International Business Machines Corporation

Nicholas C Matsakis

Karla Kay Arndt

Joseph W Gentile

David Harold Surman

Nicholas R Jones

Chung-Lung K Shum

Craig Raymond Walters

Jane Helen Bartik

Robert M Abrams

Anthony Thomas Sofia

Elpida Tzortzatos

Daniel Nieves

Harry M Yudenfriend

David Darden Chambliss

John Glenn Thompson

James Alan Ruddy

Joshua W Knight

Ronald K Kreuzenstein

Dieter Wellerdiek

John J Lee

Friedrich Matthias Gubitz

A method, system, and computer program product are provided for performance anomaly detection. Velocity data is periodically received from a workload manager for one or more address spaces. An expected velocity value is created for each of the one or more address spaces. A factor of the expected velocity value is compared to a current velocity value from the velocity data. Based on the current velocity value being lower than the factor, a remedial action is generated indicating an anomaly.

Programmatic performance anomaly detection

A shared cache line is concurrently modified by multiple processors of a computing environment. The concurrent modification is performed based, at least, on receiving one or more architected instructions (Fetch due to Non-Coherent Store instructions) that permit multiple processors to concurrently update the shared cache line absent obtaining a lock or having exclusive ownership of the data.

Concurrent modification of shared cache line by multiple processors

A technique relates to enabling a multiprocessor computer system to make a non-coherent request for a cache line. A first processor core sends a non-coherent fetch to a cache. In response to a second processor core having exclusive ownership of the cache line in the cache, the first processor core receives a stale copy of the cache line in the cache based on the non-coherent fetch. The non-coherent fetch is configured to obtain the stale copy for a predefined use. Cache coherency is maintained for the cache, such that the second processor core continues to have exclusive ownership of the cache line while the first processor core receives the stale copy of the cache line.

Non-coherent read in a strongly consistent cache system for frequently read but rarely updated data

A computer system includes memory and a processor configured to manage memory allocation. Aspects include receiving a request to execute a computer program and obtaining a learned data file for the computer program, the learned data file including a history of memory allocation requests and memory access requests by the computer program. Aspects also include receiving a memory allocation request from the computer program and allocating one or more pages of a virtual memory to the computer program, wherein a size of the one or more pages is based on the learned data file. Aspects further include backing at least one of the one or more pages of the virtual memory in the real memory prior to receiving an access request for the at least one of the one or more pages based on the learned data file.

Pre-backing virtual storage using historical learned data

Aspects relate to a computer system and a computer implemented method for resolving abnormal contention on the computer system. The method includes detecting, using a processor and at a hypervisor level of the computer system, abnormal contention of a serially reusable resource caused by a first virtual machine. The abnormal contention includes the first virtual machine experiencing resource starvation of computer system resources used for processing the first virtual machine, causing the first virtual machine to block the serially reusable resource from a second virtual machine that is waiting to use the serially reusable resource. The method also includes adjusting resource allocation at the hypervisor level of the computer system resources for the first virtual machine, processing the first virtual machine based on the resource allocation, and releasing the serially reusable resource by the first virtual machine in response to the first virtual machine processing.

Method and apparatus for resolving contention at the hypervisor level

Aspects relate to a computer implemented method for resolving abnormal contention on a computer system. The method includes detecting, using a processor, abnormal contention of a serially reusable resource caused by a first process, wherein the abnormal contention includes the first process blocking the serially reusable resource from a second process that is waiting to use the serially reusable resource. The method includes collecting, in a computer storage medium, resource data in a serialized resource history database and analyzing the resource data associated with the serially reusable resource and adjusting, using the processor, resource allocation for the first process of the serially reusable resource based on the resource data. The method also includes processing, using the processor and the serially reusable resource, the first process based on the resource allocation and releasing, using the processor, the serially reusable resource by the first process in response to the first process completing.

Method and apparatus for resolving contention in a computer system

A computer-implemented method for monitoring server stability based on a stability time specification of a server includes specifying a stability time for the server, wherein the stability time is defined as a time between a starting state of the server and a stability point of the server. The server activity is monitored by an availability manager to determine an availability status of the server. Responsive to the server activity progressing to the stability point within the stability time, an embodiment determines that the server is stable. Responsive to the server activity failing to progress to the stability point within the stability time, an embodiment determines that the server is unreliable.

Server restart management via stability time

A computer system is configured to monitor server stability based on a stability time specification of a server. An embodiment specifies a stability time for the server, wherein the stability time is defined as a time between a starting state of the server and a stability point of the server. The server activity is monitored by an availability manager to determine an availability status of the server. Responsive to the server activity progressing to the stability point within the stability time, an embodiment determines that the server is stable. Responsive to the server activity failing to progress to the stability point within the stability time, an embodiment determines that the server is unreliable.

A multi-mainframe operating system serialization method can include receiving, in a first computing system, a request to access a data set on behalf of a first peer application, sending, in the first computing system, a notification to a second peer application to obtain a normal enqueue, in response to the second peer application obtaining the normal enqueue, obtaining, in the first computing system, a first rider enqueue for the data set and sending, in the first computing system, a communication to peer instances to obtain additional rider enqueues for the data set, the additional rider enqueues corresponding to the first rider enqueue.

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Poughkeepsie, NY, United States of America

Nicholas C Matsakis