[gnodet]

Backport of #27956

Cherry-pick of 3307540 to camel-4.18.x.
Conflicts resolved automatically by backport bot agent.

[davsclaus]

TL;DR

The production change and the tests are the same as #27956. Two of the new tests do not compile on camel-4.18.x, and the upgrade-guide note is in the 4.17 to 4.18 section.

Blockers

• MiloClientProducerWriteFailureTest.java:68 calls super(new MiloClientConfiguration()). On camel-4.18.x the only MiloClientConnection constructor also takes a MonitorFilterConfiguration. The one-argument constructor came with CAMEL-25145, which is on main only. super(new MiloClientConfiguration(), new MonitorFilterConfiguration()) fixes it.
• SubscriptionManagerExceptionPropagationTest.java:155, :173 and :193 call new SubscriptionManager(config, executor, executor, 10_000). On camel-4.18.x the constructor is (MiloClientConfiguration, ScheduledExecutorService, long). The four-argument form came with CAMEL-25812 (#28111), which is on main only. new SubscriptionManager(new MiloClientConfiguration(), executor, 10_000) fixes it.

Other findings: 2

• The note === camel-milo - an awaited write, call or read that fails now fails the exchange is at camel-4x-upgrade-guide-4_18.adoc:1644, inside "Upgrading Camel 4.17 to 4.18", next to the 4.18.0 note about HEADER_AWAIT. The change ships in 4.18.6, so the note belongs under "Upgrading from 4.18.5 to 4.18.6" (line 14).
• The 4.18 guide on main does not have this note yet. It should go under "Upgrading from 4.18.5 to 4.18.6" there too. The main PR for the 4.22 note from #28367 can add this one as well.

The CI failure is this compile error. The build (17, false) job failed, and the JDK 21 job was cancelled after it. A re-run will not help until the tests are fixed. I expect the tests to pass after these two changes, but CI has not run them yet.

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Reviewed with Claude Code on behalf of @davsclaus. This review was generated by an AI agent and may contain inaccuracies; please verify all suggestions before applying.

[davsclaus]

@gnodet friendly ping: the new milo tests still call MiloClientConnection/SubscriptionManager constructors that only exist on main, so test compilation fails on camel-4.18.x (see the review from 2026-10-23).

Claude Code on behalf of davsclaus