prometheus/util/logging/dedupe_test.go
TJ Hoplock 437362a7a7 fix(deduper): use ptr to sync.RWMutex, fix panic during concurrent use
Resolves: #15559

As accurately noted in the issue description, the map is shared among
child loggers that get created when `WithAttr()`/`WithGroup()` are
called on the underlying handler, which happens via `log.With()` and
`log.WithGroup()` respectively.

The RW mutex was a value in the previous implementation that used
go-kit/log, and I should've updated it to use a pointer when I converted
the deduper.

Also adds a test.

Signed-off-by: TJ Hoplock <t.hoplock@gmail.com>
2024-12-10 02:51:46 -05:00

83 lines
2 KiB
Go

// Copyright 2019 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package logging
import (
"bytes"
"log/slog"
"strings"
"testing"
"time"
"github.com/prometheus/common/promslog"
"github.com/stretchr/testify/require"
)
func TestDedupe(t *testing.T) {
var buf bytes.Buffer
d := Dedupe(promslog.New(&promslog.Config{Writer: &buf}), 100*time.Millisecond)
dlog := slog.New(d)
defer d.Stop()
// Log 10 times quickly, ensure they are deduped.
for i := 0; i < 10; i++ {
dlog.Info("test", "hello", "world")
}
// Trim empty lines
lines := []string{}
for _, line := range strings.Split(buf.String(), "\n") {
if line != "" {
lines = append(lines, line)
}
}
require.Len(t, lines, 1)
// Wait, then log again, make sure it is logged.
time.Sleep(200 * time.Millisecond)
dlog.Info("test", "hello", "world")
// Trim empty lines
lines = []string{}
for _, line := range strings.Split(buf.String(), "\n") {
if line != "" {
lines = append(lines, line)
}
}
require.Len(t, lines, 2)
}
func TestDedupeConcurrent(t *testing.T) {
d := Dedupe(promslog.New(&promslog.Config{}), 250*time.Millisecond)
dlog := slog.New(d)
defer d.Stop()
concurrentWriteFunc := func() {
go func() {
dlog1 := dlog.With("writer", 1)
for i := 0; i < 10; i++ {
dlog1.With("foo", "bar").Info("test", "hello", "world")
}
}()
go func() {
dlog2 := dlog.With("writer", 2)
for i := 0; i < 10; i++ {
dlog2.With("foo", "bar").Info("test", "hello", "world")
}
}()
}
require.NotPanics(t, func() { concurrentWriteFunc() })
}