cmd/geth: set up cache and metrics when starting node (#19911)

cmd/geth/consolecmd.go

@@ -77,6 +77,7 @@ JavaScript API. See https://github.com/ethereum/go-ethereum/wiki/JavaScript-Cons
 // same time.
 func localConsole(ctx *cli.Context) error {
 	// Create and start the node based on the CLI flags
+	prepare(ctx)
 	node := makeFullNode(ctx)
 	startNode(ctx, node)
 	defer node.Close()

cmd/geth/main.go

@@ -242,46 +242,6 @@ func init() {
 		if err := debug.Setup(ctx, logdir); err != nil {
 			return err
 		}
-		// If we're a full node on mainnet without --cache specified, bump default cache allowance
-		if ctx.GlobalString(utils.SyncModeFlag.Name) != "light" && !ctx.GlobalIsSet(utils.CacheFlag.Name) && !ctx.GlobalIsSet(utils.NetworkIdFlag.Name) {
-			// Make sure we're not on any supported preconfigured testnet either
-			if !ctx.GlobalIsSet(utils.TestnetFlag.Name) && !ctx.GlobalIsSet(utils.RinkebyFlag.Name) && !ctx.GlobalIsSet(utils.GoerliFlag.Name) && !ctx.GlobalIsSet(utils.DeveloperFlag.Name) {
-				// Nope, we're really on mainnet. Bump that cache up!
-				log.Info("Bumping default cache on mainnet", "provided", ctx.GlobalInt(utils.CacheFlag.Name), "updated", 4096)
-				ctx.GlobalSet(utils.CacheFlag.Name, strconv.Itoa(4096))
-			}
-		}
-		// If we're running a light client on any network, drop the cache to some meaningfully low amount
-		if ctx.GlobalString(utils.SyncModeFlag.Name) == "light" && !ctx.GlobalIsSet(utils.CacheFlag.Name) {
-			log.Info("Dropping default light client cache", "provided", ctx.GlobalInt(utils.CacheFlag.Name), "updated", 128)
-			ctx.GlobalSet(utils.CacheFlag.Name, strconv.Itoa(128))
-		}
-		// Cap the cache allowance and tune the garbage collector
-		var mem gosigar.Mem
-		// Workaround until OpenBSD support lands into gosigar
-		// Check https://github.com/elastic/gosigar#supported-platforms
-		if runtime.GOOS != "openbsd" {
-			if err := mem.Get(); err == nil {
-				allowance := int(mem.Total / 1024 / 1024 / 3)
-				if cache := ctx.GlobalInt(utils.CacheFlag.Name); cache > allowance {
-					log.Warn("Sanitizing cache to Go's GC limits", "provided", cache, "updated", allowance)
-					ctx.GlobalSet(utils.CacheFlag.Name, strconv.Itoa(allowance))
-				}
-			}
-		}
-		// Ensure Go's GC ignores the database cache for trigger percentage
-		cache := ctx.GlobalInt(utils.CacheFlag.Name)
-		gogc := math.Max(20, math.Min(100, 100/(float64(cache)/1024)))
-
-		log.Debug("Sanitizing Go's GC trigger", "percent", int(gogc))
-		godebug.SetGCPercent(int(gogc))
-
-		// Start metrics export if enabled
-		utils.SetupMetrics(ctx)
-
-		// Start system runtime metrics collection
-		go metrics.CollectProcessMetrics(3 * time.Second)
-
 		return nil
 	}
 
@@ -299,6 +259,50 @@ func main() {
 	}
 }
 
+// prepare manipulates memory cache allowance and setups metric system.
+// This function should be called before launching devp2p stack.
+func prepare(ctx *cli.Context) {
+	// If we're a full node on mainnet without --cache specified, bump default cache allowance
+	if ctx.GlobalString(utils.SyncModeFlag.Name) != "light" && !ctx.GlobalIsSet(utils.CacheFlag.Name) && !ctx.GlobalIsSet(utils.NetworkIdFlag.Name) {
+		// Make sure we're not on any supported preconfigured testnet either
+		if !ctx.GlobalIsSet(utils.TestnetFlag.Name) && !ctx.GlobalIsSet(utils.RinkebyFlag.Name) && !ctx.GlobalIsSet(utils.GoerliFlag.Name) && !ctx.GlobalIsSet(utils.DeveloperFlag.Name) {
+			// Nope, we're really on mainnet. Bump that cache up!
+			log.Info("Bumping default cache on mainnet", "provided", ctx.GlobalInt(utils.CacheFlag.Name), "updated", 4096)
+			ctx.GlobalSet(utils.CacheFlag.Name, strconv.Itoa(4096))
+		}
+	}
+	// If we're running a light client on any network, drop the cache to some meaningfully low amount
+	if ctx.GlobalString(utils.SyncModeFlag.Name) == "light" && !ctx.GlobalIsSet(utils.CacheFlag.Name) {
+		log.Info("Dropping default light client cache", "provided", ctx.GlobalInt(utils.CacheFlag.Name), "updated", 128)
+		ctx.GlobalSet(utils.CacheFlag.Name, strconv.Itoa(128))
+	}
+	// Cap the cache allowance and tune the garbage collector
+	var mem gosigar.Mem
+	// Workaround until OpenBSD support lands into gosigar
+	// Check https://github.com/elastic/gosigar#supported-platforms
+	if runtime.GOOS != "openbsd" {
+		if err := mem.Get(); err == nil {
+			allowance := int(mem.Total / 1024 / 1024 / 3)
+			if cache := ctx.GlobalInt(utils.CacheFlag.Name); cache > allowance {
+				log.Warn("Sanitizing cache to Go's GC limits", "provided", cache, "updated", allowance)
+				ctx.GlobalSet(utils.CacheFlag.Name, strconv.Itoa(allowance))
+			}
+		}
+	}
+	// Ensure Go's GC ignores the database cache for trigger percentage
+	cache := ctx.GlobalInt(utils.CacheFlag.Name)
+	gogc := math.Max(20, math.Min(100, 100/(float64(cache)/1024)))
+
+	log.Debug("Sanitizing Go's GC trigger", "percent", int(gogc))
+	godebug.SetGCPercent(int(gogc))
+
+	// Start metrics export if enabled
+	utils.SetupMetrics(ctx)
+
+	// Start system runtime metrics collection
+	go metrics.CollectProcessMetrics(3 * time.Second)
+}
+
 // geth is the main entry point into the system if no special subcommand is ran.
 // It creates a default node based on the command line arguments and runs it in
 // blocking mode, waiting for it to be shut down.
@@ -306,6 +310,7 @@ func geth(ctx *cli.Context) error {
 	if args := ctx.Args(); len(args) > 0 {
 		return fmt.Errorf("invalid command: %q", args[0])
 	}
+	prepare(ctx)
 	node := makeFullNode(ctx)
 	defer node.Close()
 	startNode(ctx, node)