Analysis of Buffer Delay in Web-Server Control

Kjaer, Martin AnsbjergLund University,Lunds universitet,Institutionen för reglerteknik,Institutioner vid LTH,Lunds Tekniska Högskola,Department of Automatic Control,Departments at LTH,Faculty of Engineering, LTH (författare)

This paper addresses a problem related to control of web servers. Due to architectual issues, relevant measurements can only be taken over a limited part of the server system, which leaves the controller unaware of what happens in buffers proceeding the actual web-server (for instance, in the TCP/IP layers). In earlier presented work we modeled such a system and proved that the unmeasured buffering turned a measurement of an input disturbance into a state-dependent variable. In this paper we investigate how these new properties effect a traditional control design consisting of feedback in combination with a feed-forward mechanism. The stability analysis suggests that under certain circumstances, the system enters limit cycles due to the feedback mechanism introduced by the designed feed-forward controller. We verify the analysis by both simulations and experiments.

Robertsson, AndersLund University,Lunds universitet,Institutionen för reglerteknik,Institutioner vid LTH,Lunds Tekniska Högskola,Department of Automatic Control,Departments at LTH,Faculty of Engineering, LTH(Swepub:lu)cont-aro (författare)
Institutionen för reglerteknikInstitutioner vid LTH (creator_code:org_t)

Om ämnet

TEKNIK OCH TEKNOLOGIER: TEKNIK OCH TEKNO ...; och Elektroteknik oc ...; och Reglerteknik

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.