HAProxy 3.2: What's New, Release History & EOL Status

What Is New in HAProxy 3.2

How is DNS resolution more robust now?

HAProxy 3.2 adds native support for DNS over TCP. This is a big deal because it prevents resolution failures for large DNS responses that exceed the typical 512-byte UDP limit. In practice, this makes service discovery much more reliable when dealing with large DNS records or DNSSEC-enabled zones.

The resolver can now automatically fall back to TCP when a truncated UDP response is received. You just need to ensure your DNS server is configured to handle TCP queries.

What's new for TLS performance?

Dynamic TLS Record Sizing is a major performance enhancement. It optimizes network latency by dynamically adjusting the size of TLS records based on the type of traffic.

For bulk data transfers, it uses large records for higher throughput. For interactive traffic, it uses smaller records to reduce latency. This happens automatically and can significantly improve the user experience for HTTPS traffic.

Is HTTP/3 ready to use?

HTTP/3 support has been introduced as a tech preview. This allows you to start experimenting with the next-generation HTTP protocol which is built on QUIC instead of TCP.

Since it's a preview, it's not recommended for production workloads yet. You can enable it by adding the h3 option to a bind line. This lays the groundwork for full production-ready support in future releases.

How is service discovery improved?

You can now implement custom service discovery logic directly in Lua. The new core.register_service() function allows a Lua script to act as a DNS server, returning dynamic responses to HAProxy's resolver queries.

This is powerful for integrating with proprietary discovery systems or cloud metadata services that aren't supported by the built-in resolvers. Your Lua script gets the query and returns the IP addresses directly.

What else got better under the hood?

Logging & Observability

The Prometheus exporter now supports rich labels for metrics, and you can log the QUIC connection ID for better tracing of HTTP/3 sessions. The fc_pp_authority sample fetch was added to capture the :authority pseudo-header.

Stick Tables & Routing

Stick table counters can now be cleared using the clear table command. Server queue priority was added, allowing you to prioritize requests from certain clients when servers are busy.

HTTP Compression

The compression engine is now more efficient. It avoids trying to compress already compressed content types and supports the zstd compression algorithm.