v1.4.0-M1

Reactor Netty 1.4.0-M1 is part of 2026.0.0-M1 Release Train.

What's Changed

⚠️ Update considerations and deprecations

• Require choice between Forwarded and X-Forwarded headers by @violetagg in #4312

✨ New features and improvements

• Depend on Reactor Core v3.8.7 by @violetagg in 79ef2f6, see release notes
• Depend on Netty v4.2.17.Final by @violetagg in #4324
• Depend on Micrometer v1.18.0-M1 by @violetagg in 0b9436b
• Depend on Micrometer Tracing v1.8.0-M1 by @violetagg in 0b9436b
• Add WebSocket client metrics by @LivingLikeKrillin in #4118
• Expose pending acquire latencies to custom MeterRegistrar by @ejhnsn in #4250
• Reduce per-request CPU in the HTTP/2 connection pool by @samueldlightfoot in #4297
• Evaluate the address supplier once in AddressUtils.updatePort by @samueldlightfoot in #4298
• Reuse per-connection address and byte meters in the Micrometer client metrics path by @samueldlightfoot in #4318
• Override isH2cUpgrade in Http3Pool to always return false by @violetagg in #4325
• Drop the redundant address parameter from the HttpClient recordRead/recordWrite/startWrite by @violetagg in #4327
• HttpClient: Add API for configuring max decompression buffer size by @violetagg in e413ce9
• Ensure NonSslRedirectHandler always does a redirect based on HOST header by @violetagg in 7bd2f47
• WebSocket: Add API for configuring max decompression buffer size by @violetagg in d735cd1

🐞 Bug fixes

• Exclude HTTP/2 connections from the pool during the PING liveness check by @LivingLikeKrillin in #4255
• Add the liveness check to Http11EvictionPredicate by @LivingLikeKrillin in #4256
• Skip SNI lookup completion when the channel is already closed by @violetagg in #4266
• Do not capture caller context into pool maintenance tasks by @hocaron in #4300
• Fix WebSocket-over-HTTP/2 server metrics gauge accounting on close by @LivingLikeKrillin in #4302
• Fix NameResolverProvider#equals/hashCode by @violetagg in 5c19b57
• Refactor TracingMapHandle to handle exceptions correctly by @violetagg in 8e63e56
• Update proxy handling by @violetagg in 99365a5
• Refine header handling during redirects by @violetagg in 53e42cf
• Add back-pressure on pipelined HTTP requests by @violetagg in 38cd84c
• Proxy protocol is not supported for HTTP/3 protocol by @violetagg in afb3652

📖 Documentation

• Update javadoc for http-to-https redirect by @violetagg in ac607b0

New Contributors

• @LivingLikeKrillin made their first contribution in #4118
• @ejhnsn made their first contribution in #4250
• @hocaron made their first contribution in #4300

Full Changelog: v1.3.6...v1.4.0-M1