VictoriaMetrics/app/vmalert/datasource/vm_prom_api_timing_test.go
Roman Khavronenko 4f0525852f
app/vmalert/datasource: reduce number of allocations when parsing instant responses (#6272)
Allocations are reduced by implementing custom json parser via fastjson
lib.
The change also re-uses `promInstant` object in attempt to reduce number
of
allocations when parsing big responses, as usually happens with heavy
recording rules.

```
name                                old allocs/op  new allocs/op  delta
ParsePrometheusResponse/Instant-10     9.65k ± 0%     5.60k ± 0%   ~     (p=1.000 n=1+1)

```

Signed-off-by: hagen1778 <roman@victoriametrics.com>

---------

Signed-off-by: hagen1778 <roman@victoriametrics.com>
2024-05-15 15:18:33 +02:00

44 lines
1.0 KiB
Go

package datasource
import (
"bytes"
"io"
"net/http"
"os"
"testing"
)
func BenchmarkMetrics(b *testing.B) {
payload := []byte(`[{"metric":{"__name__":"vm_rows"},"value":[1583786142,"13763"]},{"metric":{"__name__":"vm_requests", "foo":"bar", "baz": "qux"},"value":[1583786140,"2000"]}]`)
var pi promInstant
if err := pi.Unmarshal(payload); err != nil {
b.Fatalf(err.Error())
}
b.Run("Instant", func(b *testing.B) {
for i := 0; i < b.N; i++ {
_, _ = pi.metrics()
}
})
}
func BenchmarkParsePrometheusResponse(b *testing.B) {
req, _ := http.NewRequest("GET", "", nil)
resp := &http.Response{StatusCode: http.StatusOK}
data, err := os.ReadFile("testdata/instant_response.json")
if err != nil {
b.Fatalf("error while reading file: %s", err)
}
resp.Body = io.NopCloser(bytes.NewReader(data))
b.Run("Instant", func(b *testing.B) {
for i := 0; i < b.N; i++ {
_, err := parsePrometheusResponse(req, resp)
if err != nil {
b.Fatalf("unexpected parse err: %s", err)
}
resp.Body = io.NopCloser(bytes.NewReader(data))
}
})
}