OSIS-155: do not log the expected headTenant pre-create 404 as an error

[anurag4DSB]

Intent: why does this change exist?

During tenant activation OSE probes headTenant before the account exists, so the platform answers 404 and OSIS rethrows NotFoundException. The service logged that expected pre-create case at ERROR with a full stack trace, which reads as a fault during normal activation.

System impact: what's affected, including downstream?

Service-layer logging only, inside headTenant. No change to the HTTP response, the 404 contract, or any OSE/Vault interaction.

Preserved behavior: what explicitly stays the same?

headTenant still returns a 404 (NotFoundException) in every error scenario, as OSE requires. Only the spurious ERROR log line is removed.

Intended change: what's different after this PR?

The expected pre-create 404 is no longer logged as an error with a stack trace. A regression test pins that the service emits no ERROR or WARN and no stack trace for that path while still throwing NotFoundException.

Verification: how do we know this worked, or how would we know if it didn't?

Ran the full osis-core test module including the 75% JaCoCo gate: green. The new test fails if anything reintroduces an ERROR or stack-trace log for the expected pre-create 404.

[claude]

• ScalityOsisServiceImpl.java:912 — The blanket catch (Exception e) now silently swallows ALL exceptions, not just the expected pre-create VaultServiceException(404). Unexpected errors (NPE, network failures) lose their diagnostic logging. Suggest catching NotFoundException separately to rethrow as-is, and only suppressing the log for VaultServiceException while keeping logger.error for truly unexpected exception types.

Review by Claude Code

[anurag4DSB]

Addressed in 0f149e6. The catch now distinguishes the expected pre-create not-found (a NotFoundException, or a VaultServiceException with a 404 status) from genuinely unexpected failures: the expected case logs at DEBUG with no stack trace, while anything else (NPE, network, a Vault 5xx, etc.) still logs at ERROR with its stack trace so it stays diagnosable. The headTenant "404 for any error" contract OSE relies on is unchanged. Added a regression test (testHeadTenantUnexpectedErrorIsLoggedAtError) pinning that an unexpected fault is logged at ERROR with a trace while the caller still receives a 404.

[claude]

LGTM — the logging change is clean and well-tested. The expectedNotFound discriminator correctly separates the pre-create 404 (NotFoundException and VaultServiceException with 404 status) from genuinely unexpected errors. Both branches are pinned by regression tests. No issues found.

Review by Claude Code