Bug #69414 [Asn->Opn]: Script hangs forever
Edit report at https://bugs.php.net/bug.php?id=69414&edit=1
ID: 69414
Updated by: kalle@php.net
Reported by: deivid dot garcia dot garcia at gmail dot com
Summary: Script hangs forever
-Status: Assigned
+Status: Open
Type: Bug
Package: Output Control
Operating System: IIS 8.5
PHP Version: 5.6.7
-Assigned To: mike
+Assigned To:
Block user comment: N
Private report: N
Previous Comments:
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[2015-04-13 15:04:50] mike@php.net
I doubt that this is really an "Output Control" problem wrt output.c, but I'll have a
look anyway.
I'd rather think this is a problem with the web server waiting for "Content-Length"
bytes to arrive from the FCGI backend. Nevertheless, this should be handled in the FCGI code, if it
isn't already, though, and I'll try to reproduce with another web server.
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[2015-04-10 01:39:15] deivid dot garcia dot garcia at gmail dot com
Description:
------------
I've been experiencing for a very long time IIS spinning UP hundreds of fast-cgi processes,
rendering the server unusable.
Today I came across this situation that seems related to IIS spinning up so many instances.
In Drupal, thumbnail generation is done on the fly. The Conent-Length headers are sent before
sending the file to the client, but if anything fails during this process, the client will remain
endlesly connected (waiting for the rest of the response) even if the script has finished or exit()
has been called.
It looks like the fast-cgi processes are not released until they time out, even if exit() was
called. Because IIS thinks these processes are busy, it spins up new processes (depending on the MAX
setting in IIS) or makes new requests wait until the locked fast-cgi processes have been freed.
I'm not an HTTP protocol expert, but there must be some way for PHP to tell the client that
there's nothing else to wait for because the script has already finished execution.
Test script:
---------------
<?php
header('Content-Length: 2838');
// Something went wrong while preparing the output data
// so send a 500 and exit
header('Status: 503 Service Unavailable');
print 'Custom message';
exit(500);
Expected result:
----------------
Expect to see the 'Custom Message' in the browser inmediately, instead of the client
timing out and holding the fast-cgi process hostage until it times out.
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Edit this bug report at https://bugs.php.net/bug.php?id=69414&edit=1
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