/
calculateServiceProxy.go
259 lines (243 loc) · 8.95 KB
/
calculateServiceProxy.go
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package main
import (
"context"
"errors"
"fmt"
"net"
"strconv"
"sync/atomic"
"time"
_ "github.com/GrassInWind2019/gRPC-kafkaDemo/consumer"
cpb "github.com/GrassInWind2019/gRPC-kafkaDemo/example/CalculateService_proto"
"github.com/GrassInWind2019/gRPC-kafkaDemo/producer"
"github.com/GrassInWind2019/gRPC-kafkaDemo/serviceDiscovery"
"github.com/GrassInWind2019/gRPC-kafkaDemo/uniqueID"
"github.com/fatih/color"
"github.com/go-redis/redis"
"google.golang.org/grpc"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/metadata"
"google.golang.org/grpc/status"
)
var (
tokenProducerId int32 = 0
errMissingMetadata = status.Errorf(codes.InvalidArgument, "missing metadata")
errReqExceedLimitRate = status.Errorf(codes.Unavailable, "service unavailabe")
)
type CalculateServiceServer struct {
info *serviceDiscovery.ServiceInfo
gServer *grpc.Server
ch chan struct{}
limitCh chan struct{}
ksProducer *producer.KafkaSyncProducer
rdb *redis.Client
Ctx context.Context
Cancel context.CancelFunc
}
func (s *CalculateServiceServer) Calculate(ctx context.Context, in *cpb.CalculateRequest) (*cpb.CalculateResponse, error) {
fmt.Printf("client %s called Calculate from Server: %s:%d\n", in.Name, s.info.Addr, s.info.Port)
reqId, err := uniqueID.GetUniqueID(s.rdb, "req")
if err != nil {
fmt.Println("Calculate: Get unique ID failed: ", err.Error())
return &cpb.CalculateResponse{Message: "Hello! " + in.Name + "!" + fmt.Sprintf("This is Server: %s:%d", s.info.Addr, s.info.Port), SuccessFlag: false}, nil
}
request := fmt.Sprintf("%d%s%d", in.Num1, in.Method, in.Num2)
buf := fmt.Sprintf("%d:%s", reqId, request)
//Try to get result from redis first
val, err := s.rdb.Get(request).Result()
if err == nil {
//parse result and return to client
result, err := strconv.ParseFloat(val, 32)
if err == nil {
color.Set(color.FgBlue, color.Bold)
fmt.Printf("Get result from redis: %f, reqId %d, request: %s\n", result, reqId, buf)
color.Unset()
return &cpb.CalculateResponse{Message: "Hello! " + in.Name + "!" + fmt.Sprintf("This is Server: %s:%d", s.info.Addr, s.info.Port), SuccessFlag: true, Result: result}, nil
} else {
color.Set(color.FgRed, color.Bold)
fmt.Printf("Get result from redis: Process failed for reqId %d, request: %s\n", reqId, buf)
color.Unset()
return &cpb.CalculateResponse{Message: "Hello! " + in.Name + "!" + fmt.Sprintf("This is Server: %s:%d", s.info.Addr, s.info.Port), SuccessFlag: false}, nil
}
}
pubsub := s.rdb.Subscribe(fmt.Sprintf("%d", reqId))
// Wait for confirmation that subscription is created before publishing anything.
_, err = pubsub.Receive()
if err != nil {
errStr := fmt.Sprintf("Redis subscribe failed: %s", err.Error())
return nil, errors.New(errStr)
}
defer pubsub.Close()
defer pubsub.Unsubscribe(fmt.Sprintf("%d", reqId))
//Go channel which receives messages
//When pubsub is closed channel is closed too
pubsubCh := pubsub.Channel()
//Redis didn't have the result, produce request message to kafka
if err := s.ksProducer.ProduceKafkaMessage(topics, fmt.Sprintf("%d", reqId), buf); err != nil {
color.Set(color.FgRed, color.Bold)
fmt.Printf("Calculate: produce request failed: %s\n", buf)
color.Unset()
}
t := time.NewTimer(3 * time.Second)
for {
select {
case <-t.C:
color.Set(color.FgRed, color.Bold)
fmt.Printf("time out! ReqId %d, request: %s\n", reqId, buf)
color.Unset()
return &cpb.CalculateResponse{Message: "Hello! " + in.Name + "!" + fmt.Sprintf("This is Server: %s:%d", s.info.Addr, s.info.Port), SuccessFlag: false}, errors.New("time out!")
case msg := <-pubsubCh:
result, err := strconv.ParseFloat(msg.Payload, 32)
if err != nil {
color.Set(color.FgRed, color.Bold)
fmt.Printf("Process failed for reqId %d, request: %s\n", reqId, buf)
color.Unset()
s.rdb.Set(request, "Failure", 60*time.Second).Err()
return &cpb.CalculateResponse{Message: "Hello! " + in.Name + "!" + fmt.Sprintf("This is Server: %s:%d", s.info.Addr, s.info.Port), SuccessFlag: false}, nil
}
color.Set(color.FgGreen, color.Bold)
fmt.Printf("Get result: %f, reqId %d, request: %s\n", result, reqId, buf)
color.Unset()
val := fmt.Sprintf("%f", result)
//if err = s.rdb.Do("set", request, val, "EX", "10").Err(); err != nil {
if err = s.rdb.Set(request, val, 120*time.Second).Err(); err != nil {
color.Set(color.FgYellow, color.Bold)
fmt.Printf("Set %s=%f to redis failed: %s\n", request, result, err.Error())
color.Unset()
}
color.Set(color.FgGreen, color.Bold)
fmt.Printf("Set %s=%f to redis succcess\n", request, result)
color.Unset()
return &cpb.CalculateResponse{Message: "Hello! " + in.Name + "!" + fmt.Sprintf("This is Server: %s:%d", s.info.Addr, s.info.Port), SuccessFlag: true, Result: result}, nil
/*default:
val, err := s.rdb.Get(fmt.Sprintf("%d", reqId)).Result()
if err == nil {
result, err := strconv.ParseFloat(val, 32)
if err != nil {
color.Set(color.FgRed, color.Bold)
fmt.Printf("Process failed for reqId %d, request: %s\n", reqId, buf)
color.Unset()
s.rdb.Set(request, "Failure", 60*time.Second).Err()
return &cpb.CalculateResponse{Message: "Hello! " + in.Name + "!" + fmt.Sprintf("This is Server: %s:%d", s.info.Addr, s.info.Port), SuccessFlag: false}, nil
}
color.Set(color.FgGreen, color.Bold)
fmt.Printf("Get result: %f, reqId %d, request: %s\n", result, reqId, buf)
color.Unset()
val := fmt.Sprintf("%f", result)
//if err = s.rdb.Do("set", request, val, "EX", "10").Err(); err != nil {
if err = s.rdb.Set(request, val, 120*time.Second).Err(); err != nil {
color.Set(color.FgYellow, color.Bold)
fmt.Printf("Set %s=%f to redis failed: %s\n", request, result, err.Error())
color.Unset()
}
color.Set(color.FgGreen, color.Bold)
fmt.Printf("Set %s=%f to redis succcess\n", request, result)
color.Unset()
return &cpb.CalculateResponse{Message: "Hello! " + in.Name + "!" + fmt.Sprintf("This is Server: %s:%d", s.info.Addr, s.info.Port), SuccessFlag: true, Result: result}, nil
}*/
}
}
return &cpb.CalculateResponse{Message: "Hello! " + in.Name + "!" + fmt.Sprintf("This is Server: %s:%d", s.info.Addr, s.info.Port), SuccessFlag: true}, nil
}
func StartCalculateServiceServer(server *CalculateServiceServer) {
//notify CalculateServiceServerMonitor to do recovery
defer func() {
//stop tokenProducer
server.Cancel()
server.ch <- struct{}{}
}()
lis, err := net.Listen("tcp", fmt.Sprintf("%s:%d", server.info.Addr, server.info.Port))
if err != nil {
fmt.Println("listen failed: ", err.Error())
return
}
err = serviceDiscovery.RegisterServiceToConsul(*server.info)
if err != nil {
fmt.Println(err.Error())
return
}
defer serviceDiscovery.DeregisterServiceFromConsul(*server.info)
cpb.RegisterCalculateServiceServer(server.gServer, server)
go server.tokenProducer()
if err := server.gServer.Serve(lis); err != nil {
fmt.Println("serve failed: ", err.Error())
return
}
}
func NewGRPCServer() *grpc.Server {
return grpc.NewServer(grpc.UnaryInterceptor(unaryInterceptor))
}
func NewCalculateServiceServer(port int) *CalculateServiceServer {
s := grpc.NewServer(grpc.UnaryInterceptor(unaryInterceptor))
info := &serviceDiscovery.ServiceInfo{
Addr: ip,
Port: port,
ServiceName: "CalculateService",
UpdateInterval: 5 * time.Second,
CheckInterval: 20}
ch := make(chan struct{}, 1)
limitCh := make(chan struct{}, 10)
server := &CalculateServiceServer{
info: info,
gServer: s,
ch: ch,
limitCh: limitCh,
}
//TODO: support multi brokers
ctx, cancel := context.WithCancel(context.Background())
server.Ctx = ctx
server.Cancel = cancel
var err error
server.ksProducer, err = producer.NewKafkaSyncProducer(ctx, brokers)
if err != nil {
panic(err)
}
server.rdb = redis.NewClient(&rdbOpt)
return server
}
func unaryInterceptor(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
// authentication (token verification)
_, ok := metadata.FromIncomingContext(ctx)
if !ok {
return nil, errMissingMetadata
}
if throttleHandler(info) == false {
color.Set(color.FgHiRed, color.Bold)
fmt.Printf("Request rate exceed server limts, reject!\n")
color.Unset()
return nil, errReqExceedLimitRate
}
m, err := handler(ctx, req)
if err != nil {
fmt.Printf("RPC failed with error %v\n", err)
}
return m, err
}
func throttleHandler(info *grpc.UnaryServerInfo) bool {
s := info.Server.(*CalculateServiceServer)
pass := false
select {
case <-s.limitCh:
pass = true
default:
}
return pass
}
func (s *CalculateServiceServer) tokenProducer() {
id := atomic.AddInt32(&tokenProducerId, 1)
fmt.Println("tokern producer start! ", id)
t := time.NewTicker(100 * time.Millisecond)
for {
select {
case <-t.C:
//If bucket is full, token will been dropped
select {
case s.limitCh <- struct{}{}:
default:
}
case <-s.Ctx.Done():
fmt.Println("tokenProducer stopped! ", id)
return
}
}
}