RE: [PHP] flushing AJAX scripts
As I said if the client abort or close the connection, PHP does not finish its
execution, it simply exits from the script.
If you run this code and you close the browser before 10 seconds the file will
never be created, for example.
?php
function write($stuff){
echo$stuff, PHP_EOL.br /, ob_get_clean();
@ob_flush();
@flush();
};
$seconds = 10;
ob_start();
while($seconds){
write('I should do something in '.($seconds--).' seconds');
sleep(1);
}
$fp = fopen('test.txt', 'wb');
fwrite($fp, gmdate('Y-m-d H:i:s'));
fclose($fp);
write('Finished!');
?
but, obviously, if you launch a query via PHP and PHP is killed, MySQL will go
on performing the query until it has been fully executed but if PHP would like
to do something else after that query and again, the client leave the page, PHP
will never perform that operation.
So, unless you are not creating a flagged report in one shoot and your system
is clever enough to understand what's going on in a secure way, I still suggest
delayed, crontabbed or extra threads for this task which does not suite/scale
in a webpage.
In my company we are using multi threading tasks with real status able to
constantly monitor the situation but we are in C# over SQLServer.
I did something similar in PHP and Ajax and MySQL in the old company but trust
me, it is not simple if you want to be consistent.
Regards.
Date: Sat, 28 Mar 2009 00:45:27 -0400
From: jbw2...@earthlink.net
To: an_...@hotmail.com
Subject: Re: RE: [PHP] flushing AJAX scripts
Well, the point was that I had tried the first way, submitting one AJAX
request and waiting for it to finish and it was timing out, probably on
my firewall which it shouldn't have - but it did. The reports can take
10 seconds or 10 minutes to create. Doing it this way I can still load
the report even if the original request shuts down after 3-4 minutes.
Jim
Andrea Giammarchi wrote:
Sorry Jim, I meant Jim when I wrote Kim ... and
Phico:
http://webreflection.blogspot.com/2008/04/phomet-changes-name-so-welcome-phico.html
Regards
From: an_...@hotmail.com
To: php-general@lists.php.net
Date: Fri, 27 Mar 2009 15:55:28 +0100
Subject: RE: [PHP] flushing AJAX scripts
Sorry, Kim, but why on earth you are polling with a second request to know
when the first one has finished?
I mean, when the first request inserts data in the database that's it,
you'll manage the end of the request.
$A --- do stuff; do stuff; do stuff; report ready;
$B --- report ready?
$B --- report ready?
$B --- report ready?
$B --- report ready?
report ready; --- notification to A
$B --- report ready;
the report ready, if it is when $A request has been finished, will be in
$A, the polling via $B is absolutely useless, imo.
There is no timeout from Ajax, it simply keep waiting, but obviously if
your PHP has max_execution_time 30 seconds and the script execution takes
more than 30 seconds there's no polling that could save you.
The same if the user closes the browser, connection lost, bye bye response.
To have a notice, you need Comet, try out Phico but still, a page that
requires that much is not suitable for the web. Report creation should be
a cronjob in a separed thread if it is that stressful.
Regards
Date: Fri, 27 Mar 2009 10:47:10 -0400
From: jbw2...@earthlink.net
To: an_...@hotmail.com
CC: php-general@lists.php.net
Subject: Re: RE: [PHP] flushing AJAX scripts
My page submits the AJAX request to complete a report that takes some
time, and upon completion stores results in a database. A second AJAX
request polls every 5 seconds and queries the database if the report is
ready. This hopefully will get around any timeout problems I am having
with a long running request, and seems to be working. It looks like I
can accept the default behavior for now. I don't depend on getting a
response from the original request, but is there a point where the AJAX
response script will be stopped either by Apache or PHP before it can
insert into the database?
Jim
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RE: [PHP] flushing AJAX scripts
Some browser would like to receive at list N characters (bytes) even if you force the flush, before the browser will show those characters. In any case, the Ajax request will not be completed until its readyState will be 4, which means the page execution on the server has finished (released, php has gone, flush or not flush) For a task like this one you have few options: 1 - launch new thread if your host is able to do it 2 - use a Comet like response (for php I wrote Phico some while ago) In any case, I hope this stressful operation cannot be performed from thousand of users or you can say bye bye to the service. Alternatives: 1 - optimize your database 2 - delegate the job once a time rather than every click (cronjob) 3 - if the bottleneck is PHP, create an extension in C to perform the same task Hope this help. Regards P.S. Internet Explorer a part, you can read the responseText on readystate 3 which will be called different time (most likely for each flush). If IE is not your target, you could consider this opportunity to read the sent stream so far. Date: Fri, 27 Mar 2009 08:49:35 +1100 From: dmag...@gmail.com To: jbw2...@earthlink.net CC: php-general@lists.php.net Subject: Re: [PHP] flushing AJAX scripts jim white wrote: I am using jQuery AJAX request to run a script that can take several minutes to create a report. I want to start the script and immediately echo a response to close the connection and then let the script complete a report which I can get later. I have tried several thing such as ob_start(); echo json_encode(array(time=$now, message=Report has started running!)); ob_end_flush(); Try something like this echo something; flush(); without the ob* stuff. -- Postgresql php tutorials http://www.designmagick.com/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php _ Drag n’ drop—Get easy photo sharing with Windows Live™ Photos. http://www.microsoft.com/windows/windowslive/products/photos.aspx
Re: RE: [PHP] flushing AJAX scripts
My page submits the AJAX request to complete a report that takes some time, and upon completion stores results in a database. A second AJAX request polls every 5 seconds and queries the database if the report is ready. This hopefully will get around any timeout problems I am having with a long running request, and seems to be working. It looks like I can accept the default behavior for now. I don't depend on getting a response from the original request, but is there a point where the AJAX response script will be stopped either by Apache or PHP before it can insert into the database? Jim Andrea Giammarchi wrote: Some browser would like to receive at list N characters (bytes) even if you force the flush, before the browser will show those characters. In any case, the Ajax request will not be completed until its readyState will be 4, which means the page execution on the server has finished (released, php has gone, flush or not flush) For a task like this one you have few options: 1 - launch new thread if your host is able to do it 2 - use a Comet like response (for php I wrote Phico some while ago) In any case, I hope this stressful operation cannot be performed from thousand of users or you can say bye bye to the service. Alternatives: 1 - optimize your database 2 - delegate the job once a time rather than every click (cronjob) 3 - if the bottleneck is PHP, create an extension in C to perform the same task Hope this help. Regards P.S. Internet Explorer a part, you can read the responseText on readystate 3 which will be called different time (most likely for each flush). If IE is not your target, you could consider this opportunity to read the sent stream so far. Date: Fri, 27 Mar 2009 08:49:35 +1100 From: dmag...@gmail.com To: jbw2...@earthlink.net CC: php-general@lists.php.net Subject: Re: [PHP] flushing AJAX scripts jim white wrote: I am using jQuery AJAX request to run a script that can take several minutes to create a report. I want to start the script and immediately echo a response to close the connection and then let the script complete a report which I can get later. I have tried several thing such as ob_start(); echo json_encode(array(time=$now, message=Report has started running!)); ob_end_flush(); Try something like this echo something; flush(); without the ob* stuff. -- Postgresql php tutorials http://www.designmagick.com/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php _ Drag n’ drop—Get easy photo sharing with Windows Live™ Photos. http://www.microsoft.com/windows/windowslive/products/photos.aspx -- James (Jim) B. White tel: (919)-380-9615 homepage: http://jimserver.net/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
RE: [PHP] flushing AJAX scripts
Sorry, Kim, but why on earth you are polling with a second request to know when the first one has finished? I mean, when the first request inserts data in the database that's it, you'll manage the end of the request. $A --- do stuff; do stuff; do stuff; report ready; $B --- report ready? $B --- report ready? $B --- report ready? $B --- report ready? report ready; --- notification to A $B --- report ready; the report ready, if it is when $A request has been finished, will be in $A, the polling via $B is absolutely useless, imo. There is no timeout from Ajax, it simply keep waiting, but obviously if your PHP has max_execution_time 30 seconds and the script execution takes more than 30 seconds there's no polling that could save you. The same if the user closes the browser, connection lost, bye bye response. To have a notice, you need Comet, try out Phico but still, a page that requires that much is not suitable for the web. Report creation should be a cronjob in a separed thread if it is that stressful. Regards Date: Fri, 27 Mar 2009 10:47:10 -0400 From: jbw2...@earthlink.net To: an_...@hotmail.com CC: php-general@lists.php.net Subject: Re: RE: [PHP] flushing AJAX scripts My page submits the AJAX request to complete a report that takes some time, and upon completion stores results in a database. A second AJAX request polls every 5 seconds and queries the database if the report is ready. This hopefully will get around any timeout problems I am having with a long running request, and seems to be working. It looks like I can accept the default behavior for now. I don't depend on getting a response from the original request, but is there a point where the AJAX response script will be stopped either by Apache or PHP before it can insert into the database? Jim _ News, entertainment and everything you care about at Live.com. Get it now! http://www.live.com/getstarted.aspx
RE: [PHP] flushing AJAX scripts
Sorry Jim, I meant Jim when I wrote Kim ... and Phico: http://webreflection.blogspot.com/2008/04/phomet-changes-name-so-welcome-phico.html Regards From: an_...@hotmail.com To: php-general@lists.php.net Date: Fri, 27 Mar 2009 15:55:28 +0100 Subject: RE: [PHP] flushing AJAX scripts Sorry, Kim, but why on earth you are polling with a second request to know when the first one has finished? I mean, when the first request inserts data in the database that's it, you'll manage the end of the request. $A --- do stuff; do stuff; do stuff; report ready; $B --- report ready? $B --- report ready? $B --- report ready? $B --- report ready? report ready; --- notification to A $B --- report ready; the report ready, if it is when $A request has been finished, will be in $A, the polling via $B is absolutely useless, imo. There is no timeout from Ajax, it simply keep waiting, but obviously if your PHP has max_execution_time 30 seconds and the script execution takes more than 30 seconds there's no polling that could save you. The same if the user closes the browser, connection lost, bye bye response. To have a notice, you need Comet, try out Phico but still, a page that requires that much is not suitable for the web. Report creation should be a cronjob in a separed thread if it is that stressful. Regards Date: Fri, 27 Mar 2009 10:47:10 -0400 From: jbw2...@earthlink.net To: an_...@hotmail.com CC: php-general@lists.php.net Subject: Re: RE: [PHP] flushing AJAX scripts My page submits the AJAX request to complete a report that takes some time, and upon completion stores results in a database. A second AJAX request polls every 5 seconds and queries the database if the report is ready. This hopefully will get around any timeout problems I am having with a long running request, and seems to be working. It looks like I can accept the default behavior for now. I don't depend on getting a response from the original request, but is there a point where the AJAX response script will be stopped either by Apache or PHP before it can insert into the database? Jim _ News, entertainment and everything you care about at Live.com. Get it now! http://www.live.com/getstarted.aspx _ Drag n’ drop—Get easy photo sharing with Windows Live™ Photos. http://www.microsoft.com/windows/windowslive/products/photos.aspx
Re: RE: [PHP] flushing AJAX scripts
Well, the point was that I had tried the first way, submitting one AJAX request and waiting for it to finish and it was timing out, probably on my firewall which it shouldn't have - but it did. The reports can take 10 seconds or 10 minutes to create. Doing it this way I can still load the report even if the original request shuts down after 3-4 minutes. Jim Andrea Giammarchi wrote: Sorry Jim, I meant Jim when I wrote Kim ... and Phico: http://webreflection.blogspot.com/2008/04/phomet-changes-name-so-welcome-phico.html Regards From: an_...@hotmail.com To: php-general@lists.php.net Date: Fri, 27 Mar 2009 15:55:28 +0100 Subject: RE: [PHP] flushing AJAX scripts Sorry, Kim, but why on earth you are polling with a second request to know when the first one has finished? I mean, when the first request inserts data in the database that's it, you'll manage the end of the request. $A --- do stuff; do stuff; do stuff; report ready; $B --- report ready? $B --- report ready? $B --- report ready? $B --- report ready? report ready; --- notification to A $B --- report ready; the report ready, if it is when $A request has been finished, will be in $A, the polling via $B is absolutely useless, imo. There is no timeout from Ajax, it simply keep waiting, but obviously if your PHP has max_execution_time 30 seconds and the script execution takes more than 30 seconds there's no polling that could save you. The same if the user closes the browser, connection lost, bye bye response. To have a notice, you need Comet, try out Phico but still, a page that requires that much is not suitable for the web. Report creation should be a cronjob in a separed thread if it is that stressful. Regards Date: Fri, 27 Mar 2009 10:47:10 -0400 From: jbw2...@earthlink.net To: an_...@hotmail.com CC: php-general@lists.php.net Subject: Re: RE: [PHP] flushing AJAX scripts My page submits the AJAX request to complete a report that takes some time, and upon completion stores results in a database. A second AJAX request polls every 5 seconds and queries the database if the report is ready. This hopefully will get around any timeout problems I am having with a long running request, and seems to be working. It looks like I can accept the default behavior for now. I don't depend on getting a response from the original request, but is there a point where the AJAX response script will be stopped either by Apache or PHP before it can insert into the database? Jim _ News, entertainment and everything you care about at Live.com. Get it now! http://www.live.com/getstarted.aspx _ Drag n’ drop—Get easy photo sharing with Windows Live™ Photos. http://www.microsoft.com/windows/windowslive/products/photos.aspx -- James (Jim) B. White tel: (919)-380-9615 homepage: http://jimserver.net/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] flushing AJAX scripts
jim white wrote: I am using jQuery AJAX request to run a script that can take several minutes to create a report. I want to start the script and immediately echo a response to close the connection and then let the script complete a report which I can get later. I have tried several thing such as ob_start(); echo json_encode(array(time=$now, message=Report has started running!)); ob_end_flush(); Try something like this echo something; flush(); without the ob* stuff. -- Postgresql php tutorials http://www.designmagick.com/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] flushing AJAX scripts
Hello Jim, You will need to do some low level ajax coding from the client side with the onreadychange event. If you're using jquery 1.3 then you can create your own XHR object with the xhr callback handler. To learn more about the ready state check out this link: http://www.quirksmode.org/blog/archives/2005/09/xmlhttp_notes_r_2.html You might find what you're looking for with the following ready state: 3 - Interactive Downloading, responseText holds the partial data. Raymond Irving Create Rich PHP Web Apps Today! Raxan PDI - http://raxanpdi.com/ --- On Thu, 3/26/09, jim white jbw2...@earthlink.net wrote: From: jim white jbw2...@earthlink.net Subject: [PHP] flushing AJAX scripts To: php-general@lists.php.net Date: Thursday, March 26, 2009, 4:01 PM I am using jQuery AJAX request to run a script that can take several minutes to create a report. I want to start the script and immediately echo a response to close the connection and then let the script complete a report which I can get later. I have tried several thing such as ob_start(); echo json_encode(array(time=$now, message=Report has started running!)); ob_end_flush(); However, the script does not respond and (I suppose close the connection) until the report is complete. How can I fix this behaviour? Jim -- James (Jim) B. White tel: (919)-380-9615 homepage: http://jimserver.net/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
