Question

我看到了我不完全理解的NodeJS Lambda上的行为。首先，我假设我们的代码中至少存在一个错误，但是我们难以理解的问题是，它如何影响同一Lambda实例上的子序列调用。

尽我所能理解的问题是，在初始失败之后，我的下一次调用也会失败，并且我看到一个错误，似乎表明nodejs已终止。然后我看到它重新初始化，并再次成功开始处理请求。

有一些问题：

好的，我们似乎有一个错误，我想我们可以对其进行跟踪并在某个时间点对其进行修复
随后的调用中的nodejs终止，但调用被视为成功（当然不会成功）
因为第二次调用被视为成功，所以不会重试

让我尝试展示一下外观的一些细节。首先，这是第二次调用，实际上确实失败了，NodeJS似乎终止了：

START RequestId: a71447b0-19f8-456c-b163-47e0408bf3a1 Version: $LATEST
2019-10-17T00:26:12.295Z    a71447b0-19f8-456c-b163-47e0408bf3a1    INFO    Assuming lambda role: { ... }lambda',
END RequestId: a71447b0-19f8-456c-b163-47e0408bf3a1
REPORT RequestId: a71447b0-19f8-456c-b163-47e0408bf3a1    Duration: 228.19 ms    Billed Duration: 300 ms    Memory Size: 256 MBMax Memory Used: 158 MB
RequestId: a71447b0-19f8-456c-b163-47e0408bf3a1 Error: Runtime exited with error: exit status 129

也许我误解了最后一行，但是肯定看起来NodeJS对我终止了（使用SIGHUP ??！）。之后，下一次调用将显示XRay日志记录，就像在该实例的第一次调用上看到的一样：

2019-10-17T00:55:30.531Z       undefined       INFO    AWS_XRAY_DAEMON_ADDRESS is set. Configured daemon address to 169.xxx.xxx.xxx.
2019-10-17T00:55:30.536Z       undefined       INFO    AWS_XRAY_CONTEXT_MISSING is set. Configured context missing strategy to LOG_ERROR.
2019-10-17T00:55:30.554Z       undefined       INFO    Subsegment streaming threshold set to: 0

所以它在我的lambda实例上重新启动了NodeJ？那是我们应该看到的吗？

如果我通过X射线等进行查找，则显示错误，但状态为200：

我认为值得一提的是，先前的调用似乎触发了这一点。它也成功，并且确实返回了正确的值，但完成后，我在日志中看到了这一点：

2019-10-17T00:55:29.169Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}
2019-10-17T00:55:29.326Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}
2019-10-17T00:55:29.328Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}
2019-10-17T00:55:29.329Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}
2019-10-17T00:55:29.329Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}
2019-10-17T00:55:29.330Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}
2019-10-17T00:55:29.368Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}
2019-10-17T00:55:29.388Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}
2019-10-17T00:55:29.408Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}
2019-10-17T00:55:29.428Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}
2019-10-17T00:55:29.467Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}
2019-10-17T00:55:29.468Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}
2019-10-17T00:55:29.469Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}
2019-10-17T00:55:29.567Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}
2019-10-17T00:55:29.568Z    3bf23bda-e7fa-4fd7-b373-2258baff2bb8    ERROR   Uncaught Exception  {"errorType":"Error","errorMessage":"premature close","stack":["Error: premature close","    at Duplexify.onclose (/var/task/node_modules/end-of-stream/index.js:47:67)","    at Duplexify.emit (events.js:198:13)","    at Duplexify.EventEmitter.emit (domain.js:448:20)","    at Duplexify._destroy (/var/task/node_modules/duplexify/index.js:199:8)","    at /var/task/node_modules/duplexify/index.js:182:10","    at /var/task/node_modules/async-listener/glue.js:188:31","    at process._tickCallback (internal/process/next_tick.js:61:11)"]}

毫无疑问，这是我们代码中的错误。对我来说，这可能不是很明显，因为这些库不是我们的代码使用的库。实际上，这些似乎已被AWS XRay使用。那么XRay是否存在故障，并且导致我们调用失败？

我想了解：

nodejs是否失败并正在重新启动？
是否有办法捕获此过程终止并将其至少视为失败的调用？

以下是一些~~我们要尝试的事情~~，我们尝试了但没有帮助：

升级了aws-sdk和xray软件包：没有变化
我们已经添加了异常处理和日志记录功能，而没有学习任何新知识，我们将继续沿这条路前进

更新：在“正常”情况下，包括记录了多个错误的情况，我们将做同样的事情。我们订阅了一个IoT主题，发布了一条消息，并等待长达5秒钟的响应。这些执行都没有等待响应的超时（我们最多等待5秒钟，如果未收到响应则返回错误），并且Lambda执行都没有超时。在上述情况下（请求ID a71447b0-19f8-456c-b163-47e0408bf3a1在日志中），我们不这样做，因为据我所知我们的代码未运行-没有日志表明它可以运行。

这种情况不会经常发生。在过去几天中，我正在执行25次执行中的大约1次。负担不大，因此我们只执行了大约190次调用（到目前为止，其中8次失败）。

Answer 1

几个月后返回报告，以描述这是什么以及如何解决。

尚不清楚（但事后看来，应该是这样），其根源是专门在lambda中使用MQTT.js（作为AWS IOT SDK的一部分）。特别是当lambda不活动时，有时会断开连接-这是可以预期的。这里发生的是MQTT.js在断开连接时触发一个事件，并且该事件可以在不可预知的时间运行。

总而言之，我们需要处理error和close事件。如果未处理它们，则如上所述，我们将遇到未处理的异常。解决这个问题非常简单-我们只需要处理这些事件并创建一个新的客户端等。

我认为我们应该比以前更简单地解决此问题-对我们而言，它与MQTT无关（但一旦我们意识到这是相对较快解决的，对我们而言并不明显）。

作为旁注，可能值得指出的是，最新的IoT专用AWS开发工具包无论如何都不使用MQTTjs。我不确切知道这样做的动机是什么，但是我不知道这个问题/答案在未来的改变中会有多大用处。

NodeJS Lambda似乎失败，但报告成功

1 个答案: