[api] API delay before readiness (#4516)

Author: envestcc

api/config.go

@@ -6,6 +6,8 @@
 package api
 
 import (
+	"time"
+
 	"github.com/iotexproject/iotex-core/v2/gasstation"
 	"github.com/iotexproject/iotex-core/v2/pkg/tracer"
 )
@@ -27,6 +29,8 @@ type Config struct {
 	WebsocketRateLimit int `yaml:"websocketRateLimit"`
 	// ListenerLimit is the maximum number of listeners.
 	ListenerLimit int `yaml:"listenerLimit"`
+	// ReadyDuration is the duration to wait for the server to be ready.
+	ReadyDuration time.Duration `yaml:"readyDuration"`
 }
 
 // DefaultConfig is the default config
@@ -41,4 +45,5 @@ var DefaultConfig = Config{
 	BatchRequestLimit:  _defaultBatchRequestLimit,
 	WebsocketRateLimit: 5,
 	ListenerLimit:      5000,
+	ReadyDuration:      time.Second * 30,
 }

server/itx/server.go

@@ -12,6 +12,7 @@ import (
 	"net/http/pprof"
 	"runtime"
 	"sync"
+	"time"
 
 	"github.com/pkg/errors"
 	"go.uber.org/zap"
@@ -231,9 +232,16 @@ func StartServer(ctx context.Context, svr *Server, probeSvr *probe.Server, cfg c
 			log.L().Panic("Failed to stop server.", zap.Error(err))
 		}
 	}()
+	if _, isGateway := cfg.Plugins[config.GatewayPlugin]; isGateway && cfg.API.ReadyDuration > 0 {
+		// wait for a while to make sure the server is ready
+		// The original intention was to ensure that all transactions that were not received during the restart were included in block, thereby avoiding inconsistencies in the state of the API node.
+		log.L().Info("Waiting for server to be ready.", zap.Duration("duration", cfg.API.ReadyDuration))
+		time.Sleep(cfg.API.ReadyDuration)
+	}
 	if err := probeSvr.TurnOn(); err != nil {
 		log.L().Panic("Failed to turn on probe server.", zap.Error(err))
 	}
+	log.L().Info("Server is ready.")
 
 	if cfg.System.HeartbeatInterval > 0 {
 		task := routine.NewRecurringTask(NewHeartbeatHandler(svr, cfg.Network).Log, cfg.System.HeartbeatInterval)