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<TITLE>FastCGI</TITLE>


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<P>

Open Market, Inc.

<P>

<CENTER><FONT SIZE=4 COLOR=#FFFFFF FACE="Impact">Technical White

Paper<BR>

</FONT></CENTER>

<H1>FastCGI:<BR>

A High-Performance Web Server Interface</H1>


<P>

April 1996<!--Please send comments to:-->

<HR>

<!-- payne@openmarket.com-->

<H2>1. Introduction</H2>


<P>

The surge in the use of the Web by business has created

a tremendous need for server extension applications that create

dynamic content. These are the applications that will allow businesses

to deliver products, services, and messages whose shape and content

are in part determined by the interaction with, and knowledge

of, the customers to which they are delivered.

<P>

This important movement away from static Web content

is pushing the limits and exposing the weaknesses of the environment

in which these applications are currently bound: CGI (Common Gateway

Interface). Most importantly it does not offer the performance

these applications require.  A new communication infrastructure

is needed to connect Web servers with these new applications.

This is what led Open Market to develop FastCGI.

<P>

FastCGI is a fast, open, and secure Web server interface

that solves the performance problems inherent in CGI, without

introducing the overhead and complexity of proprietary APIs (Application

Programming Interfaces).  

<P>

This paper assumes that the reader has basic familiarity

with Web technology and developing Web applications.

<H3>Common Gateway Interface</H3>


<P>

The de facto standard interface for Web server applications

is CGI, which was first implemented in the NCSA server.  CGI has

many benefits: 

<UL>

<LI><B>Simplicity.  </B><FONT>It is

easy to understand.</FONT>

<LI><B>Language independence.</B>

CGI applications can be written in nearly any language.

<LI><B>Process isolation.</B>

Since applications run in separate processes, buggy applications

cannot crash the Web server or access the server's private internal

state.

<LI><B>Open standard.</B>  Some

form of CGI has been implemented on every Web server.

<LI><B>Architecture independence.</B>

CGI is not tied to any particular server architecture (single

threaded, multi-threaded, etc.).

</UL>


<P>

CGI also has some significant drawbacks.  The leading

problem is performance:  Since a new process is created for each

request and thrown away when the request is done, efficiency is

poor.

<P>

CGI also has limited functionality:  It only supports

a simple &quot;responder&quot; role, where the application generates

the response that is returned to the client.  CGI programs can't

link into other stages of Web server request processing, such

as authorization and logging.

<H3>Server APIs</H3>


<P>

In response to the performance problems for CGI,

several vendors have developed APIs for their servers.  The two

most notable are NSAPI from Netscape and ISAPI from Microsoft.

 The freely available Apache server also has an API.

<P>

Applications linked into the server API may be significantly

faster than CGI programs.  The CGI startup/initialization problem

is improved, because the application runs in the server process

and is persistent across requests.  Web server APIs also offer

more functionality than CGI:  you can write extensions that perform

access control, get access to the server's log file, and link

in to other stages in the server's request processing.

<P>

However, APIs sacrifice all of CGI's benefits.  Vendor

APIs have the following problems:

<UL>

<LI><B>Complexity.</B>  Vendor

APIs introduce a steep learning curve, with increased implementation

and maintenance costs.

<LI><B>Language dependence.</B>

 Applications have to be written in a language supported by the

vendor API (usually C/C++).  Perl, the most popular language for

CGI programs, can't be used with any existing vendor API.

<LI><B>No process isolation.  </B><FONT>Since

the applications run in the server's address space, buggy applications

can corrupt the core server (or each other).  A malicious or buggy

application can compromise server security, and bugs in the core

server can corrupt applications.</FONT>

<LI><B>Proprietary.</B>  Coding

your application to a particular API locks you into a particular

vendor's server.

<LI><B>Tie-in to server architecture.</B>

 API applications have to share the same architecture as the server:

 If the Web server is multi-threaded, the application has to be

thread-safe.  If the Web server has single-threaded processes,

multi-threaded applications don't gain any performance advantage.

 Also, when the vendor changes the server's architecture, the

API will usually have to change, and applications will have to

be adapted or rewritten.

</UL>


<H3>FastCGI</H3>


<P>

The FastCGI interface combines the best aspects of

CGI and vendor APIs. Like CGI, FastCGI applications run in separate,

isolated processes.  FastCGI's advantages include:

<UL>

<LI><B>Performance.</B>  FastCGI

processes are persistent-they are reused to handle multiple requests.

 This solves the CGI performance problem of creating new processes

for each request.

<LI><B>Simplicity, with easy migration from CGI.</B>

 The FastCGI application library (described on page 9) simplifies

the migration of existing CGI applications.  Applications built

with the application library can also run as CGI programs, for

backward compatibility with old Web servers.

<LI><B>Language independence.</B>

Like CGI, FastCGI applications can be written in any language,

not just languages supported by the vendor API.

<LI><B>Process isolation.</B>

A buggy FastCGI application cannot crash or corrupt the core server

or other applications.  A malicious FastCGI application cannot

steal any secrets (such as session keys for encryption) from the

Web server.

<LI><B>Non-proprietary.</B> 

FastCGI is supported in all of Open Market's server products,

and support is under development for other Web servers, including

the freely available Apache and NCSA servers, as well as commercial

servers from Microsoft and Netscape.

<LI><B>Architecture independence.</B>

 The FastCGI interface is not tied to a particular server architecture.

 Any Web server can implement the FastCGI interface.  Also, FastCGI

does not impose any architecture on the application:  applications

can be single or multi-threaded, regardless of the threading architecture

of the Web server.

<LI><B>Support for distributed computing.</B>

 FastCGI provides the ability to run applications remotely, which

is useful for distributing load and managing external Web sites.

</UL>


<P>

The following sections describe the FastCGI interface,

protocol, application library, and support in Open Market's WebServer

products.

<H2>2. FastCGI Interface</H2>


<P>

The functionality provided by the FastCGI interface

is very similar to that provided by CGI.  To best understand the

FastCGI protocol, we review the CGI interface here. Basic CGI

request processing proceeds as follows:

<OL>

<LI>For each request, the server creates a new process

and the process initializes itself.

<LI>The Web server passes the request information

(such as remote host, username, HTTP headers, etc.) to the CGI

program in environment variables.

<LI>The Web server sends any client input (such as

user-entered field values from an HTML form) to the CGI program's

standard input.

<LI>The CGI program writes any output to be returned

to the client on standard output.  Error information written to

standard error is logged by the Web server.

<LI>When the CGI process exits, the request is complete.

</OL>


<P>

FastCGI is conceptually very similar to CGI, with

two major differences:

<UL>

<LI>FastCGI processes are persistent:  after finishing

a request, they wait for a new request instead of exiting.

<LI>Instead of using operating system environment

variables and pipes, the FastCGI protocol  multiplexes the environment

information, standard input, output and error over a single full-duplex

connection.  This allows FastCGI programs to run on remote machines,

using TCP connections between the Web server and the FastCGI application.

</UL>


<P>

Request processing in a single-threaded FastCGI application

proceeds as follows:

<OL>

<LI>The Web server creates FastCGI application processes

to handle requests.  The processes may be created at startup,

or created on demand.

<LI>The FastCGI program initializes itself, and waits

for a new connection from the Web server.

<LI>When a client request comes in, the Web server

opens a connection to the FastCGI process.  The server sends the

CGI environment variable information and standard input over the

connection.

<LI>The FastCGI process sends the standard output

and error information back to the server over the same connection.

<LI>When the FastCGI process closes the connection,

the request is complete.  The FastCGI process then waits for another

connection from the Web server.

</OL>


<P>

FastCGI applications can run locally (on the same

machine as the Web server) or remotely.  For local applications,

the server uses a full-duplex pipe to connect to the FastCGI application

process.  For remote applications, the server uses a TCP connection.

<P>

FastCGI applications can be single-threaded or multi-threaded.

 For single threaded applications, the Web server maintains a

pool of processes (if the application is running locally)  to

handle client requests.  The size of the pool is user configurable.

 Multi-threaded FastCGI applications may accept multiple connections

from the Web server and handle them simultaneously in a single

process.  (For example, Java's built-in multi-threading, garbage

collection, synchronization primitives, and platform independence

make it a natural implementation language for multi-threaded FastCGI

applications.)

<H3>Remote FastCGI</H3>


<P>

FastCGI's ability to run applications remotely (over

a TCP connection) provides some major benefits.  These benefits

are described in this section, along with some of the security

issues that affect remote FastCGI applications.

<H4>FastCGI with Firewalls</H4>


<P>

Applications that run on organizational (external) Web servers

and depend on internal databases can be a challenge to administer.

Figure 1 shows a typical organization, with an external Web server,

a firewall restricting access to the internal network, and internal

databases and applications.

<P>

<CENTER><IMG SRC="img00001.gif"><A NAME="_Ref352505891">Figure

1</A></CENTER>

<P>

With CGI and vendor APIs, the application has to run on the Web

server machine.  This means the server administrator has to replicate

the necessary database information onto the system hosting the

Web server (which may be difficult to do in an automated way without

compromising firewall security).  Or, the administrator may build

a &quot;bridge&quot; that allows access through the Web server

to internal databases and applications (which is effectively re-inventing

remote FastCGI).

<P>

With remote FastCGI, the applications can run on the internal

network, simplifying the administrator's job.  When used with

appropriate firewall configuration and auditing, this approach

provides a secure, high-performance, scalable way to bring internal

applications and data to the external network.

<H4>Load Distribution</H4>


<P>

For resource-intensive CGI and API applications, the Web server

machine quickly becomes the bottleneck for overall throughput.

The usual way to solve this performance problem is to buy a bigger,

faster Web server machine, or to partition the Web site across

several Web servers.

<P>

With remote FastCGI, the resource-intensive applications can be

moved off the Web server machine, giving the server administrator

additional flexibility in configuring the Web server.  The administrator

can configure FastCGI applications &quot;behind the scenes&quot;

without having to change any content links or the external view

of the Web site.  The administrator can use several smaller, inexpensive

server machines for applications, and can tailor each machine

to the application it is hosting.

<H4>Security Issues with Remote FastCGI</H4>


<P>

The two security issues with remote FastCGI connections are authentication

and privacy.  FastCGI applications should only accept connections

from Web servers that they trust (the application library includes

support for IP address validation).  Future versions of the protocol

will include support for applications authenticating Web servers,

as well as support for running remote connections over secure

transport protocols such as SSL or PCT.<!--This pargraph needs to be made stronger, going into the issues in a little more detail.-->


<H3>The FastCGI Protocol</H3>


<P>

This section offers a brief introduction to the protocol

used on the connection between the Web server and FastCGI application.

 Most application developers will use the FastCGI application

library and won't have to worry about the protocol details.  However,

specialized applications are free to implement the FastCGI protocol

directly.

<P>

FastCGI uses a simple packet record format on the

connection between the application and the Web server.  The same

record format is used in both directions and is outlined in Figure 2.

<P>

<CENTER><IMG SRC="img00002.gif"><A NAME="_Ref352404075">Figure

2</A></CENTER>

<P>

The protocol version field specifies the version

of the FastCGI protocol that is in use.  The type field specifies

the type of the record (described in the following section). 

The request ID identifies this record to a particular request,

allowing multiple requests to be multiplexed over a single connection.

 The data length field specifies the number of data bytes that

follow.

<P>

The different FastCGI packet types are:

<TABLE>


<TR><TD WIDTH=186><TT><FONT FACE="Courier">FCGI_PARAMS</FONT></TT>

</TD><TD WIDTH=228>Used for sending name/value pairs (CGI environment variables) from the Web server to the application.

</TD></TR>


<TR><TD WIDTH=186><TT><FONT FACE="Courier">FCGI_STDIN</FONT></TT>

</TD><TD WIDTH=228>Used for sending the standard input from the Web server to the application.

</TD></TR>


<TR><TD WIDTH=186><TT><FONT FACE="Courier">FCGI_DATA</FONT></TT>

</TD><TD WIDTH=228>Used for sending filter data to the application (for more information, see the filter role described on page 7.)

</TD></TR>


<TR><TD WIDTH=186><TT><FONT FACE="Courier">FCGI_STDOUT</FONT></TT>

</TD><TD WIDTH=228>Used to send standard output from the application to the Web server.

</TD></TR>


<TR><TD WIDTH=186><TT><FONT FACE="Courier">FCGI_STDERR</FONT></TT>

</TD><TD WIDTH=228>Used to send standard error information from the application to the Web server.

</TD></TR>


<TR><TD WIDTH=186><TT><FONT FACE="Courier">FCGI_END_REQUEST</FONT></TT>

</TD><TD WIDTH=228>Ends the request (can be sent by either the server or the application).

</TD></TR>


</TABLE>


<P>


<P>

For complete protocol details, see the <I>FastCGI Protocol Specification</I>,

available from the Web site listed at the end of this paper.

<H2>3. Application Roles</H2>


<P>

A major problem with CGI is its limited functionality:

 CGI programs can only provide simple responses to requests. 

FastCGI provides expanded functionality with support for three

different application &quot;roles&quot;:

<UL>

<LI><B>Responder.</B>  This is

the basic FastCGI role, and corresponds to the simple functionality

offered by CGI today.

<LI><B>Filter.</B>  The FastCGI

application filters the requested Web server file before sending

it to the client.

<LI><B>Authorizer.</B>  The FastCGI

program performs an access control decision for the request (such

as performing a username/password database lookup). 

</UL>


<P>

Other roles will be defined in the future.  For instance,

a &quot;logger&quot; role would be useful, where the FastCGI program

would receive the server's log entries for real-time processing

and analysis.

<P>

The roles are described in more detail in the following

sections.

<H3>Responder Role</H3>


<P>

FastCGI's Responder role is identical to the functionality

provided by CGI today.  When a request comes into the server,

the FastCGI program generates the response that's returned to

the client (typically an HTML page).

<H3><A NAME="_Ref352404524">Filter Role</A></H3>


<P>

The Filter role allows a FastCGI application to process

a requested file before it is returned to the client. 

<P>

Let's assume that the Web server is configured so

that all files with the .<TT><FONT FACE="Courier">sgml

</FONT></TT>extension are processed by a SGML-to-HTML

FastCGI filter application, and the user accesses the following

URL:

<P>

 <TT><FONT FACE="Courier">/document.sgml</FONT></TT>

<P>

After the Web server makes an access control decision

and maps this URL to a content file, it invokes the FastCGI filter

application with this file available as input.  The FastCGI program's

HTML output is sent back to the client, just as in the responder

role.  The process is outlined in Figure 3.

<P>

<CENTER><IMG SRC="img00003.gif"><A NAME="_Ref352560526">Figure

3</A></CENTER>

<P>

Filter applications can significantly improve performance

by caching filter results (the server provides the modification

time in the request information so that applications can flush

the cache when the server file has been modified).

<P>

The Filter role is useful for:

<UL>

<LI>On-the-fly format conversions

<LI>Dynamic documents (such as documents with embedded

SQL queries, or dynamic advertisement insertion)

<LI>Applying a standard template:  headers, footers,

and backgrounds

</UL>


<H3>Authorizer Role</H3>


<P>

The Authorizer role allows a FastCGI application

to make an access control decision for a request.  The FastCGI

application is invoked with all of the request information, just

as in the Responder role.  If the authorizer application generates

a &quot;200 OK&quot; HTTP result, the Web server assumes that

access is allowed and proceeds with the request.  (The Web server

may process other access checks, including other FastCGI authorizers,

before access is ultimately allowed.)  If the application generates

any other response, that response is returned to the client and

the request is ended.  The response can be any valid HTTP response,

including &quot;Access Denied&quot; or &quot;Redirect&quot;.

<P>

The Authorizer role is useful for:

<UL>

<LI>Access control based on username and password,

where the user information is looked up in an external database.

<LI>Complex access policies, such as time-of-day

based access.

<LI>Smart-card challenge/response authentication.

<LI>Dynamic redirects, where the user is sent to

different pages based on the request profile. 

</UL>


<H2><A NAME="_Ref352251764">4. FastCGI Application Library</A></H2>


<P>

Open Market has developed a FastCGI application library

that implements the FastCGI protocol (hiding the protocol details

from the developer). This library makes implementing FastCGI programs

as easy as writing CGI applications.

<P>

The application library provides a replacement for

the C language standard I/O (stdio) routines, such as <TT><FONT FACE="Courier">printf()</FONT></TT>

and <TT><FONT FACE="Courier">gets()</FONT></TT>.

 The library converts references to standard input, standard output,

and standard error to the FastCGI protocol.  References to other

files &quot;fall through&quot; to the underlying operating system

standard I/O routines.

<P>

This approach has several benefits:

<UL>

<LI>Developers don't have to learn a new API to develop

FastCGI applications.

<LI>Existing CGI programs can be migrated with minimal

source changes (CGI migration is described in more detail in the

following section).

<LI>FastCGI interpreters for Perl, Tcl, and other

interpreted languages can be built without modifying the interpreter

source code.

</UL>


<P>

Here's a simple FastCGI application:<P>
<PRE>
    #include &lt;fcgi_stdio.h&gt;

    void main(void)
    {
        int count = 0;
        while(FCGI_Accept() &gt;= 0) {
            printf("Content-type: text/html\r\n");
            printf("\r\n");
            printf("Hello world!&lt;br&gt;\r\n");
            printf("Request number %d.", count++);
        }
        exit(0);
    }
</PRE>
This application returns a &quot;Hello world&quot;

HTML response to the client.  It also keeps a counter of the number

of times it has been accessed, displaying the value of the counter

at each request.

<P>

The <TT>fcgi_stdio.h</TT>

header file provides the FastCGI replacement routines for the

C standard I/O library.  The <TT>FCGI_Accept()</TT>

routine accepts a new request from the Web server.

<H3>Migrating Existing CGI Programs</H3>


<P>

The application library was designed to make migration

of existing CGI programs as simple as possible.  Many applications

can be converted by adding a loop around the main request processing

code and recompiling with the FastCGI application library.  FastCGI

applications have the following structure, with an initialization

section and a request processing loop:<p>


<I>Initialize application;<BR>

</I><TT>while(FCGI_Accept() &gt;= 0) {</TT><BR>

  <I>Process request</I>;<BR>

<TT>}</TT>

<P>

To ease migration to FastCGI, executables built with

the application library can run as either CGI or FastCGI programs,

depending on how they are invoked.  The library detects the execution

environment and automatically selects FastCGI or regular I/O routines,

as appropriate.

<P>

After migration, developers can clean up their FastCGI

applications for best performance:

<UL>

<LI>Fix any resource leaks.  Many CGI programs do

not attempt to manage memory or close files, because they assume

the world is going to be cleaned up when they exit. (If you don't

want to clean up your program, you can just have your process

assume that it is leaking memory and exit after processing some

fixed number of requests.)  Purify from Pure Software is one of

a number of excellent tools for finding leaks and other memory

use problems.

<LI>Fix any problems with retained application state.

 The application must ensure that any state that it creates in

processing one request has no unintended effects on later requests.

 
<LI>Collapse functionality.  A common practice with

CGI applications is to implement many small programs, with one

function per program.  CGI encourages this, because smaller programs

load faster.  With FastCGI, it's better to have related functionality

in a single executable, so there are fewer processes to manage

and applications can take advantage of sharing cached information

across functions.

</UL>


<P>

Applications written in Perl, Tcl, and other scripting

languages can be migrated by using a language interpreter built

with the application library.  FastCGI-integrated Tcl and Perl

interpreters for popular Unix platforms are available from Open

Market.  The interpreters are backward-compatible:  They can run

standard Tcl and Perl applications. 

<H2>5. FastCGI in the Open Market WebServer</H2>


<P>

This section describes the FastCGI support in the

following Open Market server products:

<UL>

<LI>Open Market WebServer V2.0

<LI>Open Market Secure WebServer V2.0

<LI>Open Market Secure WebServer (Global) V2.0

</UL>


<P>

For more information about FastCGI support,  see

the <I>Open Market WebServer Installation and Configuration Guide</I>.

<H3>Server Configuration</H3>


<P>

FastCGI applications are configured with the server's

configuration file.  Configuration has two parts.

<P>

First, the server administrator defines an <I>application

class</I>.  For local applications, the application class specifies

the details of running the FastCGI application, such as:

<UL>

<LI>The pathname of the application executable.

<LI>Any arguments and environment variables to pass

to the process at startup.

<LI>The number of processes to run.

</UL>


<P>

For remote applications, the class configuration

information includes the host and TCP port to connect to.  The

Web server assumes that the FastCGI application has been started

on the remote host.  If a request comes in and the server can't

connect to the FastCGI TCP port, the server logs an error and

returns an error page to the client.

<P>

The second configuration step is mapping the application

class to a role:

<UL>

<LI>For responder roles, the administrator configures

some part of the URL space to be handled by the FastCGI application.

 For example, all URLs beginning with <FONT FACE="Courier">/rollcall/</FONT>

might be handled by the employee database application.

<LI>For filter roles, the administrator configures

a file extension to be handled by a filter application.  For example,

all files with the <FONT FACE="Courier">.sql</FONT>

extension could be handled by a SQL query lookup filter. 

<LI>For authorizer roles, the administrator configures

an authorizer application in the same manner as other access methods

(hostname, username/password, etc.)  A request must pass <I>all

</I>access control checks (possibly including multiple FastCGI

authorizers) before access is allowed. 

</UL>


<H3>Basic FastCGI</H3>


<P>

To simplify migration for existing CGI programs,

the WebServer provides a simple way to install new FastCGI programs

without having to reconfigure the server. However, this approach

doesn't offer all of the performance benefits of FastCGI application

classes.

<P>

The WebServer treats any file with the extension

<FONT FACE="Courier">.fcg</FONT> as

a FastCGI application.  When a request corresponds to such a file,

the WebServer creates a new FastCGI process to handle the request,

and shuts down the process when the request is complete (just

as in CGI).  In this mode of operation performance is comparable

to CGI.  Future versions of the WebServer will improve performance

by automatically caching processes and re-using them for subsequent

requests.

<H3>Session Affinity</H3>


<P>

FastCGI programs can improve performance by caching

information in the application process.  For applications that

require frequent but expensive operations such as validating a

username/password in an external database for each request, this

technique can significantly improve performance.

<P>

To improve the effectiveness of this technique, the

WebServer implements <I>session affinity</I>.  When session affinity

is enabled, the WebServer arranges for all requests in a user

session to be handled by the same FastCGI application process.

  What constitutes a &quot;session&quot; is configurable.  The

default configuration uses the WebServer's built-in session tracking

facility to identify user sessions.  However, the server administrator

can use any part of the request information for the session affinity

mapping:  the URL path, the client's hostname, the username, etc.<!--Talk about applications that need to hold onto resources for the user (such as open connections to the database).-->


<H2>6. FastCGI Performance Analysis</H2>


<P>

How fast is FastCGI?  The answer depends on the application.

 This section contains some real FastCGI performance measurements,

as well as guidelines for estimating the FastCGI speedup.  

<H3>FastCGI vs CGI</H3>


<P>

We measured the relative performance of CGI, FastCGI,

and static files on the Open Market WebServer, using a simple

application that generates a fixed number of output bytes.  The

following table shows the measured request processing time for

different request types on a typical platform.  The times are

measured from the client perspective and include client, server,

and application processing time.

<TABLE BORDERCOLOR=#000000 BORDER=2>


<TR><TD WIDTH=72><CENTER><FONT SIZE=2 FACE="Arial Narrow">Static file</FONT></CENTER>

</TD><TD WIDTH=180><CENTER><FONT SIZE=2 FACE="Arial Narrow">21ms + 0.19ms per Kbyte</FONT></CENTER>

</TD></TR>


<TR><TD WIDTH=72><CENTER><FONT SIZE=2 FACE="Arial Narrow">FastCGI</FONT></CENTER>

</TD><TD WIDTH=180><CENTER><FONT SIZE=2 FACE="Arial Narrow">22ms + 0.28ms per Kbyte</FONT></CENTER>

</TD></TR>


<TR><TD WIDTH=72><CENTER><FONT SIZE=2 FACE="Arial Narrow">CGI</FONT></CENTER>

</TD><TD WIDTH=180><CENTER><FONT SIZE=2 FACE="Arial Narrow">59ms + 0.37ms per Kbyte</FONT></CENTER>

</TD></TR>


</TABLE>


<P>

FastCGI performance is comparable to serving static files, and

significantly better than CGI (clearly showing the high overhead

for process creation).  Real applications have an additional time

component: process initialization, which should be added to overall

request processing time.

<P>

Let's use this data to estimate the speedup from migrating a typical

database CGI application to FastCGI.  Assume the application takes

50ms to initialize the database connection and generates 5K of

output data.  Request performance can be computed as follows:

<TABLE>


<TR><TD WIDTH=108>CGI </TD><TD WIDTH=331>59ms + 50ms + (0.37ms)(5) = 111ms

</TD></TR>


<TR><TD WIDTH=108>FastCGI</TD><TD WIDTH=331>22ms + (0.28ms)(5) = 23ms

</TD></TR>


</TABLE>


<P>

In this example, FastCGI has a 5x performance advantage over CGI,

mostly due to savings from not having to create and initialize

new processes for each request.<!--Need to talk about FastCGI vs proprietary APIs.-->


<H2>7. Conclusions</H2>


<P>

Today's Web business applications need a platform

that's fast, open, maintainable, straightforward, stable, and

secure.  FastCGI's design meets these requirements, and provides

for a logical extension from proven and widely deployed CGI technology.

 This allows developers to take advantage of FastCGI's benefits

without losing their existing investment in CGI applications.<!--Need to talk about NT.-->

<!--Need to give &quot;more punch&quot; to this conclusion: include info about uses for FastCGI (accessing legacy data in databases, access control, distributed applications, apps that have to run in multiple OS environments. -->

<H2>8. For More Information</H2>


<P>

For more information about Open Market and our products,

visit our Web site at:<FONT FACE="Courier">http://www.openmarket.com/</FONT>

<P>

For more information about the FastCGI protocol and

the developer's kit, and the latest information about FastCGI

standardization and support in other Web servers, visit the FastCGI

project page at:<FONT FACE="Courier">http://www.openmarket.com/fastcgi/</FONT>

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