Ok, so new problem. I have a delay node set to rate limit. Is there a way that if it has messages queued up (queueing up?) and the first one completes, can I send the node a signal to send the next message? As in: not peek at it, but actually step to the next message. Thanks.

Does sending a message with no payload, and msg.flush = 1 not release the next message from the delay node?

I recommend node-red-contrib-queue-gate (node) - Node-RED when doing this sort of thing

I’ll throw my hat in this one :slightly_smiling_face: [image] @marcus-j-davies/node-red-semaphore-plus An advanced set of semaphore Nodes for Node RED, with a dynamic fail-safe May help you also, may not - but just in case

@cymplecy Thanks! Forgot I had that. Not to add more nodes, I'll use it. Silly me for forgetting I had it.

Sending in msg.flush set to a number will release that many right away. So msg.flush=1 will release the next message

That's a point of contention. FLUSH..... So that sends the next message or PEEKS at it? I seem to remember the latter. That causes all sorts of trouble. OK, I was wrong. Thanks. That maybe nicer to apply.

Here is my standard flow, using a delay node, for handling messages sequentially. Open the comment node for full details of how to use it. If you want to include a retry feature to retry messages that fail for some reason (for example sending email messages where the send may fail) then you can us…

Thanks. Just completed something just like that.

You may already have this built-in but there should probably be some kind of limiter on the total number of messages queued? In theory, it would be possible to crash Node-RED without any limiter I think?

Yes - setting nodeMessageBufferMaxLength can set a max number of messages to store - default is "infinite" ie no limit. But you can set it if you are worried... of course what to set it to will depend on size of messages being held, rate of arrival, processing, and physical space etc....

[image] TotallyInformation: there should probably be some kind of limiter on the total number of messages queued? In theory, it would be possible to crash Node-RED The same is true of a simple Delay node in rate limit mode, and queuing intermediate messages. If you send it messages at a rate …

Help with `delay` node set to `rate limit`

General

dceejay 4 July 2026 11:44 16

It applies to the switch, delay, sort, batch and split nodes - ie the core ones that can potentially buffer up a load of messages. When exceeded it throws a "too many messages" error and drops any stored messages.

We have http-request, tcp-request, serial-request - any objections to an mqtt-request?

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Help with `delay` node set to `rate limit`

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