RabbitMQ

RabbitMQ 4.4.0 adds delayed message delivery and policy-driven delivery-limit updates for quorum queues, exclusive AMQP 1.0 container ID ownership, a new v2 on-disk classic queue store format, and native x-modulus-hash routing no longer tied to a plugin. Because OpenID Connect discovery validation is now stricter and legacy AMQP 1.0-related headers are no longer parsed, deployments with non-HTTPS or mismatched-issuer identity providers (such as Cloud Foundry UAA) must set auth_oauth2.discovery.verify_issuer and/or verify_https_endpoints to false before upgrading, and any caller of the removed GET /api/auth/hash_password/{password} endpoint must switch to POST /api/auth/hash_password.

Matters for: This matters for teams running RabbitMQ clusters with OAuth2/OIDC authentication through identity providers like Cloud Foundry UAA, and for operators performing rolling upgrades across classic and quorum queue storage formats.