Timestamp proces start and end

Questions
1

I want to log each process run, by setting a starting and ending timestamp.

At present I have two Function nodes, with code like this:

items[0].json.processStart = new Date();
return items;

which runs as the first node of the workflow, and:

items[0].json.processEnd = new Date();
return items;

which runs after all other nodes have completed.

These are then merged, and fires a set of nodes that use the json.processStart and json.processEnd values from the Merge node, to insert this into an auditing table in my PG database.

It works well, but I was wondering:

  • Is this the best approach?
  • Does n8n have the concept of global variables that I can use to set these values? Or, is using the output from Function nodes the only way?
2

The only other way would be to use the static workflow data as documented here:

Not sure however if that is a huge improvement.

Apart from that do you not have to merge the data of the two Function-Nodes. In the second Function-Node you can directly access the data of first one via $node as documented here:

That would make your workflow at least a little bit simpler.