lect5.ppt - 02/23/06 cis 4100 systems performance and evaluation lecture 6 by zornitza genova...
DESCRIPTION
ZGP003 Performance Issues of Web Services Server Architectures Web Server: An HTTP server (or HTTP daemon) - SW programs that control the flow of incoming and outgoing data on a computer connected to an intranet or to the Internet. listens for HTTP requests coming from clients over the network establishes the requested connection between itself and the client sends the requested file, and returns to its listening mode HTTP servers handle more than one request at a time.TRANSCRIPT
Lect5.ppt - 02/23/06
CIS 4100 Systems Performance and Evaluation
Lecture 6
byZornitza Genova Prodanoff
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Lecture Outline
CHAPTER 4 - Performance Issues of Web Services
From Boxes to Services - Web Server Overview
Perception of Performance
Where Are the Delays?
Web Infrastructure
Server Architectures Networks
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Performance Issues of Web Services
Server Architectures
Web Server: An HTTP server (or HTTP daemon) - SW programs that control the flow of incoming and outgoing data on a computer connected to an intranet or to the Internet.
• listens for HTTP requests coming from clients over the network
• establishes the requested connection between itself and the client
• sends the requested file,
• and returns to its listening mode
• HTTP servers handle more than one request at a time.
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Performance Issues of Web Services
Server ArchitecturesWeb Server
Problems of CGI scripts
• use FastCGI scripts (see Fig. 4.9b) - persistent processes that communicate with the Web server either through TCP or local interprocess communication
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Performance Issues of Web Services
Server ArchitecturesWeb Server
FastCGIs provide isolation and persistency better performance than CGI scripts
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Performance Issues of Web Services
Server ArchitecturesWeb Server
As shown in Fig. 4.9b, the FastCGI script is present throughout the entire life
of one or more requests.
The communication between the Web server and FastCGI scripts usually involves system calls.
Fig. 4.9b
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Performance Issues of Web Services
Server ArchitecturesWeb Server
The third approach, shown in Fig. 4.9c, is of applications that run within the
context of the Web server. The application is invoked through APIs provided by the Web server software. Examples include ISAPI for Microsoft's IISTM Web server and NSAPI for Netscape's Web server.
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Performance Issues of Web Services
Server ArchitecturesWeb Server
Fig. 4.9c
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Performance Issues of Web Services
Server ArchitecturesWeb Server
The last approach is the use of server-side scripting. The page, retrieved from the document tree, contains HTML code and a script written in a scripting language. Microsoft's Active Server Pages (ASP )TM allow the use of Javascript and VBscript with ActiveX controls in a page and Netscape's Livewire allow the use of server-side Javascript.
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Performance Issues of Web Services
Server ArchitecturesWeb Server
A script interpreter at the Web server interprets the script and dynamically generates an HTML page that is returned to the browser (see Fig. 4.10).
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Server Architectures: Application Server
Transaction and Database Server Streaming Server Multi-Tier Architecture Dynamic Load Balancing
Performance Issues of Web Services
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Networks
Bandwidth and Latency Traffic Special Features
Performance Issues of Web Services
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Networks
Bandwidth and Latency Traffic Special Features
Performance Issues of Web Services
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Networks
Bandwidth and Latency Traffic Special Features
Performance Issues of Web Services