the pointer can be dynamically determined.

Abstract: Memory management by garbage collection involves a memory area that is allocated in a computer. Data is created in the memory area in accordance with a program executed by a processor of the computer, and it is checked whether or not data necessary to execute the program exists in the memory area to be released, in response to an explicit instruction to release the memory area. As a result of the check, if data necessary to execute the program does not exist in the memory area, the memory area is released. As a result of the check, if data necessary to execute the program exists in the memory area, the data is moved to a memory area different from the memory area to be released.

Abstract: If garbage collection is executed in every thread-local heap in order to secure processing responsiveness, a memory area may be fragmented or collectable areas may be reduced as the program execution proceeds. To overcome such problems, memory is divided into an area where thread specific data is allocated and an area where referenceable data from other threads is allocated, and is managed separately. More specifically, data that is referenced specifically by each thread is allocated to a thread-local heap, while data that is referenced from other threads is allocated to a global heap.