AMOP 使用案例
AMOP（Advanced Messages Onchain Protocol）即链上信使协议，旨在为联盟链提供一个安全高效的消息信道，联盟链中的各个机构，只要部署了区块链节点，无论是共识节点还是观察节点，均可使用AMOP进行通讯，AMOP有如下优势：
- 实时：AMOP消息不依赖区块链交易和共识，消息在节点间实时传输，延时在毫秒级。
- 可靠：AMOP消息传输时，自动寻找区块链网络中所有可行的链路进行通讯，只要收发双方至少有一个链路可用，消息就保证可达。
- 高效：AMOP消息结构简洁、处理逻辑高效，仅需少量cpu占用，能充分利用网络带宽。
- 安全：AMOP的所有通讯链路使用SSL加密，加密算法可配置,支持身份认证机制。
- 易用：使用AMOP时，无需在SDK做任何额外配置。
进一步了解 AMOP，请参考：链上信使协议。案例源码，请参考：go-sdk
初始化：
- 搭建单群组四节点区块链网络，可参考：安装。
单播案例
单播 指的是节点从监听相同 Topic 的多个订阅者中随机抽取一个订阅者转发消息，流程详细可参考 单播时序图
-
启动 AMOP 消息订阅者：
```shell
go run examples/amop/sub/subscriber.go [endpoint] [topic]
go run examples/amop/sub/subscriber.go 127.0.0.1:20201 hello
Subscriber success 2020/08/11 21:21:50 received: hello, FISCO BCOS, I am unique broadcast publisher! 0 2020/08/11 21:21:52 received: hello, FISCO BCOS, I am unique broadcast publisher! 1 2020/08/11 21:21:54 received: hello, FISCO BCOS, I am unique broadcast publisher! 2 2020/08/11 21:21:56 received: hello, FISCO BCOS, I am unique broadcast publisher! 3 ```
-
运行 AMOP 消息发布者：
```shell
go run examples/amop/unicast_pub/publisher.go [endpoint] [topic]
go run examples/amop/unicast_pub/publisher.go 127.0.0.1:20200 hello
2020/08/11 21:21:50 publish message: hello, FISCO BCOS, I am unique broadcast publisher! 0 2020/08/11 21:21:52 publish message: hello, FISCO BCOS, I am unique broadcast publisher! 1 2020/08/11 21:21:54 publish message: hello, FISCO BCOS, I am unique broadcast publisher! 2 2020/08/11 21:21:56 publish message: hello, FISCO BCOS, I am unique broadcast publisher! 3 ```
多播案例
多播 指的是节点向监听相同 Topic 的所有订阅者转发消息。只要网络正常，即使没有监听 Topic 的订阅者，消息发布者也会收到节点消息推送成功的响应包，流程详细可参考 多播时序图
-
启动 AMOP 消息订阅者：
```shell
go run examples/amop/sub/subscriber.go [endpoint] [topic]
go run examples/amop/sub/subscriber.go 127.0.0.1:20201 hello
Subscriber success 2020/08/11 21:23:54 received: hello, FISCO BCOS, I am multi broadcast publisher! 0 2020/08/11 21:23:56 received: hello, FISCO BCOS, I am multi broadcast publisher! 1 2020/08/11 21:23:58 received: hello, FISCO BCOS, I am multi broadcast publisher! 2 2020/08/11 21:24:00 received: hello, FISCO BCOS, I am multi broadcast publisher! 3 ```
-
运行 AMOP 消息发布者：
```shell
go run examples/amop/multicast_pub/publisher.go [endpoint] [topic]
go run examples/amop/multicast_pub/publisher.go 127.0.0.1:20200 hello
2020/08/11 21:23:54 publish message: hello, FISCO BCOS, I am multi broadcast publisher! 0 2020/08/11 21:23:56 publish message: hello, FISCO BCOS, I am multi broadcast publisher! 1 2020/08/11 21:23:58 publish message: hello, FISCO BCOS, I am multi broadcast publisher! 2 2020/08/11 21:24:00 publish message: hello, FISCO BCOS, I am multi broadcast publisher! 3 ```
身份验证单播案例
常规场景中，任何一个监听了某topic的接收者都能接受到发送者推送的消息。但在某些场景下，发送者只希望特定的接收者能接收到消息，不希望无关的接收者能任意的监听此topic。针对此类场景，FISCO BCOS 推出了 topic 认证功能。 认证功能是指对于特定的topic消息，只允许通过认证的接收者接收消息。详细请参考：Topic认证功能
-
启动 AMOP 消息订阅者：
```shell
go run examples/amop_auth/sub/subscriber.go [endpoint] [topic]
go run examples/amop_auth/sub/subscriber.go 127.0.0.1:20201 hello
Subscriber success 2020/08/27 15:59:33 received: Hi, FISCO BCOS! 0 2020/08/27 15:59:35 received: Hi, FISCO BCOS! 1 2020/08/27 15:59:37 received: Hi, FISCO BCOS! 2 2020/08/27 15:59:39 received: Hi, FISCO BCOS! 3 ```
-
运行 AMOP 消息发布者：
```shell
go run examples/amop_auth/unicast_pub/publisher.go [endpoint] [topic]
go run examples/amop_auth/unicast_pub/publisher.go 127.0.0.1:20200 hello
publish topic success 2020/08/27 15:59:33 publish message: Hi, FISCO BCOS! 0 2020/08/27 15:59:35 publish message: Hi, FISCO BCOS! 1 2020/08/27 15:59:37 publish message: Hi, FISCO BCOS! 2 2020/08/27 15:59:39 publish message: Hi, FISCO BCOS! 3 ```
身份验证多播案例
同理，FISCO BCOS 支持带身份验证的消息多播功能
-
启动 AMOP 消息订阅者：
```shell
go run examples/amop_auth/sub/subscriber.go [endpoint] [topic]
go run examples/amop_auth/sub/subscriber.go 127.0.0.1:20201 hello
Subscriber success 2020/08/27 16:02:39 received: Hi, FISCO BCOS! 1 2020/08/27 16:02:41 received: Hi, FISCO BCOS! 2 2020/08/27 16:02:43 received: Hi, FISCO BCOS! 3 2020/08/27 16:02:45 received: Hi, FISCO BCOS! 4 ```
-
运行 AMOP 消息发布者：
```shell
go run examples/amop_auth/multicast_pub/publisher.go [endpoint] [topic]
go run examples/amop_auth/multicast_pub/publisher.go 127.0.0.1:20200 hello
publish topic success 2020/08/27 16:02:37 publish message: Hi, FISCO BCOS! 0 2020/08/27 16:02:39 publish message: Hi, FISCO BCOS! 1 2020/08/27 16:02:41 publish message: Hi, FISCO BCOS! 2 2020/08/27 16:02:43 publish message: Hi, FISCO BCOS! 3 2020/08/27 16:02:45 publish message: Hi, FISCO BCOS! 4 ```