Error: connect ECONNREFUSED 127.0.0.1:17017 code example

Example 1: Error: Redis connection to 127.0.0.1:6379 failed - connect ECONNREFUSED 127.0.0.1:6379

sudo service redis-server status

Example 2: Connection error: connect ECONNREFUSED 127.0.0.1:5432

database system is ready to accept connections