Aggregator Pattern

The Aggregator Pattern is a software architectural pattern that allows you to collect information from multiple sources and present it as a unified interface. This pattern is especially useful when dealing with microservices, APIs, or any scenario where data is dispersed across various systems.

• **Data Aggregation**: The process of collecting and summarizing data from various sources.
• **Unified Interface**: A single point of access for clients to retrieve data, simplifying interaction.
• **Decoupling**: Reduces dependencies between services, promoting flexibility and scalability.

1. Identify data sources that need to be aggregated.
2. Define the data schema for the aggregated output.
3. Implement a service that fetches data from the identified sources.
4. Transform and combine the data into the defined schema.
5. Expose the aggregated data through an API or interface.

Example Code

class Aggregator {
    constructor() {
        this.sources = [];
    }

    addSource(source) {
        this.sources.push(source);
    }

    async fetchData() {
        const results = await Promise.all(this.sources.map(source => fetch(source)));
        const data = await Promise.all(results.map(res => res.json()));
        return this.aggregateData(data);
    }

    aggregateData(data) {
        // Custom aggregation logic here
        return data.reduce((acc, item) => ({ ...acc, ...item }), {});
    }
}

// Usage
const aggregator = new Aggregator();
aggregator.addSource('https://api.service1.com/data');
aggregator.addSource('https://api.service2.com/data');
aggregator.fetchData().then(aggregatedData => console.log(aggregatedData));
                

• Implement caching for better performance.
• Use asynchronous calls to fetch data concurrently.
• Monitor and log data fetching for troubleshooting.
• Consider using a message broker for real-time data aggregation.