{"action":"created","issue":{"url":"https://api.github.com/repos/mesosphere/marathon/issues/2925","repository_url":"https://api.github.com/repos/mesosphere/marathon","labels_url":"https://api.github.com/repos/mesosphere/marathon/issues/2925/labels{/name}","comments_url":"https://api.github.com/repos/mesosphere/marathon/issues/2925/comments","events_url":"https://api.github.com/repos/mesosphere/marathon/issues/2925/events","html_url":"https://github.com/mesosphere/marathon/issues/2925","id":125592157,"number":2925,"title":"Unclear description of GROUP BY constraint","user":{"login":"medzin","id":763199,"avatar_url":"https://avatars.githubusercontent.com/u/763199?v=3","gravatar_id":"","url":"https://api.github.com/users/medzin","html_url":"https://github.com/medzin","followers_url":"https://api.github.com/users/medzin/followers","following_url":"https://api.github.com/users/medzin/following{/other_user}","gists_url":"https://api.github.com/users/medzin/gists{/gist_id}","starred_url":"https://api.github.com/users/medzin/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/medzin/subscriptions","organizations_url":"https://api.github.com/users/medzin/orgs","repos_url":"https://api.github.com/users/medzin/repos","events_url":"https://api.github.com/users/medzin/events{/privacy}","received_events_url":"https://api.github.com/users/medzin/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/mesosphere/marathon/labels/docs","name":"docs","color":"fef2c0"}],"state":"open","locked":false,"assignee":{"login":"sascala","id":13338969,"avatar_url":"https://avatars.githubusercontent.com/u/13338969?v=3","gravatar_id":"","url":"https://api.github.com/users/sascala","html_url":"https://github.com/sascala","followers_url":"https://api.github.com/users/sascala/followers","following_url":"https://api.github.com/users/sascala/following{/other_user}","gists_url":"https://api.github.com/users/sascala/gists{/gist_id}","starred_url":"https://api.github.com/users/sascala/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/sascala/subscriptions","organizations_url":"https://api.github.com/users/sascala/orgs","repos_url":"https://api.github.com/users/sascala/repos","events_url":"https://api.github.com/users/sascala/events{/privacy}","received_events_url":"https://api.github.com/users/sascala/received_events","type":"User","site_admin":false},"milestone":{"url":"https://api.github.com/repos/mesosphere/marathon/milestones/27","html_url":"https://github.com/mesosphere/marathon/milestones/Next","labels_url":"https://api.github.com/repos/mesosphere/marathon/milestones/27/labels","id":1425063,"number":27,"title":"Next","description":"","creator":{"login":"mwasn","id":12829900,"avatar_url":"https://avatars.githubusercontent.com/u/12829900?v=3","gravatar_id":"","url":"https://api.github.com/users/mwasn","html_url":"https://github.com/mwasn","followers_url":"https://api.github.com/users/mwasn/followers","following_url":"https://api.github.com/users/mwasn/following{/other_user}","gists_url":"https://api.github.com/users/mwasn/gists{/gist_id}","starred_url":"https://api.github.com/users/mwasn/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mwasn/subscriptions","organizations_url":"https://api.github.com/users/mwasn/orgs","repos_url":"https://api.github.com/users/mwasn/repos","events_url":"https://api.github.com/users/mwasn/events{/privacy}","received_events_url":"https://api.github.com/users/mwasn/received_events","type":"User","site_admin":false},"open_issues":53,"closed_issues":3,"state":"open","created_at":"2015-11-23T13:58:10Z","updated_at":"2016-02-09T17:06:21Z","due_on":null,"closed_at":null},"comments":7,"created_at":"2016-01-08T11:21:13Z","updated_at":"2016-02-12T12:09:14Z","closed_at":null,"body":"The current documentation of GROUP_BY constraints states that:\r\n\r\n> It is important to note that Marathon only knows about different values of the attribute (e.g. \"rack_id\") by analyzing current running tasks.\r\n\r\nWhat is not very precise, because AppTaskLauncherActor and later ResourceMatcher have only a list of application tasks for which they match constraints:\r\n\r\nhttps://github.com/mesosphere/marathon/blob/v0.13.0/src/main/scala/mesosphere/marathon/core/launchqueue/impl/AppTaskLauncherActor.scala#L108-L109\r\n\r\nIt raises the question of whether it makes sense to run applications with GROUP_BY constraint without providing the number of values in constraints, because new applications never know this number and it all depends on what kind of offers they receive from Mesos, which eventually results in quite random behavior."},"comment":{"url":"https://api.github.com/repos/mesosphere/marathon/issues/comments/183297813","html_url":"https://github.com/mesosphere/marathon/issues/2925#issuecomment-183297813","issue_url":"https://api.github.com/repos/mesosphere/marathon/issues/2925","id":183297813,"user":{"login":"timoreimann","id":694826,"avatar_url":"https://avatars.githubusercontent.com/u/694826?v=3","gravatar_id":"","url":"https://api.github.com/users/timoreimann","html_url":"https://github.com/timoreimann","followers_url":"https://api.github.com/users/timoreimann/followers","following_url":"https://api.github.com/users/timoreimann/following{/other_user}","gists_url":"https://api.github.com/users/timoreimann/gists{/gist_id}","starred_url":"https://api.github.com/users/timoreimann/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/timoreimann/subscriptions","organizations_url":"https://api.github.com/users/timoreimann/orgs","repos_url":"https://api.github.com/users/timoreimann/repos","events_url":"https://api.github.com/users/timoreimann/events{/privacy}","received_events_url":"https://api.github.com/users/timoreimann/received_events","type":"User","site_admin":false},"created_at":"2016-02-12T12:09:14Z","updated_at":"2016-02-12T12:09:14Z","body":"As the doc update has made it to the github.io page, this issue can be considered done and be closed."}}