Best practices for a high traffic dapp launch

Getting help

There are few resources where developers get help while building a dapp:

• Developer forum
• Developer Discord

Testing the dapp

Stress testing

The IC does not have a testnet. Instead developers are encouraged to use the mainnet for test purposes. Before developers deploy the production ready dapp to mainnet and enable access to it to the world, they should first deploy test versions to mainnet. They should then stress it by emulating the anticipated load on it and see how well the dapp and the platform in general fares. If the desired performance is not achieved, developers are encouraged to get help by using the links provided above. Often times, the desired performance can be achieved by performing minor tweaks to the dapps.

Lessons from past launches

Motoko version

Motoko is a language being actively developed so it is recommended to use the latest version of Motoko to get maximal stability and performance.

Inter-canister calls

The Internet Computer system provides inter-canister communication that follows the actor model: Inter-canister 'calls' are implemented via two asynchronous 'messages', one to initiate the call, and one to return the response. Canisters process messages atomically (and roll back upon certain error conditions), but not complete calls. This makes programming with inter-canister calls error-prone. Possible common sources for bugs, vulnerabilities or simply unexpected behavior are:

• Reading global state before issuing an inter-canister call, and assuming it to still hold when the call comes back.

• Changing global state before issuing an inter-canister call, changing it again in the response handler, but assuming nothing else changes the state in between (reentrancy).

• Changing global state before issuing an inter-canister call, and not handling failures correctly, e.g. when the code handling the callback rolls backs.

If you find such a pattern in your code, you should analyze if a malicious party can trigger them, and assess the severity that effect. These issues apply to all canisters, and are not Motoko-specific.