The log to opensearch suddenly error 400 when call POST '/_bulk'

[volethanh]

Hi @vduseev ,

I'm using this library to write directly log to opensearch. But I've got the issue that when I start the application, it write the log to opensearch normally, but It suddenly got error 400 and then I stucked with the 400, it can't POST to url /_bulk anymore

This is my picture that I've got in local environment and I also get this problem in the Azure App Service

Note that: When I run debug, I've just started the app and then I did not do anything even try any APIs

[vduseev]

Hey @volethanh.

This looks like an issue with the OpenSearch rather than the library. The code in the library does not do anything special to cause the OpenSearch instance to suddenly stop accepting _bulk requests.

You mentioning that you can't send _bulk even using the API of the OpenSearch directly once it errors out only confirms this hypothesis.

I can recommend checking several things:

1. Health status of OpenSearch when this happens.
2. Logs of that OpenSearch instance. Maybe it's out of memory? Maybe it's out of available file handlers? Disk full?
3. Testing your app against a different OpenSearch instance, for example, one that you run locally.

If none of that yields any significant results, then we'd need to figure out the smallest reproducible setup. Can you reproduce this problem using an extremely simple example? If so, I can try to reproduce it on my side using your code.

Otherwise, so far, there is not enough data to figure out what is wrong. But something tells me it's OpenSearch rather than the library.

Hope that helps!

[volethanh]

Thanks for the reply, now I know why I got this issue. It is because I’ve used the latest opensearch 2.11, when I downgrade to 2.10, it worked as expected