In modern applications, data synchronization plays a vital role in ensuring consistency and availability across different systems. When working with web applications that use IndexedDB for client-side data storage and Apache ZooKeeper for coordination and distributed synchronization, it becomes crucial to implement data synchronization between these two systems.

In this blog post, we will discuss how to achieve data synchronization between IndexedDB and Apache ZooKeeper using a combination of client-side and server-side techniques.

Client-Side Synchronization

On the client-side, we can leverage the capabilities of IndexedDB to store and retrieve data. To implement synchronization with Apache ZooKeeper, we can follow these steps:

1. Create a Change Log: Track any changes made to the data stored in IndexedDB. This can be achieved by intercepting database operations like adding, updating, or deleting records and capturing the corresponding changes in a change log.

// JavaScript code
let changeLog = [];

function handleAddRecord(record) {
  // Handle add record operation
  // ...
  changeLog.push({ operation: 'add', record });
}

function handleUpdateRecord(record) {
  // Handle update record operation
  // ...
  changeLog.push({ operation: 'update', record });
}

function handleDeleteRecord(record) {
  // Handle delete record operation
  // ...
  changeLog.push({ operation: 'delete', record });
}

1. Send Changes to ZooKeeper: Periodically send the changes from the change log to Apache ZooKeeper using HTTP or a custom API. The client-side app should have the necessary permissions to communicate with ZooKeeper and perform the required operations.

// JavaScript code
function sendChangesToZooKeeper() {
  // Iterate over changeLog and send changes to ZooKeeper
  // ...
}

Server-Side Synchronization

On the server-side, we need to implement communication with Apache ZooKeeper and ensure data consistency with IndexedDB. Here are the steps involved:

1. Receive Changes from Client-App: Create an API or server endpoint that can receive the changes sent by the client app. This endpoint should authenticate and validate the received changes before applying them to IndexedDB.

# Python code
@app.route('/sync', methods=['POST'])
def handleSyncRequest():
  # Authenticate and validate the request
  # ...
  
  changes = request.json.get('changes')
  
  for change in changes:
    operation = change['operation']
    record = change['record']
    
    if operation == 'add':
      handleAddRecord(record)
    elif operation == 'update':
      handleUpdateRecord(record)
    elif operation == 'delete':
      handleDeleteRecord(record)
  
  return 'OK'

1. Apply Changes to IndexedDB: Write server-side code to apply the received changes to the IndexedDB. This will ensure that the data in both ZooKeeper and IndexedDB remain synchronized.

# Python code
def handleAddRecord(record):
  # Handle add record operation in IndexedDB
  # ...

def handleUpdateRecord(record):
  # Handle update record operation in IndexedDB
  # ...

def handleDeleteRecord(record):
  # Handle delete record operation in IndexedDB
  # ...

Conclusion

Implementing data synchronization between IndexedDB and Apache ZooKeeper allows for efficient coordination and consistency across distributed systems. By incorporating client-side change tracking and server-side synchronization, we can ensure that data changes made on the client are propagated to ZooKeeper and applied to IndexedDB.

Harnessing the power of IndexedDB for client-side storage and Apache ZooKeeper for coordination, applications can achieve robust data synchronization in a reliable and scalable manner.

#dataSync #IndexedDB #ApacheZooKeeper