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--- litespeed_wiki:config:understanding_500 [2018/05/16 15:10]
Jackson Zhang [Run out of Memory on php.ini]
+++ litespeed_wiki:config:understanding_500 [2018/09/20 13:33]
Jackson Zhang [PHP Code with wrong php configuration settings]
@@ Line 1: / Line 1: @@
 ====== Understanding 500 Internal Server Error ======
-The 500 status code, or Internal Server Error, means that server cannot process the request for an unknown reason. Sometimes this code will appear when more specific 5xx errors are more appropriate.
+The 500 status code, or "Internal Server Error," means that the server cannot process the request for an unknown reason. Sometimes this code will appear when more specific 5xx errors are more appropriate.
-This most common cause for this error is server misconfiguration (e.g. a malformed .htaccess file) or missing packages (e.g. trying to execute a PHP file without PHP installed properly), permission or ownership changes, Improperly configured php.ini, a PHP upgrade ...etc, anything can trigger a 500 error in a website. The impact of the error can vary based on the cause that triggered it.
+The most common causes for this error are server misconfiguration (e.g. a malformed ''.htaccess'' file), missing packages (e.g. trying to execute a PHP file without PHP installed properly), permission or ownership changes, improperly configured ''php.ini'', a PHP upgrade, etc. //Anything// that the server doesn't know how to handle can trigger a 500 error in a website. The impact of the error can vary based on the event that triggered it.
-error is not a LiteSpeed web server specific error. If you use a control panel like cpanel, you can try the same steps with apache. Most likely Apache will return the same 500 error as LSWS. You will need to find out the reason which causes the problem. If it does not happen to apache server but only on LSWS, you can log a ticket with us for further investigation.
+error is not a LiteSpeed Web Server specific error. If you use a control panel like cPanel, you can try the same steps with Apache. Most likely, Apache will return the same 500 error as LSWS. You will need to find root cause of the problem. If it does not happen to Apache server but only on LSWS, you can [[https://store.litespeedtech.com/store/clientarea.php|log a ticket with us]] for further investigation.
-To troubleshoote 500 error, first to check whether the error affects just one site or every site in the server. Depending on the impact of the error, we debug further. If only one domain it affected, it can be pin-pointed to the specific script error or permission issues. If multiple domains show 500 error, it could be due to some server wide setting change or update.
+To troubleshoot a 500 error, first check whether the error affects just one site or every site in the server. Depending on the impact of the error, you can debug further. If only one domain is affected, it can be pin-pointed to a specific script error or permission issue. If multiple domains show a 500 error, it could be due to some server wide setting change or update.
-You can check server error_log , stderr.log or PHP error-log(normally located where the PHP script running) to see if there is any hint of the error. During the troubleshooting, you may want to ensure PHP error reporting is on in php.ini. Please reverse them back when you done with debuging.
+You can check the server ''error_log'', ''stderr.log'' or PHP error log (normally located where the PHP script is running) to see if there is any hint of the error. During the troubleshooting, you may want to ensure PHP error reporting is on in ''php.ini''. Please reverse the settings back when you're done with debuging.
   error_reporting = E_ALL & ~E_DEPRECATED & ~E_STRICT  ->   error_reporting = E_ALL
   display_errors = Off -> display_errors = On
   display_startup_errors = Off -> display_startup_errors = On
-Please be aware that not all 500 errors log into the logs and it is common that you don’t see any hint in log files, which will make the troubleshooting more difficult then you expected.
+Please be aware that not all 500 errors appear in the logs and it is common not to see any hint in log files This makes troubleshooting more difficult.
-This will list some of the common reasons/examples, which may help you during the troubleshooting processes.
+Here are some of the common reasons/examples, which may help you during the troubleshooting process.
-=====   permission or ownership changes =====
+===== Permission or Ownership Changes =====
- Permission or ownership changes may cause 500 error. For example, to enable LiteMage extension to your Magento installation through ssh, you will need to run as user. However, if you run command incorrectly as the root user, Magento front end may return 500 instantly. The fix is to reverse file ownership and permission back to the original.
+ Permission or ownership changes may cause 500 error.
+ For example, to enable the LiteMage extension in your Magento installation through SSH, you will need to run a a non-root user. However, if you run the command incorrectly as the root user, the Magento front end may return 500 instantly. The fix is to reverse file ownership and permissions back to the original user.
-===== faulty .htaccess =====
+===== phpinfo.php owned by root instead of user =====
-There is a huge range of things .htaccess can do and isn't difficult to use, however, if you do not enter the syntax correctly it can result in a Server 500 Error.
+Sometimes we need to check phpinfo page during the troubleshooting. When ssh login as root to server, go to document root and create phpinfo.php, the phpinfo.php file will be owned by root:root instead of user:user.
+Sometimes it may return 500 error when accessing domain.com/phpinfo.php if some restriction set there but not always.
+The server error may show the following:
+[Thu Jun 07 21:04:36.450359 2018] [:error] [pid 3807521:tid 139749549020928] [client 77.82.94.132:9254] SoftException in Application.cpp:382: UID of script "/home/vivi/public_html/phpBB2/info.php" is smaller than min_uid
+[Thu Jun 07 21:04:36.450651 2018] [core:error] [pid 3807521:tid 139749549020928] [client 77.82.94.132:9254] End of script output before headers: info.php
+Changing the info.php to be owned by user:user will generally fix the issue.
+===== Faulty .htaccess =====
+There is a huge range of things ''.htaccess'' can do and it isn't difficult to use, however, if you do not enter the syntax correctly it can result in a Server 500 Error.
+==== Example 1 ====
 For example,
-  RewriteRule ^(.*) http://www.example.com/$1 [P]  <- wrong , will bring site to 500 error
+  RewriteRule ^(.*) http://www.example.com/$1 [P]
-changed to
+Will cause a 500 error. But change it to
-RewriteRule (.*) http://www.example.com/$1 [R=301,L]   <- will fix the issue
+  RewriteRule (.*) http://www.example.com/$1 [R=301,L]
-To confirm whether a misconfiguration .htaccess is the cause of the 500 Internal Server error, either remove or rename the .htaccess file temporarily and then try to reload the page.
+and that will fix the issue.
+==== Example 2 ====
+<Directory>...</Directory > can not be used in .htacess and it will cause 500 error for Apache, While LSWS will ignore the unsupported directive instead of giving 500 error.
+For example, the following should not be used in .htaccess.
+  <Directory /home/user1/public_html/wp-admin/>
+    Deny from all
+  </Directory>
+instead, you can create .htaccess under /wp-admin/ and place diretive there.
+  Deny from all
+To confirm whether a misconfiguration in ''.htaccess'' is the cause of the 500 Internal Server error, either remove or rename the .htaccess file temporarily and then try to reload the page.
+==== Example 3 ====
+The following "Alias" directive in .htaccess will cause 500 on Apache (LSWS will ignore it without returning 500) since "Alias" directive is not allowed in .htaccess.
+  Alias "/" "/home/$USER1/public_html/"
+==== Example 4 ====
+Syntax is wrong for the followintg directive:
+  Header always set Strict-Transport-Security: max-age=63072000; includeSubDomains; preload
+which will lead to "Too many arguments to directive" error in error_log:
+  [Tue Sep 11 19:59:40.864917 2018] [core:alert] [pid 15738] [client 66.666.76.139:64740] /home/example/public_html/.htaccess: Too many arguments to directive
+The correct syntax is the following and it should fix the 500 error for Apache:
+  Header always set Strict-Transport-Security: "max-age=63072000; includeSubDomains; preload"
+===== Different level of Rewrite rules misplaced to the wrong level =====
+Per virtual host rewrite rules (rewrite rules in Apache virtual host configuration) and per directory rewrite rules (rewrite rules in .htaccess) are different.  When placing the same rules to the wrong place, it may cause 500 error.
+For example, the following works in .htaccess:
+  RewriteEngine On
+  RewriteCond %{REQUEST_FILENAME} !-f
+  RewriteRule . /index.php [L]
+Putting the same thing in Apache VirtualHost config doesn’t work at all:
+  <VirtualHost *:80>
+    ServerName example.com
+    DocumentRoot /var/www/example/
+    <Directory /var/www/example/>
+        Allow From All
+    </Directory>
+    RewriteEngine On
+    RewriteCond %{REQUEST_FILENAME} !-f
+    RewriteRule . /index.php [L]
+  </VirtualHost>
+Apache doesn’t tell you why it doesn’t work. It just doesn’t work. You most likely will get an Error 500 status with a message in the logs that looks like this:
+Request exceeded the limit of 10 internal redirects due to probable configuration error. Use ‘LimitInternalRecursion’ to increase the limit if necessary. Use ‘LogLevel debug’ to get a backtrace.
+===== Incorrect Rewrite Rules misplace in differernt directories =====
+The following rewrite rules in subfolder is incorrect and it will cause 500 for LiteSpeed.
+/home/user1/public_html/subfolder1] vi .htaccess
+  RewriteEngine On
+  RewriteCond %{REQUEST_FILENAME} !-f
+  RewriteCond %{REQUEST_FILENAME} !-d
+  RewriteRule ^(.*)$ subfolder1/index.php/$1 [L]
+The correct rule should be:
+/home/user1/public_html/subfolder1] vi .htaccess
+  RewriteEngine On
+  RewriteCond %{REQUEST_FILENAME} !-f
+  RewriteCond %{REQUEST_FILENAME} !-d
+  RewriteRule ^(.*)$ index.php/$1 [L]
+=====  Improperly Configured php.ini =====
+An improperly configured ''php.ini'' may lead to 500 error.
+For example, set the following in ''php.ini'':
+  open_basedir = "/path/to/folder"
+If the ''/path/to/folder'' directory does not exist, it will cause a 500 error.
-=====  Improperly configured php.ini =====
+===== Bad PHP Code =====
-Improperly configured php.ini may lead to 500 error.
+Bad PHP code will bring a website to 500 immediately.
-For example, set the following in php.ini
- open_basedir = "/path/to/folder"
-However /path/to/folder directory does not exist at all in the system, it will cause 500 error.
-===== Bad PHP code =====
+For example, the right syntax should be:
-Bad php code will bring website to 500 immediately.
-For example, right syntax should be like:
    $this->getResponse()->setRedirect(Mage::getBaseUrl()) ;
-If “$” is removed somehow:
+If the “$” is removed somehow:
     this->getResponse()->setRedirect(Mage::getBaseUrl()) ;
-It will bring website to 500 immediately.
+It will bring the website to 500 immediately.
-This is only one of the examples. Many times, wrong syntax PHP error will lead to 500 error.
+This is only one example. Many times, wrong PHP syntax will lead to a 500 error.
-===== PHP handler not set =====
+===== PHP Code with wrong php configuration settings =====
-On Plesk, PHP handler not set , prompt 500 error
-===== CloudLinux LVE limit reached =====
+Sometimes, 500 error may be not easy to locate. If you move .htaccess to .htaccess.bak and move php.ini to php.ini, the 500 error still happens, it might be something wrong in the PHP code and it might be hard to find.
-When using CloudLinux, If the site is limited by memory or number of processes limits, then the user may receive 500 errors that server cannot execute the script.
-https://docs.cloudlinux.com/index.html?lve.html
+We experienced a case with WHMCS. In **configuration.php**, someone placed **wrong php setting** there:
+  $display_errors = E_All;
+"E_All" is an incorrect value for PHP setting "$display_errors" and it is for "$error_reporting". "$display_errors" should be either "true"/"false", or "on"/"off". Changed it to the following as "true" and it fixed the 500 error.
+  $display_errors = true;
-===== PHP upgrade =====
-Sometimes PHP upgrade with bug may cause 500 error.
-===== Unsupport version of PHP =====
-unsupport php version by the site/theme/plugin/module may lead to 500 error.
-===== PHP coding timing out =====
+===== PHP Handler Not Set =====
-If your PHP script makes external network connections, the connections may time out. If too many connections are attempted and time out, this will cause a "500 Internal Server Error." To prevent these time outs and errors, you'll want to make sure that PHP scripts be coded with some timeout rules. Typically, however, catching a timeout error when connecting to a database or externally to remote resources are difficult. They, in effect, freeze the script from continuing to run.
+On Plesk, if a PHP handler is not set, it will prompt a 500 error.
-===== SYNTAX OR CODING ERRORS IN YOUR CGI/PERL SCRIPT =====
+===== CloudLinux LVE Limit Reached =====
-If it is a web page ending in .cgi or .pl that is producing the error, check your script for errors.
+When using CloudLinux, If the site is limited by memory or process limits, then the user may receive 500 errors because the server cannot execute the script. [[https://docs.cloudlinux.com/index.html?lve.html| Learn more.]]
-===== Run out of Memory on php.ini =====
+===== PHP Upgrade =====
-check stderr,
+Sometimes if PHP upgrades with a bug, it may cause a 500 error.
- tail /var/log/httpd/stderr.log
--03-01 12:07:03.573 [STDERR] Tue Mar  1 12:07:03 2016 (12700): Fatal Error Unable to allocate shared memory segment of 134217728 bytes: shmat: Cannot allocate memory (12)
+===== Unsupported Version of PHP =====
+Unsupported PHP version used by the site/theme/plugin/module may lead to a 500 error.
-Further check phpinfo page and memory limit was set to “128M” only.  While opcode cache sonsution is “128M”.
+===== PHP Scripts Time out =====
+If your PHP script makes external network connections, the connections may time out. If too many connections are attempted and time out, this will cause a "500 Internal Server Error." To prevent these time outs and errors, make sure that PHP scripts are coded with some timeout rules. Typically, it's difficult to catch a timeout error when connecting to a database or remote resources, as they effectively freeze the script.
-Which leads to 500 error.
+===== Syntax or Coding Errors in Your CGI/Perl Script =====
+If it is a web page ending in ''.cgi'' or ''.pl'' that is producing the error, check your script for errors.
-Increate php memory limit from “128M” to 1024M” then fix the issue.
+===== Out of Memory in php.ini =====
+In this example, we checked ''stderr'':
+  tail /var/log/httpd/stderr.log
+-03-01 12:07:03.573 [STDERR] Tue Mar  1 12:07:03 2016 (12700): Fatal Error Unable to allocate shared memory segment of 134217728 bytes: shmat: Cannot allocate memory (12)
-===== too many php processes =====
+We further checked the phpinfo page and found the memory limit was set to “128M” only. Opcode cache solution is “128M” by itself, and so there is no memory left for anything else. This leads to a 500 error.
-If too many processes in the server queue, it could exceed resources and lead to 500 error.
-===== PHP open_basedir may cause 500 error =====
+Increase the PHP memory limit from “128M” to 1024M” to fix the issue.
-When php open_basedir enabled, it may lead to 500 error.  Try to turn off open_basedir for that domain to see how it is going.
-The following error log captured with openlitespeed when PHP open_basedir intentionally set to a non-exist folder /111, phpinfo page returns 500 error.
+===== Too Many PHP Processes ==
+If there are too many processes in the server queue, it could exceed resources and lead to a 500 error.
--05-16 10:59:51.391153 [NOTICE] [192.168.0.198:14271] [STDERR] PHP Warning:  Unknown: open_basedir restriction in effect. File(/usr/local/lsws/Example/html/phpinfo.php) is not within the allowed path(s): (/111) in Unknown on line 0
+===== Apache Running as SuEXEC while LSWS not on cPanel =====
--05-16 10:59:51.391251 [NOTICE] [192.168.0.198:14271] [STDERR] PHP Warning:  Unknown: failed to open stream: Operation not permitted in Unknown on line 0
+In a cPanel/WHM environment, Apache runs as SuEXEC, however LSWS doesn’t.
--05-16 10:59:51.391263 [NOTICE] [192.168.0.198:14271] [STDERR] PHP Fatal error:  Unknown: Failed opening required '/usr/local/lsws/Example/html/phpinfo.php' (include_path='.:/usr/local/lib/php') in Unknown on line 0
-===== apache run as SuEXEC while LSWS not on cpanel =====
-On a cpanel/WHM environment, apache runs as SuEXEC , however LSWS doesn’t.
 -03-10 15:39:45.601 [NOTICE] [173.245.52.237:51548] [STDERR] PHP Warning: require_once(/home/demowebsites/public_html/goodmail/wp-config.php): failed to open stream: Permission denied in /home/demowebsites/public_html/goodmail/wp-load.php on line 37
 -03-10 15:39:45.601 [NOTICE] [173.245.52.237:51548] [STDERR] PHP Fatal error: require_once(): Failed opening required '/home/demowebsites/public_html/goodmail/wp-config.php' (include_path='.:/opt/cpanel/ea-php70/root/usr/share/pear') in /home/demowebsites/public_html/goodmail/wp-load.php on line 37
-Need to keep LSWS to the same setting to apache. Enabled LSWS PHP SuEXEC and fixed the issue.
+It is necessary to keep LSWS set the same as Apache. Enable LSWS PHP SuEXEC to fix the issue.
- =====  Run out of swap space =====
+=====  Run Out of Swap Space =====
-Check error.log, it shows: "Failed to obtain or reinitialize VMemBuf. possibly running out of swap space” and return 500 error. Relocating LSWS swap directory to a partition with enough space will fix the issue.
+Checking ''error.log'' shows:
+  Failed to obtain or reinitialize VMemBuf. possibly running out of swap space
-===== Missing php packages =====
+error is returned. Relocating the LSWS swap directory to a partition with enough space will fix the issue.
-Install prestashop but 500 returns in Chrome. Check error log and it shows php70-json package missing. Install the missing packages and 500 is gone.
-===== missing opcode cache module =====
+===== Missing PHP Packages =====
-A wordpress site returned 500 error when using go2pay, but there is no hint in server error_log, stderr.log or PHP error_log. Upgrading php version and adding opcode cache module fix the issue. Some applications or plugins may need opcode cache to run.
+Installing PrestaShop returns a 500 error in Chrome. Check the error log and it shows ''php70-json'' package is missing. Install the missing packages and the 500 error is gone.
-===== PHP module code complicting =====
+===== Missing Opcode Cache Module =====
-Then run magento, it returns 500 error and show module conflicting
+A WordPress site returns a 500 error when using go2pay, but there is no hint in the server ''error_log'', ''stderr.log'' or PHP ''error_log''. Upgrading the PHP version and adding the opcode cache module fixes the issue. Some applications or plugins may need opcode cache to run.
-a:5:{i:0;s:54:"Mage registry key "umm_top_menu_exists" already exists";i:1;s:4439:"#0 /home/yourhome/public_html/app/Mage.php(223): Mage::throwException('Mage registry k...')
+===== PHP Module Code Conflicting =====
- #1 /home/yourhome/public_html/app/design/frontend/ultimo/default/template/infortis/ultramegamenu/mainmenu.phtml(54): Mage::register('umm_top_menu_ex...', true)
+Magento returns a 500 error and shows a module conflict.
- #2 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Template.php(241): include('/home/furnishyo...')
- #3 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Template.php(272): Mage_Core_Block_Template->fetchView('frontend/ultimo...')
+  a:5:{i:0;s:54:"Mage registry key "umm_top_menu_exists" already exists";i:1;s:4439:"#0 /home/yourhome/public_html/app/Mage.php(223): Mage::throwException('Mage registry k...')
- #4 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Template.php(286): Mage_Core_Block_Template->renderView()
+  #1 /home/yourhome/public_html/app/design/frontend/ultimo/default/template/infortis/ultramegamenu/mainmenu.phtml(54): Mage::register('umm_top_menu_ex...', true)
- #5 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Abstract.php(923): Mage_Core_Block_Template->_toHtml()
+  #2 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Template.php(241): include('/home/furnishyo...')
- #6 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Text/List.php(43): Mage_Core_Block_Abstract->toHtml()
+  #3 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Template.php(272): Mage_Core_Block_Template->fetchView('frontend/ultimo...')
- #7 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Abstract.php(923): Mage_Core_Block_Text_List->_toHtml()
+  #4 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Template.php(286): Mage_Core_Block_Template->renderView()
- #8 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Abstract.php(641): Mage_Core_Block_Abstract->toHtml()
+  #5 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Abstract.php(923): Mage_Core_Block_Template->_toHtml()
- #9 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Abstract.php(585): Mage_Core_Block_Abstract->_getChildHtml('topMenu', true)
+  #6 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Text/List.php(43): Mage_Core_Block_Abstract->toHtml()
+  #7 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Abstract.php(923): Mage_Core_Block_Text_List->_toHtml()
+  #8 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Abstract.php(641): Mage_Core_Block_Abstract->toHtml()
+  #9 /home/yourhome/public_html/app/code/core/Mage/Core/Block/Abstract.php(585): Mage_Core_Block_Abstract->_getChildHtml('topMenu', true)
+===== Disable/Enable Some Magento Modules =====
+When disabling ''extendare_EWCore.xml'' by changing from “True” to “false, it shows a 500 error.
+Remove Magento cache files and fix the problem:
-===== disabling/enable some magento modules =====
-When disabling extendare_EWCore.xml by changing from “True” to “false, it shows 500 error.
-Remove magento cache files and fix the problem.
   rm -rf var/cache/*
-===== some mod security rules may cause 500 error =====
+===== Some mod_security Rules May Cause a 500 Error =====
-Add java script to a wordpress plugin, but it causes 500 error. Enable LSWS debug logging and found:
+Adding Javascript to a WordPress plugin causes a 500 error. Enable LSWS debug logging and find:
+<code>
 -05-12 04:13:16.673307 [NOTICE] [47.22.54.182:54823#APVH_latampolitics.carinsurancegeorgia.org] mod_security rule [Id '2000145'] triggered! [Sat May 12 04:13:16 2018] [error] [client 47.22.54.182] ModSecurity: Access denied with code 500, [Rule: 'REQUEST_URI|REQUEST_BODY' '<space:(script|about|applet|activex|chrome) >.(script|about|applet|activex|chrome)space: >'] [id "2000145"] [rev "1"] [msg "xss"] [severity "CRITICAL"]
+</code>
+A mod_security rule lead to the 500 error. Disable that mod_security rule to fix the issue.
-Mod_security rule leads to 500 error.  Try to disable that mod security rule and fix the issue.
+===== Hacked Site =====
+If your site is being hacked, it may trigger a 500 error.
-===== hacked site =====
+===== Perl script missing "Content-Type" header may return 500 =====
-If your site is being hacked, it may trigger 500 error.
+Run a simple "Hello World" perl script at http://exmaple.com/cgi-bin/test.pl but it return 500 error.
+vi test.pl
+<code>
+  #!/usr/bin/perl
+  print "Hello, World!\n";
+</code>
+A Perl CGI script must output the header, HTML code and also must begin with a special first line. In this case, header "Content-type" is missing and it is not a CGI script. Please also be aware that there is a blank line after **print "Content-Type: text/html\n\n";**.
+the right script should be:
+<code>
+<code>
+  #!/usr/bin/perl
+  print "Content-Type: text/html\n\n";
+  print "Hello, World!\n";
+</code>
+You can check the example [[https://users.cs.cf.ac.uk/Dave.Marshall/PERL/node196.html|here]].