Evanesco Main Chain

The goal of Evanesco Main Chain is to bring programmability and interoperability to Evanesco Ecology. In order to embrace the existing popular community and advanced technology, it will bring huge benefits by staying compatible with all the existing smart contracts on Ethereum and Ethereum tooling. And to achieve that, the easiest solution is to develop based on go-ethereum fork, as we respect the great work of Ethereum very much.

Evanesco Main Chain starts its development based on go-ethereum fork. So you may see many toolings, binaries and also docs are based on Ethereum ones.

The Evanesco Main Chain will be:

• A self-sovereign blockchain: Provides security and safety with miner and elected validators.
• EVM-compatible: Supports all the existing Ethereum tooling along with faster finality and cheaper transaction fees.
• Interoperable: Comes with efficient native dual chain communication; Optimized for scaling high-performance dApps that require fast and smooth user experience.
• Distributed with on-chain governance: GPOW brings in decentralization and community participants. As the native token, EVA will serve as both the gas of smart contract execution and tokens for staking.

Cross-chain transfer and other communication are possible due to native support of interoperability. CrossWrapper and on-chain contracts are developed to support that.

More details in White Paper.

Key features

Grandpa over PoW

Although Proof-of-Work (PoW) has been approved as a practical mechanism to implement a decentralized network, it is not friendly to the environment and also requires a large size of participants to maintain the security and consistency.

To combine PoW and Grandpa for consensus, Evanesco Main Chain implement a novel consensus engine called GPoW that:

GPoW consensus includes two layers of consensus mechanisms, which are nested, influence each other and play different roles. GPoW algorithm not only provides almost real-time, asynchronous and safe finality similar to GRANDPA algorithm, but also can fairly distribute new tokens according to PoW, enabling a wider range of communities to go in for the construction of the whole ecology. The basic steps of the GPoW consensus are:

1. When the whole network starts, the network miners start to run PoW algorithm and transmit data based on the privacy cascade communication protocol. a.In the case of transaction or routing data, public or cascaded private transmission is set based on transaction settings b.In the case of a PoW block, it is publicly broadcast to nearby network nodes c.On average, the network miner calculates a PoW block and broadcasts it every 10 minutes

2. The two-layer Sorter network packages the broadcast transactions into blocks, and determines the final consistency of the whole chain according to GRANDPA protocol. a.In the case of transaction data, the block-generating person is obtained according to the drawing algorithm, and the block is generated and determined as final (second level) b.In the case of a PoW block, the most suitable block is determined according to the content of the block broadcast by the block-generating person and the finality is determined (10 minutes)

Evanesco α Chain introduces a system of 7 validators with POA consensus that can support Privacy Account and EVM-compatible privacy-middleware.

Native Token

EVA will run on Evanesco Main Chain in the same way as ETH runs on Ethereum so that it remains as native token for Evanesco. This means, EVA will be used to:

1. pay gas to deploy or invoke Smart Contract on Evanesco Main Chain
2. perform cross-chain operations, such as transfer token assets across Evanesco Main Chain and Ethereum.

Building the source

Many of the below are the same as or similar to go-ethereum.

For prerequisites and detailed build instructions please read the Installation Instructions.

Building eva requires both a Go (version 1.14 or later) and a C compiler. You can install them using your favourite package manager. Once the dependencies are installed, run

make eva

or, to build the full suite of utilities:

make all

Running eva

Going through all the possible command line flags is out of scope here, but we've enumerated a few common parameter combos to get you up to speed quickly on how you can run your own eva instance.

Hardware Requirements

The hardware must meet certain requirements to run a full node.

• PC or VPS running recent versions of Mac OS X or Linux.
• 100G of SSD storage for EVA mainnet and another 10G if you start miner on full node.
• 2 gigabytes of memory (RAM) for EVA mainnet and another 4 gigabytes of memory (RAM) if you start miner on full node.
• A broadband Internet connection with upload/download speeds of at least 10 megabyte per second

Run Full node to Join EVA MainNet

1. Preparation

First, go to the source code directory go-evaneso and follow the instruction above to build eva. Then, make a new directory. Here we name this new directory evanode.

mkdir evanode

Copy these 4 files into evanode with this command:

cp ./build/bin/eva ./evanode
cp ./eva.json ./evanode
cp ./eva.toml ./evanode

Make a new directory to store blockchain data with this command:

mkdir data

2. Generate Account

Generate a new account with this command, and remember the password you entered for this account:

./eva --datadir data account new

3. Init Genesis Block

Init genesis block with this command:

./eva --datadir data init ./eva.json

4. Start Full Node

Start up full node with this command:

./eva --datadir ./data --syncmode 'fast' --networkid 2213 --port 30304 --rpc --rpcaddr '0.0.0.0' --rpccorsdomain "*" --rpcport 8546 --rpcapi 'personal,eth,net,web3,txpool,miner,clique' --ws --ws.addr '0.0.0.0' --ws.port 7778 --ws.api 'personal,eth,net,web3,txpool,miner,clique' --config ./eva.toml

This will connect your node to the EVA network, logs like the following will be printed:

INFO [08-25|20:25:23.922] Block synchronisation started 
INFO [08-25|20:25:24.861] Downloader queue stats                   receiptTasks=0 blockTasks=0 itemSize=592.71B throttle=8192
INFO [08-25|20:25:24.863] Imported new chain segment               blocks=11 txs=0 mgas=0.000 elapsed=1.809ms mgasps=0.000 number=495 hash=f90dce..88cb1c dirty=0.00B      ignored=1
INFO [08-25|20:25:25.630] Imported new chain segment               blocks=1  txs=0 mgas=0.000 elapsed="293.044µs" mgasps=0.000 number=496 hash=a9e7a8..46b0bc dirty=0.00B
INFO [08-25|20:25:31.130] Imported new chain segment               blocks=1  txs=0 mgas=0.000 elapsed="462.746µs" mgasps=0.000 number=497 hash=2beba7..83b028 dirty=0.00B
INFO [08-25|20:25:37.128] Imported new chain segment               blocks=1  txs=0 mgas=0.000 elapsed="216.098µs" mgasps=0.000 number=498 hash=fef60d..a92615 dirty=0.00B
INFO [08-25|20:25:43.612] Imported new chain segment               blocks=1  txs=0 mgas=0.000 elapsed="725.186µs" mgasps=0.000 number=499 hash=0043f8..05f977 dirty=0.00B

The http RPC port is 8546 and the WebSocket rpc port is 7778. Try use RPC request to check block number with this command:

curl --location --request POST 'localhost:8546/' \
--header 'Content-Type: application/json' \
--data-raw '{
	"jsonrpc":"2.0",
	"method":"eth_blockNumber",
	"params":[],
	"id":83
}'

Upgrade PoS

We may update our code and restart the EVA network. Follow the steps below to restart the full node.

1. Rebuild

Download the latest code from go-evanesco in branch main. Build the latest code and get the new executable file eva with command:

make eva

2. Replace

Go to the directory of your previous full node. If you follow the guide above to run full node before, this directory should be named evanode.

Remove the old executable file eva and copy the new eva into it.

4. Restart full node

Stop the full node with command depending on how you started it.

Then restart it with this command:

./eva --datadir ./data --syncmode 'fast' --networkid 2213 --port 30304 --rpc --rpcaddr '0.0.0.0' --rpccorsdomain "*" --rpcport 8546 --rpcapi 'personal,eth,net,web3,txpool,miner,clique' --ws --ws.addr '0.0.0.0' --ws.port 7778 --ws.api 'personal,eth,net,web3,txpool,miner,clique' --config ./eva.toml

Configuration

As an alternative to passing the numerous flags to the eva binary, you can also pass a configuration file via:

$ eva --config /path/to/your_config.toml

Notice that you should keep the [Node.P2P] section in the eva.toml.

To get an idea how the file should look like you can use the dumpconfig subcommand to export your existing configuration:

$ eva --your-favourite-flags dumpconfig

Programmatically interfacing eva nodes

As a developer, sooner rather than later you'll want to start interacting with eva and the Evanesco network via your own programs and not manually through the console. To aid this, eva has built-in support for a JSON-RPC based APIs, as on Ethereum, (standard APIs)

These can be exposed via HTTP, WebSockets and IPC (UNIX sockets on UNIX based platforms, and named pipes on Windows).

The IPC interface is enabled by default and exposes all the APIs supported by eva, whereas the HTTP and WS interfaces need to manually be enabled and only expose a subset of APIs due to security reasons. These can be turned on/off and configured as you'd expect.

HTTP based JSON-RPC API options:

• --http Enable the HTTP-RPC server
• --http.addr HTTP-RPC server listening interface (default: localhost)
• --http.port HTTP-RPC server listening port (default: 8545)
• --http.api API's offered over the HTTP-RPC interface (default: eth,net,web3)
• --http.corsdomain Comma separated list of domains from which to accept cross origin requests (browser enforced)
• --ws Enable the WS-RPC server
• --ws.addr WS-RPC server listening interface (default: localhost)
• --ws.port WS-RPC server listening port (default: 8546)
• --ws.api API's offered over the WS-RPC interface (default: eth,net,web3)
• --ws.origins Origins from which to accept websockets requests
• --ipcdisable Disable the IPC-RPC server
• --ipcapi API's offered over the IPC-RPC interface (default: admin,debug,eth,miner,net,personal,shh,txpool,web3)
• --ipcpath Filename for IPC socket/pipe within the datadir (explicit paths escape it)

You'll need to use your own programming environments' capabilities (libraries, tools, etc) to connect via HTTP, WS or IPC to a eva node configured with the above flags and you'll need to speak JSON-RPC on all transports. You can reuse the same connection for multiple requests!

Note: Please understand the security implications of opening up an HTTP/WS based transport before doing so! Hackers on the internet are actively trying to subvert Evanesco Main Chain nodes with exposed APIs! Further, all browser tabs can access locally running web servers, so malicious web pages could try to subvert locally available APIs!

Contribution

Thank you for considering to help out with the source code! We welcome contributions from anyone on the internet, and are grateful for even the smallest of fixes!

If you'd like to contribute to evanesco, please fork, fix, commit and send a pull request for the maintainers to review and merge into the main code base. If you wish to submit more complex changes though, please check up with the core devs first on our discord channel to ensure those changes are in line with the general philosophy of the project and/or get some early feedback which can make both your efforts much lighter as well as our review and merge procedures quick and simple.

Please make sure your contributions adhere to our coding guidelines:

• Code must adhere to the official Go formatting guidelines (i.e. uses gofmt).
• Code must be documented adhering to the official Go commentary guidelines.
• Pull requests need to be based on and opened against the master branch.
• Commit messages should be prefixed with the package(s) they modify.
  • E.g. "eth, rpc: make trace configs optional"

License

The evanesco library (i.e. all code outside of the cmd directory) is licensed under the GNU Lesser General Public License v3.0, also included in our repository in the COPYING.LESSER file.

The evanesco binaries (i.e. all code inside of the cmd directory) is licensed under the GNU General Public License v3.0, also included in our repository in the COPYING file.