Repository is one of the fondamental maven concept. It's simple to understand but fair usage request a bit of practise.

You should have a clearer idea of repository management best practises through the following examples and counterexamples.

Initial configuration

This configuration come with maven without doing anything.

The "simple project" pom.

Extended usage

Without repository manager

Take a look on the "extended project" pom.

With repository manager

The "extended project" pom don't change, we just add mirrors section in the settings.xml (M2_HOME/conf/settings.xml or ~/.m2/settings.xml).
Take a look on the Mirrors definitions in settings.xml.

Complex usage

Counterexamples

Single repo mirroring multiple repositories

THIS IS A COUNTEREXAMPLE

Mirror repository defined in place of original repository.

THIS IS A COUNTEREXAMPLE

Annexes

pom.xml

Simple project

Extended project

Note that some repository declarations are useless:

Jetty is now available on central repository so you can remove

Project only need snapshot version of cargo plugin so you can remove

The project don't have any dependencies on snapshot version of codehaus artefacts so you can remove

Repository management best practices