Gateways
The concept of a gateway radically simplifies Hyperledger Fabric 2 application programming. Let's understand why.
It has not escaped our notice that there are a lot of moving parts in Hyperledger Fabric: smart contracts, transactions, ledgers, peers, ordering services, certificate authorities, channels, MSPs, policies, and identities. Individually they may be easy to understand, but in combination, they present a significant mental hurdle.
Why gateways are useful
A gateway elegantly brings together all the components of Hyperledger Fabric in a single, easy-to-understand and easy-to-use concept, allowing an application to focus on three simple operations: query, submit, and notification.
Let's look more closely at the idea of a gateway in the following example:
Figure 7.8: A gateway in the network access point for an application interacting with a network channel
In Figure 7.8, we see a relatively small Hyperledger Fabric topology...
