调用一次lambda函数，执行两次

本文介绍了调用一次lambda函数，执行两次的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

这不是问题，而是更多的问题，但是，以前有人遇到过吗?有人知道如何预防吗?

This is more of a concern than a question, but still, has anyone experienced this before? Does anyone know how to prevent it?

我有一个lambda函数(L1)，它调用了所有用NodeJs编写的第二个lambda函数(L2)(运行时:Node.Js 8.10，而aws-sdk应该是v2.488.0-但我只是将其粘贴到文档).简而言之，L1应该调用L2，并且在执行L2时执行两次！我通过将日志写入CloudWatch发现了这一点，并且可以看到一个L1日志和两个L2日志.

I have a lambda function (L1) which calls a second lambda function (L2) all written in NodeJs (runtime: Node.Js 8.10, and aws-sdk should be v2.488.0 - but I'm just pasting that from the documentation). The short story is that L1 is supposed to call L2, and when it does L2 is executed twice! I discovered this by writing logs to CloudWatch and I could see one L1 log and two L2 logs.

这是L1和L2的简化版本.

Here's a simplified version of L1 and L2.

L1:

const AWS = require('aws-sdk');
const lambda = new AWS.Lambda();

module.exports = {
    handler: async (event, context, callback) => {
        const lambdaParams = {
            FunctionName: 'L2',
            Qualifier: `dev`,
            Payload: JSON.stringify({}),
        };

        console.log(`Calling: ${JSON.stringify(lambdaParams)}`);
        return await lambda.invoke(lambdaParams).promise();
    },
};

L2:

module.exports = {
    handler: async (event, context, callback) => {
        console.log(`L2 called`);
    },
};

在CloudWatch中，我可以看到一个Calling ....和两个L2 called！

In CloudWatch I can see one Calling .... and two L2 called!

顺便说一句，这并非一直都发生.这是步骤函数过程的一部分，该过程将调用L1 10k次.我的代码的编写方式是，如果L2执行两次(每个调用一次)，它将使整个过程失败(因为L2仅在记录不存在时才向DB插入记录，而在记录不存在时会失败).到目前为止，我设法记录了3次此行为.它们全部处理相同的10k项，每次都面对不同迭代的问题.

BTW, this does not happen all the time. This is part of a step function process which was going to call L1 10k times. My code is written in a way that if L2 is executed twice (per one call), it will fail the whole process (because L2 inserts a record to DB only if it does not exist and fails if it does). So far, I managed to log this behaviour three times. All of them processing the same 10k items, facing the issue at a different iteration each time.

有人有相同的经历吗?甚至更好的是，知道如何确保一个调用导致一个执行?

Does anyone have the same experience? Or even better, knows how to make sure one call leads to exactly one execution?

Process

调用一次lambda函数，执行两次

问题描述

推荐答案