Consider changing `aether.connector.basic.parallelPut` feature

[cstamas]

Affected version

1.9.x and master

Bug description

We may want to flip the default to false, it just causes to many problems. It was known to cause issues with AF and NX3, but it seems NX2 staging is affected as well, causing issues on doing release against RAO.

[slawekjaranowski]

As not all features of repository managers are affected, I'm not sure if we should disable it by default.

We can documented it on https://maven.apache.org/docs/3.9.12/release-notes.html as know issue with workaround

[slawekjaranowski]

ref:

• Add known issues to 3.9.12 maven-site#1507
• Maven 3.9.12 - parallel PUT maven#11634

[slawekjaranowski]

I hope we have documented ... we will see what feedback will be

[kwin]

NX2 is affected in general, not sure about others. I would rather go ahead with reverting as starting with parallel PUTs only from the 2nd one onwards should have only a small performance impact

[cstamas]

As I tested, NX2 staging is affected only (parallel put was tested by me locally using Nx2 OSS and deploys to release or snapshot repositories works okay). OTOH, Nx3 and AF have been reported by users as having issues to cope with parallel deploys of any kind.

But yes, I agree to revert to "first goes alone, and rest in parallel".

[cstamas]

We basically talk about partial revert of this commit: f299b25 on master and 09c3fa9 on 1.9.x branch: only the basic connector change, while the rest is okay.