config: add state sync discovery_time setting (#5399)

Reduces the state sync discovery time from 20 to 15 seconds, and makes it configurable.

config/config.go

@@ -726,12 +726,13 @@ func (cfg *MempoolConfig) ValidateBasic() error {
 
 // StateSyncConfig defines the configuration for the Tendermint state sync service
 type StateSyncConfig struct {
-	Enable      bool          `mapstructure:"enable"`
-	TempDir     string        `mapstructure:"temp_dir"`
-	RPCServers  []string      `mapstructure:"rpc_servers"`
-	TrustPeriod time.Duration `mapstructure:"trust_period"`
-	TrustHeight int64         `mapstructure:"trust_height"`
-	TrustHash   string        `mapstructure:"trust_hash"`
+	Enable        bool          `mapstructure:"enable"`
+	TempDir       string        `mapstructure:"temp_dir"`
+	RPCServers    []string      `mapstructure:"rpc_servers"`
+	TrustPeriod   time.Duration `mapstructure:"trust_period"`
+	TrustHeight   int64         `mapstructure:"trust_height"`
+	TrustHash     string        `mapstructure:"trust_hash"`
+	DiscoveryTime time.Duration `mapstructure:"discovery_time"`
 }
 
 func (cfg *StateSyncConfig) TrustHashBytes() []byte {
@@ -746,7 +747,8 @@ func (cfg *StateSyncConfig) TrustHashBytes() []byte {
 // DefaultStateSyncConfig returns a default configuration for the state sync service
 func DefaultStateSyncConfig() *StateSyncConfig {
 	return &StateSyncConfig{
-		TrustPeriod: 168 * time.Hour,
+		TrustPeriod:   168 * time.Hour,
+		DiscoveryTime: 15 * time.Second,
 	}
 }
 

config/toml.go

@@ -355,6 +355,9 @@ trust_height = {{ .StateSync.TrustHeight }}
 trust_hash = "{{ .StateSync.TrustHash }}"
 trust_period = "{{ .StateSync.TrustPeriod }}"
 
+# Time to spend discovering snapshots before initiating a restore.
+discovery_time = "{{ .StateSync.DiscoveryTime }}"
+
 # Temporary directory for state sync snapshot chunks, defaults to the OS tempdir (typically /tmp).
 # Will create a new, randomly named directory within, and remove it when done.
 temp_dir = "{{ .StateSync.TempDir }}"