fix(mdx-web): retain Jackson JSON converter for actuator serialization - #390
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gerfboy wants to merge 1 commit into
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fix(mdx-web): retain Jackson JSON converter for actuator serialization#390gerfboy wants to merge 1 commit into
gerfboy wants to merge 1 commit into
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MdxOnDemandSerializationWebMvcConfigurer strips every message converter
not in its allowlist. Under Spring Boot 4 the actuator health endpoint
returns SystemHealthDescriptor, which is serialized with Jackson; with
the Jackson JSON converter removed there is no writable converter for it,
so /actuator/health fails with HttpMessageNotWritableException ("No
converter for [SystemHealthDescriptor] with preset Content-Type 'null'")
and Kubernetes health probes never pass.
Add JacksonJsonHttpMessageConverter to the allowlist so actuator (and any
non-MDX JSON) endpoints can serialize, while MDX endpoints continue to
use Gson.
gerfboy
requested review from
SandhyaBhatia,
mattnichols,
meotch,
stevecl5 and
tessstoddard
as code owners
September 9, 2026 19:51
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Summary of Changes
Under Spring Boot 4.1.0, path connectors on
mdx-webfail their Kubernetes health probes./actuator/healththrows:MdxOnDemandSerializationWebMvcConfigurer.extendMessageConvertersremoves every HTTP message converter not in its allowlist (CONVERT_CLASSES: Gson, String, ByteArray) and appends a custom XML converter. Under Spring Boot 4 the actuator health payload (SystemHealthDescriptor) is serialized with Jackson, so with the Jackson JSON converter stripped there is no writable converter for it and the endpoint fails. This is a regression from the Boot 4 migration.This change adds
JacksonJsonHttpMessageConverterto the allowlist so actuator (and any non-MDX JSON) endpoints can serialize, while MDX endpoints continue to use Gson.Jira: MC-15733
Public API Additions/Changes
None. Internal Spring MVC message-converter configuration only.
Downstream Consumer Impact
Bug fix. Restores serialization of Spring Boot actuator endpoints (e.g.
/actuator/health), which unblocks Kubernetes health probes for connectors on Boot 4. MDX endpoints are unaffected — they continue to serialize via Gson. No behavior change for existing MDX request/response paths.How Has This Been Tested?
./gradlew :mdx-web:check(JDK 21) — build, checkstyle, spotbugs, and tests passMdxOnDemandSerializationWebMvcConfigurerTestto assert the Jackson JSON converter survives converter filtering (retained alongside Gson/String/ByteArray, custom XML converter still appended last)Checklist: