[#22] node: Add optional linters

Includes `block` and `mutex` profiles configuration.

Signed-off-by: Pavel Karpy <p.karpy@yadro.com>

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

@@ -1,6 +1,7 @@
 package profilerconfig
 
 import (
+	"runtime"
 	"time"
 
 	"github.com/TrueCloudLab/frostfs-node/cmd/frostfs-node/config"
@@ -51,3 +52,35 @@ func Address(c *config.Config) string {
 
 	return AddressDefault
 }
+
+const profilesSubsection = "profiles"
+
+// Profiles returns structure that provides access to a "profiles"
+// configuration subsection.
+func Profiles(c *config.Config) ProfilesConfig {
+	runtime.SetBlockProfileRate()
+	runtime.SetMutexProfileFraction()
+
+	return ProfilesConfig{
+		c.Sub(subsection).Sub(profilesSubsection),
+	}
+}
+
+// ProfilesConfig is a wrapper over "pprof.profiles" config section
+// which provides access to the configuration of the specific
+// profiles.
+type ProfilesConfig struct {
+	cfg *config.Config
+}
+
+// BlockRates returns the value of "block" config parameter
+// from "pprof.profiles" section.
+func (c ProfilesConfig) BlockRates() int {
+	return int(config.IntSafe(c.cfg, "block"))
+}
+
+// MutexRate returns the value of "mutex" config parameter
+// from "pprof.profiles" section.
+func (c ProfilesConfig) MutexRate() int {
+	return int(config.IntSafe(c.cfg, "mutex"))
+}

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

@@ -18,6 +18,11 @@ func TestProfilerSection(t *testing.T) {
 		require.Equal(t, profilerconfig.ShutdownTimeoutDefault, to)
 		require.Equal(t, profilerconfig.AddressDefault, addr)
 		require.False(t, profilerconfig.Enabled(configtest.EmptyConfig()))
+
+		pp := profilerconfig.Profiles(configtest.EmptyConfig())
+
+		require.Zero(t, pp.BlockRates())
+		require.Zero(t, pp.MutexRate())
 	})
 
 	const path = "../../../../config/example/node"
@@ -29,6 +34,11 @@ func TestProfilerSection(t *testing.T) {
 		require.Equal(t, 15*time.Second, to)
 		require.Equal(t, "localhost:6060", addr)
 		require.True(t, profilerconfig.Enabled(c))
+
+		pp := profilerconfig.Profiles(c)
+
+		require.Equal(t, int(1), pp.BlockRates())
+		require.Equal(t, int(1), pp.MutexRate())
 	}
 
 	configtest.ForEachFileType(path, fileConfigTest)

cmd/frostfs-node/pprof.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"runtime"
 
 	profilerconfig "github.com/TrueCloudLab/frostfs-node/cmd/frostfs-node/config/profiler"
 	httputil "github.com/TrueCloudLab/frostfs-node/pkg/util/http"
@@ -14,6 +15,19 @@ func initProfiler(c *cfg) {
 		return
 	}
 
+	profiles := profilerconfig.Profiles(c.appCfg)
+	blockRate := profiles.BlockRates()
+	mutexRate := profiles.MutexRate()
+
+	if mutexRate == 0 {
+		// according to docs, setting mutex rate to "0" just
+		// returns current rate not disables it
+		mutexRate = -1
+	}
+
+	runtime.SetBlockProfileRate(blockRate)
+	runtime.SetMutexProfileFraction(mutexRate)
+
 	var prm httputil.Prm
 
 	prm.Address = profilerconfig.Address(c.appCfg)

config/example/node.env

@@ -3,6 +3,8 @@ NEOFS_LOGGER_LEVEL=debug
 NEOFS_PPROF_ENABLED=true
 NEOFS_PPROF_ADDRESS=localhost:6060
 NEOFS_PPROF_SHUTDOWN_TIMEOUT=15s
+NEOFS_PPROF_PROFILES_BLOCK=1
+NEOFS_PPROF_PROFILES_MUTEX=1
 
 NEOFS_PROMETHEUS_ENABLED=true
 NEOFS_PROMETHEUS_ADDRESS=localhost:9090

config/example/node.json

@@ -5,7 +5,11 @@
   "pprof": {
     "enabled": true,
     "address": "localhost:6060",
-    "shutdown_timeout": "15s"
+    "shutdown_timeout": "15s",
+    "profiles": {
+      "block": 1,
+      "mutex": 1
+    }
   },
   "prometheus": {
     "enabled": true,

config/example/node.yaml

@@ -5,6 +5,9 @@ pprof:
   enabled: true
   address: localhost:6060  # endpoint for Node profiling
   shutdown_timeout: 15s  # timeout for profiling HTTP server graceful shutdown
+  profiles:
+    block: 1  # sampling rate: an average of one blocking event per rate nanoseconds spent blocked is reported; "1" reports every blocking event; "0" disables profiler
+    mutex: 1  # sampling rate: on average 1/rate events are reported; "0" disables profiler
 
 prometheus:
   enabled: true

docs/storage-node-configuration.md

@@ -76,12 +76,22 @@ element.
 Contains configuration for the `pprof` profiler.
 
 | Parameter          | Type                                    | Default value | Description                             |
-|--------------------|------------|---------------|-----------------------------------------|
+|--------------------|-----------------------------------------|---------------|-----------------------------------------|
 | `enabled`          | `bool`                                  | `false`       | Flag to enable the service.             |
 | `address`          | `string`                                |               | Address that service listener binds to. |
 | `shutdown_timeout` | `duration`                              | `30s`         | Time to wait for a graceful shutdown.   |
+| `profiles`         | [Profiles config](#profiles-subsection) |               | Optional profiles configuration         |
 
 
+## `profiles` subsection
+
+Contains optional profiles configuration.
+
+| Parameter | Type  | Default value | Description                                                                                                                                                                                                                                  |
+|-----------|-------|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `block`   | `int` | `0`           | Controls the fraction of goroutine blocking events that are reported in the blocking profile. The profiler aims to sample an average of one blocking event per rate nanoseconds spent blocked. Non-positive values disable profiler reports. |
+| `mutex`   | `int` | `0`           | Controls the fraction of mutex contention events that are reported in the mutex profile. On average 1/rate events are reported. The previous rate is returned. Non-positive values disable profiler reports.                                 |
+
 # `prometheus` section
 
 Contains configuration for the `prometheus` metrics service.