How do I manage failure for flow having 40+ processors in Nifi

[#1]

I have a flow which does the following:

1. Fetches month startdate/enddate for each month for number of months configured

2. Monthly fetch the records from DB based on above startdate/endtime

3. Delete records in saved csv file in from previous 7 days

4. Add records with from previous 7 days to existing csv files.

This flow contains approx 40 processors for which I have not yet done failure handling.

How do I proceed with failure handling for each processor. Can please somebody let me know