From 810009426a240303218837bf94e91152b0bea0bf Mon Sep 17 00:00:00 2001 From: "Eric D. Schabell" Date: Sun, 9 Aug 2026 20:35:27 +0200 Subject: [PATCH] docs: installation: upgrade-notes: document 5.1 input rate metrics and rate gate Add an upgrade-notes entry for the new input rate_window/rate_gate settings and fluentbit_input_rate_* metrics, which landed in administration and pipeline docs but weren't cross-referenced in the v5.1 upgrade notes. Also reword the mutual TLS note to clear a Vale WordList suggestion on "terminate". Also documenting rate_window setting. Signed-off-by: Eric D. Schabell --- installation/upgrade-notes.md | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/installation/upgrade-notes.md b/installation/upgrade-notes.md index 6e761b080..c91e61180 100644 --- a/installation/upgrade-notes.md +++ b/installation/upgrade-notes.md @@ -18,6 +18,12 @@ Upgrading the `fluent-bit` package on Debian or Ubuntu now runs `systemctl daemo The [Syslog output](../pipeline/outputs/syslog.md) `mode` setting now accepts `tls` and `dtls`, both of which automatically enable TLS, in addition to the existing `tcp` and `udp` values. Existing configurations that pair `mode: tcp` with a separate `tls: on` setting are unaffected. +### Input rate metrics and rate gate + +All input plugins now measure their own ingestion rate and can optionally pause when that rate is too high. Rate measurement is always on and exposes new `fluentbit_input_rate_bytes` and `fluentbit_input_rate_records` metrics. The `rate_window` setting controls the time window used to measure this byte and record rate, and defaults to `1s`. The rate gate itself is opt-in: set `rate_gate` to `true` and configure `rate_gate.max_bytes` or `rate_gate.max_records` to pause ingestion once it exceeds a threshold, with `rate_gate.backpressure` and `rate_gate.resume_ratio` controlling how the effective limit and resume behavior work. See [Rate metrics and rate limiting for inputs](../administration/configuring-fluent-bit/yaml/pipeline-section.md#rate-metrics-and-rate-limiting-for-inputs) and [per-input buffering settings](../pipeline/buffering.md#per-input-settings) for details. + +No action is required unless you want to opt in to the new rate gate. + ### 64-bit timestamp handling beyond 2038 Event timestamps at or after the 2038 32-bit `time_t` rollover now round-trip correctly through the internal msgpack `EventTime` encoding that Fluent Bit uses. On platforms where `time_t` is still 32-bit, timestamps remain bound by that platform's range. @@ -50,7 +56,7 @@ If you tune `http`, `splunk`, `elasticsearch`, `opentelemetry`, or `prometheus_r Input plugins that support TLS now also support `tls.verify_client_cert`. Enable this option to require and validate the client certificate presented by the sender. -If you terminate TLS directly in Fluent Bit and need mutual TLS (`mTLS`), add `tls.verify_client_cert on` together with the usual `tls.crt_file` and `tls.key_file` settings. +If Fluent Bit is the TLS termination point and you need mutual TLS (`mTLS`), add `tls.verify_client_cert on` together with the usual `tls.crt_file` and `tls.key_file` settings. ### New internal logs input