5.2. サーキットブレーカーイベントのイベントハンドラーを使用するアプリケーションの例

...

// Import the circuit breaker add-on
const Opossum = require('@redhat/opossum');

...

// Create a new circuit breaker instance and pass the
// protected function call as its first parameter
const circuit = new Opossum(() => $.get(route), circuitOptions);

...

// Listen for success events emitted when the
// circuit breaker action completes successfully
circuit.on('success',
  (result) => {
    console.log(`SUCCESS: ${JSON.stringify(result)}`);
  }

// Listen for timeout events emitted when the timeout
// period for the circuit breaker action expires
circuit.on('timeout',
  (result) => {
    console.log(`TIMEOUT: ${url} is taking too long to respond.`);
  }

// Listen for reject events emitted when the
// circuit breaker has an open or half-open state
circuit.on('reject',
  (result) => {
    console.log(`REJECTED: The breaker for ${url} is open. Failing fast.`);
  }

// Listen for open events emitted when the
// circuit breaker moves to an open state
circuit.on('open',
  (result) => {
    console.log(`OPEN: The breaker for ${url} just opened.`);
  }

// Listen for halfOpen events emitted when the
// circuit breaker moves to a half-open state
circuit.on('halfOpen',
  (result) => {
    console.log(`HALF_OPEN: The breaker for ${url} is half open.`);
  }

// Listen for close events emitted when the
// circuit breaker moves to a closed state
circuit.on('close',
  (result) => {
    console.log(`CLOSE: The breaker for ${url} has closed. Service OK.`);
  }

// Listen for fallback events emitted when
// a fallback function is executed
circuit.on('fallback',
  (result) => {
    console.log(`FALLBACK: ${JSON.stringify(data)}`);
  }