Chapter 13. Remotely Executing Server-Side Tasks

Data Grid server tasks are classes that extend the org.infinispan.tasks.ServerTask interface and generally include the following method calls:

The following HelloTask class implementation provides an example task that has one parameter:

package example;

import org.infinispan.tasks.ServerTask;
import org.infinispan.tasks.TaskContext;

public class HelloTask implements ServerTask<String> {

   private TaskContext ctx;

   @Override
   public void setTaskContext(TaskContext ctx) {
      this.ctx = ctx;
   }

   @Override
   public String call() throws Exception {
      String name = (String) ctx.getParameters().get().get("name");
      return "Hello " + name;
   }

   @Override
   public String getName() {
      return "hello-task";
   }

}

Add your custom server task classes to Data Grid servers.

Data Grid server scripting is based on the javax.script API and is compatible with any JVM-based ScriptEngine implementation.

// mode=local,language=javascript,parameters=[greetee]
"Hello " + greetee

When you run the preceding script, you pass a value for the greetee parameter and Data Grid returns "Hello ${value}".

// name=test, language=javascript
// mode=local, parameters=[a,b,c]

// mode=local,language=javascript
multiplicand * multiplier

Use the command line interface to add scripts to Data Grid servers.

Assign users the deployer role at minimum if you use default authorization settings.

Add scripts with the Hot Rod RemoteCache interface as in the following example:

RemoteCache<String, String> scriptCache = cacheManager.getCache("___script_cache");
scriptCache.put("multiplication.js",
  "// mode=local,language=javascript\n" +
  "multiplicand * multiplier\n");

Use the command line interface to run tasks and scripts on Data Grid clusters.

Call the execute() method to run scripts with the Hot Rod RemoteCache interface, as in the following example:

RemoteCache<String, Integer> cache = cacheManager.getCache();
// Create parameters for script execution.
Map<String, Object> params = new HashMap<>();
params.put("multiplicand", 10);
params.put("multiplier", 20);
// Run the script with the parameters.
Object result = cache.execute("multiplication.js", params);

Call the execute() method to run tasks with the Hot Rod RemoteCache interface, as in the following example:

// Add configuration for a locally running server.
ConfigurationBuilder builder = new ConfigurationBuilder();
builder.addServer().host("127.0.0.1").port(11222);

// Connect to the server.
RemoteCacheManager cacheManager = new RemoteCacheManager(builder.build());

// Retrieve the remote cache.
RemoteCache<String, String> cache = cacheManager.getCache();

// Create task parameters.
Map<String, String> parameters = new HashMap<>();
parameters.put("name", "developer");

// Run the server task.
String greet = cache.execute("hello-task", parameters);
System.out.println(greet);