We have updated the php-ext-snappy PHP extension from 0.1.6 to 0.1.9. Snappy is the preferred compression algorithm used by Cm_Cache_Backend_Redis (from Magento 1.9 on this module is built-in and named Mage_Cache_Backend_Redis), and it is used in Magento 2 as well.
This release enables snappy for PHP 5.6 (and soon 7.1), previously it was only enabled for PHP 5.5 and 7.0 on Hypernode. For more information about this module see this earlier changelog or take a look at our Debian packaging.