[Bug] Metrics Initialization Causing Flaky Tests in `dubbo-config/dubbo-config-spring`

[Anshul-creator]

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Apache Dubbo Component

Java SDK (apache/dubbo)

Dubbo Version

Dubbo 3.3.7
JDK 17/21

Steps to reproduce this issue

Several tests across dubbo-config/dubbo-config-api exhibit flaky behavior when execution order or JVM internal iteration order changes. These flakes were consistently reproduced using:

./mvnw -q -pl dubbo-config/dubbo-config-api \
  edu.illinois:nondex-maven-plugin:2.2.1:nondex \
  -DnondexRuns=20

What you expected to happen

The reason for the flakiness are below:

Micrometer metrics subsystem initialization

• CompositeMeterRegistry uses mutable global structures
• IdentityHashMap iteration order varies
• Metrics are initialized implicitly during DubboBootstrap.start()

DubboBootstrap global state not reset across tests

• ApplicationModel / FrameworkModel carry over state
• Reference cache survives between tests
• System properties affect bootstrap behavior if not cleared

Anything else

I have opened several PR's for solving the issue. I opened one PR per test file. The PRs below have been accepted:

• Fix: Stabilize ExporterSideConfigUrlTest by disabling metrics initialization during URL export #15778
• Stabilize MethodConfigTest by disabling metrics initialization to avoid Micrometer nondeterminism #15782
• Fix: Stabilize multiple tests in ServiceConfigTest by isolating system properties and cached state #15785

The rest of the PR's mentioned below are open for review and follow the same method to solving the flakiness used in the PRs that were accepted above:

• Fix: Stabilize ReferenceConfigTest by Disabling Metrics Initialization and Ensuring Test Isolation #15787
• Fix: Stabilize ProtocolConfigTest by Disabling Metrics Initialization and Ensuring Test Isolation #15789
• Fix: Stabilize ConsumerConfigTest by Disabling Metrics Initialization and Ensuring Test Isolation #15790
• Fix: Stabilize ApplicationConfigTest by Disabling Metrics Initialization and Ensuring Test Isolation  #15791
• Fix: Stabilize ConfigCenterConfigTest by Disabling Metrics Initialization and Ensuring Test Isolation  #15792
• Fix: Stabilize DubboBootstrapTest by Disabling Metrics Initialization and Ensuring Test Isolation  #15793
• Fix: Stabilize ReferenceCacheTest by Disabling Metrics Initialization and Ensuring Test Isolation  #15794

Are you willing to submit a pull request to fix on your own?

• Yes I am willing to submit a pull request on my own!

Code of Conduct

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