exec from php is causing an “Premature end of scri

Question

I have a php script written which calls an external command using exec which compiles a spacial database query result into a shape file. In tables with lots of records (say 15,000), this command can take as long as 7 minutes to execute. The script works fine on scripts which do not take too long (maybe <2min) but on longer scripts (like the 7 minute one) the page will display "500 internal server error". Upon reviewing the Apache server log, the error states: "Premature end of script headers: php-cgi.exe". I have already adjusted the php maximum execution time to allow more than enough time, so I know it is not this. Is there an Apache maximum that's being hit, or something else?

Answer 1

Apparently, the default httpd.conf file included in Apache 2.4 doesn't automatically include the extra file httpd-default.conf under /conf/extra (probably by design), which includes the timeout parameter. Since the timeout parameter isn't defined, it reverts back to the default value of 30 seconds, and your script(s) time out.

I did the following to resolve it:

• Opened httpd.conf and added the following line to the bottom:

Include conf/extra/httpd-default.conf

• Restarted Apache, and it worked.

An alternative would be to simply add the following line(s) to the httpd.conf file:

Timeout 300
KeepAlive On
MaxKeepAliveRequests 100
KeepAliveTimeout 5

Hope this helps someone out there :)

Answer 2

Premature end of script headers means that webserver's timeout for CGI scripts was exceeded by your script. This is a webserver timeout and it has nothing to do with php.ini configuration. You need to look at your CGI handler configuration to increase time allowed for CGI scripts to run.

E.g. if you are using mod_fastcgi you may want to specify the following option in your Apache config: FastCgiServer -idle-timeout 600 which will give you timeout of 10 minutes. By default fastcgi provides 30 seconds. You could find some other fastcgi options here http://www.fastcgi.com/mod_fastcgi/docs/mod_fastcgi.html