The mainnet as a network will never be reset. However, sometimes your individual node's state may have been corrupted - e.g., you were too late to a major upgrade, then you might want to reset your node and re-index.
cd ~/taraxa-ops-master/taraxa_compose
wget -O docker-compose-new.yml https://raw.githubusercontent.com/Taraxa-project/taraxa-ops/master/taraxa_compose_mainnet/docker-compose.yml && mv docker-compose-new.yml docker-compose.yml
sudo docker-compose down -v
sudo docker-compose pull
rm -f config/mainnet.json
sudo docker-compose up -d
sudo docker-compose logs -f
