Issue with large webhook response

Describe the problem/error/question

We have a system calling n8n (tested and duplicated with Postman). N8N calls a third party system and receives a JSON, cleans the data and SHOULD respond to the calling webhook with that the JSON. We are calling the respond to webhook with all incoming items. N8N says it ran the flow successfully, but our calling system and Postman never get anything back from the n8n respond to webhook. The responding webhook is over 1200 items. Does n8n have a limit that we are reaching with the webhook response?

Share the output returned by the last node

Information on your n8n setup

  • n8n version: 1.29.1
  • Database (default: SQLite): n8n cloud
  • n8n EXECUTIONS_PROCESS setting (default: own, main): n8n cloud
  • Running n8n via (Docker, npm, n8n cloud, desktop app): n8n cloud
  • Operating system: n8n cloud

Edit: I am wrong here, i thought it gave an error if the payload was too big
As long as there isn’t an error then it shouldn’t be, unless something is different on cloud accounts but I doubt it.

Would you be able to share the sample data so i could try it out? I can message you a webhook link where you could send it to if you’re able to share

Let me know

n8n has a limit for the payload. It’s 16 MB of data by default (see N8N_PAYLOAD_SIZE_MAX variable in the Environment variables reference | n8n Docs)

Plus n8n will save all execution data in the memory, so it may be also a run-out-of-memory issue.
For such a large amount of items better to use an external message broker service (like rabbitMQ or AMQP)

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I’m on cloud so I don’t have the options to change those type of settings. And really the json isn’t that large, its only 2.6Mb

I think I have a cleaned up JSON that has confidential data removed. I tried making a Postman Mock server but it just creashes it.

The JSON is ~2.66Mb currently and ~440,000 lines. Unfortunately I’m limited to getting the data in one call currently so I have to be able to get all of those, and its continuing to grow process and returned to the system. calling and requesting the data. The flow works fine with a smaller data sample.

Sample JSON Linked here testset.json - Google Drive

Actually it is about 15 MB

According to the JSON, why you need a Loop node? As you have only one big item from the HTTP request node. So that one should acts the same

I think our original mindset was to get it to work with such as large dataset. I’m trying different options right now.

When I try the flow similar to yours i’m run into the issue where it sees it as X amount of items, but only sends the first item in the response.

I got the full data set to run and give me the a json to return, but I doesn’t actually return the data set to the webhhook. Why NOT? It says its done but my postman run that triggered still hasn’t received anything from n8n on the respond to webhook. Postman still says Sending Request. n8n is refusing to send a response back on a larger dataset no matter what I do.

Did you try to open the webhook manually and see what will be there?

I don’t see any issues with the curl

Another reason that may occur is the timeout for the request. Maybe Postman/n8n forces the connection to close after a certain amount of time