Start of Node Red stalling

I put together a new node red server on a Pi yesterday and all went well apart from a couple of times it seems to hang when starting node red, i looks like it's stopping just after connecting to the Cloud MQTT server, any ideas?
This is what the terminal window says

Starting as a systemd service.
Started Node-RED graphical event wiring tool.
16 Jul 06:33:37 - [info]
Welcome to Node-RED
16 Jul 06:33:37 - [info] Node-RED version: v0.18.7
16 Jul 06:33:37 - [info] Node.js  version: v8.11.3
16 Jul 06:33:37 - [info] Linux 4.14.52-v7+ arm LE
16 Jul 06:33:38 - [info] Loading palette nodes
16 Jul 06:33:41 - [info] Dashboard version 2.9.4 started at /ui
16 Jul 06:33:43 - [info] Settings file  : /home/pi/.node-red/settings.js
16 Jul 06:33:43 - [info] User directory : /home/pi/.node-red
16 Jul 06:33:43 - [warn] Projects disabled : editorTheme.projects.enabled=false
16 Jul 06:33:43 - [info] Flows file     : /home/pi/.node-red/flows_raspberrypi.json
16 Jul 06:33:43 - [info] Server now running at
16 Jul 06:33:43 - [warn]
Your flow credentials file is encrypted using a system-generated key.
If the system-generated key is lost for any reason, your credentials
file will not be recoverable, you will have to delete it and re-enter
your credentials.
You should set your own key using the 'credentialSecret' option in
your settings file. Node-RED will then re-encrypt your credentials
file using your chosen key the next time you deploy a change.
16 Jul 06:33:43 - [info] Starting flows
16 Jul 06:33:43 - [info] Started flows
16 Jul 06:33:43 - [info] serial port /dev/ttyAMA0 opened at 9600 baud 8N1
16 Jul 06:33:43 - [info] [mqtt-broker:CloudMQTT] Connected to broker: mqtt://

I noticed that the dashboard page is running OK so I suppose Node red is actually running but when I visit the IP address of the server I just get the node red title bar and sometimes the animated bars at the top left but it does not show the flows or any nodes.

It stops here.


After approximately 5 min's the full flows appeared so it appears to be a long delay rather than a stall, maybe it's the WiFi connection?

Which Pi are you on ? It will take a time to start on a Pi zero or 1 - but more like 20-30 secs. ? Are you using the browser on the or browsing in from a remote device ? an external browser should be faster.

I'm running it on a Pi 3, not the latest though and accessing it from a remote browser, I've also noticed that sometimes when I deploy it is very quick and other times it takes 30 - 40 seconds to deploy.

Anything else running on the pi?
How many tabs in NR?
How many nodes?
Do you experience delay getting to outside sites when this happens?
Any equipment running that could effect the wireless(like microwave or electrical motors)?

Nothing else running that I've added, fresh install.
Three tabs, ESPlogon for the ESP8266s I have to read temp and display temp. another to take the temp from MQTT and send it to the display and the last that's currently not doing anything.
The delay doen't affect any other internet acces (70MB fibre)
Don't think so, no issues with other WiFi kit and now connected the Pi to a Ethernet cable.

Still getting random long delays for the node red flows to appear and deploying can take 2 seconds or 30 seconds.
I might just start again with another SD card maybe something to do with that?

By fresh install do you mean of the OS or NR and did you use the bash script to update it?

Fresh OS install and yes I ran the script.

so is it the display that is using the serial port?
I have had slow issues in the past on my pi where’ I was suing the serial port, it was down to specific versions of node and serial port.

Have you followed the advice online about using the serial port? eg

I'll remove the serial port for now see if it makes a difference, the display is a remote esp that I send MQTT data to.

I have used this exact setup before without any problems though.

Thanks for the suggestions

Something strange is going on, I left it for a couple of hours and came back to see that it had gone really slow again and I noticed that the chip surface temp (IR thermometer) had gone from running at about 45 C with a load of 0 - 1% to 69 C (no heat-sinks) and a load of 45% a reboot got it back to normal.

Not sure what's going on but something is loading it up, I've removed the serial port node from the flow and I'll see how it goes and maybe add a flow to log the system temp over time.

(You can use an exec command and vcgencmd measure_temp to get the local Gpu temp which may be an ok proxy)

Had some more strange issues so started from scratch again and so far all is well, I've not added the serial port yet so we'll see if that makes a difference.