[dbnode] Raise rlimit to number of file limit by default (#1792)

src/dbnode/server/server.go

@@ -30,7 +30,6 @@ import (
 	"path"
 	"runtime"
 	"runtime/debug"
-	"strings"
 	"time"
 
 	clusterclient "github.com/m3db/m3/src/cluster/client"
@@ -92,8 +91,6 @@ const (
 	maxBgProcessLimitMonitorDuration = 5 * time.Minute
 	filePathPrefixLockFile           = ".lock"
 	defaultServiceName               = "m3dbnode"
-	raiseProcessLimitsEnvVar         = "PROCESS_LIMITS_RAISE"
-	raiseProcessLimitsEnvVarTrue     = "true"
 )
 
 // RunOptions provides options for running the server
@@ -152,19 +149,17 @@ func Run(runOpts RunOptions) {
 	}
 	defer logger.Sync()
 
-	raiseLimits := strings.TrimSpace(os.Getenv(raiseProcessLimitsEnvVar))
-	if raiseLimits == raiseProcessLimitsEnvVarTrue {
-		// Raise fd limits to nr_open system limit
-		result, err := xos.RaiseProcessNoFileToNROpen()
-		if err != nil {
-			logger.Warn("unable to raise rlimit", zap.Error(err))
-		} else {
-			logger.Info("raised rlimit no file fds limit",
-				zap.Bool("required", result.RaisePerformed),
-				zap.Uint64("sysNROpenValue", result.NROpenValue),
-				zap.Uint64("noFileMaxValue", result.NoFileMaxValue),
-				zap.Uint64("noFileCurrValue", result.NoFileCurrValue))
-		}
+	// Raise fd limits to nr_open system limit
+	result, err := xos.RaiseProcessNoFileToNROpen()
+	if err != nil {
+		logger.Warn("unable to raise rlimit to no file fds limit",
+			zap.Error(err))
+	} else {
+		logger.Info("raised rlimit no file fds limit",
+			zap.Bool("required", result.RaisePerformed),
+			zap.Uint64("sysNROpenValue", result.NROpenValue),
+			zap.Uint64("noFileMaxValue", result.NoFileMaxValue),
+			zap.Uint64("noFileCurrValue", result.NoFileCurrValue))
 	}
 
 	// Parse file and directory modes