[dbnode] Add ability to force enable cold writes from config (#3002)

src/cmd/services/m3dbnode/config/config.go

@@ -160,6 +160,10 @@ type DBConfiguration struct {
 
 	// TChannel exposes TChannel config options.
 	TChannel *TChannelConfiguration `yaml:"tchannel"`
+
+	// ForceColdWritesEnabled will force enable cold writes for all namespaces
+	// if set.
+	ForceColdWritesEnabled *bool `yaml:"forceColdWritesEnabled"`
 }
 
 // InitDefaultsAndValidate initializes all default values and validates the Configuration.

src/cmd/services/m3dbnode/config/config_test.go

@@ -728,6 +728,7 @@ func TestConfiguration(t *testing.T) {
     maxOutstandingRepairedBytes: 0
     maxEncodersPerBlock: 0
   tchannel: null
+  forceColdWritesEnabled: null
 coordinator: null
 `
 

src/dbnode/server/server.go

@@ -589,6 +589,12 @@ func Run(runOpts RunOptions) {
 	}
 	opts = opts.SetPersistManager(pm)
 
+	forceEnableColdWrites := runOpts.StorageOptions.ForceColdWritesEnabled
+	if value := cfg.ForceColdWritesEnabled; value != nil {
+		// Allow forcing cold writes to be enabled by config.
+		forceEnableColdWrites = *value
+	}
+
 	var (
 		envCfg environment.ConfigureResults
 	)
@@ -599,7 +605,7 @@ func Run(runOpts RunOptions) {
 			InstrumentOpts:         iopts,
 			HashingSeed:            cfg.Hashing.Seed,
 			NewDirectoryMode:       newDirectoryMode,
-			ForceColdWritesEnabled: runOpts.StorageOptions.ForceColdWritesEnabled,
+			ForceColdWritesEnabled: forceEnableColdWrites,
 		})
 		if err != nil {
 			logger.Fatal("could not initialize dynamic config", zap.Error(err))
@@ -610,7 +616,7 @@ func Run(runOpts RunOptions) {
 		envCfg, err = cfg.EnvironmentConfig.Configure(environment.ConfigurationParameters{
 			InstrumentOpts:         iopts,
 			HostID:                 hostID,
-			ForceColdWritesEnabled: runOpts.StorageOptions.ForceColdWritesEnabled,
+			ForceColdWritesEnabled: forceEnableColdWrites,
 		})
 		if err != nil {
 			logger.Fatal("could not initialize static config", zap.Error(err))