Fatal Error – Too many open files

I try to run PHPUnit Tests in my new machine and I get this error:

PHP Fatal error: Uncaught exception ‘UnexpectedValueException’ with message ‘RecursiveDirectoryIterator::__construct(/usr/lib/php/pear/File/Iterator): failed to open dir: Too many open files’ in /usr/lib/php/pear/File/Iterator/Factory.php:114

The same code on the old machine run well…

New machine environment: PHP Version: PHP 5.3.21 (cli) Older: PHP 5.3.14

PHPUnit output every time:

................EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE 65 / 66 ( 98%)
E

Time: 34 seconds, Memory: 438.50Mb

There were 50 errors:

1) XXXXXXXXXXX
PHP Fatal error:  Uncaught exception 'UnexpectedValueException' with message 'RecursiveDirectoryIterator::__construct(/usr/lib/php/pear/File/Iterator): failed to open dir: Too many open files' in /usr/lib/php/pear/File/Iterator/Factory.php:114

Answer

This can be a limitation on the server where the code is running. Every operating system only allows for a certain number of open files/handles/sockets. This limit is usually further reduced when the server is virtualized. On a Linux server you can check the current limit with ulimit -n, if you have root access you can increase it with the same command. I assume there is a method for Windows server as well. Otherwise there is not much you can do about it (except ask your hoster or administrator to increase it).

More configurable limits:

Change in /etc/security/limits.conf

soft nofile 1024
hard nofile 65535

Increase ulimit by ulimit -n 65535 or echo 65535 > /proc/sys/fs/file-max or in /etc/sysctl.conf:

fs.file-max=65535