symbol
Symbol Statistics Service
It periodically collects information from the network's nodes and produces useful metrics and insights, such as the total number of nodes, their health or their geographical distribution.
Architecture
The project uses Typescript, Node Express, and MongoDB as database.
+---------------+
| Application |
+----+----^-----+
| |
| |
| | Request / Response
| |
Symbol Statistics Service | |
+---------------------------v----+--+
| |
| +-Express Server--------+ |
| | | |
| | | |
| | Task Manager | |
| | | |
| | | |
| +-----------+-----------+ |
| | |
| +-Services--v-----------------+ |
| | | |
| | - Node Monitor | |
| | | | +------------------+
| | - Chain Height Monitor +---+---> |
| | | | | Mongodb Database |
| | - Geolocation Monitor <---+---+ |
| | | | +------------------+
| +-----------------------------+ |
| |
+-----------------------------------+Node Monitor Task
To discover nodes on the network, a request is made to the catapult-rest endpoint /node/peer. This returns the list of peers known to that node, which the task then explores recursively.
To start the process, the task uses the nodes maintained by the community.
Once the whole list of nodes is known, additional information is gathered from each one of them such as /node/info and /chain/info.
When the search completes, all node information is updated on the Node collection.
Chain Height Monitor Task
The finalized height from each node is gathered and height statistics are produced. This can help monitoring chain forks, for example.
Geolocation Monitor Task
A 3rd party service (ip-api.com) is used to obtain geolocalization for each node. This can be used by users to select a nearby access node, for example.
Source Code Structure
/src/config: Statistics service configuration./src/routes: REST endpoint routes./src/models: Database collection and mongoose schema./src/service: Service logic, such as requesting geolocation./src/infrastructure: Logger and pagination component.
Reference Documentation
Configuration
The default config file can be found at src/config/config.json.
If you want to overwrite the configuration you need to create an .env file in the root path.
Installation
Clone the project.
git clone https://github.com/symbol/symbol-statistics-service.gitInstall the required dependencies.
cd symbol-statistics-service npm installRun the application in development mode.
npm run dev
Docker Setup
Build Docker image.
docker build -t symbol-statistics-service .Run the Docker image with the following Docker compose file.
version: "3" services: app: container_name: statistics-service restart: always build: . environment: - MONGODB_ENDPOINT=mongodb+srv://mongodbURI - NODES=["http://symbol-node-1.io:3000",http://symbol-node-2.io:3000"] - PORT=4001 ports: - "3000:4001"