diff --git a/docs/querying/functions.md b/docs/querying/functions.md index bf2701b88..e13628c5c 100644 --- a/docs/querying/functions.md +++ b/docs/querying/functions.md @@ -619,7 +619,7 @@ Like `sort`, `sort_desc` only affects the results of instant queries, as range q **This function has to be enabled via the [feature flag](../feature_flags.md#experimental-promql-functions) `--enable-feature=promql-experimental-functions`.** -`sort_by_label(v instant-vector, label string, ...)` returns vector elements sorted by their label values and sample value in case of label values being equal, in ascending order. +`sort_by_label(v instant-vector, label string, ...)` returns vector elements sorted by the values of the given labels in ascending order. In case these label values are equal, elements are sorted by their full label sets. Please note that the sort by label functions only affect the results of instant queries, as range query results always have a fixed output ordering. diff --git a/promql/functions.go b/promql/functions.go index 2af06c174..61a2dd076 100644 --- a/promql/functions.go +++ b/promql/functions.go @@ -406,17 +406,22 @@ func funcSortDesc(vals []parser.Value, args parser.Expressions, enh *EvalNodeHel // === sort_by_label(vector parser.ValueTypeVector, label parser.ValueTypeString...) (Vector, Annotations) === func funcSortByLabel(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) { - // In case the labels are the same, NaN should sort to the bottom, so take - // ascending sort with NaN first and reverse it. - var anno annotations.Annotations - vals[0], anno = funcSort(vals, args, enh) + // First, sort by the full label set. This ensures a consistent ordering in case sorting by the + // labels provided as arguments is not conclusive. + slices.SortFunc(vals[0].(Vector), func(a, b Sample) int { + return labels.Compare(a.Metric, b.Metric) + }) + labels := stringSliceFromArgs(args[1:]) + // Next, sort by the labels provided as arguments. slices.SortFunc(vals[0].(Vector), func(a, b Sample) int { - // Iterate over each given label + // Iterate over each given label. for _, label := range labels { lv1 := a.Metric.Get(label) lv2 := b.Metric.Get(label) + // If we encounter multiple samples with the same label values, the sorting which was + // performed in the first step will act as a "tie breaker". if lv1 == lv2 { continue } @@ -431,22 +436,27 @@ func funcSortByLabel(vals []parser.Value, args parser.Expressions, enh *EvalNode return 0 }) - return vals[0].(Vector), anno + return vals[0].(Vector), nil } // === sort_by_label_desc(vector parser.ValueTypeVector, label parser.ValueTypeString...) (Vector, Annotations) === func funcSortByLabelDesc(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) { - // In case the labels are the same, NaN should sort to the bottom, so take - // ascending sort with NaN first and reverse it. - var anno annotations.Annotations - vals[0], anno = funcSortDesc(vals, args, enh) + // First, sort by the full label set. This ensures a consistent ordering in case sorting by the + // labels provided as arguments is not conclusive. + slices.SortFunc(vals[0].(Vector), func(a, b Sample) int { + return labels.Compare(b.Metric, a.Metric) + }) + labels := stringSliceFromArgs(args[1:]) + // Next, sort by the labels provided as arguments. slices.SortFunc(vals[0].(Vector), func(a, b Sample) int { - // Iterate over each given label + // Iterate over each given label. for _, label := range labels { lv1 := a.Metric.Get(label) lv2 := b.Metric.Get(label) + // If we encounter multiple samples with the same label values, the sorting which was + // performed in the first step will act as a "tie breaker". if lv1 == lv2 { continue } @@ -461,7 +471,7 @@ func funcSortByLabelDesc(vals []parser.Value, args parser.Expressions, enh *Eval return 0 }) - return vals[0].(Vector), anno + return vals[0].(Vector), nil } // === clamp(Vector parser.ValueTypeVector, min, max Scalar) (Vector, Annotations) === diff --git a/promql/promqltest/testdata/functions.test b/promql/promqltest/testdata/functions.test index b89d44fce..6e2b3630b 100644 --- a/promql/promqltest/testdata/functions.test +++ b/promql/promqltest/testdata/functions.test @@ -523,16 +523,16 @@ load 5m node_uname_info{job="node_exporter", instance="4m1000", release="1.111.3"} 0+10x10 eval_ordered instant at 50m sort_by_label(http_requests, "instance") - http_requests{group="production", instance="0", job="api-server"} 100 http_requests{group="canary", instance="0", job="api-server"} 300 - http_requests{group="production", instance="0", job="app-server"} 500 http_requests{group="canary", instance="0", job="app-server"} 700 - http_requests{group="production", instance="1", job="api-server"} 200 + http_requests{group="production", instance="0", job="api-server"} 100 + http_requests{group="production", instance="0", job="app-server"} 500 http_requests{group="canary", instance="1", job="api-server"} 400 - http_requests{group="production", instance="1", job="app-server"} 600 http_requests{group="canary", instance="1", job="app-server"} 800 - http_requests{group="production", instance="2", job="api-server"} 100 + http_requests{group="production", instance="1", job="api-server"} 200 + http_requests{group="production", instance="1", job="app-server"} 600 http_requests{group="canary", instance="2", job="api-server"} NaN + http_requests{group="production", instance="2", job="api-server"} 100 eval_ordered instant at 50m sort_by_label(http_requests, "instance", "group") http_requests{group="canary", instance="0", job="api-server"} 300 @@ -585,14 +585,14 @@ eval_ordered instant at 50m sort_by_label(http_requests, "job", "instance", "gro eval_ordered instant at 50m sort_by_label_desc(http_requests, "instance") http_requests{group="production", instance="2", job="api-server"} 100 http_requests{group="canary", instance="2", job="api-server"} NaN - http_requests{group="canary", instance="1", job="app-server"} 800 http_requests{group="production", instance="1", job="app-server"} 600 - http_requests{group="canary", instance="1", job="api-server"} 400 http_requests{group="production", instance="1", job="api-server"} 200 - http_requests{group="canary", instance="0", job="app-server"} 700 + http_requests{group="canary", instance="1", job="app-server"} 800 + http_requests{group="canary", instance="1", job="api-server"} 400 http_requests{group="production", instance="0", job="app-server"} 500 - http_requests{group="canary", instance="0", job="api-server"} 300 http_requests{group="production", instance="0", job="api-server"} 100 + http_requests{group="canary", instance="0", job="app-server"} 700 + http_requests{group="canary", instance="0", job="api-server"} 300 eval_ordered instant at 50m sort_by_label_desc(http_requests, "instance", "group") http_requests{group="production", instance="2", job="api-server"} 100