Plugin: is Tcl needed on Server to access files on server 
Author Message
 Plugin: is Tcl needed on Server to access files on server

Quote:

> ... I maintain a Webpage which should be updated
> periodically. I don't always have the time to do it so I would allow a couple
> other people to do it through a Tk interface. They would enter the info for
> the page and the app/tclet would create the HTML info. The people who would
> be using this aren't (yet) HTML- or even Internet-protocols-savvy.

The Plugin (along with what we call 'tclet') deals with *client*-side
execution. It is useful *only* when existing HTML facilities like FORMs
don't give you the wanted interactivity. In your case, maybe a simple
FORM with a vanilla text entry field is sufficient, all
HTML-beautification being done automatically on the server. Up to you :)

Now the server-side task may also be done in Tcl, either with the
standard CGI interface if you're using a standard HTTP server, or "by
hand" (socket -server) if you can afford (or prefer) to have a
standalone server in Tcl for it.

-Alex



Sat, 10 Mar 2001 03:00:00 GMT  
 Plugin: is Tcl needed on Server to access files on server


:Now the server-side task may also be done in Tcl, either with the
:standard CGI interface if you're using a standard HTTP server, or "by
:hand" (socket -server) if you can afford (or prefer) to have a
:standalone server in Tcl for it.

Another growing area of programming is 'servlets' - using the ability of
a few http servers to run pieces of tcl code on the server side rather
than on the client side.  I've not found an comparative analysis of the
alternatives, such as NeoWebScript, binevolve, QB3, tcl_httpd, and
probably others.
--

<*> O- <URL:http://www.purl.org/NET/lvirden/> |     only planning.
Unless explicitly stated to the contrary, nothing in this posting
should be construed as representing my employer's opinions.



Sat, 10 Mar 2001 03:00:00 GMT  
 Plugin: is Tcl needed on Server to access files on server

Quote:


> :Now the server-side task may also be done in Tcl, either with the
> :standard CGI interface if you're using a standard HTTP server, or "by
> :hand" (socket -server) if you can afford (or prefer) to have a
> :standalone server in Tcl for it.

> Another growing area of programming is 'servlets' - using the ability of
> a few http servers to run pieces of tcl code on the server side rather
> than on the client side.  I've not found an comparative analysis of the
> alternatives, such as NeoWebScript, binevolve, QB3, tcl_httpd, and
> probably others.

Forgive my ignorance Larry: but is there considerable difference with
CGI ? Or do the servlets run as 8.1 threads-interpreters inside a single
httpd process address space ?

-Alex



Sun, 11 Mar 2001 03:00:00 GMT  
 Plugin: is Tcl needed on Server to access files on server


                        .
                        .
                        .

Quote:
>> Another growing area of programming is 'servlets' - using the ability of
>> a few http servers to run pieces of tcl code on the server side rather
>> than on the client side.  I've not found an comparative analysis of the
>> alternatives, such as NeoWebScript, binevolve, QB3, tcl_httpd, and
>> probably others.

>Forgive my ignorance Larry: but is there considerable difference with
>CGI ? Or do the servlets run as 8.1 threads-interpreters inside a single
>httpd process address space ?

>-Alex

'Depends on how you see differences and samenesses.  I
remember realizing on a particular day in '96 that CGI
was old and doomed.  It took another half-year before
I faced up to the fact that, like fortran and public
education, it'll be with us for a long time into the
future.

In any case, the first complaint most people seem to
have with CGI has to do with performance.  NWS and VET
can easily multiply peak service capacities by a factor
of ten.  Yes, they run in-process, with the advantages
and disadvantages you'd expect in comparison with CGI's
model.

I haven't written comparisons of these yet.  Pointers
appear at <URL:http://
starbase.neosoft.com/~claird/comp.lang.tcl/server_side_tcl.html>
--

Cameron Laird           http://starbase.neosoft.com/~claird/home.html



Sun, 11 Mar 2001 03:00:00 GMT  
 Plugin: is Tcl needed on Server to access files on server


:>

:> :Now the server-side task may also be done in Tcl, either with the
:> :standard CGI interface if you're using a standard HTTP server, or "by
:> :hand" (socket -server) if you can afford (or prefer) to have a
:> :standalone server in Tcl for it.
:>
:> Another growing area of programming is 'servlets' - using the ability of
:> a few http servers to run pieces of tcl code on the server side rather
:> than on the client side.  I've not found an comparative analysis of the
:> alternatives, such as NeoWebScript, binevolve, QB3, tcl_httpd, and
:> probably others.
:
:Forgive my ignorance Larry: but is there considerable difference with
:CGI ? Or do the servlets run as 8.1 threads-interpreters inside a single
:httpd process address space ?

It all depends on the 'weight' (environmental impact) of the program
doing the interpretation.  For instance, many people find that certain
large but popular cgi scripting languages named after jewelry spend more
time starting up , opening database connections, etc. than they do
actually doing transactions.  The idea of servlets allows one the potential
to start up one interpreter, perhaps open a series of files and
databases, then operate against these resources.

--

<*> O- <URL:http://www.purl.org/NET/lvirden/> |     only planning.
Unless explicitly stated to the contrary, nothing in this posting
should be construed as representing my employer's opinions.



Mon, 12 Mar 2001 03:00:00 GMT  
 Plugin: is Tcl needed on Server to access files on server
Hello,

  Larry is quite right about the startup time for the
interpreter and database connections taking up a very
significant amount of time and resources in the CGI model.
Unfortunately this applies to Tcl as well as languages
named after jewlery.

  We've found that simply getting rid of the overhead
of CGI (starting up a new process for each request and
loading up the Tcl interpreter) can result in significant
speed ups. Our tests show between 2 to 5 times faster,
with real life programs coming in around 3-4 times faster.
That is, using the same exact script under CGI and under
the 'servlet' model (in this case, http://www.VelociGen.com/).

  Once you have persistent processes a lot of good things
happen. For example, you can have persistent database
connections, which can buy you even greater speedups
(it's not uncommon to see a script that connects to
Oracle go 25 times faster).
  You can also get clever about caching byte-compiled copies
of code, potentially making things even faster.

  As for the actual implementation, it varies. NeoWebScript,
for example, puts the interpreter inside the http process.
This works well with multi-process http servers such as Apache.
VelociGen separates the process spaces and  uses a group of
persistent 'Tcl engine's, allowing it to work with thread based
http servers as well as Apache (see
http://www.binevolve.com/vet/architecture.vep.html).
tcl_httpd is a pure Tcl http server, and executes the Tcl
script in process (I believe). I'm not familiar with QB3.
None of these use threads (to the best of my knowledge).

  And of course there's the added benefit of being able to
use html templates with embedded Tcl code, which makes life
much easier.

Best,
        Tony Darugar
        http://www.BinaryEvolution.com/

Quote:

> ....
> :> Another growing area of programming is 'servlets' - using the ability of
> :> a few http servers to run pieces of tcl code on the server side rather
> :> than on the client side.  I've not found an comparative analysis of the
> :> alternatives, such as NeoWebScript, binevolve, QB3, tcl_httpd, and
> :> probably others.
> :
> :Forgive my ignorance Larry: but is there considerable difference with
> :CGI ? Or do the servlets run as 8.1 threads-interpreters inside a single
> :httpd process address space ?

> It all depends on the 'weight' (environmental impact) of the program
> doing the interpretation.  For instance, many people find that certain
> large but popular cgi scripting languages named after jewelry spend more
> time starting up , opening database connections, etc. than they do
> actually doing transactions.  The idea of servlets allows one the potential
> to start up one interpreter, perhaps open a series of files and
> databases, then operate against these resources.



Tue, 13 Mar 2001 03:00:00 GMT  
 
 [ 7 post ] 

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