REST/SSE

• Fix SSE handler blocking behavior that could stall responses under certain conditions.
  PR: fix: SSE handler blocking by @wuqinqiang (@5181)
• Reduce log noise for transient I/O conditions by downgrading SetWriteDeadline errors to debug level in REST SSE.
  PR: fix(rest): change SSE SetWriteDeadline error log to debug level by @wuqinqiang (@5162)
• Add sseSlowThreshold to surface slow SSE writes, enabling better observability about backpressure or slow clients.
  PR: feat(handler): add sseSlowThreshold by @wuqinqiang (@5196)

MapReduce

• Improve panic stacktrace reporting in mapreduce, making error contexts clearer and debugging faster.
  PR: optimize: mapreduce panic stacktrace by @kevwan (@5168)

Performance and Runtime

• Optimize machine performance data reading to lower collection overhead and reduce runtime impact.
  PR: opt: optimization of machine performance data reading by @wanwusangzhi (@5174)

Bug Fixes

• Fix gRPC → HTTP mapping issue in gateway.
  PR: fix: issue-5110 by @guonaihong (@5113)

Migration and Usage Notes

• Logging key customization:
  • If you rely on specific field names in log pipelines, consider setting the new custom key configuration to preserve schema consistency.
• JSON log output:
  • If your types implement json.Marshaler, expect more accurate JSON in logs. If you previously depended on stringified representations, review downstream consumers to ensure compatibility.
• SSE tuning:
  • Consider using SetSSESlowThreshold to flag slow clients or network conditions in environments sensitive to latency.
  • The SetWriteDeadline log level change reduces noise; adjust logger settings if you still want to surface these events.

Acknowledgements

• Thanks to all contributors in this release: @WqyJh, @guonaihong, @wanwusangzhi, @kevwan, @wuqinqiang, and first-time contributor @Copilot. Your work improves performance, reliability, and developer ergonomics for everyone using go-zero.

Full Changelog

• v1.9.0...v1.9.1