php - "php_connect_nonb() failed: Operation now in progress (115)" happens intermittently

Question

We send some files across to a third party with a PHP cron job via FTP.

However sometimes we get the following error:

ErrorException [ 2 ]: ftp_put(): php_connect_nonb() failed: Operation 
now in progress (115) ~ MODPATH/fileop/classes/Drivers/Fileop/Ftp.php [ 37 ]

When I say "sometimes" I mean exactly that; most times it goes across fine but about 1 in 5 times we get that error. It's not to do with the files themselves, because they will go happily if we try again.

We've found similar issues online - relating to a bug in PHP with NAT devices or to do with firewall configuration but again the implication is that if this were the case it would never work.

So, why would this work some times and not others?

Answer 1

ftp_set_option($ftpconn, FTP_USEPASVADDRESS, false);

This line of code before setting passivity of the connection ftp_pasv($ftpconn, true);

Solved my problem