nodejsnotes

Topic 022: Node.js: Optimizing Token Management Using Caching for API Calls

Topic 022: Node.js: Optimizing Token Management Using Caching for API Calls

Optimizing Token Management Using Caching for API Calls

In modern API-driven applications, managing tokens efficiently is critical for performance and security. Often, APIs use tokens for authentication, with OAuth 2.0 being one of the most popular mechanisms. However, token generation comes with its own set of challenges—especially when dealing with token expiry and reducing the overhead of constant token requests. This post explores an efficient approach to managing tokens by using caching, which can significantly reduce redundant token generation and improve overall API performance.

The Problem: Token Expiry and Performance Testing

When interacting with APIs that use OAuth tokens, a common challenge is that these tokens have a limited lifespan, typically 4 hours. In performance testing scenarios, we want to minimize API calls that generate tokens, as they can be costly in terms of network latency and server load.

A typical solution involves generating a new token every 4 hours and stubbing the response for testing. However, in real-world scenarios where stubbing is not viable, a more efficient approach is needed—enter caching.

Architect’s Recommendation: Caching Tokens for Reuse

Instead of generating a new token for every API call, the architect suggests storing the token in a cache when it is first generated and retrieving it for subsequent API calls. This reduces unnecessary token regeneration and enhances overall system performance.

In this approach:

Step-by-Step Solution for Caching Tokens

Here’s how you can implement this approach:

1. Token Generation and Caching

When a new token is needed (either because it has expired or hasn’t been generated yet), the following steps are followed:

Here’s an example in JavaScript using axios for the token generation and an api object to cache the token:

async function censoredFunction1(api, event, basicAuth) {
  let tempToken = "";
  const cacheKey = "auth_token"; // Unique key to identify the token in cache

  // Check cache for existing token
  const cachedToken = api.cache.get(cacheKey);
  if (cachedToken) {
    console.log("Using cached token");
    return cachedToken; // Return cached token if available
  }

  // Generate a new token if cache is empty or token has expired
  const options = {
    headers: {
      Accept: "application/json",
      "Content-Type": "application/x-www-form-urlencoded",
      Authorization: basicAuth,
    },
  };

  try {
    const response = await axios.post(oAuthTokenUrl, "grant_type=client_credentials", options);
    tempToken = JSON.parse(JSON.stringify(response.data)).access_token;
    console.log("Access token: " + tempToken);

    // Store token in cache with a 4-hour expiry (TTL)
    api.cache.set(cacheKey, tempToken, { ttl: 4 * 60 * 60 }); // ttl = 4 hours
  } catch (error) {
    console.error("Error getting access token: ", JSON.stringify(error.response.data));
    // Handle error (e.g., redirect to error page or retry)
  }

  return tempToken; // Return the newly generated token
}

2. Token Retrieval During Post Login Action

Once the token is stored in the cache, the next step is to use it during API calls. Here’s how you can retrieve the token during the post-login action or when making any API request:

async function censoredFunction2(api, event, basicAuth) {
  // Retrieve token from cache or generate a new one if necessary
  const token = await censoredFunction1(api, event, basicAuth);

  // Use the retrieved token to make authenticated API requests
  if (token) {
    const apiResponse = await axios.get(apiEndpoint, {
      headers: {
        Authorization: `Bearer ${token}`,
      },
    });

    // Process the API response as needed
  }
}

How Caching Improves API Performance

  1. Minimizes Token Generation Overhead: By caching the token, you significantly reduce the number of requests to the OAuth server, which in turn reduces network traffic and speeds up your system.

  2. Improved Response Time: Instead of waiting for a new token to be generated every time, cached tokens can be retrieved almost instantly, leading to faster API response times.

  3. Better Resource Utilization: Caching tokens decreases the load on the authentication server, improving resource utilization, especially in high-traffic environments.

Key Considerations for Token Caching