International Business Machines Corporation

Jesse Mannes Gordon

Rajiv Arora

Frank Eliot Levine

Robert John Urquhart

Robert Francis Berry

Riaz Yousuf Hussain

Jimmie Earl DeWitt, Jr

Enio Manuel Pineda

Kean G Kuiper

Robert J Urguhart

Systems for detecting Nagling on a TCP network connection are disclosed. Embodiments may generally include a system with a Nagle detection threshold determiner for determining a Nagle detection threshold based on the network connection. The system may also generally include a Nagle detection module in communication with the Nagle detection threshold determiner for observing a small segment at a second time following an acknowledgement indicative of a Nagling condition at a first time, wherein the Nagle detection module also may detect a Nagling condition if the difference between the second time and the first time is less than or equal to the Nagle detection threshold. The system may be a receiver computer or a network computer. The system may also generate and transmit a notification of the Nagling condition, increment a Nagle monitor counter, or save an indication of the Nagling condition in a log.

Systems for detecting nagling on a TCP network connection

Systems and media for detecting outbound Nagling on a TCP network connection are disclosed. Embodiments may include creating by a sender computer one or more segments to be transmitted to a receiver computer and determining by the sender computer whether any of the one or more segments to be transmitted are small segments and determining whether a previously transmitted small segment is unacknowledged by the receiver computer. If the previously transmitted small segment is unacknowledged by the receiver computer and at least one of the segments to be transmitted is a small segment, embodiments may also include detecting by the sender computer a Nagling condition on the network connection. Further embodiments may include modifying a Nagle algorithm configuration of the network connection in response to the detected Nagling condition by turning off the Nagle algorithm or reducing a delayed acknowledgement timer for the network connection.

Detecting outbound nagling on a TCP network connection

A computer implemented method, apparatus, and computer usable program code to collect information for a system or processor having a transition between an idle state and a non-idle state to form collected system or processor information. The collected system or processor information is provided for analysis by an application. Idle counts occurring during execution of code are collected. The idle counts are provided to an application for analyzing why a processor becomes idle.

Method and apparatus for analyzing idle states in a data processing system

Methods for detecting outbound Nagling on a TCP network connection are disclosed. Embodiments may include creating by a sender computer one or more segments to be transmitted to a receiver computer and determining by the sender computer whether any of the one or more segments to be transmitted are small segments and determining whether a previously transmitted small segment is unacknowledged by the receiver computer. If the previously transmitted small segment is unacknowledged by the receiver computer and at least one of the segments to be transmitted is a small segment, embodiments may also include detecting by the sender computer a Nagling condition on the network connection. Further embodiments may include modifying a Nagle algorithm configuration of the network connection in response to the detected Nagling condition by turning off the Nagle algorithm or reducing a delayed acknowledgement timer for the network connection.

Methods for detecting outbound nagling on a TCP network connection

A computer implemented method, apparatus, and computer usable program code to collect information for a system or processor having a transition between an idle state and a non-idle state. Idle counts occurring during execution of code are collected to form collected system or processor information. The collected system or processor information is provided to an application for analyzing why a processor becomes idle.

Methods for detecting Nagling on a TCP network connection are disclosed. Embodiments may generally include a system with a Nagle detection threshold determiner for determining a Nagle detection threshold based on the network connection. The system may also generally include a Nagle detection module in communication with the Nagle detection threshold determiner for observing a small segment at a second time following an acknowledgement indicative of a Nagling condition at a first time, wherein the Nagle detection module also may detect a Nagling condition if the difference between the second time and the first time is less than or equal to the Nagle detection threshold. The system may be a receiver computer or a network computer. The system may also generate and transmit a notification of the Nagling condition, increment a Nagle monitor counter, or save an indication of the Nagling condition in a log.

Methods for detecting nagling on a TCP network connection

A data processing system performs a multithreaded performance benchmark with a rampup interval and a rampdown interval. The master thread signals a start test event and begins the rampup interval. After the rampup interval, the master thread signals a start measurement event. In response to the start measurement event, the worker threads record the units of work they complete. After the measurement interval, the master signals the workers to stop measuring, but to continue running. This begins the rampdown interval. After the rampdown interval, the master thread signals a stop test event. The rampup and rampdown intervals are long enough to ensure that measurements are not recorded during skew intervals. Thus, thread skew does not impact the results.

Method, apparatus, and program for eliminating thread skew in multithreaded performance benchmarks

Server performance is bench marked using multiple master processes. A local master process is created for each client computer system applying load on the server. Then a global master process is created on a physical computer system on which neither client nor server processes are running. The global master is responsible for the proper execution of the bench mark. The global master uses an inter-master communications protocol that enforces coordination among the disparate client systems and processes.

Method, apparatus, and program for measuring server performance using multiple clients

A program is profiled with enablement of trace record generation during a first period of time and with disablement of trace record generation during a second period of time. The number of trace records output during the first period of time is determined, and a trace overhead calibration value is computed as an average time for writing the number of trace records output during the first period of time. The trace overhead calibration value may be stored for subsequent use in a profiling-related process in the data processing system. The trace overhead compensation value represents the amount of time required to generate a trace record, and the trace times retrieved from the trace records are adjusted to compensate for the amount of time required to generate those trace records.

Determining and compensating for temporal overhead in trace record generation and processing

A method and system for compensating for output overhead in trace data is provided by analyzing and compensating for the overhead associated with outputting trace information to a trace buffer or a trace file in the form of trace records. A trace record represents an occurrence of some profiling event of interest. Each trace record contains a starting timestamp representing the time at which the generation of the trace record was commenced and an ending timestamp representing the time at which the generation of the trace record was completed. In order to compute the period of execution time attributable to the application program or system being profiled, a starting timestamp of a trace record is compared with the ending timestamp of a preceding trace record, and the difference between the timestamps is directly related to the execution time of the application program or system being profiled. The time period between the timestamps in a trace record is implicitly disregarded as attributable to overhead in the generation of trace records.

Method and system for compensating for output overhead in trace date using trace record information

A method and system for compensating for trace overhead is provided by analyzing and compensating for the temporal overhead associated with generating or outputting trace information to a trace buffer or a trace file in the form of trace records. A trace record generally represents an occurrence of a profiling event of interest. The amount of time required to generate a trace record may be determined, and the trace times retrieved from the trace records are adjusted to compensate for the amount of time required to generate those trace records. A trace overhead calibration value may be determined by computing the average time necessary to generate a trace record, or in certain cases, by computing the minimum time necessary to generate a trace record. The trace overhead calibration value is stored for subsequent use in a profiling-related process in the data processing system.

Method and system for compensating for output overhead in trace data using initial calibration information

A method and system for compensating for instrumentation overhead in trace data is provided. To profile a program, the program is executed to generate trace records that are written to a trace file. A set of event trace records in a trace file is processed to determine one or more trace overhead compensation values. The trace overhead compensation values are determined by computing, for each successive pair of event trace records in the trace file, a difference between a first timestamp in a preceding event trace record and a second timestamp in a succeeding event trace record. The minimum value of all of these differences is then stored as a trace overhead compensation value representing an amount of time for instrumentation processing of an event. The one or more trace overhead compensation values are applied to the event trace records during subsequent processing of the set of event trace records.

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Austin, TX, United States of America

Jesse Mannes Gordon