NATS初識
https://github.com/nats-io
https://github.com/nats-io/nats-server
https://github.com/nats-io/nats.go
https://github.com/nats-io/nats-streaming-server
https://github.com/nats-io/stan.go
https://nats.io/download/
https://docs.nats.io/running-a-nats-service/introduction/installation
https://docs.nats.io/running-a-nats-service/clients
核心 nats-server 無持久化。
nats-streaming-server streaming內置nats-server服務器，帶持久化 。
nats-server 的啟動與測試
1、服務啟動
下載 https://github.com/nats-io/nats-server 后， 進入目錄../nats/nats-io/nats-server-main
執行 go build， 生成可執行文件 nats-server
執行 ./nats-server
localhost:nats-server-main chong$ ./nats-server [9854] 2022/01/10 15:43:29.571138 [INF] Starting nats-server [9854] 2022/01/10 15:43:29.571426 [INF] Version: 2.7.0-beta [9854] 2022/01/10 15:43:29.571430 [INF] Git: [not set] [9854] 2022/01/10 15:43:29.571440 [INF] Name: NBNLIDMD3YGE7XIQ54PVN2WYRFINJ6NONBIQJYP6F4VSTHYMS4ORFHPQ [9854] 2022/01/10 15:43:29.571460 [INF] ID: NBNLIDMD3YGE7XIQ54PVN2WYRFINJ6NONBIQJYP6F4VSTHYMS4ORFHPQ [9854] 2022/01/10 15:43:29.584612 [INF] Listening for client connections on 0.0.0.0:4222 [9854] 2022/01/10 15:43:29.585148 [INF] Server is ready
2、基本測試用例
這是go版本的nats客戶端
下載 https://github.com/nats-io/nats.go 后， 進入目錄../nats/nats.go-main/examples
先啟用主題監聽 go run nats-sub/main.go -s nats://127.0.0.1:4222 -t foo
發布主題及消息 go run nats-pub/main.go -s nats://127.0.0.1:4222 foo "msg two"
localhost:examples chong$ go run nats-pub/main.go -s nats://127.0.0.1:4222 foo "msg two" Published [foo] : 'msg two' localhost:examples chong$ localhost:examples chong$ go run nats-pub/main.go -s nats://127.0.0.1:4222 foo "msg two" Published [foo] : 'msg two'
localhost:examples chong$ go run nats-sub/main.go -s nats://127.0.0.1:4222 -t foo Listening on [foo] 2022/01/10 15:51:35 [#1] Received on [foo]: 'msg two' 2022/01/10 15:51:47 [#2] Received on [foo]: 'msg two' 2022/01/10 15:51:52 Disconnected due to:EOF, will attempt reconnects for 10m 2022/01/10 15:51:53 Reconnected [nats://127.0.0.1:4222] 2022/01/10 15:52:06 [#3] Received on [foo]: 'msg one'
nats-streaming-serve 的啟動與測試
1、服務啟動
下載源碼 https://github.com/nats-io/nats-streaming-server 后，進入../nats/nats-streaming-server-main目錄
執行 go build ， 生成可執行文件 nats-streaming-server
不帶參數的啟動命令 ./nats-streaming-server
帶參數的的啟動命令
./nats-streaming-server --store file --dir /Users/chong/Documents/code/go/nats/streaming-store-files --max_msgs 0 --max_bytes 0
localhost:nats-streaming-server-main chong$ ./nats-streaming-server --store file \
--dir /Users/chong/Documents/code/go/nats/streaming-store-files \
--max_msgs 0 --max_bytes 0 [91741] 2022/01/09 09:28:54.749153 [INF] STREAM:
Starting nats-streaming-server[test-cluster] version 0.23.2 [91741] 2022/01/09 09:28:54.749378 [INF] STREAM: ServerID: iL8tEmZBdTqud0rQbwzuro [91741] 2022/01/09 09:28:54.749382 [INF] STREAM: Go version: go1.17.3 [91741] 2022/01/09 09:28:54.749385 [INF] STREAM: Git commit: [not set] [91741] 2022/01/09 09:28:54.753269 [INF] Starting nats-server [91741] 2022/01/09 09:28:54.753288 [INF] Version: 2.6.5 [91741] 2022/01/09 09:28:54.753292 [INF] Git: [not set] [91741] 2022/01/09 09:28:54.753302 [INF] Name: NDBGMWEP6JYRPYAMU3XUZLCIRJHEZNDRLIZEUTLMOTHH [91741] 2022/01/09 09:28:54.753306 [INF] ID: NDBGMWEP6JYRPYAMU3XUZLCIRJ3HZNDRLIZEUTLMOTHH [91741] 2022/01/09 09:28:54.758760 [INF] Listening for client connections on 0.0.0.0:4222 [91741] 2022/01/09 09:28:54.759308 [INF] Server is ready [91741] 2022/01/09 09:28:54.785453 [INF] STREAM: Recovering the state... [91741] 2022/01/09 09:28:54.785841 [INF] STREAM: No recovered state [91741] 2022/01/09 09:28:54.787267 [INF] STREAM: Message store is FILE [91741] 2022/01/09 09:28:54.787276 [INF] STREAM: Store location:
/Users/chong/Documents/code/go/nats/streaming-store-files [91741] 2022/01/09 09:28:54.787338 [INF] STREAM: ---------- Store Limits ---------- [91741] 2022/01/09 09:28:54.787343 [INF] STREAM: Channels: 100 * [91741] 2022/01/09 09:28:54.787346 [INF] STREAM: --------- Channels Limits -------- [91741] 2022/01/09 09:28:54.787350 [INF] STREAM: Subscriptions: 1000 * [91741] 2022/01/09 09:28:54.787353 [INF] STREAM: Messages : unlimited [91741] 2022/01/09 09:28:54.787356 [INF] STREAM: Bytes : unlimited [91741] 2022/01/09 09:28:54.787359 [INF] STREAM: Age : unlimited * [91741] 2022/01/09 09:28:54.787362 [INF] STREAM: Inactivity : unlimited * [91741] 2022/01/09 09:28:54.787365 [INF] STREAM: ---------------------------------- [91741] 2022/01/09 09:28:54.787368 [INF] STREAM: Streaming Server is ready
2、測試用例
下載源碼 https://github.com/nats-io/stan.go ， 進入目錄 ../nats/stan.go-main/examples
發布主題及消息 go run stan-pub/main.go -s nats://127.0.0.1:4222 foo "msg nine..."
訂閱主題 go run stan-sub/main.go -s nats://127.0.0.1:4222 -t foo
發布過程如下：
localhost:examples chong$ go run stan-pub/main.go foo "msg nine..." go: downloading github.com/nats-io/nats.go v1.13.0 go: downloading github.com/gogo/protobuf v1.3.2 Published [foo] : 'msg nine...' localhost:examples chong$ localhost:examples chong$ localhost:examples chong$ localhost:examples chong$ localhost:examples chong$ go run stan-pub/main.go foo "msg nine..." Published [foo] : 'msg nine...' localhost:examples chong$ localhost:examples chong$ localhost:examples chong$ go run stan-pub/main.go foo "msg nine..." Published [foo] : 'msg nine...' localhost:examples chong$ localhost:examples chong$ pwd /Users/chong/Documents/code/go/nats/stan.go-main/examples localhost:examples chong$ localhost:examples chong$ localhost:examples chong$ go run stan-pub/main.go -s nats://127.0.0.1:4222 foo "msg nine..." Published [foo] : 'msg nine...' localhost:examples chong$
首次執行時，go會根據 go.mod 獲取、安裝依賴。
訂閱情況如下：
localhost:examples chong$ go run stan-sub/main.go -s nats://127.0.0.1:4222 -t foo Connected to nats://127.0.0.1:4222 clusterID: [test-cluster] clientID: [stan-sub] Listening on [foo], clientID=[stan-sub], qgroup=[] durable=[] 2022/01/10 16:26:43 [#1] Received: sequence:1 subject:"foo" data:"msg nine..." timestamp:1641802805067115000 2022/01/10 16:26:43 [#2] Received: sequence:2 subject:"foo" data:"msg nine..." timestamp:1641802826574706000 2022/01/10 16:26:43 [#3] Received: sequence:3 subject:"foo" data:"msg nine..." timestamp:1641802869268707000 2022/01/10 16:26:43 [#4] Received: sequence:4 subject:"foo" data:"msg nine..." timestamp:1641803177556474000
訂閱中的可選參數
go run examples/stan-sub/main.go -s nats://127.0.0.1:4222 --all -c test-cluster -id stan-sub -t foo
go run examples/stan-sub/main.go -s nats://127.0.0.1:4222 --seq 4 -c test-cluster -id stan-sub -t foo
go run examples/stan-sub/main.go -s nats://127.0.0.1:4222 --last -c test-cluster -id stan-sub -t foo
--seq <seqno> 從指定的序列號開始 --all 接受所有發送的數據 --last 從上一次最后一次發送的那條數據開始 --since <duration> 從當前往前的時間段開始接收(例如:1s, 1hr, 具體可以參看：https://golang.org/pkg/time/#ParseDuration) --durable <name> 永久訂閱者的名稱 --unsubscribe 退出時解除永久訂閱
附：命令備份
go env -w GO111MODULE=on #開啟go mod管理，同理off就是關閉
開啟之后，我們要import自己的包就會在go.mod路徑下進行尋址
go.mod內容如下:
#這里的go.mod是使用go mod init xx生成的
module 05-go
go 1.17
安裝gopls go get -v
運行nats的測試用例
進入測試用例目錄 nats.go-main/examples
發布主題為foo的消息
go run nats-pub/main.go -s nats://127.0.0.1:4222 foo "msg one"
訂閱主題為foo的消息
go run nats-sub/main.go -s nats://127.0.0.1:4222 -t foo
在 goland 中啟動 nats-server
1、配置
2、啟動
4、在命令行測試
開兩個 cmd 窗口 A 和 B， 分別執行 telnet 10.60.80.11 4222
顯示如下：
[D:\git\go\etcd]$ telnet 10.60.80.11 4222 Connecting to 10.60.80.11:4222... Connection established. To escape to local shell, press 'Ctrl+Alt+]'. INFO {"server_id":"NDI3F7PI75QKRAY2MH2X6YAL7XVQDX6LWODFU5H5HBNM4LQSYSIF3V25",
"server_name":"NDI3F7PI75QKRAY2MH2X6YAL7XVQDX6LWODFU5H5HBNM4LQSYSIF3V25",
"version":"2.9.0-RC.3","proto":1,"go":"go1.18.4","host":"0.0.0.0","port":4222,"headers":true,
"max_payload":1048576,"client_id":4,"client_ip":"10.60.80.11"}
在A中訂閱主題
sub topic001.* 89 +OK
在B中發布主題 ，注意這兩行分兩次輸入， 發布主題為 topic001.uu ，內容長度為5 的主題，
再輸入內容 hello， 此時在A中就顯示主閱到
pub topic001.uu 5
hello
+OK
A中顯示
sub topic001.* 89 +OK MSG topic001.uu 89 5 hello
ps:
為goland配置go sdk報錯問題
低版本的goland還需要配置GOROOT，但是在配置go1.17以上的時候就一直報這個錯誤
Goland配置GOROOT報錯：The selected directory is not a valid home for Go Sdk
原因goland版本過低，當go版本大於1.17時就會報此異常。
解決方案：
編輯自己go安裝目錄下的：go\src\runtime\internal\sys\zversion.go
增加一行自己的版本:
const TheVersion = `go1.18.4`