{"action":"created","issue":{"url":"https://api.github.com/repos/SciTools/iris/issues/1287","labels_url":"https://api.github.com/repos/SciTools/iris/issues/1287/labels{/name}","comments_url":"https://api.github.com/repos/SciTools/iris/issues/1287/comments","events_url":"https://api.github.com/repos/SciTools/iris/issues/1287/events","html_url":"https://github.com/SciTools/iris/issues/1287","id":40916575,"number":1287,"title":"Iris has turned very slow for reading 4D data from ocean datasets","user":{"login":"rsignell-usgs","id":1872600,"avatar_url":"https://avatars.githubusercontent.com/u/1872600?v=3","gravatar_id":"","url":"https://api.github.com/users/rsignell-usgs","html_url":"https://github.com/rsignell-usgs","followers_url":"https://api.github.com/users/rsignell-usgs/followers","following_url":"https://api.github.com/users/rsignell-usgs/following{/other_user}","gists_url":"https://api.github.com/users/rsignell-usgs/gists{/gist_id}","starred_url":"https://api.github.com/users/rsignell-usgs/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/rsignell-usgs/subscriptions","organizations_url":"https://api.github.com/users/rsignell-usgs/orgs","repos_url":"https://api.github.com/users/rsignell-usgs/repos","events_url":"https://api.github.com/users/rsignell-usgs/events{/privacy}","received_events_url":"https://api.github.com/users/rsignell-usgs/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/SciTools/iris/labels/performance","name":"performance","color":"FEB657"}],"state":"open","locked":false,"assignee":null,"milestone":{"url":"https://api.github.com/repos/SciTools/iris/milestones/9","html_url":"https://github.com/SciTools/iris/milestones/v1.7","labels_url":"https://api.github.com/repos/SciTools/iris/milestones/9/labels","id":629167,"number":9,"title":"v1.7","description":null,"creator":{"login":"rhattersley","id":917914,"avatar_url":"https://avatars.githubusercontent.com/u/917914?v=3","gravatar_id":"","url":"https://api.github.com/users/rhattersley","html_url":"https://github.com/rhattersley","followers_url":"https://api.github.com/users/rhattersley/followers","following_url":"https://api.github.com/users/rhattersley/following{/other_user}","gists_url":"https://api.github.com/users/rhattersley/gists{/gist_id}","starred_url":"https://api.github.com/users/rhattersley/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/rhattersley/subscriptions","organizations_url":"https://api.github.com/users/rhattersley/orgs","repos_url":"https://api.github.com/users/rhattersley/repos","events_url":"https://api.github.com/users/rhattersley/events{/privacy}","received_events_url":"https://api.github.com/users/rhattersley/received_events","type":"User","site_admin":false},"open_issues":6,"closed_issues":46,"state":"open","created_at":"2014-04-14T11:43:43Z","updated_at":"2015-03-24T20:22:50Z","due_on":null,"closed_at":null},"comments":19,"created_at":"2014-08-22T15:00:36Z","updated_at":"2015-07-14T08:59:34Z","closed_at":null,"body":"I'm not sure when it happened, but Iris has turned very slow for reading 4D data from ocean model datasets.   I used to run a demo showing Iris loading sea surface temperature from a variety of models to illustrate the power C Conventions in Iris,  but now it takes so long I can no longer run it.   I'm not sure what version this happened at.  If anybody has an older version, perhaps they can try this out:\r\n```\r\nurl='http://tds.marine.rutgers.edu/thredds/dodsC/roms/espresso/2013_da/his_Best/ESPRESSO_Real-Time_v2_History_Best_Available_best.ncd'\r\nvar='sea_water_potential_temperature'\r\ncube = iris.load_cube(url,var)\r\n```\r\n\r\nThis used to take about 10 seconds, but now it takes 120 seconds or more.    If you do just a load_raw, it takes a few seconds.  \r\n\r\nAnd using netcdf4, I can load a layer of a 4D variable (e.g. temperature) along with lon and lat coordinates and plot it up in about 3 seconds.  \r\n\r\nHere's a Wakari bundle as proof:  https://www.wakari.io/sharing/bundle/rsignell/iris_test_v1.7.1\r\n\r\nMy best guess is that Iris is loading a bunch of coordinate data -- perhaps the z coordinates for all time steps?    \r\nAnd it would make sense that ocean models with more time steps are either timing out or giving memory issues, as in  #1280.   \r\n\r\nI really hope this issue can be resolved soon -- it has effectively broken many of our workflows. \r\n"},"comment":{"url":"https://api.github.com/repos/SciTools/iris/issues/comments/121172547","html_url":"https://github.com/SciTools/iris/issues/1287#issuecomment-121172547","issue_url":"https://api.github.com/repos/SciTools/iris/issues/1287","id":121172547,"user":{"login":"ajdawson","id":390602,"avatar_url":"https://avatars.githubusercontent.com/u/390602?v=3","gravatar_id":"","url":"https://api.github.com/users/ajdawson","html_url":"https://github.com/ajdawson","followers_url":"https://api.github.com/users/ajdawson/followers","following_url":"https://api.github.com/users/ajdawson/following{/other_user}","gists_url":"https://api.github.com/users/ajdawson/gists{/gist_id}","starred_url":"https://api.github.com/users/ajdawson/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ajdawson/subscriptions","organizations_url":"https://api.github.com/users/ajdawson/orgs","repos_url":"https://api.github.com/users/ajdawson/repos","events_url":"https://api.github.com/users/ajdawson/events{/privacy}","received_events_url":"https://api.github.com/users/ajdawson/received_events","type":"User","site_admin":false},"created_at":"2015-07-14T08:59:34Z","updated_at":"2015-07-14T08:59:34Z","body":"Did #1560 fix this issue?"}}