1 / 20

Seminar Fehlertoleranz und Echtzeit für E-Commerce Prof. Miroslaw Malek Peter K. Ibach

Seminar Fehlertoleranz und Echtzeit für E-Commerce Prof. Miroslaw Malek Peter K. Ibach. e-l ab. Terminplan. Terminplan. Dependability Tree (Laprie 95). Combined Fault Classes (Laprie 95). Failure Classification (Laprie 95). Fault Model (Christian 1991).

cai
Télécharger la présentation

Seminar Fehlertoleranz und Echtzeit für E-Commerce Prof. Miroslaw Malek Peter K. Ibach

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SeminarFehlertoleranz und Echtzeitfür E-CommerceProf. Miroslaw MalekPeter K. Ibach e-lab

  2. Terminplan

  3. Terminplan

  4. Dependability Tree (Laprie 95)

  5. Combined Fault Classes (Laprie 95)

  6. Failure Classification (Laprie 95)

  7. Fault Model (Christian 1991) • Timing Fault (TF): the task completes after the deadline specified or never (ei > ci) • Crash Fault (CF): a server omits to respond to all subsequent input until it restarts • Fail Stop (FS): a server informs the system in case of a crash fault • Value fault: the output is incorrect (not subject to be tolerated) Suitable model if: • a server can exceed the specified task worst-case execution time, or • the network can delay messages, but • it is unlikely that computation results or messages are corrupted.

  8. Timing error The task completes after the deadline specified or never (ei > ci). Special cases of the (arbitrary) timing error are the early timingerror, the late timing error, and the infinitely late timing error. Software fault: programming faults in the code of a task instance that produce infinite loops or other execution delay. Specification fault: bad (under-estimated) evaluation of WCET ci. Crash fault: A server omits to respond to all subsequent input until it restarts Fail ftop: A server informs the system in case of a crash fault Value error The task completes with an incorrect result. Impromptu error The system spontaneously delivers a service item that was not specified. Error Classes

  9. Fault Tolerance Techniques • Error detection • Error diagnosis • Error recovery • Backward recovery • Forward recovery • Compensation • Hardware Fault Tolerance • Software Fault Tolerance

  10. Echtzeit-Systeme DSPecialist.ppt

  11. Echtzeit-Systeme RTsystems.ppt

  12. Vorhersage von Antwortzeiten Predictor.ppt

  13. IBM "Autumn School" • vom 2.10. bis 6.10.2000 • "Autumn School" zum Themenkreis e-Business • Ort: Berlin • Praktiker von IBM stellen Vorgehensweisen im Bereich Projektmanagement vor • Lösungsarchitekturen werden diskutiert • Hands-On Erfahrungen • eingeladen: Hauptstudiums-/Promotions- Studenten mit e-Business Qualifikation

  14. Scheduling for Responsiveness How should real-time tasks be allocated to nodes and in what order should they be executed?

  15. Responsiveness Reliability (system specific) R(t) = P(no system failure until time t) Responsiveness (specific to load and fault assumptions) r(t) = P(no task failure** until time t)

  16. Task fault probability of task i Responsiveness without replication Responsiveness with duplication Responsiveness

  17. Themen (1) • Hardware • Ausfallsichere Linux Cluster • Shared Disk Systeme - Zugriff auf gemeinsame Festplatten • Redundanter Netzzugang - Betrieb mehrerer Netzwerkanschlüsse • Unterbrechungsfreie Stromversorgung

  18. Themen (2) • Middleware • Clustering/Lastballancierung - Middleware Lösungen für Commodity (Massenware) Cluster • Echtzeit – Lastanalysen, Bearbeitung der Anfragen nach Prioritäten bzw. Zeitschranken, Überlastsicherung, Zeitvorhersagen • Verteilte Datenbanken - Was ist in E-Commerce Transaktionssystemen zu beachten? • Mobile Endgeräte - Wie kann man Handys (WAP, SMS) und andere Endgeräte integrieren?

  19. Themen (3) • E-Commerce Anwendungen • Shop Lösungen - Intershop und Co. Überblick über die Features der verbreiteten Shopsysteme • ePayment systeme - Wie kann man bezahlen? • Auktionssysteme • Satellitenkomponenten - Personalisierung, B2B, Navigation/Retrieval, etc?

  20. Themen (4) • Beispielszenarien / Content • Virtual Office – Daten sind von überall aus über beliebige Endgeräte zugreifbar • Elektronische Second-Hand Börse – Vermittlung von gebrauchten Gegenständen • Börsensystem • Game/Entertainment – Videoserver, Netzwerkspiele, Majority Voting Chess • Allgemeine Shoplösung Integration von Prewiev, Photos, Warenkorb, Bezahlfunktion, Bestellauslösung

More Related