{"action":"opened","issue":{"url":"https://api.github.com/repos/pachyderm/pachyderm/issues/260","repository_url":"https://api.github.com/repos/pachyderm/pachyderm","labels_url":"https://api.github.com/repos/pachyderm/pachyderm/issues/260/labels{/name}","comments_url":"https://api.github.com/repos/pachyderm/pachyderm/issues/260/comments","events_url":"https://api.github.com/repos/pachyderm/pachyderm/issues/260/events","html_url":"https://github.com/pachyderm/pachyderm/issues/260","id":145821290,"number":260,"title":"Make sure that every shard starts with some input data","user":{"login":"derekchiang","id":1535686,"avatar_url":"https://avatars.githubusercontent.com/u/1535686?v=3","gravatar_id":"","url":"https://api.github.com/users/derekchiang","html_url":"https://github.com/derekchiang","followers_url":"https://api.github.com/users/derekchiang/followers","following_url":"https://api.github.com/users/derekchiang/following{/other_user}","gists_url":"https://api.github.com/users/derekchiang/gists{/gist_id}","starred_url":"https://api.github.com/users/derekchiang/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/derekchiang/subscriptions","organizations_url":"https://api.github.com/users/derekchiang/orgs","repos_url":"https://api.github.com/users/derekchiang/repos","events_url":"https://api.github.com/users/derekchiang/events{/privacy}","received_events_url":"https://api.github.com/users/derekchiang/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2016-04-04T22:24:39Z","updated_at":"2016-04-04T22:24:39Z","closed_at":null,"body":"When `max(blocks_per_file) < shards`, or `num_files < shards` in the case of a reduce job, some shards are started without any input data at all.  This results in resources being wasted, and some jobs might even fail if they do not shut down gracefully with empty data."}}