# Looking for advice on how to

**URL:** <https://discourse.nodered.org/t/looking-for-advice-on-how-to/23738>\
**Category:** General\
**Created:** [27 March 2020 14:22 UTC](https://discourse.nodered.org/t/looking-for-advice-on-how-to/23738 "2020-03-27T14:22:07Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![shuri1](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@shuri1](https://discourse.nodered.org/u/shuri1)\
**Post date:** [27 March 2020 14:22 UTC](https://discourse.nodered.org/t/looking-for-advice-on-how-to/23738/1 "2020-03-27T14:22:07Z")

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I'm being asked to build an app on a multitech conduit using node red.

It needs to do the following:

1. Receive Lora messages
2. Send them off to a web service
3. If the send fails, resend.....without ever losing a msg

#1 and #2 are easy....i cant figure out a reasonably straightforward way to do #3

Thanks  
Larry

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**Author:** ![afelix](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/afelix/32/9743_2.png) [@afelix](https://discourse.nodered.org/u/afelix)\
**Post date:** [27 March 2020 14:48 UTC](https://discourse.nodered.org/t/looking-for-advice-on-how-to/23738/2 "2020-03-27T14:48:43Z")

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Have you thought about utilising the catch/status nodes to start a flow for 3?  
[https://cookbook.nodered.org/basic/retry-on-error](https://cookbook.nodered.org/basic/retry-on-error)

> [@](#):
>
> The `Catch` receives the error which passes the message back to the `Function` node to retry. It also includes a `Delay` node as, in some circumstances, it is suitable to wait for a short interval before retrying.

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<div class="post-metadata">

**Author:** ![shuri1](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@shuri1](https://discourse.nodered.org/u/shuri1)\
**Post date:** [28 March 2020 17:17 UTC](https://discourse.nodered.org/t/looking-for-advice-on-how-to/23738/3 "2020-03-28T17:17:00Z")

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I tried that but i am talking about potentially dozens of messages and it seems to have a limit. Additionally, are they persisted?

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**Author:** ![krambriw](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/krambriw/32/5429_2.png) [@krambriw](https://discourse.nodered.org/u/krambriw)\
**Post date:** [29 March 2020 07:04 UTC](https://discourse.nodered.org/t/looking-for-advice-on-how-to/23738/4 "2020-03-29T07:04:50Z")

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I suppose you receive an ack from the web service on successful transmission? And hopefully you always know the status of it?

I would just build up a FIFO "pile" of messages in context when transmission fails and as soon as the connection is working again, resend them again.

But,,,

- you may have to think about the order messages are sent
- should you go for FIFO or LIFO?
- what if connection is broken and then suddenly works? Should you send the current message first or should you work through the pile first?
- do you need to think about messages getting "too old", could it happen they become obsolete after a while?
- do you have to consider total number of messages to keep?
- what if the web service is down for a longer period?

Where do we send the bill for this consultancy?

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [28 May 2020 07:04 UTC](https://discourse.nodered.org/t/looking-for-advice-on-how-to/23738/5 "2020-05-28T07:04:52Z")

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