From 60f1eb2b883c763e9ccc9ddfb7c8544c41b3a6d5 Mon Sep 17 00:00:00 2001 From: Carlos Neto Date: Fri, 13 Feb 2026 15:46:58 -0300 Subject: [PATCH] docs: add metrics section for Tail input plugin in documentation Signed-off-by: Carlos Neto docs: add metrics for Tail Input Plugin in monitoring documentation docs: correct capitalization and typos in Tail input plugin metrics section Signed-off-by: Carlos Neto docs: update heading capitalization in Tail input metrics section Signed-off-by: Carlos Neto docs: fix links to Tail input plugin documentation in monitoring and tail metrics sections Signed-off-by: Carlos Neto --- administration/monitoring.md | 13 +++++++++++++ pipeline/inputs/tail.md | 4 ++++ 2 files changed, 17 insertions(+) diff --git a/administration/monitoring.md b/administration/monitoring.md index ef990070b..6e954b723 100644 --- a/administration/monitoring.md +++ b/administration/monitoring.md @@ -233,6 +233,19 @@ The following are detailed descriptions for the metrics collected by the storage | `fluentbit_output_upstream_total_connections` | name: the name or alias for the output instance | The sum of the connection count of each output plugins. | gauge | bytes | | `fluentbit_output_upstream_busy_connections` | name: the name or alias for the output instance | The sum of the connection count in a busy state of each output plugins. | gauge | bytes | +#### Tail input plugin metrics + +The following are detailed descriptions for the metrics collected when using the [Tail](../pipeline/inputs/tail.md) Input Plugin. + +| Metric Name | Labels | Description | Type | Unit | +|---------------------------------------------|------------------------------|---------------|---------|---------| +| `fluentbit_input_files_closed_total` | name: the name or alias for the input instance | Total number of closed files. | counter | records | +| `fluentbit_input_files_opened_total` | name: the name or alias for the input instance | Total number of opened files. | counter | records | +| `fluentbit_input_files_rotated_total` | name: the name or alias for the input instance | Total number of rotated files. | counter | records | +| `fluentbit_input_long_line_skipped_total` | name: the name or alias for the input instance | Total number of skipped occurrences for long lines. This metric is only created when `skip_long_lines` is set to `true`. | counter | records | +| `fluentbit_input_long_line_truncated_total` | name: the name or alias for the input instance | Total number of truncated occurrences for long lines. This metric is only created when `truncate_long_lines` is set to `true`. | counter | records | +| `fluentbit_input_multiline_truncated_total` | name: the name or alias for the input instance. | Total number of truncated occurrences for multiline. This metric is only created when `multiline.parser` is defined. | counter | records | + ### Output latency metric Introduced in Fluent Bit 4.0.6, the `fluentbit_output_latency_seconds` histogram metric captures end-to-end latency from the time a chunk is created by an input plugin until it's successfully delivered by an output plugin. This provides observability into chunk-level pipeline performance and helps identify slowdowns or bottlenecks in the output path. diff --git a/pipeline/inputs/tail.md b/pipeline/inputs/tail.md index 8a9a5b906..dcddc0df8 100644 --- a/pipeline/inputs/tail.md +++ b/pipeline/inputs/tail.md @@ -569,3 +569,7 @@ pipeline: {% endtab %} {% endtabs %} + +### Input tail metrics + +The Tail input plugin provides several dedicated metrics related to skipped long lines, truncated lines, and others. For detailed information about available metrics and how to use them, see [Monitoring](../../administration/monitoring.md).