timeout <= 0 not working for deleteTopics function

[aditya81070]

Describe the bug
In the deleteTopics docs, the description for timeout field is missing. It only says it is a number. There is no clear description of whether it is the max time taken in deleting all topics or the timeout of sending a deletion request (connecting to broker and all).

To find out, how this timeout is working under the hood, I jumped into the code and found that admin.deleteTopics is calling broker.deleteTopics under the hood and it has this doc (jsdocs comments). According to this doc, if timeout <= 0 then it will trigger the topic deletion and will return but when I provide timeout value as 0 or 1, it throws REQUEST_TIMED_OUT error.

Are these comments up to date? If no, is there any way I can trigger topic deletion asynchronously?

The asynchronous part is important for some applications. In my case, I am writing a scheduler that will clean up stale topics daily (a lambda function) but I don't want to pay for lambda execution time until all topics are deleted. I just want to send an async deletion request and if something goes wrong, I will pick those topics in the next run.

To Reproduce
Please provide either a link to a:

1. [failing test in a KafkaJS fork]
   Sorry, I am not running KafkaJS locally.
2. [repository with an example project reproducing the issue]
   Not possible

If none of the above is possible to provide, please write down the exact steps to reproduce the behavior:

1. Create a Kafka client.
2. Create an admin using const admin = client.admin() and connect to the admin using await admin.connect().
3. Call await admin.deleteTopics({topics: ['an-existing-topic'], timeout: 0 or -1}).

Expected behavior
The delete request should be sent successfully and I should get an ok response from deleteTopics call.

Observed behavior
The request failed with the REQUEST_TIMED_OUT exception when passing timeout as <= 0 value.

Environment:

• OS: MacOS 11.4
• KafkaJS version: 1.14.0
• Kafka version: 2.7.0
• NodeJS: node:12.13.1

[tulios]

Hi @aditya81070 , the comments are correct. I think this is a bug, the protocol layer for deleteTopics is probably not taking this scenario in consideration.

[aditya81070]

@tulios Thanks for quick response. Are there any plans to fix this one in upcoming release?
If it is a easy fix , I can raise a PR. I went deep down in the code to the some Encoder thing but couldn't understand fully. Some guidance on this will be helpful.

[Nevon]

I wasn't able to find any mention of timeout values <= 0 making topic deletion async. There's no KIP mentioning it and nothing in the Java client docs or anywhere else, so I think this is incorrect. I'm removing that comment in #1427 and updating the docs to include the default value.