Cross-Site Replication

What You Will Learn

How to configure a Hot Rod client with backup clusters, perform cache operations across two sites (LON and NYC) with active-passive replication, and manually switch between clusters.

Prerequisites

Java 17+
Two Infinispan clusters running with cross-site replication enabled (use the provided docker-compose or minikube setup in this module, then run the create-data.sh script)

Step 1: Connect to the Primary Cluster and Add a Backup

Configure the client to connect to the default LON cluster and add NYC as a backup cluster:

      ConfigurationBuilder builder = TutorialsConnectorHelper.connectionConfig();
      builder.addCluster("NYC").addClusterNodes("localhost:31223");
      client = TutorialsConnectorHelper.connect(builder);

Step 2: Create or Get the Cross-Site Cache

Create the cross-site cache on both clusters:

      cache = client.administration()
              // this cache should exist if you start with docker-compose and run the create-data.sh script
              .getOrCreateCache(XSITE_CACHE, new StringConfiguration("<distributed-cache/>"));
      client.switchToCluster("NYC");
      client.administration().getOrCreateCache(XSITE_CACHE, new StringConfiguration("<distributed-cache/>"));
      client.switchToDefaultCluster();

Step 3: Put Data and Switch Clusters

Put data on LON, switch to NYC to read it (replicated via active-passive), then put data on NYC:

      cache.put("hello", "world");
      printCluster("LON", cache);
      System.out.println("hello " + cache.get("hello") + " from LON");
      printCluster("NYC", cache);
      System.out.println("hello " + cache.get("hello") + " from NYC");
      cache.put("hello-nyc", "world");
      System.out.println("hello-nyc " + cache.get("hello-nyc") + " from NYC");
      client.switchToDefaultCluster();
      printCluster("LON", cache);

Data put on LON replicates to NYC, but data put directly on NYC does not replicate back to LON (active-passive).

Step 4: Run the Tutorial

mvn package exec:java

After running, you can verify:

LON (localhost:11222/console): contains hello but not hello-nyc
NYC (localhost:31222/console): contains both hello (replicated) and hello-nyc

What’s Next

Get started with basic remote cache operations
Use near-caching for faster reads