504 Gateway Time-out error in batch process
I have find the answer...

Please increase memory limit, excution time and max input time.

1. File php.ini

memory_limit = 768M
max_execution_time = 3600
max_input_time = 3600


OR

Define in settings.php

&lt;?php
    ini_set('memory_limit ', '768M');
    ini_set('max_execution_time', 3600);
    ini_set('max_input_time', 3600);    
?&gt;


My problem is solve. :)