Slow project.js / app/views/show.js.erb

[stefan-langenmaier]

platform: 2.3.1 # supported: 2.2.4, 2.3.2
backlogs: 1.0.2 but this part of the code is the same as with the current 1.0.3 # supported: 1.0.5
ruby: 1.9.3 # supported: 1.9.3, 2.0.0

The rendering of the backlogs tab is slow here because the server has to load project.js which is created with app/views/show.js.erb if I see it correctly. This file takes about 7s out of the 8-9s total loading time on my test system.

In this file the following code part is responsible for about 90% of that time.

=begin
 a release can contain stories of all projects which it is visible
 but droppables are only self_and_descendants of the current view to avoid user confusion by vanishing stories
=end
    project_releases = Hash[Project.visible.find(:all).map{|project|
      [
        project.id.to_s,
        project.shared_releases.open.visible.reject{|r|
          !@project.projects_in_shared_product_backlog.include? project
          }.collect{|v| v.id.to_s }
      ] if project
    }]

The installation has about 25k issues, with about 500 projects that can be nested up to 4 levels deep.

Is anyone else having similar problems? Are there configuration options to improve the speed, if not all sprint/version sharing modes are used? Can the code be optimized?

As I can see in this commit the code is there for a reason. What would happen if it got removed?

[bohansen]

Haven't had that many projects, but it looks like a case of bad scaling with lots of projects. I have done a small performance improvement, but we might have to consider another way of fetching this information.
It determines which stories are allowed to be moved into which release on the backlogs page.
You might try latest master and see if it helps anything.

[stefan-langenmaier]

I think there is a small improvement (or actually big, about ~1s) relative to the whole loading process. Nevertheless I just haven't enough data to really verify performance changes.

The only thing I can verify is that it is still slow/not fast and that's caused by the project.js request as you can see in the attached screenshot.

[bohansen]

I have a few improvements. Could you test latest master?

[stefan-langenmaier]

Yes that's a huge speed improvement. No problems for me so far. I see if I can get it tested by more people.

[bohansen]

Excellent, I have made a new release. Out of curiosity how much did it improve? I don't have as big a database to test :).

[stefan-langenmaier]

The specific code is now 10 times faster and the whole page loads in a fifth of the time (for my data).

[bohansen]

Cool, I saw something similar from 3-4 seconds to 400ms for the show.js. There are definitely still places which could be improved, but I think we got bang for the buck with this one :). Thanks for the analysis and testing.