{"action":"opened","issue":{"url":"https://api.github.com/repos/cryptonomex/graphene/issues/412","labels_url":"https://api.github.com/repos/cryptonomex/graphene/issues/412/labels{/name}","comments_url":"https://api.github.com/repos/cryptonomex/graphene/issues/412/comments","events_url":"https://api.github.com/repos/cryptonomex/graphene/issues/412/events","html_url":"https://github.com/cryptonomex/graphene/issues/412","id":114279169,"number":412,"title":"Witness wakeup unreliable when system clock is far out of sync with NTP","user":{"login":"theoreticalbts","id":10215982,"avatar_url":"https://avatars.githubusercontent.com/u/10215982?v=3","gravatar_id":"","url":"https://api.github.com/users/theoreticalbts","html_url":"https://github.com/theoreticalbts","followers_url":"https://api.github.com/users/theoreticalbts/followers","following_url":"https://api.github.com/users/theoreticalbts/following{/other_user}","gists_url":"https://api.github.com/users/theoreticalbts/gists{/gist_id}","starred_url":"https://api.github.com/users/theoreticalbts/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/theoreticalbts/subscriptions","organizations_url":"https://api.github.com/users/theoreticalbts/orgs","repos_url":"https://api.github.com/users/theoreticalbts/repos","events_url":"https://api.github.com/users/theoreticalbts/events{/privacy}","received_events_url":"https://api.github.com/users/theoreticalbts/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-10-30T14:20:58Z","updated_at":"2015-10-30T14:20:58Z","closed_at":null,"body":"\r\nThe problem is that FC task scheduling uses the local system clock, but the witness is passing FC task scheduling a wakeup time based on NTP.\r\n\r\nThe solution is to pass FC a wakeup time based on the local system clock, by assuming it has a fixed offset from NTP, which can be estimated (accurately enough) by sequentially querying NTP and FC for the time and taking the difference."}}