http_server/health: Implement throughput health check

[tarruda]

Signed-off-by: Thiago Padilha [email protected]

This enhances the /api/v1/health endpoint with an optional throughput check.

hc_throughput is used to enable the check (disabled by default). Note that there are no defaults, if hc_throughput is provided, then all other options must also be configured.

• hc_throughput_input_plugins: Comma separated list of input plugins used to calculate input rate
• hc_throughput_output_plugins: Comma separated list of output plugins used to calculate output rate
• hc_throughput_ratio_threshold: Ratio of output rate and input rate at which we consider the throughput to have problems.
• hc_throughput_min_failures: Minimum count at which ratio is below threshold for the health check to return error.

Example:

    hc_throughput                  On
    hc_throughput_input_plugins    tail.0
    hc_throughput_output_plugins   http.0
    hc_throughput_ratio_threshold  0.1
    hc_throughput_min_failures     60

In the above example, we would consider http.0/tail.0 for output/input rate calculation, and if the ratio is below 0.1 for 60 consecutive checks, then the health check would return an error. Note that we use the health check period (configured by hc_period) which has a default value of 1 second. So in this case we would only return an error if ratio is below threshold for 1 minute.

@agup006 @lecaros

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Fluent Bit is licensed under Apache 2.0, by submitting this pull request I understand that this code will be released under the terms of that license.

[tarruda]

Docs PR: fluent/fluent-bit-docs#850

[leonardo-albertovich]

Everything except the lacking flb_free calls is only relevant if we plan to upstream this code.

[github-actions]

This PR is stale because it has been open 45 days with no activity. Remove stale label or comment or this will be closed in 10 days.

[tarruda]

@lecaros rebase done

[github-actions]

This PR is stale because it has been open 45 days with no activity. Remove stale label or comment or this will be closed in 10 days.

[github-actions]

This PR is stale because it has been open 45 days with no activity. Remove stale label or comment or this will be closed in 10 days.