Enum Sli 

pub enum Sli {
    Events {
        error_query: String,
        total_query: String,
    },
    Raw {
        error_ratio_query: String,
    },
    Latency {
        histogram_metric: String,
        threshold: String,
        selector: Option<String>,
    },
}

How an SLO’s error ratio is computed from Prometheus.

Covers sloth’s two SLI shapes (events-based and raw) plus a slokit extension, Sli::Latency, that generates the histogram bucket query for the common “fraction of requests slower than a threshold” SLO.

Variants

Events

Bad events divided by total events. Both queries should contain the WINDOW_TOKEN.

Fields

error_query: String

Query counting failing events over the window.

total_query: String

Query counting all events over the window.

Raw

A query that already yields an error ratio in [0, 1]. Should contain the WINDOW_TOKEN.

Fields

error_ratio_query: String

Query yielding the error ratio over the window.

Latency

A latency SLI built from a Prometheus histogram: the fraction of requests that took longer than threshold (the le bucket boundary). The error ratio query is generated, so it needs no WINDOW_TOKEN.

Fields

histogram_metric: String

Histogram base metric name, without the _bucket/_count suffix, e.g. http_request_duration_seconds.

threshold: String

The le bucket boundary, kept as a string to match the label exactly, e.g. "0.3".

selector: Option<String>

Optional label matchers, written without braces, e.g. job="api".

Implementations

impl Sli

pub fn error_ratio_expr(&self, window: Window) -> String

Render the SLI’s error-ratio PromQL expression for a given window, substituting WINDOW_TOKEN with the Prometheus duration.

For Sli::Events this is (error) / (total); for Sli::Raw it is the raw query as written.

pub fn queries(&self) -> Vec<&str>

Every user-supplied query string this SLI carries, for validation. A Sli::Latency carries none (its query is generated).

Trait Implementations

impl Clone for Sli

fn clone(&self) -> Sli

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Sli

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for Sli

impl PartialEq for Sli

fn eq(&self, other: &Sli) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Sli