Magento 1.x Cron Debugging

mage1-cron-debug.txt

Notes from conversations with David Alger and Zach Nanninga about Magento 1.x cron jobs runnign duplicate processes

running double cron jobs because of this section in cron.php:

if ($isShellDisabled) {
        Mage::dispatchEvent('always');
        Mage::dispatchEvent('default');
    } else {
        Mage::dispatchEvent($cronMode);
    }

If you don't have shell_exec enabled and you have the crontab configured as outlined in your blog article, the cron will run default x 2 and always x 2 every time.

http://davidalger.com/development/magento/a-new-breed-of-cron-in-magento-ee-1-13-2/

Alternatively, another solution is you just use something like the following in the crontab:
php -d disable_functions= <path_to_cron>

That's defining the disable_functions as an empty list, meaning it enables shell_exec. The -d flag does precisely what they're doing, but much better, and specific to what you're doing.

To test whether shell_exec is enabled, you can do this:
php -r "var_dump(is_callable('shell_exec') && false === stripos(ini_get('disable_functions'), 'shell_exec'));"
If that evaluates to "true" then you are good. Otherwise adding the -d flag like David mentioned should cause it to be true.

syntax error: "Could not open input file..."
    * ! test -e /home/xxxxxx/xxxxxx.com/html/maintenance.flag && /home/xxxxxx/xxxxxx.com/html/cron.sh "php -d disable_functions= cron.php" -m=default

cd /home/xxxxxx/xxxxxx.com/html && ! test -e ./maintenance.flag && ./cron.sh "/usr/bin/php -d disable_functions= cron.php" -m=always
^ that should do it, without making the command crazy long.

?: Could not open input file: .//usr/bin/php
?: It's prepending /usr with ./
?: This is what it produces:
?: /opt/nexcess/php55u/root/usr/bin/php /usr/bin/php -d disable_functions= cron.php

cd /home/xxxxxx/xxxxxx.com/html && ! test -e ./maintenance.flag && ./cron.sh "-d disable_functions= cron.php" -m=always

maybe it's just best to get the shell_exec set to be allowed on the server