Method and system to alleviate denial-of-service conditions on a server

• US 7,386,848 B2
• Filed: 10/02/2003
• Issued: 06/10/2008
• Est. Priority Date: 10/02/2003
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Cavage, Mark Joseph, Williams, Gary Dale, Hazlewood, Kristin M., Heller, Richard Allyn
• Primary Examiner(s): Bullock; Lewis A
• Assistant Examiner(s): WAI, ERIC CHARLES
• Application Number:
  US10/677,659
• Publication Number:
  US 20050076335A1
• Time in Patent Office: 1,713 Days
• Field of Search: 718/103, 718/106
• US Class Current: 718/102
• CPC Class Codes: G06F 11/0715 in a system implementing multitasking multitasking per se G06F9/46
• CPC Class Codes: G06F 11/0793 Remedial or corrective actions recovery from an exception in an instruction pipeline G06F9/3861; by retry G06F11/1402; for recovering from a failure of a protocol instance or entity H04L69/40
• CPC Class Codes: G06F 9/3851 from multiple instruction streams, e.g. multistreaming
• CPC Class Codes: H04L 63/1458 Denial of Service

Abstract

A method is presented for processing data in a multithreaded application to alleviate impaired or substandard performance conditions. Work items that are pending processing by the multithreaded application are placed into a data structure. The work items are processed by a plurality of threads within the multithreaded application in accordance with a first algorithm, e.g., first-in first-out (FIFO). A thread within the multithreaded application is configured apart from the plurality of threads such that it processes work items in accordance with a second algorithm that differs from the first algorithm, thereby avoiding the impairing condition. For example, the thread may process a pending work item only if it has a particular characteristic. The thread restricts its own processing of work items by intermittently evaluating workflow conditions for the plurality of threads; if the workflow conditions improve or are unimpaired, then the thread does not process any work items.

Claims

1. A method for processing data in a multithreaded application in a data processing system, the method comprising:

placing work items into a data structure that is maintained in the data processing system, wherein the work items are pending processing by the multithreaded application;

processing work items from the data structure by a plurality of threads within the multithreaded application in accordance with a first algorithm;

processing work items from the data structure by a thread within the multithreaded application in accordance with a second algorithm that differs from the first algorithm, wherein the thread is configured distinctly from the plurality of threads; and

restricting the processing of work items by the thread in accordance with a second set of parameters used to evaluate workflow conditions, wherein the step of restricting the processing of work items by the thread in accordance with a second set of parameters further comprises;

evaluating workflow conditions of the plurality of threads for a characteristic of a workflow condition as controlled by the second set of parameters;

in response to a determination of whether or not the workflow conditions of the plurality of threads has a characteristic indicated by the second set of parameters, processing or not processing work items by the thread, respectively;

reevaluating workflow conditions of the plurality of threads for a characteristic of a workflow condition as controlled by the second set of parameters in response to processing a work item by the thread;

in response to a determination of whether or not the workflow conditions of the plurality of threads has a characteristic indicated by the second set of parameters, processing or not processing work items by the thread, respectively; and

adjusting one or more parameters in the second set of parameters in accordance with a third set of parameters used to regulate a time period associated with processing the work items by the thread in response to a determination that workflow conditions do not have a characteristic indicated by the second set of parameters.

2. The method of claim 1 wherein the step of adjusting one or more parameters in the second set of parameters in accordance with a third set of parameters further comprises:

comparing a number of work items in the data structure that have been examined by the thread with a threshold value indicated by a parameter in the third set of parameters; and

determining whether or not to adjust one or more parameters in the second set of parameters based on an outcome of the comparison of the number of work items examined by the thread with the indicated threshold value.

3. A method for processing data in a multithreaded application in a data processing system, the method comprising:

placing work items into a data structure that is maintained in the data processing system, wherein the work items are pending processing by the multithreaded application;

processing work items from the data structure by a plurality of threads within the multithreaded application in accordance with a first algorithm;

processing work items from the data structure by a thread within the multithreaded application in accordance with a second algorithm that differs from the first algorithm, wherein the thread is configured distinctly from the plurality of threads; and

restricting the processing of work items by the thread in accordance with a second set of parameters used to evaluate workflow conditions, wherein the step of restricting the processing of work items by the thread in accordance with a second set of parameters further comprises;

evaluating workflow conditions of the plurality of threads for a characteristic of a workflow condition as controlled by the second set of parameters; and

in response to a determination of whether or not the workflow conditions of the plurality of threads has a characteristic indicated by the second set of parameters, processing or not processing work items by the thread, respectively;

selecting one or more characteristics of the workflow conditions to be evaluated as indicated by a parameter in the second set of parameters;

indicating, by the parameter, one or more characteristics from the group consisting of;

a number of work items in the data structure;

a time period since a work item in the data structure has been processed by the plurality of threads;

the number of work items and the time period;

or the number of work items or the time period.