Modbus-flex-server Node crashing once a day with EHOSTUNREACH

Hi there we are running a flow that is using the Modbus-flex-server Node - and it is crashing once a day with an EHOSTUNREACH error.

This is happening on 2 different networks and on multiple different hardware devices. Is there any way to ensure the server restarts after such crash or how do we gather more info about a crash like that? Or is there another way to recover without restarting the flow.

Can you provide the node-red log showing the log trace of the crash?

Are you making multiple requests at the same time or sequencing your requests?

Do you make the most of grouping reads to minimise traffic? (This article explains what I mean and why I ask that)

Hi Steve,

The only error associated with the modbus-flex-server issue that I could find in the logs were:

error: read EHOSTUNREACH

I did enable the error log output option for the server, but I am still unsure how we can get a more detailed version of the server status. Please let me know if you have any suggestions regarding this as well.



@avermeulen said :

So is node-red actually crashing or not?

Also, answer other question.


So the Modbus-flex-server is crashing, node-red keeps on running. The problem is that the Modbus-flex-server does not recover from the issue. Hope that makes it more clear?


If that is all you could find how do you know it is associated with the server node?

Hi Colin,

The server is unreachable and we cannot get any response from it. We need to restart the node-red instance to get the server working again. We tracked the server comms connection, and it dropped out at the same time as the when the error: read EHOSTUNREACH log was generated.


I suggest you raise an issue on the repository.