Store running time of the task in a different measurement

I am running InfluxDB 2.0 as a container in my ec2 instance. and I am getting real-time data using telegraf it goes to InfluxDB I am running many tasks on real-time data and storing in different measurements. I also had historical data so I already computed the down-sampled data and pushed it into the same measurement. Now when my task is running data is going in the same measurement after the computation.
I switched off the EC2 instance for some time due to various reason but data keep coming to telegraf and as soon as my ec2 instance turn on data comes to InfluxDB but tasks will run on real-time.
Now I have a data gap so I want to store the last running time of the task in one measurement so I can take that timestamp and current timestamp and push the data using the query.

InfluxDB version - 2.0.4
telegraf version - 1.17.2