●Change8

Migrating to HAProxy v3.5-dev2

Version v3.5-dev2 introduces 3 breaking changes. This guide details how to update your code.

Released: 7/8/2026

3
Breaking Changes
3
Migration Steps
98
Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

proxyOpenTracingdispatchtransparentcli/show-fdconnectionbackendtraceh3mux_quicsslhttpclienthq-interopserversamplehbufinitstconnhaloadlogtoolshtxmux-quichttp-htxquic_frametrace/h3trace/configtrace/tree-widemakefilequicfdmworkerhatermreadmeocspscripts/run-regtests.shvmactions/freebsd-vmhaloadhatermssl_sock_init_srv()agent.healthsrv_settings_init()SMP_F_CONSTSRV_F_NAME_REFDset server nameport_rangehbuf APIno listener modehaload streamshldstream structOBJ_TYPE_HALOADsc_hastream()__sc_hastream()sc_new()app_log_raw()send_log_raw()strl2ic()htx_xfer()qcs_http_rcv_buf()gccssl_sock_handshakehaproxymux-h2debug/tracechunk_frm_appendf()trace decodingtrace definitiontrace.cssl_trace.cenable_optsdisable_optsUSE_H2USE_FCGIUSE_SPOEtinySTOP_SENDINGmux_quicQCSSTREAMMUX closuretgroups fdsmaster-workerworkerpatchbothld_strm_task()be2hexchunkhtxstreambe_max_retriescur_max_retrieshttp-convurl-dechaterm build targethaproxy -ccREQUIRE_OPTIONREQUIRE_SERVICEPROMEX

Breaking Changes

●Issue #1

Removed support for 'dispatch' and 'transparent' proxy keywords. Users should remove these keywords from their proxy configurations.

●Issue #2

Removed deprecated OpenTracing support. Applications relying on OpenTracing will need to migrate to an alternative tracing solution.

●Issue #3

Removed deprecated 'master-worker' global keyword. Users should migrate to the 'worker' keyword.

Migration Steps

  1. 1
    Remove 'dispatch' and 'transparent' proxy keywords from configurations.
  2. 2
    Migrate away from OpenTracing to an alternative tracing solution.
  3. 3
    Replace the 'master-worker' global keyword with 'worker'.

Release Summary

Version 3.5-dev2 introduces new features like runtime server renaming and binary-safe logging, alongside significant bug fixes in areas like QUIC and HTTP/2. It also removes support for deprecated proxy keywords and OpenTracing.

Need More Details?

View the full release notes and all changes for HAProxy v3.5-dev2.

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