dubbo-go client, dubbo-Java server, server can't get "remote.application" key attachment

[zhangcunli]

Environment

• Server: Dubbo-Java, v3.3.0
• Client: Dubbo-go, v3.2.0-rc2
• Protocol: tri
• Registry: zookeeper

Issue description

Server can't get "remote.application" key from attachment.

Logs

1.client, dubbo-go v3.2.0-rc2

		atm := make(map[string]interface{})
		atm["key1"] = "value1"
		atm["remote.application"] = "appname"
		atm["remote.application2"] = "appname"
		ctx1 := context.WithValue(context.Background(), v3constant.AttachmentKey, atm)

2.server:

        Map<String, Object> serverAttachments = RpcContext.getServerAttachment().getObjectAttachments();
        System.out.println("ContextService serverAttachments:" + JSON.toJSONString(serverAttachments));

3. server print:

{
    "key1": "value1",
    "retries": "",
    "remote.application2": "appname"
}

"remote.application" key is null

[AlexStocks]

zhangcunli 反馈：如果把 “remote.application” 发送到 dubbo 端，这个 attachment 就丢失了

[solisamicus]

For reference, there's a related article that might help: Reference Article. Hope it helps!

[AlexStocks]

这里先给出结论：这不是一个 bug，之所以 attachment 中 key 为 "remote.application" 的 item 在 dubbo server 端被过滤掉，是因为该 key 是 dubbo(Java) attachment 中的保留字段，不允许用户使用。