Build under sonarscanner is way slower

I am trying to run test coverage as part of a PR check and is slow, average time is 25 min.
We are using:

  • SonarQube Enterprise Edition Version 9.9 (build 65466)
  • ‘dotnet-sonarscanner’ (version ‘6.2.0’)
  • code is C#

If I run:
dotnet build ProjA
dotnet build ProjB
dotnet build ProjC

dotnet sonarscanner begin

dotnet test TestProjA
dotnet test TestProjB
dotnet test TestProjC
dotnet test TestProjD

dotnet sonarscanner end

The build part takes under 3 min, the test part takes around 5 min, sonarscanner end another 5, and with the other things I have to install like dotnet, java and so on it takes a total of around 15 min. But the problem with this approach is that not all lines are reported to Sonar so coverage is wrong. I should have around 190k lines reported but this way I only have 113k.

If I run:
dotnet sonarscanner begin

dotnet build ProjA
dotnet build ProjB
dotnet build ProjC

dotnet test TestProjA
dotnet test TestProjB
dotnet test TestProjC
dotnet test TestProjD

dotnet sonarscanner end

The build part takes over 7 min, the test part takes around 5-6 min, sonarscanner end another 6, in the end it takes a total of around 23 min. Even the previous 15 min is long, 23 min is unsustainable as code will be merged in the mean time and the the branch needs to be updated and all checks start again.

Also, running the test part outside of the sonarscanner only takes 3.5b min.

How can I make it faster?

Hi,

It’s not shocking that you get a strange linecount if you begin after the build is complete. In fact, it’s surprising that you’re not complaining of more than just a strange linecount. begin is supposed to run at… the beginning because it initiates analysis, which actually runs during the build.

That’s why the build takes longer with analysis.

That said, I’m not sure you’re going to get what you expect either from this:

I think (and my memory is fuzzy on this and I’m not finding it explicitly in the docs) that you’re going to be better off with this:

dotnet sonarscanner begin
dotnet build ProjA
dotnet test TestProjA
dotnet sonarscanner end

dotnet sonarscanner begin
dotnet build ProjB
dotnet test TestProjB
dotnet sonarscanner end

::&etc

That is more work overall, I suppose, but will give you faster results for ProjA, at least. Without TestProjD I would lean in hard to the recommendation to split this out, and further recommend that you parallelize it on multiple build agents for much faster results across the board. Maybe that’s still an option?

 
Ann

The issue is that I can’t run them that way. ProjB depends on Proj A, and ProjC depends on both ProjA and ProjB. Then the test projects test different functionalities on the Projects A to C. So I need to build all projects in the dependency order then run the tests.

Hi,

Unfortunately, I doubt there’s anything you can do to speed this up.

For other languages, excluding parts of the code from analysis might help, but .NET still analyzes everything and uses exclusions to filter what’s reported.

On a side note, all of your build and test operations take part in the same directory, right?

 
Thx,
Ann

All source code is under a main folder named Source. All build dlls go into Source\bin. Test dlls go into

  • Source\Tests\ProjA\bin\
  • *Source\Tests\ProjB\bin\
  • Source\Tests\ProjC\bin\

Does it matter?

1 Like

Hi,

In your case, it doesn’t matter, but after poking around on this topic, I’m (we’re) not quite sure it would work right if they weren’t all together.

 
Ann

I tried setting output for the dotnet test to the Source\bin folder and coverage went down (almost 0 )

Hi,

It’s not clear to me why you changed the test output.

 
Ann

Hi @oana.marina,

Have you tried

  1. creating a solution
  2. adding all your projects to the solution
  3. running

dotnet sonarscanner begin
dotnet build solution.sln
dotnet test solution.sln --no-build
dotnet sonarscanner end

This might shave off a bit if some rebuild happens during the test phase.
You might also want to experiment with doing just

dotnet sonarscanner begin
dotnet test solution.sln
dotnet sonarscanner end

Normally, dotnet test builds your solution before testing. This might optimize things a bit, because testing should not be impacted by our analysis, so I believe there is something to be gained here. Note that, in that case, you do NOT want the --no-build flag.

That being said, as Ann mentioned, there is a cost to everything. The analysis runs during the build so increased time for the build phase is to be expected. Gathering coverage during tests also has a non-trivial impact on running the tests, unfortunately (but that is out of our control and specific to your collector).

Also, you mention having to install java, dotnet etc. What type of CI are you using? Are the agents hosted or on-premises? If they are hosted, is there not an image that already has the required dependencies? If it is self-hosted, can you preinstall those things so you do not have to do it every single time?

Denis.