Getting errors on server, what do they mean?

I can’t get amp to work, and I’m getting the following error in my logs on the Nginx server. Can anyone tell me what I need to do to resolve this? Any help is much appreciated.

2016/12/13 11:37:13 [error] 12658#12658: *3174151 FastCGI sent in stderr: “PHP message: PHP Warning: fopen(): php_network_getaddresses: getaddrinfo failed: Name or service not known in /var/www/humortimes/wp-content/plugins/amp/includes/lib/class-fastimage.php on line 31
PHP message: PHP Warning: fopen(https://27.media.tumblr.com/tumblr_lpydexMkaT1qzfjcvo1_500.jpg): failed to open stream: php_network_getaddresses: getaddrinfo failed: Name or service not known in /var/www/humortimes/wp-content/plugins/amp/includes/lib/class-fastimage.php on line 31” while reading response header from upstream, client: 66.249.65.189, server: content.humortimes.com, request: “GET /3299/attack-of-the-giant-gastropods/amp/ HTTP/1.1”, upstream: “fastcgi://unix:/var/run/php-fpm/php-fpm.sock:”, host: “www.humortimes.com”