ethereum-stats

Daily statistics for Ethereum blockchain

Quick start

• Install node.js or run nvm use from the repo.
• Install git lfs
• Install yarn npm install -g yarn

$ cp .env.default .env

1. Open .env in a text editor and set the following variables:

• ETHEREUM_NODE_URL (Use websockets as protocol)

Example of .env file:

   ETHEREUM_NODE_URL=wss://rinkeby.infura.io/ws/v3/.....
   NODE_ENV=dev
   DB_HOST=localhost
   DB_NAME=ethereum_stats
   DB_USER=ethereum-stats
   DB_PASS=ethereum-stats
   DB_PORT=5435

2. Setup account

$ yarn setup:account

3. Add gas through facet

• this depends on what network you plan on testing

4. Deploy contract

$ yarn setup:contract

Start the service

$ docker-compose up -d db # spin up local postgresql 14
$ yarn install
$ yarn start

Local deployment

Prerequisites

1. node v14
2. yarn
   If you don't have yarn installed run

$ npm install --global yarn

3. docker
4. docker-compose

External services

1. Service to connect to ethereum blockchain

   • infura.io

2. Postgresql database

   • run from terminal docker-compose up -d db to setup local postgresql

Start the service

$ yarn install
$ yarn start

Improvements

Smart contract

• Currently the contract is just appending Stats to a variable. How much "Stats" is possible to save on ethereum blockchain? What's the price?

• Gas optimizations, which I'm sure there is plenty

Code optimizations

• Error handling in general (always a problem with typescript), one case stands out and that is http connection timeout (or web socket timeouts in this case)
• Stale/dead web socket connection to ethereum node (didn't see this one happen but I'm sure it can)

Tests

• Update number of unit tests, especially for src/sync.ts
• Local node to test run integrations test on the blockchain
• E2E test which connects the database and the ethereum blockchain

Features

• Currently if the process fails and restarts after X amount of days, the non synced stats will not be written to the ethereum blockchain. I would add another database entity Stats which would stand for all the daily stats already written to the blockchain.

ToDo's

Define what small level tasks I want to accomplish

• Setup postgres as docker service
• Setup typeorm and connect to postgres
• Setup testing
• Setup integration testing
• check if date is in format in smart contract "YYYY-mm-dd"
• Setup Block model
• Create a query to extract and sum all gas fees for that day.
• Write to Smart Contract to save Gas Spend on a given day
• Catch errors while reading/writing from ethereum blockchain
• Add retry logic to ethereum.service.fetchBlock()...
• Setup github actions to automatically run tests
• Setup hardhat for contract development (I assume this is a must)
• Write synced timestamps to database to reduce calls gas when trying to resync
• Check if websocket connection to ethereum node gets stale
• Setup local etherum network (geth | ganache cli)
• Move contract to mappings instead of an array

The Plan (Original)

1. Setup project, basic typescript. ✓
2. MVP for reading form Ethereum blockchain ✓
   1. Try connecting to the blockchain and read blocks/transactions ✓
   2. Based on data structures and relation ships define which database will be used ✓
   3. Setup a ethereum service as an abstraction for reading. ✓
3. MVP for Smart Contract ✓
   1. Develop & publish smart contract ✓
4. Connect service to Smart Contract ✓
5. Look for edge cases when reading from Ethereum blockchain