International Business Machines Corporation

John Joseph Stecher

Steven Joseph Branda

William Thomas Newport

Robert William Wisniewski

Kristi Paula Peterson

Curtis E Hrischuk

Andrew Russell Low

Peter Duncan Shipton

Chris D Johnson

Robert Vaughn Geiner

Matthew Ryan Weaver

Randall Paul Baartman

John Matthew Santosuosso

Eric L Barsness

Christopher D Johnson

Eric Nels Herness

James Lee Van Oosten

Matthew Ara Goshgarian

Bhushan Kamlakar Lokhande

Eric Lawrence Barsness

A method, system and computer program product for optimizing memory usage associated with duplicate string objects in a Java virtual machine. The method comprises scanning a heap of the Java virtual machine at the end of the start-up process of the virtual machine to identify duplicate strings associated with the virtual machine, storing the identified strings in a string cache file, and determining whether a new string that needs to be created during start-up already exists in the string cache file. The duplicate strings are added to an interned strings table. A reference to a duplicate string is returned if a string to be created is already in the string cache file.

String cache file for optimizing memory usage in a Java virtual machine

In an embodiment, a first debug agent at a first computer receives a packet. The first debug agent adds a debug command and an identifier of the first debug agent to the packet and sends the packet to a receiving computer. A second debug agent at the receiving computer removes the debug command and the identifier of the first debug agent from the packet and sends the packet to a second program that executes at the receiving computer. The second debug agent further executes the debug command, which causes the second program that executes on the receiving computer to halt execution at a breakpoint or address watch memory location. The second debug agent sends the state of the second program to the first debug agent, which presents, at the first computer, the state and a listing of the second program.

Distributed debugging

String cache file for optimizing memory usage in a java virtual machine

A method and apparatus for managing thread priority based on object creation rates. Embodiments of the invention provide a thread monitor configured to reduce the execution priority of a thread creating a sufficient number of new objects to be disruptive of system performance. Thus, although the thread may still create a large number of objects, by monitoring object creation rates and reducing the execution priority of such a thread, overall system performance may be improved. In other words, a given thread may still 'misbehave,' but receive fewer opportunities to do so.

Thread priority based on object creation rates

A method, apparatus and program product deallocate an object from a memory heap in a virtual machine environment by, in part, determining that the object is replaceable using an object reference associated with the object. The object may additionally be automatically determined as being properly removable by using a value indicative of a number of object references associated with the object. Where these conditions are met, the object may be removed from the memory heap. Where a new object can fit into a space within the memory from which the object was removed, the new object may be automatically allocated into the space. The object may be designated as being replaceable using automated or manual processes. A garbage collector algorithm may additionally execute, as needed.

Object deallocation system and method

A database access facility for accessing databases includes a monitoring function which monitors accesses by requestors of database data. The monitoring function tracks which database fields are requested to dynamically determine the fields which the application needs. Once sufficient tracking data is obtained, subsequent accesses to the database on behalf of an application are automatically modified by the application server to request only the fields which are likely to be needed. Preferably, the database access facility is an application server for one or middle tier applications which access the database on behalf of multiple clients in a three-tier client-server environment.

Autonomically regulating information transfer when accessing database resources

In an embodiment, a conditional branch is detected that selects between execution of a first alternative block and a second alternative block. A first count and a second count are saved, where the first count is a number of times the first alternative block was executed, and the second count is a number of times the second alternative block was executed. If the first count is greater than a threshold and the second count equals zero, the first alternative block is compiled into first alternative block object code and the second alternative block is not compiled. If the first count is not greater than the threshold, the first alternative block is compiled into the first alternative block object code and the second alternative block is compiled into second alternative block object code.

Controlling compiler optimizations

A combination of synchronous and asynchronous replication of data is used to replicate a local database to a replicated database. The typical tradeoff between synchronous and asynchronous replication is optimized by using hybrid replication, which is to use synchronous replication for inserting new data and asynchronous replication for updating existing data. The combined use of synchronous and asynchronous in this manner provides an efficient replicated database where the replicated database can tolerate some delay in data updates but requires no data loss of new data.

Real time data replication

Disclosed is an apparatus, method, service product, and program product which each provide an enhanced, registration-based event handler mechanism. Listener programs are located and compiled before notification is needed. When notification is ultimately required, the pre-located listeners can be called directly without incurring the performance expense associated with first locating and then calling each listener.

Mechanism that provides more efficient event handler processing

A computer implemented method, apparatus and program product for analyzing performance data particular to an algorithm using a profiler algorithm, and automatically associates the performance data with a reference clock time. The performance data may be automatically associated with a tag, also associated with the reference clock time. Using the tag, the performance data may be associated with a portion of the algorithm. For instance, the tag may be associated with a corresponding tag associated with the algorithm. User input may be received that designates both the tag and an additional tag associated with the program code. Aspects may identify tags in the performance data that correspond to both the tag and additional tag of program code. The portion of the performance data bounded by the identified tags in the performance data may be retrieved and displayed to a user. In this manner, the performance data may be automatically associated with a portion of algorithm.

Method and system for associating profiler data with a reference clock

A method, apparatus and program product facilitate the collaborative development of an algorithm by, in part, displaying an algorithm associated with a performance attribute, and receiving user input relating to the algorithm from a plurality of networked users. The performance attribute of the algorithm may be automatically modified based on the user input. The modified performance attribute may be displayed to the plurality of networked users. A query may be received from a user interested in the algorithm. In response to the user query, the algorithm may be located from among a plurality of algorithms. For instance, the algorithm may be located from among the plurality of algorithms by matching the performance attribute to a criterion of the user query. Alternatively or additionally, the algorithm may be located by matching the performance attribute to a profile of the user submitting the user query. Also in response to the user query, a second algorithm and/or performance attribute related to the algorithm, or another, may be displayed.

Collaborative program development method and system

A program product, apparatuses, and methods provide for the collection of profile information for a component of a software program by generating a data structure that maps at least one method to a component. The method includes a name, and the data structure maps the method to the component using at least a portion of the name of the method. A class or pattern may also be mapped to a component. Furthermore, during profiling, a statistic associated with the execution of the method is determined; the data structure is accessed using the name of the method to determine the associated component; and the determined statistic is associated with the determined component. By doing so, method level and class level information can be aggregated to improve profiling, often leading to a clearer picture of which components are contributing to the performance and memory footprint of large scale software programs.

Mapping a class, method, package, and/or pattern to a component

A method, apparatus, and program product manage a plurality of resources of at least one logically partitioned computing system of the type that includes a plurality of logical partitions managed by a partition manager with an application level administrative console resident in a logical partition of the computing system. Each logical partition is allocated at least a portion of the plurality of resources. A user request to adjust the allocation of at least a portion of the resources using the administrative console is received. The resources of the logically partitioned computing system to adjust in order to satisfy the user request are determined using the application level administrative console. The application level administrative console accesses the partition manager through a resource allocation interface to adjust the determined resources of the logically partitioned computing system in order to satisfy the user request.

Expansion and contraction of logical partitions on virtualized hardware

A database access facility for accessing databases includes a monitoring function which monitors accesses by requesters of database data. The monitoring function tracks which database fields are requested to dynamically determine the fields which the application needs. Once sufficient tracking data is obtained, subsequent accesses to the database on behalf of an application are automatically modified by the application server to request only the fields which are likely to be needed. Preferably, the database access facility is an application server for one or middle tier applications which access the database on behalf of multiple clients in a three-tier client-server environment.

Growing community of inventors

Rochester, MN, United States of America

John Joseph Stecher