Branislav Kontur
3d9439f646
## Problem During the bumping of the `polkadot-fellows` repository to `polkadot-sdk@1.6.0`, I encountered a situation where the benchmarks `teleport_assets` and `reserve_transfer_assets` in AssetHubKusama started to fail. This issue arose due to a decreased ED balance for AssetHubs introduced [here](https://github.com/polkadot-fellows/runtimes/pull/158/files#diff-80668ff8e793b64f36a9a3ec512df5cbca4ad448c157a5d81abda1b15f35f1daR213), and also because of a [missing CI pipeline](https://github.com/polkadot-fellows/runtimes/issues/197) to check the benchmarks, which went unnoticed. These benchmarks expect the `caller` to have enough: 1. balance to transfer (BTT) 2. balance for paying delivery (BFPD). So the initial balance was calculated as `ED * 100`, which seems reasonable: ``` const ED_MULTIPLIER: u32 = 100; let balance = existential_deposit.saturating_mul(ED_MULTIPLIER.into());` ``` The problem arises when the price for delivery is 100 times higher than the existential deposit. In other words, when `ED * 100` does not cover `BTT` + `BFPD`. I check AHR/AHW/AHK/AHP and this problem has only AssetHubKusama ``` ED: 3333333 calculated price to parent delivery: 1031666634 (from xcm logs from the benchmark) --- 3333333 * 100 - BTT(3333333) - BFPD(1031666634) = −701666667 ``` which results in the error; ``` 2024-02-23 09:19:42 Unable to charge fee with error Module(ModuleError { index: 31, error: [17, 0, 0, 0], message: Some("FeesNotMet") }) Error: Input("Benchmark pallet_xcm::reserve_transfer_assets failed: FeesNotMet") ``` ## Solution The benchmarks `teleport_assets` and `reserve_transfer_assets` were fixed by removing `ED * 100` and replacing it with `DeliveryHelper` logic, which calculates the (almost real) price for delivery and sets it along with the existential deposit as the initial balance for the account used in the benchmark. ## TODO - [ ] patch for 1.6 - https://github.com/paritytech/polkadot-sdk/pull/3466 - [ ] patch for 1.7 - https://github.com/paritytech/polkadot-sdk/pull/3465 - [ ] patch for 1.8 - TODO: PR --------- Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>
Contracts 📝
This is a parachain node for smart contracts; it contains a default configuration of
Substrate's module for smart contracts ‒ the pallet-contracts.
The node is only available on Rococo, a testnet for Polkadot and Kusama parachains.
It has been configured as a common good parachain, as such it uses the Rococo relay
chain's native token ROC instead of defining a token of its own.
See the section Rococo Deployment below for more details.
If you have any questions, it's best to ask in the Substrate StackExchange.
Smart Contracts Development
This node contains Substrate's smart contracts module ‒ the
pallet-contracts.
This pallet takes smart contracts as WebAssembly blobs and defines an API
for everything a smart contract needs (storage access, …).
As long as a programming language compiles to WebAssembly and there exists an implementation
of this API in it, you can write a smart contract for this pallet (and thus for this parachain)
in that language.
This is a list of languages you can currently choose from:
- Parity's ink! for Rust.
- ask! for Assembly Script.
- The Solang compiler for Solidity.
There are also different user interfaces and command-line tools you can use to deploy or interact with contracts:
- Contracts UI ‒ a beginner-friendly UI for smart contract developers.
polkadot-js‒ the go-to expert UI for smart contract developers.cargo-contract‒ a CLI tool, ideal for scripting or your terminal workflow.
If you are looking for a quickstart, we can recommend ink!'s Guided Tutorial for Beginners.
Build & Launch a Node
To run a Contracts node that connects to Rococo
you will need to compile the polkadot-parachain binary:
cargo build --release --locked --bin polkadot-parachain
Once the executable is built, launch the parachain node via:
./target/release/polkadot-parachain --chain contracts-rococo
Refer to the setup instructions to run a local network for development.
Rococo Deployment
We have a live deployment on Rococo ‒ a testnet for Polkadot and Kusama parachains.
You can interact with the network through Polkadot JS Apps, click here for a direct link to the parachain.
This parachain uses the Rococo relay chain's native token ROC instead of defining a token of its own.
Due to this you'll need ROC in order to deploy contracts on this parachain.
As a first step, you should create an account. See here for a detailed guide.
As a second step, you have to get ROC testnet tokens through the Rococo Faucet.
This is a chat room in which you'd need to post the following message:
!drip YOUR_SS_58_ADDRESS:1002
The number 1002 is the id of this parachain on Rococo, by supplying it the faucet will teleport ROC
tokens directly to your account on the parachain.
If everything worked out, the teleported ROC tokens will show up under
the "Accounts" tab.
Once you have ROC you can deploy a contract as you would normally.
If you're unsure about this, our guided tutorial
will clarify that for you in no time.