PHP, MySQL and IPv6: still slow

Years ago, I noticed that PHP connections to MySQL were significantly slower over IPV6 (where a hostname has an IPv6 address or AAAA record), when no MySQL service is listening on that address. The connection is refused, and PHP has to fallback to IPv4. The fallback takes a significant amount of time. Too much time if you’d asked me. Unfortunately this fallback to IPv4 is […]

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How to set a good PHP realpath_cache_size

The PHP directive realpath_cache_size sets the size of the realpath cache to be used by PHP. Increasing realpath_cache_size might greatly improve PHP performance, as PHP states: “this value should be increased on systems where PHP opens many files.” Setting a correct value for PHP realpath_cache_size can greatly improve PHP performance and optimize WordPress – and other CMS’s – websites.

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Set or remove the read-only attribute assigned to files with PHP chmod

Chmod.php, change file attributes with PHP, to make files read only or normally accessible on Windows IIS servers. Sometimes you need chmod to make files read only on your website, or make them normally accessible in case they already are read only. For instance Drupal’s settings.php configuration file, or WordPress Contact Form 7 temporary captcha files, are examples of read-only files.

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