aws xray如何实现应用log和trace的关联关系

参考资料

• https://community.aws/tutorials/solving-problems-you-cant-see-using-aws-x-ray-and-cloudwatch-for-user-level-observability-in-your-serverless-microservices-applications
• https://stackoverflow.com/questions/76000811/search-cloudwatch-logs-for-aws-xray-trace-id-in-code

ecs容器环境下应用生成的trace信息没有log关联，但是在lambda环境中测试时发现可以进行关联

检查发现，trace的rawdata中存在aws的cwlog字段

在控制台查看网络请求，此时会向cloudwatchlog服务发送log insight请求

当我们在控制台点击跳转到loginsight时，语句如下。

fields @log, @timestamp, @message
| filter @message like "1-66570681-3cb9b1bc917ab87c3dd8b303" or @message like "665706813cb9b1bc917ab87c3dd8b303"
| sort @timestamp, @message desc

经过以上步骤我们对两个问题有所了解

• xray如何找到日志组？通过aws.cloudwatch_log属性
• log如何呈现在xray控制台？通过发送loginsight的xhr请求

那么，接下来我们需要考虑如何在ecs应用中实现以上条件。参考链接（https://stackoverflow.com/questions/76000811/search-cloudwatch-logs-for-aws-xray-trace-id-in-code）中的说明

For API Gateway, Lambdas, the application logs group name are embedded in X-Ray traces out of box, so you don’t need to do anything specially.

For the trace Id injection to application logs, today it is only supported by X-Ray/OTel Java SDKs. For Javascript applications, you’ll need to inject and print X-Ray trace ids AWS-XRAY-TRACE-ID: 1-5d77f256-19f12e4eaa02e3f76c78f46a to your application log entries yourself.

对于条件1，我们需要编辑segment，加入aws.cloudwatch_log属性

对于条件2，我们需要在log内容中注入traceID

参考链接（https://blog.csdn.net/sinat_41567654/article/details/129317614）中的步骤创建xray和ecs集成环境，加入以下额外逻辑

• 在segment中加入aws.cloudwatch_log属性
• 模拟输出了一条日志并嵌入traceID

app.get('/', (req, res) => {var document = AWSXRay.getSegment();// 加入aws.cloudwatch_log属性document.aws.cloudwatch_logs = [{"log_group": "/ecs/ecs-xray-demo-fargaet"}]traceId = document.trace_id;console.log(document)// 模拟输出了一条日志并嵌入traceIDconsole.log("2019-09-10 18:58:30.844 [nio-5000-exec-4]  AWS-XRAY-TRACE-ID: " + traceId + " WARN 1 - Your logging message here")
})
app.use(AWSXRay.express.closeSegment());

查看ecs的应用日志如下，trace和log成功关联

查看xray服务的控制台成功实现关联