Spring Boot 4.2.0 M2 Release Notes

Spring Boot 4.2.0-M2 Release Notes

For changes in earlier milestones, please refer to:

v4.2.0-M1

Upgrading from Spring Boot 4.1

New and Noteworthy

Tip	Check the configuration changelog for a complete overview of the changes in configuration.

SSL Bundle Support for LDAP

The auto-configured LdapContextSource can now connect over LDAPS using an SSL bundle. Configure the bundle to use with the spring.ldap.ssl.bundle property and an ldaps:// URL in spring.ldap.urls, which is also switched to default to ldaps://localhost:636 once a bundle is configured. If you only need the platform’s default trust and key material rather than a bundle, set spring.ldap.ssl.enabled to true instead.

Reloaded bundle key and trust material is picked up by subsequent connections automatically.

See the reference documentation for more details.

Observability improvements

Common OTLP Configuration Fallback

The OTLP endpoint, headers, and compression can now be configured once under management.opentelemetry.otlp and shared across the tracing, logging, and metrics exporters. Each signal-specific property still takes precedence when set, and falls back to the common value otherwise:

management.opentelemetry.otlp.endpoint - used when a signal has no endpoint of its own configured, with the OTLP signal path (/v1/traces, /v1/logs, /v1/metrics) appended automatically for HTTP transport.
management.opentelemetry.otlp.headers - merged with any signal-specific headers, which take precedence on conflicting keys.
management.opentelemetry.otlp.compression - used when a signal has no compression of its own configured.

Configurable Tracing MDC Keys

The MDC keys under which Micrometer Tracing puts the trace and span IDs can now be customized:

management.tracing.mdc.trace-id-key - key for the trace ID, traceId by default.
management.tracing.mdc.span-id-key - key for the span ID, spanId by default.

Both keys are applied to OpenTelemetry and Brave, and the default correlation ID in the log output follows them automatically, so log correlation keeps working without any further configuration.