Quick Guide to Realtime Data in Azure Files without Webhooks

Aug 7, 2024 • 9 minute read

Hey there, fellow JavaScript devs! Ready to dive into the world of real-time data with Azure Files? Let's skip the webhook drama and focus on a tried-and-true method: good ol' polling. Buckle up, because we're about to make your Azure Files integration smoother than a freshly waxed surfboard.

Setting the Stage: Azure Files API Access

First things first, let's get you set up with Azure Files API access. I'm assuming you've already got your Azure account sorted, so let's jump straight to the good stuff:

Head to the Azure Portal
Create a new Azure Files share (if you haven't already)
Grab your storage account name and access key

Got 'em? Great! Now you're ready to start polling like a pro.

Polling 101: The Basics

Alright, let's kick things off with a simple polling function. Here's a basic example to get your feet wet:

async function pollAzureFiles() {
  while (true) {
    try {
      const data = await fetchDataFromAzureFiles();
      processData(data);
    } catch (error) {
      console.error('Oops! Something went wrong:', error);
    }
    await new Promise(resolve => setTimeout(resolve, 5000)); // Poll every 5 seconds
  }
}

Not too shabby, right? But hold your horses, we're just getting started!

Leveling Up: Optimized Polling for Azure Files

Now, let's make this polling function work smarter, not harder. We'll add some rate limiting and error handling to keep Azure happy:

const MAX_RETRIES = 3;
const RETRY_DELAY = 1000;

async function pollAzureFiles() {
  let retries = 0;
  while (true) {
    try {
      const data = await fetchDataFromAzureFiles();
      processData(data);
      retries = 0; // Reset retries on successful fetch
    } catch (error) {
      console.error('Uh-oh! Error fetching data:', error);
      if (++retries > MAX_RETRIES) {
        console.error('Max retries reached. Taking a breather...');
        await new Promise(resolve => setTimeout(resolve, RETRY_DELAY * 10));
        retries = 0;
      }
    }
    await new Promise(resolve => setTimeout(resolve, 5000 + Math.random() * 1000)); // Add jitter
  }
}

See what we did there? We added retry logic and a touch of randomness to our polling interval. Azure will thank you for being so considerate!

The Secret Sauce: Efficient Data Fetching

Now, let's talk about change tokens. These little beauties help us fetch only the data that's changed since our last poll. Check this out:

let changeToken = null;

async function fetchDataFromAzureFiles() {
  const url = `https://${storageAccount}.file.core.windows.net/${shareNa
me}?restype=directory&comp=list&sharesnapshot=&prefix=&maxresults=5000`;
  
  const headers = {
    'x-ms-version': '2019-07-07',
    'Authorization': `SharedKey ${storageAccount}:${signature}`,
  };

  if (changeToken) {
    headers['x-ms-marker'] = changeToken;
  }

  const response = await fetch(url, { headers });
  const data = await response.json();
  
  changeToken = data.NextMarker;
  return data.Entries;
}

Boom! Now you're only fetching what you need. Efficiency: 100!

Keeping Track: Managing Polling State

Let's not forget about keeping track of our polling state. Here's a simple way to manage that:

const state = {
  lastPolledTimestamp: null,
  changeToken: null,
};

function updateState(newData) {
  state.lastPolledTimestamp = Date.now();
  state.changeToken = newData.NextMarker;
  // Save state to persistent storage here
}

async function pollAzureFiles() {
  while (true) {
    try {
      const data = await fetchDataFromAzureFiles(state.changeToken);
      processData(data);
      updateState(data);
    } catch (error) {
      console.error('Oops! Something went wrong:', error);
    }
    await new Promise(resolve => setTimeout(resolve, 5000));
  }
}

Now you're tracking like a pro!

When Things Go South: Error Handling and Retry Logic

Let's beef up our error handling with some exponential backoff:

async function pollWithBackoff() {
  let backoffTime = 1000;
  while (true) {
    try {
      await pollAzureFiles();
      backoffTime = 1000; // Reset on success
    } catch (error) {
      console.error('Error in polling:', error);
      await new Promise(resolve => setTimeout(resolve, backoffTime));
      backoffTime = Math.min(backoffTime * 2, 60000); // Cap at 1 minute
    }
  }
}

Now that's what I call resilient!

Speed Demon: Performance Considerations

Remember, every API call counts. Let's optimize our data processing:

async function processData(entries) {
  const promises = entries.map(async entry => {
    // Process each entry concurrently
    await processEntry(entry);
  });
  await Promise.all(promises);
}

Parallel processing for the win!

Scaling Up: Polling for Multiple Users

Got a bunch of users? No problem! Let's implement a simple polling queue:

class PollingQueue {
  constructor() {
    this.queue = [];
    this.isProcessing = false;
  }

  addUser(userId) {
    this.queue.push(userId);
    if (!this.isProcessing) {
      this.processQueue();
    }
  }

  async processQueue() {
    this.isProcessing = true;
    while (this.queue.length > 0) {
      const userId = this.queue.shift();
      await pollAzureFilesForUser(userId);
    }
    this.isProcessing = false;
  }
}

const pollingQueue = new PollingQueue();

Now you're ready to handle data for all your users like a boss!

Wrapping Up

And there you have it, folks! You've just leveled up your Azure Files polling game. Remember, while webhooks have their place, sometimes a well-implemented polling solution is just what the doctor ordered. It's reliable, it's scalable, and now, thanks to you, it's optimized!

Keep experimenting, keep optimizing, and most importantly, keep coding. You've got this!

Want More?

Hungry for more Azure Files goodness? Check out these resources:

Now go forth and poll like a champion! 🚀