fix: interleave the go and cpp log (#46004)

issue: #45640

Signed-off-by: chyezh <chyezh@outlook.com>

pkg/log/config.go

@@ -153,7 +153,7 @@ func (cfg *Config) initialize() {
 		cfg.AsyncWritePendingLength = 1024
 	}
 	if cfg.AsyncWriteBufferSize <= 0 {
-		cfg.AsyncWriteBufferSize = 1024 * 1024
+		cfg.AsyncWriteBufferSize = 4 * 1024
 	}
 	if cfg.AsyncWriteMaxBytesPerLog <= 0 {
 		cfg.AsyncWriteMaxBytesPerLog = 1024 * 1024

pkg/util/paramtable/component_param.go

@@ -1675,11 +1675,14 @@ The larger the pending length, the more memory is used, the less logging writes
 
 	l.AsyncWriteBufferSize = ParamItem{
 		Key:          "log.asyncWrite.bufferSize",
-		DefaultValue: "1m",
+		DefaultValue: "4k",
 		Version:      "2.6.7",
 		Doc: `The buffer size of the underlying bufio writer. 
 The larger the buffer size, the more memory is used, 
-but the less the number of writes to the underlying file system.`,
+but the less the number of writes to the underlying file system.
+Because the cpp will print the log message into stdout, 
+when the logging is woring with pipe like tty/docker log driver/k8s,
+PIPE_BUF=4096 may interleave the go log and cpp log together, so 4kb is set as default value to avoid this.`,
 		Export: false,
 	}
 	l.AsyncWriteBufferSize.Init(base.mgr)

pkg/util/paramtable/component_param_test.go

@@ -163,7 +163,7 @@ func TestComponentParam(t *testing.T) {
 		assert.Equal(t, "error", Params.AsyncWriteNonDroppableLevel.GetValue())
 		assert.Equal(t, 1*time.Second, Params.AsyncWriteStopTimeout.GetAsDurationByParse())
 		assert.Equal(t, 1024, Params.AsyncWritePendingLength.GetAsInt())
-		assert.Equal(t, int64(1024*1024), Params.AsyncWriteBufferSize.GetAsSize())
+		assert.Equal(t, int64(4*1024), Params.AsyncWriteBufferSize.GetAsSize())
 		assert.Equal(t, int64(1024*1024), Params.AsyncWriteMaxBytesPerLog.GetAsSize())
 	})