在脚本之间实现共享变量或如何实现服务器端进度的正确方法？

Question

I have a long job serving to fill a table in a db. This job may takes various time to finish. So, I need a progress bar. Just counting on the page is enough. As far I found several solutions:

1. Using _SESSION. OK, it works on most of servers I used, but I have many problem with ERR_RESPONSE_HEADERS_TOO_BIG error on chrome and sometimes - "headers already sent" on some servers, caused by session_start/session_write_close called in a loop. I loved this method but now I have reject it
2. Using kind of ob_start/ob_end_flush inside of the long operation's loop. This doesn't work. It just displays all buffered echo-ed messaged after the end of script.
3. Using db to store a shared variable (not tried yet)
4. Using separate (temporary) file. (not tried yet).

I have already implemented infrastructure: one script for long job (populating a table in db) and another one used by JS to read shared variable containing progress status. Both these scripts I called with jQuery .ajax method expecting the results in .done function.

Is there any other methods? It seems I will like to use 4) variant, but I want to know what is the usual practice for implementing progress bar.

Thanks:)

Answer 1

Firstly, if you aren't already, I would run the PHP code as a separate process.

 <?php 

 exec('/usr/bin/php /Path/to/script.php  {$param1} {$param2} > /dev/null 2>/dev/null &'); 

 ?>

I would then get this process to update a DB with its progress against the ID of the user, you could then use a ajax call inside a timeout function to get the status (how many DB writes complete, how many left, etc) from the DB.