网站尺寸规范,家在深圳歌词,全国最好的装修平台,厦门市做网站优化1、gRPC负载均衡(客户端负载均衡)(etcd)
本篇将基于etcd的服务发现前提下#xff0c;介绍如何实现gRPC客户端负载均衡。
1.1 gRPC负载均衡
gRPC官方文档提供了关于gRPC负载均衡方案Load Balancing in gRPC
https://github.com/grpc/grpc/blob/master/doc/load-balancing.m…1、gRPC负载均衡(客户端负载均衡)(etcd)
本篇将基于etcd的服务发现前提下介绍如何实现gRPC客户端负载均衡。
1.1 gRPC负载均衡
gRPC官方文档提供了关于gRPC负载均衡方案Load Balancing in gRPC
https://github.com/grpc/grpc/blob/master/doc/load-balancing.md
此方案是为gRPC设计的下面我们对此进行分析。
1.1.1 对每次调用进行负载均衡
gRPC中的负载平衡是以每次调用为基础而不是以每个连接为基础。换句话说即使所有的请求都来自一个客户
端我们仍希望它们在所有的服务器上实现负载平衡。
1.1.2 负载均衡的方法
集中式Proxy Model 在服务消费者和服务提供者之间有一个独立的负载均衡LB通常是专门的硬件设备如 F5或者基于软件如
LVSHAproxy等实现。LB上有所有服务的地址映射表通常由运维配置注册当服务消费方调用某个目标服务
时它向LB发起请求由LB以某种策略比如轮询Round-Robin做负载均衡后将请求转发到目标服务。LB一
般具备健康检查能力能自动摘除不健康的服务实例。
该方案主要问题服务消费方、提供方之间增加了一级有一定性能开销请求量大时效率较低。 可能有读者会认为集中式负载均衡存在这样的问题一旦负载均衡服务挂掉那整个系统将不能使用。 解决方案可以对负载均衡服务进行DNS负载均衡通过对一个域名设置多个IP地址每次DNS解析时轮询 返回负载均衡服务地址从而实现简单的DNS负载均衡。 客户端负载Balancing-aware Client 针对第一个方案的不足此方案将LB的功能集成到服务消费方进程里也被称为软负载或者客户端负载方案。服
务提供方启动时首先将服务地址注册到服务注册表同时定期报心跳到服务注册表以表明服务的存活状态相当
于健康检查服务消费方要访问某个服务时它通过内置的LB组件向服务注册表查询同时缓存并定期刷新目标
服务地址列表然后以某种负载均衡策略选择一个目标服务地址最后向目标服务发起请求。LB和服务发现能力
被分散到每一个服务消费者的进程内部同时服务消费方和服务提供方之间是直接调用没有额外开销性能比较
好。
该方案主要问题要用多种语言、多个版本的客户端编写和维护负载均衡策略使客户端的代码大大复杂化。
独立LB服务External Load Balancing Service 该方案是针对第二种方案的不足而提出的一种折中方案原理和第二种方案基本类似。
不同之处是将LB和服务发现功能从进程内移出来变成主机上的一个独立进程。主机上的一个或者多个服务要访
问目标服务时他们都通过同一主机上的独立LB进程做服务发现和负载均衡。该方案也是一种分布式方案没有单
点问题服务调用方和LB之间是进程内调用性能好同时该方案还简化了服务调用方不需要为不同语言开发客
户库。
本篇将介绍第二种负载均衡方法客户端负载均衡。
1.2 实现gRPC客户端负载均衡
gRPC已提供了简单的负载均衡策略如Round Robin我们只需实现它提供的Builder和Resolver接口
就能完成gRPC客户端负载均衡。
type Builder interface {Build(target Target, cc ClientConn, opts BuildOption) (Resolver, error)Scheme() string
}Builder接口创建一个resolver本文称之服务发现用于监视名称解析更新。
Build方法为给定目标创建一个新的resolver当调用grpc.Dial()时执行。
Scheme方法返回此resolver支持的方案。
Scheme定义可参考https://github.com/grpc/grpc/blob/master/doc/naming.md
type Resolver interface {ResolveNow(ResolveNowOption)Close()
}Resolver接口监视指定目标的更新包括地址更新和服务配置更新。
ResolveNow方法被 gRPC 调用以尝试再次解析目标名称。只用于提示可忽略该方法。
Close方法关闭resolver。
根据以上两个接口我们把服务发现的功能写在Build方法中把获取到的负载均衡服务地址返回到客户端并
监视服务更新情况以修改客户端连接。
1.3 服务发现代码修改
服务发现代码./etcdv3/discovery.go的内容
package etcdv3import (contextgithub.com/coreos/etcd/mvcc/mvccpbgo.etcd.io/etcd/clientv3google.golang.org/grpc/resolverlogsynctime
)const schema grpclb// ServiceDiscovery 服务发现
type ServiceDiscovery struct {// etcd clientcli *clientv3.Clientcc resolver.ClientConn// 服务列表serverList sync.Map
}// NewServiceDiscovery新建发现服务
func NewServiceDiscovery(endpoints []string) resolver.Builder {cli, err : clientv3.New(clientv3.Config{Endpoints: endpoints,DialTimeout: 5 * time.Second,})if err ! nil {log.Fatal(err)}return ServiceDiscovery{cli: cli,}
}// Build为给定目标创建一个新的resolver,当调用grpc.Dial()时执行
func (s *ServiceDiscovery) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOption) (resolver.Resolver, error) {log.Println(Build)s.cc cc// /grpclb/simple_grpc/prefix : / target.Scheme / target.Endpoint /// 根据前缀获取现有的keyresp, err : s.cli.Get(context.Background(), prefix, clientv3.WithPrefix())if err ! nil {return nil, err}for _, ev : range resp.Kvs {s.SetServiceList(string(ev.Key), string(ev.Value))}s.cc.UpdateState(resolver.State{Addresses: s.getServices()})// 监视前缀修改变更的servergo s.watcher(prefix)return s, nil
}// ResolveNow监视目标更新
func (s *ServiceDiscovery) ResolveNow(rn resolver.ResolveNowOption) {log.Println(ResolveNow)
}// Scheme return schema
func (s *ServiceDiscovery) Scheme() string {return schema
}// Close关闭
func (s *ServiceDiscovery) Close() {log.Println(Close)s.cli.Close()
}// watcher监听前缀
func (s *ServiceDiscovery) watcher(prefix string) {rch : s.cli.Watch(context.Background(), prefix, clientv3.WithPrefix())log.Printf(watching prefix:%s now..., prefix)for wresp : range rch {for _, ev : range wresp.Events {switch ev.Type {// 新增或修改case mvccpb.PUT:s.SetServiceList(string(ev.Kv.Key), string(ev.Kv.Value))// 删除case mvccpb.DELETE:s.DelServiceList(string(ev.Kv.Key))}}}
}// SetServiceList新增服务地址
func (s *ServiceDiscovery) SetServiceList(key, val string) {s.serverList.Store(key, resolver.Address{Addr: val})s.cc.UpdateState(resolver.State{Addresses: s.getServices()})log.Println(put key :, key, val:, val)
}// DelServiceList删除服务地址
func (s *ServiceDiscovery) DelServiceList(key string) {s.serverList.Delete(key)s.cc.UpdateState(resolver.State{Addresses: s.getServices()})log.Println(del key:, key)
}// GetServices获取服务地址
func (s *ServiceDiscovery) getServices() []resolver.Address {addrs : make([]resolver.Address, 0, 10)s.serverList.Range(func(k, v interface{}) bool {addrs append(addrs, v.(resolver.Address))return true})// [{localhost:8000 nil 0 nil}]return addrs
}代码主要修改以下地方
1、把获取的服务地址转成resolver.Address供gRPC客户端连接。
2、根据schema的定义规则修改key格式。
1.4 服务注册代码修改
服务发现代码./etcdv3/register.go的内容
package etcdv3import (contextgo.etcd.io/etcd/clientv3logtime
)// ServiceRegister创建租约注册服务
type ServiceRegister struct {// etcd clientcli *clientv3.Client// 租约IDleaseID clientv3.LeaseID// 租约keepalieve相应chankeepAliveChan -chan *clientv3.LeaseKeepAliveResponse// keykey string// valueval string
}// NewServiceRegister 新建注册服务
func NewServiceRegister(endpoints []string, serName, addr string, lease int64) (*ServiceRegister, error) {cli, err : clientv3.New(clientv3.Config{Endpoints: endpoints,DialTimeout: 5 * time.Second,})if err ! nil {log.Fatal(err)}ser : ServiceRegister{cli: cli,// /grpclb/simple_grpc/localhost:8000key: / schema / serName / addr,val: addr,}// 申请租约设置时间keepaliveif err : ser.putKeyWithLease(lease); err ! nil {return nil, err}return ser, nil
}// 设置租约
func (s *ServiceRegister) putKeyWithLease(lease int64) error {// 设置租约时间resp, err : s.cli.Grant(context.Background(), lease)if err ! nil {return err}// 注册服务并绑定租约_, err s.cli.Put(context.Background(), s.key, s.val, clientv3.WithLease(resp.ID))if err ! nil {return err}// 设置续租 定期发送需求请求leaseRespChan, err : s.cli.KeepAlive(context.Background(), resp.ID)if err ! nil {return err}s.leaseID resp.IDs.keepAliveChan leaseRespChanlog.Printf(Put key:%s val:%s success!, s.key, s.val)return nil
}// ListenLeaseRespChan监听续租情况
func (s *ServiceRegister) ListenLeaseRespChan() {for leaseKeepResp : range s.keepAliveChan {log.Println(续约成功, leaseKeepResp)}log.Println(关闭续租)
}// Close注销服务
func (s *ServiceRegister) Close() error {// 撤销租约if _, err : s.cli.Revoke(context.Background(), s.leaseID); err ! nil {return err}log.Println(撤销租约)return s.cli.Close()
}服务注册主要修改key存储格式。
1.5 proto编写和编译
simple.proto文件的内容
// 协议为proto3
syntax proto3;
package proto;
option go_package ./proto;proto;// 定义发送请求信息
message SimpleRequest{// 定义发送的参数采用驼峰命名方式小写加下划线如student_name// 参数类型 参数名 标识号(不可重复)string data 1;
}// 定义响应信息
message SimpleResponse{// 定义接收的参数// 参数类型 参数名 标识号(不可重复)int32 code 1;string value 2;
}// 定义我们的服务可定义多个服务,每个服务可定义多个接口
service Simple{rpc Route (SimpleRequest) returns (SimpleResponse){};
}编译simple.proto文件
$ protoc --go_outpluginsgrpc:. simple.proto1.6 gRPC客户端
gRPC内置了简单的负载均衡策略round_robin根据负载均衡地址以轮询的方式进行调用服务。
客户端修改gRPC连接服务的部分代码client.go内容如下
package mainimport (contextetcd2/etcdv3pb etcd2/protofmtgoogle.golang.org/grpcgoogle.golang.org/grpc/resolverlogstrconvtime
)var (// EtcdEndpoints etcd集群地址EtcdEndpoints []string{localhost:2379}// SerName服务名称SerName simple_grpcgrpcClient pb.SimpleClient
)func main() {r : etcdv3.NewServiceDiscovery(EtcdEndpoints)resolver.Register(r)// 连接服务器conn, err : grpc.Dial(// grpclb:///simple_grpcfmt.Sprintf(%s:///%s, r.Scheme(), SerName),grpc.WithBalancerName(round_robin),grpc.WithInsecure(),)if err ! nil {log.Fatalf(net.Connect err: %v, err)}defer conn.Close()// 建立gRPC连接grpcClient pb.NewSimpleClient(conn)for i : 0; i 100; i {route(i)time.Sleep(1 * time.Second)}
}// route调用服务端Route方法
func route(i int) {// 创建发送结构体req : pb.SimpleRequest{Data: grpc strconv.Itoa(i),}// 调用我们的服务(Route方法)// 同时传入了一个 context.Context 在有需要时可以让我们改变RPC的行为比如超时/取消一个正在运行的RPCres, err : grpcClient.Route(context.Background(), req)if err ! nil {log.Fatalf(Call Route err: %v, err)}// 打印返回值log.Println(res)
}1.7 gRPC服务端
服务端启动时把服务地址注册到etcd中即可server.go内容如下
package mainimport (contextetcd2/etcdv3pb etcd2/protogoogle.golang.org/grpclognet
)// SimpleService定义我们的服务
type SimpleService struct{}const (// Address监听地址,服务端地址Address string localhost:8000// Network网络通信协议Network string tcp// SerName服务名称SerName string simple_grpc
)// EtcdEndpoints etcd集群地址
var EtcdEndpoints []string{localhost:2379}func main() {// 监听本地端口listener, err : net.Listen(Network, Address)if err ! nil {log.Fatalf(net.Listen err: %v, err)}log.Println(Address net.Listing...)// 新建gRPC服务器实例grpcServer : grpc.NewServer()// 在gRPC服务器注册我们的服务pb.RegisterSimpleServer(grpcServer, SimpleService{})// 把服务注册到etcdser, err : etcdv3.NewServiceRegister(EtcdEndpoints, SerName, Address, 5)if err ! nil {log.Fatalf(register service err: %v, err)}defer ser.Close()// 用服务器Serve()方法以及我们的端口信息区实现阻塞等待,直到进程被杀死或者Stop()被调用err grpcServer.Serve(listener)if err ! nil {log.Fatalf(grpcServer.Serve err: %v, err)}
}// Route实现Route方法
func (s *SimpleService) Route(ctx context.Context, req *pb.SimpleRequest) (*pb.SimpleResponse, error) {log.Println(receive: req.Data)res : pb.SimpleResponse{Code: 200,Value: hello req.Data,}return res, nil
}1.8 运行效果
我们先启动并注册三个服务
[rootzsx etcd2]# go run server.go
2023-02-13 20:51:54.173418 I | localhost:8000 net.Listing...
2023-02-13 20:51:54.207555 I | Put key:/grpclb/simple_grpc/localhost:8000 val:localhost:8000 success![rootzsx etcd2]# go run server1.go
2023-02-13 20:52:02.041409 I | localhost:8001 net.Listing...
2023-02-13 20:52:02.046411 I | Put key:/grpclb/simple_grpc/localhost:8001 val:localhost:8001 success![rootzsx etcd2]# go run server2.go
2023-02-13 20:52:06.644427 I | localhost:8002 net.Listing...
2023-02-13 20:52:06.647214 I | Put key:/grpclb/simple_grpc/localhost:8002 val:localhost:8002 success!然后客户端进行调用
[rootzsx etcd2]# go run client.go
2023-02-13 20:53:43.841502 I | Build
2023-02-13 20:53:43.844638 I | put key : /grpclb/simple_grpc/localhost:8000 val: localhost:8000
2023-02-13 20:53:43.844659 I | put key : /grpclb/simple_grpc/localhost:8001 val: localhost:8001
2023-02-13 20:53:43.844668 I | put key : /grpclb/simple_grpc/localhost:8002 val: localhost:8002
2023-02-13 20:53:43.849315 I | watching prefix:/grpclb/simple_grpc/ now...
2023-02-13 20:53:43.849949 I | code:200 value:hello grpc 0
2023-02-13 20:53:44.851034 I | code:200 value:hello grpc 1
2023-02-13 20:53:45.852734 I | code:200 value:hello grpc 2
2023-02-13 20:53:46.854096 I | code:200 value:hello grpc 3
2023-02-13 20:53:47.855628 I | code:200 value:hello grpc 4
2023-02-13 20:53:48.857095 I | code:200 value:hello grpc 5
2023-02-13 20:53:49.858414 I | code:200 value:hello grpc 6
2023-02-13 20:53:50.859152 I | code:200 value:hello grpc 7
2023-02-13 20:53:51.860268 I | code:200 value:hello grpc 8
2023-02-13 20:53:52.860825 I | code:200 value:hello grpc 9
2023-02-13 20:53:53.861698 I | code:200 value:hello grpc 10
2023-02-13 20:53:54.864353 I | code:200 value:hello grpc 11
2023-02-13 20:53:55.865019 I | code:200 value:hello grpc 12
2023-02-13 20:53:56.865771 I | code:200 value:hello grpc 13
2023-02-13 20:53:57.866400 I | code:200 value:hello grpc 14
2023-02-13 20:53:58.867066 I | code:200 value:hello grpc 15
2023-02-13 20:53:59.868412 I | code:200 value:hello grpc 16
2023-02-13 20:54:00.869399 I | code:200 value:hello grpc 17
2023-02-13 20:54:01.870803 I | code:200 value:hello grpc 18
2023-02-13 20:54:02.872201 I | code:200 value:hello grpc 19
2023-02-13 20:54:03.872696 I | code:200 value:hello grpc 20
2023-02-13 20:54:04.874159 I | code:200 value:hello grpc 21
2023-02-13 20:54:05.875990 I | code:200 value:hello grpc 22
2023-02-13 20:54:06.877799 I | code:200 value:hello grpc 23
2023-02-13 20:54:07.878814 I | code:200 value:hello grpc 24
2023-02-13 20:54:08.881218 I | code:200 value:hello grpc 25
......看服务端接收到的请求
[rootzsx etcd2]# go run server.go
2023-02-13 20:51:54.173418 I | localhost:8000 net.Listing...
2023-02-13 20:51:54.207555 I | Put key:/grpclb/simple_grpc/localhost:8000 val:localhost:8000 success!
2023-02-13 20:53:43.849692 I | receive: grpc 0
2023-02-13 20:53:45.852147 I | receive: grpc 2
2023-02-13 20:53:48.856715 I | receive: grpc 5
2023-02-13 20:53:51.860086 I | receive: grpc 8
2023-02-13 20:53:54.863486 I | receive: grpc 11
2023-02-13 20:53:57.866286 I | receive: grpc 14
2023-02-13 20:54:00.869018 I | receive: grpc 17
2023-02-13 20:54:03.872545 I | receive: grpc 20
2023-02-13 20:54:06.877412 I | receive: grpc 23
......[rootzsx etcd2]# go run server1.go
2023-02-13 20:52:02.041409 I | localhost:8001 net.Listing...
2023-02-13 20:52:02.046411 I | Put key:/grpclb/simple_grpc/localhost:8001 val:localhost:8001 success!
2023-02-13 20:53:46.853933 I | receive: grpc 3
2023-02-13 20:53:49.858075 I | receive: grpc 6
2023-02-13 20:53:52.860683 I | receive: grpc 9
2023-02-13 20:53:55.864896 I | receive: grpc 12
2023-02-13 20:53:58.866946 I | receive: grpc 15
2023-02-13 20:54:01.870692 I | receive: grpc 18
2023-02-13 20:54:04.874044 I | receive: grpc 21
......[rootzsx etcd2]# go run server2.go
2023-02-13 20:52:06.644427 I | localhost:8002 net.Listing...
2023-02-13 20:52:06.647214 I | Put key:/grpclb/simple_grpc/localhost:8002 val:localhost:8002 success!
2023-02-13 20:53:44.850843 I | receive: grpc 1
2023-02-13 20:53:47.855201 I | receive: grpc 4
2023-02-13 20:53:50.859003 I | receive: grpc 7
2023-02-13 20:53:53.861487 I | receive: grpc 10
2023-02-13 20:53:56.865643 I | receive: grpc 13
2023-02-13 20:53:59.868263 I | receive: grpc 16
2023-02-13 20:54:02.872082 I | receive: grpc 19
2023-02-13 20:54:05.875695 I | receive: grpc 22
2023-02-13 20:54:08.880472 I | receive: grpc 25
......关闭localhost:8000服务剩余localhost:8001和localhost:8002服务接收请求
[rootzsx etcd2]# go run server1.go
2023-02-13 20:56:48.915356 I | localhost:8001 net.Listing...
2023-02-13 20:56:48.917716 I | Put key:/grpclb/simple_grpc/localhost:8001 val:localhost:8001 success!
2023-02-13 20:56:57.599656 I | receive: grpc 1
2023-02-13 20:57:00.603955 I | receive: grpc 4
2023-02-13 20:57:03.607802 I | receive: grpc 7
2023-02-13 20:57:06.612719 I | receive: grpc 10
2023-02-13 20:57:09.615636 I | receive: grpc 13
2023-02-13 20:57:12.621450 I | receive: grpc 16
2023-02-13 20:57:15.624067 I | receive: grpc 19
2023-02-13 20:57:18.627407 I | receive: grpc 22
2023-02-13 20:57:21.630674 I | receive: grpc 25
2023-02-13 20:57:24.635254 I | receive: grpc 28
2023-02-13 20:57:27.638432 I | receive: grpc 31
2023-02-13 20:57:30.642211 I | receive: grpc 34
2023-02-13 20:57:32.644497 I | receive: grpc 36
2023-02-13 20:57:34.646649 I | receive: grpc 38
2023-02-13 20:57:36.650191 I | receive: grpc 40
2023-02-13 20:57:38.653029 I | receive: grpc 42
2023-02-13 20:57:40.654724 I | receive: grpc 44
2023-02-13 20:57:42.656665 I | receive: grpc 46
2023-02-13 20:57:44.658922 I | receive: grpc 48
2023-02-13 20:57:46.661156 I | receive: grpc 50
2023-02-13 20:57:48.663613 I | receive: grpc 52
2023-02-13 20:57:50.666520 I | receive: grpc 54
2023-02-13 20:57:52.668219 I | receive: grpc 56
2023-02-13 20:57:54.670777 I | receive: grpc 58
2023-02-13 20:57:56.673138 I | receive: grpc 60
2023-02-13 20:57:58.674908 I | receive: grpc 62
2023-02-13 20:58:00.677698 I | receive: grpc 64
2023-02-13 20:58:02.680816 I | receive: grpc 66
2023-02-13 20:58:04.686075 I | receive: grpc 68
......[rootzsx etcd2]# go run server2.go
2023-02-13 20:56:51.462814 I | localhost:8002 net.Listing...
2023-02-13 20:56:51.467130 I | Put key:/grpclb/simple_grpc/localhost:8002 val:localhost:8002 success!
2023-02-13 20:56:58.600367 I | receive: grpc 2
2023-02-13 20:57:01.605054 I | receive: grpc 5
2023-02-13 20:57:04.608898 I | receive: grpc 8
2023-02-13 20:57:07.613784 I | receive: grpc 11
2023-02-13 20:57:10.617774 I | receive: grpc 14
2023-02-13 20:57:13.622261 I | receive: grpc 17
2023-02-13 20:57:16.624596 I | receive: grpc 20
2023-02-13 20:57:19.628076 I | receive: grpc 23
2023-02-13 20:57:22.632461 I | receive: grpc 26
2023-02-13 20:57:25.636681 I | receive: grpc 29
2023-02-13 20:57:28.639889 I | receive: grpc 32
2023-02-13 20:57:31.643062 I | receive: grpc 35
2023-02-13 20:57:33.645208 I | receive: grpc 37
2023-02-13 20:57:35.648217 I | receive: grpc 39
2023-02-13 20:57:37.652005 I | receive: grpc 41
2023-02-13 20:57:39.653990 I | receive: grpc 43
2023-02-13 20:57:41.656116 I | receive: grpc 45
2023-02-13 20:57:43.657680 I | receive: grpc 47
2023-02-13 20:57:45.659936 I | receive: grpc 49
2023-02-13 20:57:47.662667 I | receive: grpc 51
2023-02-13 20:57:49.665158 I | receive: grpc 53
2023-02-13 20:57:51.667787 I | receive: grpc 55
2023-02-13 20:57:53.669130 I | receive: grpc 57
2023-02-13 20:57:55.672291 I | receive: grpc 59
2023-02-13 20:57:57.673711 I | receive: grpc 61
2023-02-13 20:57:59.676281 I | receive: grpc 63
2023-02-13 20:58:01.679348 I | receive: grpc 65
2023-02-13 20:58:03.682384 I | receive: grpc 67
2023-02-13 20:58:05.687477 I | receive: grpc 69
......重新打开localhost:8000服务
[rootzsx etcd2]# go run server.go
2023-02-13 20:58:05.315863 I | localhost:8000 net.Listing...
2023-02-13 20:58:05.322321 I | Put key:/grpclb/simple_grpc/localhost:8000 val:localhost:8000 success!
2023-02-13 20:58:06.688247 I | receive: grpc 70
2023-02-13 20:58:09.691796 I | receive: grpc 73
2023-02-13 20:58:12.697446 I | receive: grpc 76
2023-02-13 20:58:15.700649 I | receive: grpc 79
2023-02-13 20:58:18.704804 I | receive: grpc 82
2023-02-13 20:58:21.711890 I | receive: grpc 85
2023-02-13 20:58:24.721398 I | receive: grpc 88
2023-02-13 20:58:27.726881 I | receive: grpc 91
2023-02-13 20:58:30.733417 I | receive: grpc 94
2023-02-13 20:58:33.739445 I | receive: grpc 97[rootzsx etcd2]# go run server1.go
2023-02-13 20:56:48.915356 I | localhost:8001 net.Listing...
2023-02-13 20:56:48.917716 I | Put key:/grpclb/simple_grpc/localhost:8001 val:localhost:8001 success!
2023-02-13 20:56:57.599656 I | receive: grpc 1
2023-02-13 20:57:00.603955 I | receive: grpc 4
2023-02-13 20:57:03.607802 I | receive: grpc 7
2023-02-13 20:57:06.612719 I | receive: grpc 10
2023-02-13 20:57:09.615636 I | receive: grpc 13
2023-02-13 20:57:12.621450 I | receive: grpc 16
2023-02-13 20:57:15.624067 I | receive: grpc 19
2023-02-13 20:57:18.627407 I | receive: grpc 22
2023-02-13 20:57:21.630674 I | receive: grpc 25
2023-02-13 20:57:24.635254 I | receive: grpc 28
2023-02-13 20:57:27.638432 I | receive: grpc 31
2023-02-13 20:57:30.642211 I | receive: grpc 34
2023-02-13 20:57:32.644497 I | receive: grpc 36
2023-02-13 20:57:34.646649 I | receive: grpc 38
2023-02-13 20:57:36.650191 I | receive: grpc 40
2023-02-13 20:57:38.653029 I | receive: grpc 42
2023-02-13 20:57:40.654724 I | receive: grpc 44
2023-02-13 20:57:42.656665 I | receive: grpc 46
2023-02-13 20:57:44.658922 I | receive: grpc 48
2023-02-13 20:57:46.661156 I | receive: grpc 50
2023-02-13 20:57:48.663613 I | receive: grpc 52
2023-02-13 20:57:50.666520 I | receive: grpc 54
2023-02-13 20:57:52.668219 I | receive: grpc 56
2023-02-13 20:57:54.670777 I | receive: grpc 58
2023-02-13 20:57:56.673138 I | receive: grpc 60
2023-02-13 20:57:58.674908 I | receive: grpc 62
2023-02-13 20:58:00.677698 I | receive: grpc 64
2023-02-13 20:58:02.680816 I | receive: grpc 66
2023-02-13 20:58:04.686075 I | receive: grpc 68
2023-02-13 20:58:07.689105 I | receive: grpc 71
2023-02-13 20:58:10.693713 I | receive: grpc 74
2023-02-13 20:58:13.698055 I | receive: grpc 77
2023-02-13 20:58:16.701562 I | receive: grpc 80
2023-02-13 20:58:19.706860 I | receive: grpc 83
2023-02-13 20:58:22.715951 I | receive: grpc 86
2023-02-13 20:58:25.723692 I | receive: grpc 89
2023-02-13 20:58:28.728865 I | receive: grpc 92
2023-02-13 20:58:31.735971 I | receive: grpc 95
2023-02-13 20:58:34.740998 I | receive: grpc 98[rootzsx etcd2]# go run server2.go
2023-02-13 20:56:51.462814 I | localhost:8002 net.Listing...
2023-02-13 20:56:51.467130 I | Put key:/grpclb/simple_grpc/localhost:8002 val:localhost:8002 success!
2023-02-13 20:56:58.600367 I | receive: grpc 2
2023-02-13 20:57:01.605054 I | receive: grpc 5
2023-02-13 20:57:04.608898 I | receive: grpc 8
2023-02-13 20:57:07.613784 I | receive: grpc 11
2023-02-13 20:57:10.617774 I | receive: grpc 14
2023-02-13 20:57:13.622261 I | receive: grpc 17
2023-02-13 20:57:16.624596 I | receive: grpc 20
2023-02-13 20:57:19.628076 I | receive: grpc 23
2023-02-13 20:57:22.632461 I | receive: grpc 26
2023-02-13 20:57:25.636681 I | receive: grpc 29
2023-02-13 20:57:28.639889 I | receive: grpc 32
2023-02-13 20:57:31.643062 I | receive: grpc 35
2023-02-13 20:57:33.645208 I | receive: grpc 37
2023-02-13 20:57:35.648217 I | receive: grpc 39
2023-02-13 20:57:37.652005 I | receive: grpc 41
2023-02-13 20:57:39.653990 I | receive: grpc 43
2023-02-13 20:57:41.656116 I | receive: grpc 45
2023-02-13 20:57:43.657680 I | receive: grpc 47
2023-02-13 20:57:45.659936 I | receive: grpc 49
2023-02-13 20:57:47.662667 I | receive: grpc 51
2023-02-13 20:57:49.665158 I | receive: grpc 53
2023-02-13 20:57:51.667787 I | receive: grpc 55
2023-02-13 20:57:53.669130 I | receive: grpc 57
2023-02-13 20:57:55.672291 I | receive: grpc 59
2023-02-13 20:57:57.673711 I | receive: grpc 61
2023-02-13 20:57:59.676281 I | receive: grpc 63
2023-02-13 20:58:01.679348 I | receive: grpc 65
2023-02-13 20:58:03.682384 I | receive: grpc 67
2023-02-13 20:58:05.687477 I | receive: grpc 69
2023-02-13 20:58:08.690259 I | receive: grpc 72
2023-02-13 20:58:11.696068 I | receive: grpc 75
2023-02-13 20:58:14.699459 I | receive: grpc 78
2023-02-13 20:58:17.702863 I | receive: grpc 81
2023-02-13 20:58:20.709975 I | receive: grpc 84
2023-02-13 20:58:23.718648 I | receive: grpc 87
2023-02-13 20:58:26.725422 I | receive: grpc 90
2023-02-13 20:58:29.731039 I | receive: grpc 93
2023-02-13 20:58:32.737702 I | receive: grpc 96
2023-02-13 20:58:35.742928 I | receive: grpc 99可以看到gRPC客户端负载均衡运行良好。
# 项目结构
[rootzsx protoc]# tree etcd2
etcd2
├── client.go
├── etcdv3
│ ├── discovery.go
│ └── register.go
├── go.mod
├── go.sum
├── proto
│ └── simple.pb.go
├── server1.go
├── server2.go
├── server.go
└── simple.proto2 directories, 10 files1.9 总结
本文介绍了gRPC客户端负载均衡的实现它简单实现了gRPC负载均衡的功能。但在对接其他语言时候比较麻烦
需要每种语言都实现一套服务发现和负载策略。
目前官方只提供了取第一个地址pick_first和轮询round_robin两种负载均衡策略。
下篇将介绍如何自定义负载均衡策略。
有兴趣了解第三种负载均衡方法External Load Balancing Service的可以参考这个项目
https://github.com/bsm/grpclb
关于负载均衡的其它写法可以参考一下GitHub https://github.com/wothing/wonaming https://github.com/wwcd/grpc-lb
