sendEmail hangs forever

[offbeatful]

• @azure/communication-email:
• 1.0.0:
• MacOS Arm64:
• nodejs
  • v18.14.2:
• typescript
  • 5.0.4:
• Is the bug related to documentation in
  • README.md
  • source code documentation
  • SDK API docs on https://docs.microsoft.com

Describe the bug
sendEmail hangs forever. Exact steps are unknown except the issues start occurring after sending 50+ emails.

To Reproduce
Steps to reproduce the behavior:
1.

Expected behavior
Method should return always.

Additional context

The suspect is LRO lib (@azure/core-lro 2.5.3) at dist/index.js:961

    poll(options = {}) {
        if (!this.pollOncePromise) {
            this.pollOncePromise = this.pollOnce(options);
            const clearPollOncePromise = () => {
                this.pollOncePromise = undefined;
            };
            this.pollOncePromise.then(clearPollOncePromise, clearPollOncePromise).catch(this.reject);
        }
        return this.pollOncePromise;
    }

It seems that if this.pollOnce return resolved promise, then clearPollOncePromise is executed immediately, leaving this.pollOncePromise as undefined. Changing the method to something like this, solves the problem.

    poll(options = {}) {
        var returnValue = this.pollOncePromise;
        if (!returnValue) {
            returnValue = this.pollOncePromise = this.pollOnce(options);
            const clearPollOncePromise = () => {
                this.pollOncePromise = undefined;
            };
            this.pollOncePromise.then(clearPollOncePromise, clearPollOncePromise).catch(this.reject);
        }
        return returnValue;
    }

Also not sure if clearPollOncePromise should be executed twice.

[jeremymeng]

@deyaaeldeen for LRO discussion.

[MaryGao]

@offbeatful Thanks for reporting this! I am trying to reproduce this issue in my local, could you help with details:

• I guess it happened when calling client.beginSend could you share your parameter with me?
• Could you share more about what you observed on why the program is stuck?
• Just double confirm that you tried your solution in you local and it works right?

[offbeatful]

Yes, that is correct. I am basically replacing the code in node_modules in order to make code actually send emails and not hang.
I don’t do anything crazy. Just follow official guide - instantiate class and invoke method. I do this in a loop, for 100+ emails, awaiting each of these (I already asked to increase the quota, so I was able to send more than 30 per minute). For the first 30-50 emails everything seems working. And then, it starts returning faster and lat some time it stopped working - simply hangs.

[MaryGao]

@offbeatful Could you try to repro the issue and then share the logs with the fix you mention?

import { setLogLevel } from "@azure/logger";

setLogLevel("verbose");

I tried this in my local and as you said everything seems working for the first 50 emails, but after that it stopped working and simply hangs. Then I debugged the code and found the server side has complained with 429 TooManyRequests error and with retry-after header so our program just hangs and waits the timeout to retry again. I tried the code you mentioned but it still hangs and I am not sure I met the same case with you.

[github-actions]

Hi @offbeatful. Thank you for opening this issue and giving us the opportunity to assist. To help our team better understand your issue and the details of your scenario please provide a response to the question asked above or the information requested above. This will help us more accurately address your issue.

[offbeatful]

It may be a case, as I requested to increase the quota and haven’t experienced the issue before.

I will try sending 100 emails and report back soon.

[MaryGao]

@offbeatful Thanks for the info! If this is the case for server-side 429 TooManyRequests I don't think any fix in client side would work. So please let us know if any client-side fix would stop hangs and share with us logs.

We may prefer to close this issue and do you have any concern?

[github-actions]

Hi @offbeatful. Thank you for opening this issue and giving us the opportunity to assist. To help our team better understand your issue and the details of your scenario please provide a response to the question asked above or the information requested above. This will help us more accurately address your issue.

[github-actions]

Hi @offbeatful, we're sending this friendly reminder because we haven't heard back from you in 7 days. We need more information about this issue to help address it. Please be sure to give us your input. If we don't hear back from you within 14 days of this comment the issue will be automatically closed. Thank you!