{"action":"created","issue":{"url":"https://api.github.com/repos/mapbox/tippecanoe/issues/58","labels_url":"https://api.github.com/repos/mapbox/tippecanoe/issues/58/labels{/name}","comments_url":"https://api.github.com/repos/mapbox/tippecanoe/issues/58/comments","events_url":"https://api.github.com/repos/mapbox/tippecanoe/issues/58/events","html_url":"https://github.com/mapbox/tippecanoe/issues/58","id":89688048,"number":58,"title":"Multithreading","user":{"login":"ericfischer","id":1951835,"avatar_url":"https://avatars.githubusercontent.com/u/1951835?v=3","gravatar_id":"","url":"https://api.github.com/users/ericfischer","html_url":"https://github.com/ericfischer","followers_url":"https://api.github.com/users/ericfischer/followers","following_url":"https://api.github.com/users/ericfischer/following{/other_user}","gists_url":"https://api.github.com/users/ericfischer/gists{/gist_id}","starred_url":"https://api.github.com/users/ericfischer/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ericfischer/subscriptions","organizations_url":"https://api.github.com/users/ericfischer/orgs","repos_url":"https://api.github.com/users/ericfischer/repos","events_url":"https://api.github.com/users/ericfischer/events{/privacy}","received_events_url":"https://api.github.com/users/ericfischer/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":3,"created_at":"2015-06-20T00:04:34Z","updated_at":"2015-09-30T22:40:04Z","closed_at":null,"body":"Starting to work on this. Awkward things so far:\r\n\r\n * The global list of attribute names\r\n * The global bounding box and map center\r\n * The output files that each zoom is split into for the next stage. Currently there are exactly 4. I guess we should let them multiply until there are as many jobs running at once as we want, and then merge some of the sub-files after that zoom and each subsequent zoom?\r\n * Which thread owns the progress indicator?\r\n * What sqlite options are needed to allow simultaneous writes to the mbtiles from multiple threads?\r\n\r\n@aaronlidman @MateoV "},"comment":{"url":"https://api.github.com/repos/mapbox/tippecanoe/issues/comments/144565526","html_url":"https://github.com/mapbox/tippecanoe/issues/58#issuecomment-144565526","issue_url":"https://api.github.com/repos/mapbox/tippecanoe/issues/58","id":144565526,"user":{"login":"anandthakker","id":4974151,"avatar_url":"https://avatars.githubusercontent.com/u/4974151?v=3","gravatar_id":"","url":"https://api.github.com/users/anandthakker","html_url":"https://github.com/anandthakker","followers_url":"https://api.github.com/users/anandthakker/followers","following_url":"https://api.github.com/users/anandthakker/following{/other_user}","gists_url":"https://api.github.com/users/anandthakker/gists{/gist_id}","starred_url":"https://api.github.com/users/anandthakker/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/anandthakker/subscriptions","organizations_url":"https://api.github.com/users/anandthakker/orgs","repos_url":"https://api.github.com/users/anandthakker/repos","events_url":"https://api.github.com/users/anandthakker/events{/privacy}","received_events_url":"https://api.github.com/users/anandthakker/received_events","type":"User","site_admin":false},"created_at":"2015-09-30T22:40:04Z","updated_at":"2015-09-30T22:40:04Z","body":"@ericfischer Nice!  You may well already know all this stuff, but in case not, two things I learned re: concurrency & sqlite while working on [vt-grid](https://github.com/developmentseed/vt-grid):\r\n\r\n - [WAL mode](https://www.sqlite.org/wal.html) allows readers not to block writers and vice versa.\r\n - Writers still block other writers, though, so it's necessary to handle [SQLITE_BUSY](https://www.sqlite.org/rescode.html#busy).  I just set the busy timeout to something excessive because of the limitations of the node interface...\r\n"}}