# Performance / Efficiencies - best practice?
**URL:** https://discourse.nodered.org/t/performance-efficiencies-best-practice/23310
**Category:** General
**Created:** [19 March 2020 09:17 UTC](https://discourse.nodered.org/t/performance-efficiencies-best-practice/23310 "2020-03-19T09:17:50Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@bakman2](https://discourse.nodered.org/u/bakman2)
#### Post date: [19 March 2020 09:17 UTC](https://discourse.nodered.org/t/performance-efficiencies-best-practice/23310/1 "2020-03-19T09:17:50Z")
Having a lot of mqtt (out)nodes in my flows (must sound familiar), I was wondering if there is a best practice / best optimisation of (mqtt) node use.
Is there a performance impact/optimisation of using a lot of mqtt out nodes versus using a single mqtt-out node that are all linked using link nodes ?
I guess it does not apply only to mqtt, but in general, is there a degrade/gain to reuse single out-nodes via links nodes ?
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### Author:  [@knolleary](https://discourse.nodered.org/u/knolleary)
#### Post date: [19 March 2020 09:29 UTC](https://discourse.nodered.org/t/performance-efficiencies-best-practice/23310/2 "2020-03-19T09:29:26Z")
Adding the link nodes does mean the message has to go through more 'hops' between nodes before it gets published. But I doubt you'd notice the difference to be honest.
From a memory standpoint, if you are replacing N MQTT nodes with 1 MQTT node, but adding in (N+1) Link nodes, then overall you will have more node objects in the flow. Again, I doubt whether that is a difference you'd be able to measure unless you are doing things at a pretty massive scale.
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### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [19 March 2020 09:40 UTC](https://discourse.nodered.org/t/performance-efficiencies-best-practice/23310/3 "2020-03-19T09:40:30Z")
It is important that all the nodes use the same mqtt config node. But I have little doubt you have done that already. Worth saying though for others that may see this.
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### Author:  [@zenofmud](https://discourse.nodered.org/u/zenofmud)
#### Post date: [19 March 2020 09:50 UTC](https://discourse.nodered.org/t/performance-efficiencies-best-practice/23310/4 "2020-03-19T09:50:54Z")
> [@Colin](#):
>
> It is important that all the nodes use the same mqtt config node
@colin Why? what is the reason?
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### Author:  [@kuema](https://discourse.nodered.org/u/kuema)
#### Post date: [19 March 2020 09:54 UTC](https://discourse.nodered.org/t/performance-efficiencies-best-practice/23310/5 "2020-03-19T09:54:51Z")
Since the broker connection is kept open and shared between all user nodes it wouldn't make much of a difference, since all messages have to be handled in the same NodeJS process anyway. 🤔
What could have an impact is the usage of wildcards vs. distinct topics (on a larger scale).
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### Author:  [@knolleary](https://discourse.nodered.org/u/knolleary)
#### Post date: [19 March 2020 09:55 UTC](https://discourse.nodered.org/t/performance-efficiencies-best-practice/23310/6 "2020-03-19T09:55:25Z")
Each config node represents a separate connection to the broker.
if you want to maximise efficiency, use the same config node so you only have one connection to the broker.
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### Author:  [@bakman2](https://discourse.nodered.org/u/bakman2)
#### Post date: [19 March 2020 10:04 UTC](https://discourse.nodered.org/t/performance-efficiencies-best-practice/23310/7 "2020-03-19T10:04:23Z")
Sorry I should have mentioned that, but yes I assumed a single config.
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### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [19 March 2020 10:07 UTC](https://discourse.nodered.org/t/performance-efficiencies-best-practice/23310/8 "2020-03-19T10:07:42Z")
Just in case there is some confusion over terminology when you create an MQTT In/Out node there are actually two nodes involved. The In/Out node that you see on the flow and the config node that it uses to connect to the mqtt broker. On the In/Out node configuration is a drop down box to select the server (ie broker), each broker maps to a config node. So in the dropdown there should generally only be one entry for each MQTT broker that you wish to connect to,
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### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [2 April 2020 10:07 UTC](https://discourse.nodered.org/t/performance-efficiencies-best-practice/23310/9 "2020-04-02T10:07:44Z")
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