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Posted to httpclient-users@hc.apache.org by Jesper Sahner <je...@hotmail.com> on 2006/02/03 19:58:08 UTC
Basic http-question
Hi!
I have the following basic http-question.
When we use HttpClient we make a request and get a response. When looking
for some specific information we may periodically make requests until the
information is received.
My question is if it is possible - within the "http-framework" - to ask the
server to return an answer when it has the answer instead of periodically
asking for an answer which is basically waste of time.
If you have made a reservation for some article I guess you would ask the
supplier to call you when he has the article for you instead of calling him
every day.
By way of comparison how do Flash-driven websites which are dynamically
updated (e.g. stock tickers) work in this context?
Regards,
Jesper
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Re: Basic http-question
Posted by Bindul Bhowmik <bi...@gmail.com>.
On 2/4/06, Jesper Sahner <je...@hotmail.com> wrote:
>
> Hi Chris,
>
> Thanx for your answer.
>
>
> >From: Christopher L Merrill <ch...@webperformance.com>
> >Reply-To: "HttpClient User Discussion" <
> httpclient-user@jakarta.apache.org>
> >To: HttpClient User Discussion <ht...@jakarta.apache.org>
> >Subject: Re: Basic http-question
> >Date: Fri, 03 Feb 2006 15:26:01 -0500
> >
> >Jesper Sahner wrote:
> >>My question is if it is possible - within the "http-framework" - to ask
> >>the server to return an answer when it has the answer instead of
> >>periodically asking for an answer which is basically waste of time.
> >
> >HTTP is inherently a request/response protocol. You could issue a
> >request and have server wait to respond until the desired data is
> >available.
> >But the socket would eventually timeout and you'd have to re-issue the
> >request. Additionally, it needlessly ties up resources on the server.
> >
> I wonder how e.g. a mail-system like Hotmail works. If you are logged in
> you
> get a pop-up message every time a new message is received. Is that pop-up
> message the result of your request to the mail-server (guess not) or the
> mail-server just telling you that a new message is sent.
I am not a hotmail user, so can't help you with exactly how Hotmail works,
but we have built similar systems where we use JavaScript to poll the server
periodically to get the relevant updates and either reload the entire page
or just update the relevant sections of the document.
I wonder if something similar is possible with HTTP: You make an initial
> request telling the server to give you a notice every time a certain event
> occurs without making any further requests?
>
> A solution like this would be much more effective that repeatedly
> requesting
> for new events that hasn't occured.
>
> But as I read your answer, HTTP is a request/response protocol, so this is
> not possible.
>
> >>By way of comparison how do Flash-driven websites which are dynamically
> >>updated (e.g. stock tickers) work in this context?
> >
> >At least some of them are polling the server with requests every N
> seconds.
> >Some can open raw sockets to the server, but these methods have trouble
> >getting through firewalls.
> >
> >C
> >
> >--
> >-------------------------------------------------------------------------
> >Chris Merrill | http://www.webperformance.com
> >Web Performance Inc.
> >
> >Website Load Testing and Stress Testing Software
> >-------------------------------------------------------------------------
> >
> >---------------------------------------------------------------------
> >To unsubscribe, e-mail: httpclient-user-unsubscribe@jakarta.apache.org
> >For additional commands, e-mail: httpclient-user-help@jakarta.apache.org
> >
>
>
>
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_ Bindul
Re: Basic http-question
Posted by Jesper Sahner <je...@hotmail.com>.
Hi Chris,
Thanx for your answer.
>From: Christopher L Merrill <ch...@webperformance.com>
>Reply-To: "HttpClient User Discussion" <ht...@jakarta.apache.org>
>To: HttpClient User Discussion <ht...@jakarta.apache.org>
>Subject: Re: Basic http-question
>Date: Fri, 03 Feb 2006 15:26:01 -0500
>
>Jesper Sahner wrote:
>>My question is if it is possible - within the "http-framework" - to ask
>>the server to return an answer when it has the answer instead of
>>periodically asking for an answer which is basically waste of time.
>
>HTTP is inherently a request/response protocol. You could issue a
>request and have server wait to respond until the desired data is
>available.
>But the socket would eventually timeout and you'd have to re-issue the
>request. Additionally, it needlessly ties up resources on the server.
>
I wonder how e.g. a mail-system like Hotmail works. If you are logged in you
get a pop-up message every time a new message is received. Is that pop-up
message the result of your request to the mail-server (guess not) or the
mail-server just telling you that a new message is sent.
I wonder if something similar is possible with HTTP: You make an initial
request telling the server to give you a notice every time a certain event
occurs without making any further requests?
A solution like this would be much more effective that repeatedly requesting
for new events that hasn't occured.
But as I read your answer, HTTP is a request/response protocol, so this is
not possible.
>>By way of comparison how do Flash-driven websites which are dynamically
>>updated (e.g. stock tickers) work in this context?
>
>At least some of them are polling the server with requests every N seconds.
>Some can open raw sockets to the server, but these methods have trouble
>getting through firewalls.
>
>C
>
>--
>-------------------------------------------------------------------------
>Chris Merrill | http://www.webperformance.com
>Web Performance Inc.
>
>Website Load Testing and Stress Testing Software
>-------------------------------------------------------------------------
>
>---------------------------------------------------------------------
>To unsubscribe, e-mail: httpclient-user-unsubscribe@jakarta.apache.org
>For additional commands, e-mail: httpclient-user-help@jakarta.apache.org
>
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Re: Basic http-question
Posted by Christopher L Merrill <ch...@webperformance.com>.
Jesper Sahner wrote:
> My question is if it is possible - within the "http-framework" - to ask
> the server to return an answer when it has the answer instead of
> periodically asking for an answer which is basically waste of time.
HTTP is inherently a request/response protocol. You could issue a
request and have server wait to respond until the desired data is available.
But the socket would eventually timeout and you'd have to re-issue the
request. Additionally, it needlessly ties up resources on the server.
> By way of comparison how do Flash-driven websites which are dynamically
> updated (e.g. stock tickers) work in this context?
At least some of them are polling the server with requests every N seconds.
Some can open raw sockets to the server, but these methods have trouble
getting through firewalls.
C
--
-------------------------------------------------------------------------
Chris Merrill | http://www.webperformance.com
Web Performance Inc.
Website Load Testing and Stress Testing Software
-------------------------------------------------------------------------
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