Solana: How to retry an rpc order using web3.js 2.0?

Request RPC subscription using Web3.js 2.0

When using Web3.js 2.0, establishing a long-term WebSocket connection can be a little more difficult than with previous versions of the library. A common problem is reconnecting after disconnection, which can lead to the loss of transactions or repeated sending of data.

In this article, we will look at how to repeat an RPC subscription using Web3.js 2.0.

Why ask again?

Remote Procedure Call (RPC) subscriptions allow you to perform blockchain functions remotely without having to worry about establishing a direct connection between the client and the server. However, as with any asynchronous operation, there is always the possibility of a connection break or an error.

In the event of a disconnection, the application may lose its position in the processed blockchain transactions. As a result, it can resend all pending transactions several times, which leads to wasted gas and loss of value.

Solution: Repeat mechanism

To solve this problem, we implement a retry mechanism using the built-in error handling functions of Web3.js 2.0. Our solution will use the retry function from the web3 package to automatically reconnect when necessary.

Here’s an example of how you can modify the code to include repetition:

const web3 = require('web3');
const { retry } = require('web3');
// Replace with the URL of your Web3.js provider
const provider = new web3.providers.HttpProvider("
// Initialize the connection to the blockchain network
async function connectToBlockchain() {
const chainId = await web3.eth.getChainId();
console.log(Connected to blockchain ${chainId}...);
// Create a new instance of Web3 with your provider
const web3Instance = new web3(vendor);
return web3Instance;
}
// Set the RPC subscription
async function EstablishRpcSubscription() {
ask {
const wsSubscription = await createWeb3RpcSubscription(
'0xYourPublicKey', // Your RPC endpoint
{ network: 'mainnet' } // Specifies the blockchain network (for example, mainnet, testnet)
);
console.log(RPC subscription successfully established!);
return wsSubscription;
} catch (error) {
if (error.message.includes('Disabled')) {
// Retry connection request after disconnection
repeat(error, 5);
}
console.error('Error creating RPC subscription:', error);
issue an error;
}
}
// The main entry point for your application
async function main() {
const web3Instance = await connectToBlockchain();
const wsSubscription = await EstablishRpcSubscription();
// Handle any errors that occur during the connection
ask {
console.log('WebSocket connection established.');
} catch (error) {
issue an error;
}
return wsSubscription;
}

How ​​it works:

• The connectToBlockchain function establishes a new instance of Web3 with your provider.

• The installRpcSubscription function attempts to create an RPC subscription using the established connection.

• If the subscription is created successfully, it returns a new WebSocket object (wsSubscription).

• Otherwise, if a shutdown occurs, the replay mechanism is activated after a short delay (5 seconds) using the “retry” web3 function.

• After all requests are exhausted or successful, the original error is re-issued.

Conclusion:

By implementing such a repeat request mechanism, you can guarantee that your Web3.js applications will remain responsive and efficient even if outages or errors occur in blockchain transactions. This approach also helps minimize gas wastage and loss of value due to repeated demands.