fix: Allows users to customize the KeysLimit value at server start (D…

…iceDB#888)

Co-authored-by: Jyotinder Singh <[email protected]>

config/config.go

@@ -24,6 +24,8 @@ const (
 	EvictAllKeysRandom = "allkeys-random"
 	EvictAllKeysLRU    = "allkeys-lru"
 	EvictAllKeysLFU    = "allkeys-lfu"
+
+	DefaultKeysLimit int = 200000000
 )
 
 var (
@@ -44,6 +46,8 @@ var (
 	FileLocation         = utils.EmptyStr
 
 	InitConfigCmd = false
+
+	KeysLimit = DefaultKeysLimit
 )
 
 type Config struct {
@@ -114,7 +118,7 @@ var baseConfig = Config{
 		MaxMemory:              0,
 		EvictionPolicy:         EvictAllKeysLFU,
 		EvictionRatio:          0.9,
-		KeysLimit:              200000000,
+		KeysLimit:              DefaultKeysLimit,
 		AOFFile:                "./dice-master.aof",
 		PersistenceEnabled:     true,
 		WriteAOFOnCleanup:      false,
@@ -293,6 +297,10 @@ func mergeFlagsWithConfig() {
 	if Port != DefaultPort {
 		DiceConfig.Server.Port = Port
 	}
+
+	if KeysLimit != DefaultKeysLimit {
+		DiceConfig.Server.KeysLimit = KeysLimit
+	}
 }
 
 // This function checks if the config file is present or not at ConfigFileLocation

main.go

@@ -32,6 +32,9 @@ func init() {
 	flag.StringVar(&config.CustomConfigFilePath, "o", config.CustomConfigFilePath, "dir path to create the config file")
 	flag.StringVar(&config.FileLocation, "c", config.FileLocation, "file path of the config file")
 	flag.BoolVar(&config.InitConfigCmd, "init-config", false, "initialize a new config file")
+	flag.IntVar(&config.KeysLimit, "keys-limit", config.KeysLimit, "keys limit for the dice server. "+
+		"This flag controls the number of keys each shard holds at startup. You can multiply this number with the "+
+		"total number of shard threads to estimate how much memory will be required at system start up.")
 	flag.Parse()
 
 	config.SetupConfig()