[#537] node: Add runtime.memory_limit config parameter

This parameter allows to set soft memory limit for Go GC.

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

cmd/frostfs-node/config.go

@@ -1055,6 +1055,10 @@ func (c *cfg) reloadConfig(ctx context.Context) {
 	}
 
 	components = append(components, dCmp{"logger", logPrm.Reload})
+	components = append(components, dCmp{"runtime", func() error {
+		setRuntimeParameters(c)
+		return nil
+	}})
 	components = append(components, dCmp{"tracing", func() error {
 		updated, err := tracing.Setup(ctx, *tracingconfig.ToTracingConfig(c.appCfg))
 		if updated {

cmd/frostfs-node/config/runtime/config.go

@@ -0,0 +1,23 @@
+package runtime
+
+import (
+	"math"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/cmd/frostfs-node/config"
+)
+
+const (
+	subsection         = "runtime"
+	memoryLimitDefault = math.MaxInt64
+)
+
+// GCMemoryLimitBytes returns the  value of "soft_memory_limit" config parameter from "runtime" section.
+func GCMemoryLimitBytes(c *config.Config) int64 {
+	l := config.SizeInBytesSafe(c.Sub(subsection), "soft_memory_limit")
+
+	if l > 0 {
+		return int64(l)
+	}
+
+	return memoryLimitDefault
+}

cmd/frostfs-node/config/runtime/config_test.go

@@ -0,0 +1,30 @@
+package runtime
+
+import (
+	"math"
+	"testing"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/cmd/frostfs-node/config"
+	configtest "git.frostfs.info/TrueCloudLab/frostfs-node/cmd/frostfs-node/config/test"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGCMemoryLimit(t *testing.T) {
+	t.Run("defaults", func(t *testing.T) {
+		empty := configtest.EmptyConfig()
+
+		require.Equal(t, int64(math.MaxInt64), GCMemoryLimitBytes(empty))
+	})
+
+	const path = "../../../../config/example/node"
+
+	fileConfigTest := func(c *config.Config) {
+		require.Equal(t, int64(1073741824), GCMemoryLimitBytes(c))
+	}
+
+	configtest.ForEachFileType(path, fileConfigTest)
+
+	t.Run("ENV", func(t *testing.T) {
+		configtest.ForEnvFileType(t, path, fileConfigTest)
+	})
+}

cmd/frostfs-node/main.go

@@ -84,6 +84,7 @@ func initApp(ctx context.Context, c *cfg) {
 		c.wg.Done()
 	}()
 
+	setRuntimeParameters(c)
 	metrics, _ := metricsComponent(c)
 	initAndLog(c, "profiler", initProfilerService)
 	initAndLog(c, metrics.name, metrics.init)

cmd/frostfs-node/runtime.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"os"
+	"runtime/debug"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/cmd/frostfs-node/config/runtime"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
+	"go.uber.org/zap"
+)
+
+func setRuntimeParameters(c *cfg) {
+	if len(os.Getenv("GOMEMLIMIT")) != 0 {
+		// default limit < yaml limit < app env limit < GOMEMLIMIT
+		c.log.Warn(logs.RuntimeSoftMemoryDefinedWithGOMEMLIMIT)
+		return
+	}
+
+	memLimitBytes := runtime.GCMemoryLimitBytes(c.appCfg)
+	previous := debug.SetMemoryLimit(memLimitBytes)
+	if memLimitBytes != previous {
+		c.log.Info(logs.RuntimeSoftMemoryLimitUpdated,
+			zap.Int64("new_value", memLimitBytes),
+			zap.Int64("old_value", previous))
+	}
+}