I was wondering if anybody knew of a method to configure apache to fall back to returning a static HTML page, should it (Apache) be able to determine that PHP has died? This would provide the developer with a elegant solution to displaying an error page and not (worst case scenario) the source code of the PHP page that should have been executed.
Thanks.
The PHP source code is only displayed when apache is not configured correctly to handle php files. That is, when a proper handler has not been defined.
On errors, what is shown can be configured on php.ini, mainly the display_errors variable. That should be set to off and log_errors to on on a production environment.
If php actually dies, apache will return the appropriate HTTP status code (usually 500) with the page defined by the ErrorDocument directive. If it didn't die, but got stuck in a loop, there is not much you can do as far as I know.
You can specify a different page for different error codes.
I would assume that this typically results in a 500 error, and you can configure apaches 500 handler to show a static page:
ErrorDocument 500 /500error.html
You can also read about error handlers on apaches documentation site
The real problem is that PHP fatal errors don't cause Apache to return a 500 code. Errors except for E_FATAL and E_PARSE can be handled however you like using set_error_handler().
There are 2 ways to use PHP and Apache.
1. Install PHP as an Apache module: this way the PHP execution is a thread inside the apache process. So if PHP execution fails, then Apache process fails too. there is no fallback strategy.
2. Install PHP as a CGI script handler: this way Apache will start a new PHP process for each request. If the PHP execution fails, then Apache will know that, and there might be a way to handle the error.
regardless of the way you install PHP, when PHP execution fails you can handle errors in the php.ini file.
Related
I am having an issue when I have a php application that is returning an internal server error (500) however nothing is showing up in the error log.
Now I know there are error with what I am trying to run, I know I have missing some files and what not but something should show in the apache error log (otherwise how are I supposed to know exactly what I am missing).
I created a test script is errors it in under the same vhost configuration and those error show up fine so everything seems configured right as far as php/apache. Are there certain php errors that does show up in the error log (php is configure to display any type of notice, warning, , error, fatal error, etc...)?
This is running on ubunut 10.04 with the standard apache and php from the ubuntu repo with apt-get.
Scan your source files to find #.
From php documentation site
Currently the "#" error-control operator prefix will even disable
error reporting for critical errors that will terminate script
execution. Among other things, this means that if you use "#" to
suppress errors from a certain function and either it isn't available
or has been mistyped, the script will die right there with no
indication as to why.
Copy and paste the following into a new .htaccess file and place it on your website's root folder :
php_flag display_errors on
php_flag display_startup_errors on
Errors will be shown directly in your page.
That's the best way to debug quickly but don't use it for long time because it could be a security breach.
If you still have 500 error and no logs you can try to execute from command line:
php -f file.php
it will not work exactly like in a browser (from server) but if there is syntax error in your code, you will see error message in console.
Maybe something turns off error output. (I understand that you are trying to say that other scripts properly output their errors to the errorlog?)
You could start debugging the script by determining where it exits the script (start by adding a echo 1; exit; to the first line of the script and checking whether the browser outputs 1 and then move that line down).
In the past, I had no error logs in two cases:
The user under which Apache was running had no permissions to modify php_error_log file.
Error 500 occurred because of bad configuration of .htaccess, for example wrong rewrite module settings. In this situation errors are logged to Apache error_log file.
For Symfony projects, be sure to check files in the project'es app/logs
More details available on this post :
How to debug 500 Error in Symfony 2
Btw, other frameworks or CMS share this kind of behaviour.
Here is another reason why errors might not be visible:
I had the same issue. In my case, I had copied the source from a production environment. Hence the ENVIRONMENT variable defined in index.php was set to 'production'. This caused error_reporting to be set to 0 (no logging). Just set it to 'development' and you should start seeing error messages in apache log.
Turned out the 500 was due to a semi colon missing in database config :-)
Another case which happened to me, is I did a CURL to some of my pages, and got internal server error and nothing was in the apache logs, even when I enabled all error reporting.
My problem was that in the CURL I set
curl_setopt($CR, CURLOPT_FAILONERROR, true);
Which then didn't show me my error, though there was one, this happened because the error was on a framework level and not a PHP one, so it didn't appear in the logs.
You need to enable the PHP error log.
This is due to some random glitch in the web server when you have a php error, it throws a 500 internal error (i have the same issue).
If you look in the PHP error log, you should find your solution.
see here in the doc of how to enable it in the php.ini
Be sure your file permissions are correct. If apache doesn't have permission to read the file then it can't write to the log.
What happened for me when this was an issue, was that the site had used too much memory, so I'm guessing that it couldn't write to an error log or displayed the error. For clarity, it was a Wordpress site that did this. Upping the memory limit on the server showed the site again.
SOLVED
I struggled with this and later on, I realized that I was working on PHP 5.6, so I upgraded to PHP 7.0, then I released there were comments placed by git for conflicting codes. I found something like this in my code <<<<<<<< But solved it.
There is a folder on my apache server containing several php scripts. All the php scripts in this folder work except for 1. All the php scripts including the script that doesn't work have the same rights.
When I run the script in my browser I get this error:
HTTP ERROR 500
Details that may be helpful:
PHP Version 7.0.11
Apache/2.2.15 (CentOS)
An Apache status code of 500 means "internal server error". Without seeing the code that is producing this error it is hard to say what is causing it but the first things to check are server configuration and your .htaccess file. Make sure your server is running properly then check your .htaccess file as a bad rule can force some types of PHP to malfunction. As #RiggsFolly stated, it is also possible that the problem is some very poorly written PHP which can be tested by replacing it with a simple program like:
<?php
echo "test";
?>
SOLUTION: In my case the problem of 500 error was the upgrade from php 5.x to 7; BUT: I imagine this error can come from many other reasons, so if it does not apply, good luck finding the other solutions. In this case, it worked - and the solution is to rewrite the code or downgrade to old PHP version until you re-code the incompatible parts.
EXPLANATION / DEBUGGING PROCESS: After several tests to identify what is happening (commenting parts of code, testing functions, reading documentation), I found that deprecated functions from previous versions of PHP will generate a 500 Error.
For example, in a script written for PHP<7 you may still have old mysql queryes like mysql_connect, and once your server is updated to 7 (and you must use mysqli), this script will throw 500 error.
I imagine this happens to any other function that became deprecated.
In your case, my bet is most of the scripts are compatible with 7, one is not.
Im running a long php script which handles large amounts of data.
The problem is that the script suddenly stops and no exception is thrown or could be found on the error_log.
I have set the display_errors and the error_logging to 1 in the .ini config file.
Few more details:
1) The scripts executes the 'file_get_contents' function for many times.
2) The scripts contains recursion when the file_get_contents fails.
Any help would be appriciated.
It might have hit the max execution time.
set_time_limit(0); // to increase the timelimit to infinity
Error loging configs are different depending on your hosting environment. I'd first verify that you're editing the right php.ini file. Take a look at your phpinfo output and make sure that those params are indeed set and check the path/file for where errors are being logged to. Sometimes it goes to the apache error log, other times it can be sent to a dedicated php log. Are you able to get any error output if you purposefully create a syntax error? You might also consider looking in your syslog to see if there's anything there.
I am having an issue when I have a php application that is returning an internal server error (500) however nothing is showing up in the error log.
Now I know there are error with what I am trying to run, I know I have missing some files and what not but something should show in the apache error log (otherwise how are I supposed to know exactly what I am missing).
I created a test script is errors it in under the same vhost configuration and those error show up fine so everything seems configured right as far as php/apache. Are there certain php errors that does show up in the error log (php is configure to display any type of notice, warning, , error, fatal error, etc...)?
This is running on ubunut 10.04 with the standard apache and php from the ubuntu repo with apt-get.
Scan your source files to find #.
From php documentation site
Currently the "#" error-control operator prefix will even disable
error reporting for critical errors that will terminate script
execution. Among other things, this means that if you use "#" to
suppress errors from a certain function and either it isn't available
or has been mistyped, the script will die right there with no
indication as to why.
Copy and paste the following into a new .htaccess file and place it on your website's root folder :
php_flag display_errors on
php_flag display_startup_errors on
Errors will be shown directly in your page.
That's the best way to debug quickly but don't use it for long time because it could be a security breach.
If you still have 500 error and no logs you can try to execute from command line:
php -f file.php
it will not work exactly like in a browser (from server) but if there is syntax error in your code, you will see error message in console.
Maybe something turns off error output. (I understand that you are trying to say that other scripts properly output their errors to the errorlog?)
You could start debugging the script by determining where it exits the script (start by adding a echo 1; exit; to the first line of the script and checking whether the browser outputs 1 and then move that line down).
In the past, I had no error logs in two cases:
The user under which Apache was running had no permissions to modify php_error_log file.
Error 500 occurred because of bad configuration of .htaccess, for example wrong rewrite module settings. In this situation errors are logged to Apache error_log file.
For Symfony projects, be sure to check files in the project'es app/logs
More details available on this post :
How to debug 500 Error in Symfony 2
Btw, other frameworks or CMS share this kind of behaviour.
Here is another reason why errors might not be visible:
I had the same issue. In my case, I had copied the source from a production environment. Hence the ENVIRONMENT variable defined in index.php was set to 'production'. This caused error_reporting to be set to 0 (no logging). Just set it to 'development' and you should start seeing error messages in apache log.
Turned out the 500 was due to a semi colon missing in database config :-)
Another case which happened to me, is I did a CURL to some of my pages, and got internal server error and nothing was in the apache logs, even when I enabled all error reporting.
My problem was that in the CURL I set
curl_setopt($CR, CURLOPT_FAILONERROR, true);
Which then didn't show me my error, though there was one, this happened because the error was on a framework level and not a PHP one, so it didn't appear in the logs.
You need to enable the PHP error log.
This is due to some random glitch in the web server when you have a php error, it throws a 500 internal error (i have the same issue).
If you look in the PHP error log, you should find your solution.
see here in the doc of how to enable it in the php.ini
Be sure your file permissions are correct. If apache doesn't have permission to read the file then it can't write to the log.
What happened for me when this was an issue, was that the site had used too much memory, so I'm guessing that it couldn't write to an error log or displayed the error. For clarity, it was a Wordpress site that did this. Upping the memory limit on the server showed the site again.
SOLVED
I struggled with this and later on, I realized that I was working on PHP 5.6, so I upgraded to PHP 7.0, then I released there were comments placed by git for conflicting codes. I found something like this in my code <<<<<<<< But solved it.
We are migrating to a new server running Windows 2003 and IIS 6. When my PHP code runs, it has a warning on a particular line (which I'm expecting at the moment but will fix shortly). However, when it hits the warning, it immediately halts processing and returns a 500 error in the HTTP header. Normally, I would expect PHP to output the warning, but continue processing the script.
Is there something in the configuration for IIS, FastCGI, or PHP that would be returning 500 errors when PHP hits a warning?
To clarify: I don't want to suppress the warnings; I want them to display. I do not want the script to stop processing on warnings.
Figured out the issue. log_errors in php.ini was set to On, but error_log was unset. This was causing PHP to stop everything. After setting display_errors to on, the warnings now display so I can see where things are breaking in the output.
This thread was helpful: http://forums.iis.net/p/1146102/1856222.aspx#1856222
I don't know about IIS or FastCGI, but afaik php has no such option. You can however set error_reporting (in your php.ini) to
E_COMPILE_ERROR|E_RECOVERABLE_ERROR|E_ERROR|E_CORE_ERROR
to make warnings go away.
That depends very much on your PHP code as well, if you are doing something complicated within the code and an error occurs, web servers sometimes throw 500 errors. I would suggest you:
Put an # on the line to suppress the error, i.e :
$x=#my_function($y);
See your web server logs for the exact error message you get, then post it here and perhaps we could offer you a better solution.