mempool: add TTL configuration to mempool (#6715)

config/config.go

@@ -784,25 +784,47 @@ type MempoolConfig struct {
 	RootDir   string `mapstructure:"home"`
 	Recheck   bool   `mapstructure:"recheck"`
 	Broadcast bool   `mapstructure:"broadcast"`
+
 	// Maximum number of transactions in the mempool
 	Size int `mapstructure:"size"`
+
 	// Limit the total size of all txs in the mempool.
 	// This only accounts for raw transactions (e.g. given 1MB transactions and
 	// max-txs-bytes=5MB, mempool will only accept 5 transactions).
 	MaxTxsBytes int64 `mapstructure:"max-txs-bytes"`
+
 	// Size of the cache (used to filter transactions we saw earlier) in transactions
 	CacheSize int `mapstructure:"cache-size"`
+
 	// Do not remove invalid transactions from the cache (default: false)
 	// Set to true if it's not possible for any invalid transaction to become
 	// valid again in the future.
 	KeepInvalidTxsInCache bool `mapstructure:"keep-invalid-txs-in-cache"`
+
 	// Maximum size of a single transaction
 	// NOTE: the max size of a tx transmitted over the network is {max-tx-bytes}.
 	MaxTxBytes int `mapstructure:"max-tx-bytes"`
+
 	// Maximum size of a batch of transactions to send to a peer
 	// Including space needed by encoding (one varint per transaction).
 	// XXX: Unused due to https://github.com/tendermint/tendermint/issues/5796
 	MaxBatchBytes int `mapstructure:"max-batch-bytes"`
+
+	// TTLDuration, if non-zero, defines the maximum amount of time a transaction
+	// can exist for in the mempool.
+	//
+	// Note, if TTLNumBlocks is also defined, a transaction will be removed if it
+	// has existed in the mempool at least TTLNumBlocks number of blocks or if it's
+	// insertion time into the mempool is beyond TTLDuration.
+	TTLDuration time.Duration `mapstructure:"ttl-duration"`
+
+	// TTLNumBlocks, if non-zero, defines the maximum number of blocks a transaction
+	// can exist for in the mempool.
+	//
+	// Note, if TTLDuration is also defined, a transaction will be removed if it
+	// has existed in the mempool at least TTLNumBlocks number of blocks or if
+	// it's insertion time into the mempool is beyond TTLDuration.
+	TTLNumBlocks int64 `mapstructure:"ttl-num-blocks"`
 }
 
 // DefaultMempoolConfig returns a default configuration for the Tendermint mempool.
@@ -813,10 +835,12 @@ func DefaultMempoolConfig() *MempoolConfig {
 		Broadcast: true,
 		// Each signature verification takes .5ms, Size reduced until we implement
 		// ABCI Recheck
-		Size:        5000,
-		MaxTxsBytes: 1024 * 1024 * 1024, // 1GB
-		CacheSize:   10000,
-		MaxTxBytes:  1024 * 1024, // 1MB
+		Size:         5000,
+		MaxTxsBytes:  1024 * 1024 * 1024, // 1GB
+		CacheSize:    10000,
+		MaxTxBytes:   1024 * 1024, // 1MB
+		TTLDuration:  0 * time.Second,
+		TTLNumBlocks: 0,
 	}
 }
 
@@ -842,6 +866,13 @@ func (cfg *MempoolConfig) ValidateBasic() error {
 	if cfg.MaxTxBytes < 0 {
 		return errors.New("max-tx-bytes can't be negative")
 	}
+	if cfg.TTLDuration < 0 {
+		return errors.New("ttl-duration can't be negative")
+	}
+	if cfg.TTLNumBlocks < 0 {
+		return errors.New("ttl-num-blocks can't be negative")
+	}
+
 	return nil
 }
 

config/toml.go

@@ -399,6 +399,22 @@ max-tx-bytes = {{ .Mempool.MaxTxBytes }}
 # XXX: Unused due to https://github.com/tendermint/tendermint/issues/5796
 max-batch-bytes = {{ .Mempool.MaxBatchBytes }}
 
+# ttl-duration, if non-zero, defines the maximum amount of time a transaction
+# can exist for in the mempool.
+#
+# Note, if ttl-num-blocks is also defined, a transaction will be removed if it
+# has existed in the mempool at least ttl-num-blocks number of blocks or if it's
+# insertion time into the mempool is beyond ttl-duration.
+ttl-duration = "{{ .Mempool.TTLDuration }}"
+
+# ttl-num-blocks, if non-zero, defines the maximum number of blocks a transaction
+# can exist for in the mempool.
+#
+# Note, if ttl-duration is also defined, a transaction will be removed if it
+# has existed in the mempool at least ttl-num-blocks number of blocks or if
+# it's insertion time into the mempool is beyond ttl-duration.
+ttl-num-blocks = {{ .Mempool.TTLNumBlocks }}
+
 #######################################################
 ###         State Sync Configuration Options        ###
 #######################################################