Services are used in computations to avoid heavy lambda serializations.
Ignite allows deploying multiple instances of a given Service across the cluster and ensures proper deployment and fault tolerance of deployed services.
import org.apache.ignite.*;
import org.apache.ignite.services.*;
public class App {
public static void main(String[] args) {
Ignite ignite = Ignition.start();
ignite.services().deployClusterSingleton("my-service", new MyService());
String value = ignite.services().service("my-service").myServiceComputation();
}
}Service deployment can be adjusted by 4 means:
- cluster service: only one instance is deployed across all nodes.
- Node service: one instance is deployed in each node.
- Custom service: x instances are deployed in every node with y instances maximum per node.
- Affinity service: service is deployed according to cache entry location (service is collocated with data)
Complete TODOs in Step1_ServiceGrid to fix all tests in Step1_ServiceGridTest.