{"action":"created","issue":{"url":"https://api.github.com/repos/pagespeed/mod_pagespeed/issues/1220","labels_url":"https://api.github.com/repos/pagespeed/mod_pagespeed/issues/1220/labels{/name}","comments_url":"https://api.github.com/repos/pagespeed/mod_pagespeed/issues/1220/comments","events_url":"https://api.github.com/repos/pagespeed/mod_pagespeed/issues/1220/events","html_url":"https://github.com/pagespeed/mod_pagespeed/issues/1220","id":122528826,"number":1220,"title":"Decrease TTL on unoptimized IPRO resources","user":{"login":"jeffkaufman","id":262566,"avatar_url":"https://avatars.githubusercontent.com/u/262566?v=3","gravatar_id":"","url":"https://api.github.com/users/jeffkaufman","html_url":"https://github.com/jeffkaufman","followers_url":"https://api.github.com/users/jeffkaufman/followers","following_url":"https://api.github.com/users/jeffkaufman/following{/other_user}","gists_url":"https://api.github.com/users/jeffkaufman/gists{/gist_id}","starred_url":"https://api.github.com/users/jeffkaufman/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jeffkaufman/subscriptions","organizations_url":"https://api.github.com/users/jeffkaufman/orgs","repos_url":"https://api.github.com/users/jeffkaufman/repos","events_url":"https://api.github.com/users/jeffkaufman/events{/privacy}","received_events_url":"https://api.github.com/users/jeffkaufman/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":3,"created_at":"2015-12-16T15:28:11Z","updated_at":"2015-12-18T17:54:29Z","closed_at":null,"body":"When an IPRO resource hasn't been optimized yet we should serve it with a low TTL.\r\n\r\nThis is needed for integration with downstream caches.  If you have:\r\n\r\n     user ---> cache ---> pagespeed\r\n\r\nand if the original resource is indefinitely cacheable, then after the first request the cache will hold an indefinitely cacheable unoptimized resource.  If instead we lower the ttl, the cache will only hold the unoptimized resource for a short time, and then will check back with pagespeed to get the indefinitely cacheable optimized resource.\r\n\r\nOne thing we need to be very careful of here is that resources that PageSpeed tries and fails to optimize can't have their cache lifetimes cut short.  Nothing should be served with a low ttl for very long."},"comment":{"url":"https://api.github.com/repos/pagespeed/mod_pagespeed/issues/comments/165854730","html_url":"https://github.com/pagespeed/mod_pagespeed/issues/1220#issuecomment-165854730","issue_url":"https://api.github.com/repos/pagespeed/mod_pagespeed/issues/1220","id":165854730,"user":{"login":"oschaaf","id":2239556,"avatar_url":"https://avatars.githubusercontent.com/u/2239556?v=3","gravatar_id":"","url":"https://api.github.com/users/oschaaf","html_url":"https://github.com/oschaaf","followers_url":"https://api.github.com/users/oschaaf/followers","following_url":"https://api.github.com/users/oschaaf/following{/other_user}","gists_url":"https://api.github.com/users/oschaaf/gists{/gist_id}","starred_url":"https://api.github.com/users/oschaaf/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/oschaaf/subscriptions","organizations_url":"https://api.github.com/users/oschaaf/orgs","repos_url":"https://api.github.com/users/oschaaf/repos","events_url":"https://api.github.com/users/oschaaf/events{/privacy}","received_events_url":"https://api.github.com/users/oschaaf/received_events","type":"User","site_admin":false},"created_at":"2015-12-18T17:54:29Z","updated_at":"2015-12-18T17:54:29Z","body":"Perhaps als consider `Via:` as an indication of having a cache in front?"}}