{"action":"created","issue":{"url":"https://api.github.com/repos/JuliaLang/julia/issues/14768","labels_url":"https://api.github.com/repos/JuliaLang/julia/issues/14768/labels{/name}","comments_url":"https://api.github.com/repos/JuliaLang/julia/issues/14768/comments","events_url":"https://api.github.com/repos/JuliaLang/julia/issues/14768/events","html_url":"https://github.com/JuliaLang/julia/issues/14768","id":128268430,"number":14768,"title":"Problem with addprocs on Amazon EC2","user":{"login":"lruthotto","id":4249607,"avatar_url":"https://avatars.githubusercontent.com/u/4249607?v=3","gravatar_id":"","url":"https://api.github.com/users/lruthotto","html_url":"https://github.com/lruthotto","followers_url":"https://api.github.com/users/lruthotto/followers","following_url":"https://api.github.com/users/lruthotto/following{/other_user}","gists_url":"https://api.github.com/users/lruthotto/gists{/gist_id}","starred_url":"https://api.github.com/users/lruthotto/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/lruthotto/subscriptions","organizations_url":"https://api.github.com/users/lruthotto/orgs","repos_url":"https://api.github.com/users/lruthotto/repos","events_url":"https://api.github.com/users/lruthotto/events{/privacy}","received_events_url":"https://api.github.com/users/lruthotto/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/JuliaLang/julia/labels/parallel","name":"parallel","color":"f7e102"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":2,"created_at":"2016-01-22T23:15:28Z","updated_at":"2016-01-23T04:47:06Z","closed_at":null,"body":"I have problems connecting establishing a connection between instances of the same AMI on the Amazon EC2. \r\n\r\nI roughly followed @mlubin's tutorial here: http://julialang.org/blog/2013/04/distributed-numerical-optimization/  to setup my workers and change the file `/etc/ssh/ssh_config` to turn off `StrictHostKeyChecking` and also providing the ssh key.\r\n\r\nAfter this I can ssh between the workers with no problem (outside julia) by typing\r\n```\r\nssh xxx.xx.xx.xx6\r\n```\r\n(no password prompt or key file). Starting on worker xxx.xx.xx.xx7 julia I see a weird behavior:\r\n\r\n```\r\n   _       _ _(_)_     |  A fresh approach to technical computing\r\n  (_)     | (_) (_)    |  Documentation: http://docs.julialang.org\r\n   _ _   _| |_  __ _   |  Type \"?help\" for help.\r\n  | | | | | | |/ _` |  |\r\n  | | |_| | | | (_| |  |  Version 0.4.4-pre+2 (2016-01-18 02:17 UTC)\r\n _/ |\\__'_|_|_|\\__'_|  |  Commit a85c3a0* (4 days old release-0.4)\r\n|__/                   |  x86_64-linux-gnu\r\n\r\njulia> addprocs([\"ubuntu@xxx.xx.xx.xx6\"],tunnel=true)\r\n1-element Array{Int64,1}:\r\n 2\r\njulia> addprocs([\"ubuntu@xxx.xx.xx.xx6\"],tunnel=true)\r\n1-element Array{Int64,1}:\r\n 3\r\n\r\njulia> addprocs([\"ubuntu@xxx.xx.xx.xx7\"],tunnel=true)\r\n```\r\nThe first two commands work and two remote workers are added. The last command stalls forever and eventually times out. I tried this in many different variants. For example, reversing the order gives the same problem (first adding a worker on xxx.xx.xx.xx7 is okay, but then adding one on xxx.xx.xx.xx6 fails).\r\n \r\nCan anybody please explain me whats going on?\r\n\r\n"},"comment":{"url":"https://api.github.com/repos/JuliaLang/julia/issues/comments/174139555","html_url":"https://github.com/JuliaLang/julia/issues/14768#issuecomment-174139555","issue_url":"https://api.github.com/repos/JuliaLang/julia/issues/14768","id":174139555,"user":{"login":"tanmaykm","id":1010989,"avatar_url":"https://avatars.githubusercontent.com/u/1010989?v=3","gravatar_id":"","url":"https://api.github.com/users/tanmaykm","html_url":"https://github.com/tanmaykm","followers_url":"https://api.github.com/users/tanmaykm/followers","following_url":"https://api.github.com/users/tanmaykm/following{/other_user}","gists_url":"https://api.github.com/users/tanmaykm/gists{/gist_id}","starred_url":"https://api.github.com/users/tanmaykm/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/tanmaykm/subscriptions","organizations_url":"https://api.github.com/users/tanmaykm/orgs","repos_url":"https://api.github.com/users/tanmaykm/repos","events_url":"https://api.github.com/users/tanmaykm/events{/privacy}","received_events_url":"https://api.github.com/users/tanmaykm/received_events","type":"User","site_admin":false},"created_at":"2016-01-23T04:47:06Z","updated_at":"2016-01-23T04:47:06Z","body":"It could possibly be due to connections timing out. Could you try setting `JULIA_WORKER_TIMEOUT` to a higher value? See: http://docs.julialang.org/en/latest/stdlib/parallel/#Base.addprocs\r\n\r\nIf that's the case, putting all ec2 instances in the same placement group may help."}}