asynchronousClient.java

    private static ArrayList<String> asynchronousClient(int numberOfInstances) throws Exception {
        long startTime = System.nanoTime();
        System.out.println("-----------------------------------------------------------------------");
        ArrayList<String> instanceIds = new ArrayList<>();
        // Futures for async handlers
        List<Future<LaunchInstanceResponse>> futures = new CopyOnWriteArrayList<>();

        AsyncHandler<LaunchInstanceRequest, LaunchInstanceResponse> handler = new AsyncHandler<LaunchInstanceRequest, LaunchInstanceResponse>() {
            @Override
            public void onSuccess(LaunchInstanceRequest request, LaunchInstanceResponse response) {
                String requestId = response.getOpcRequestId();
                Instance instance = response.getInstance();
                // System.out.println(requestId);
                // System.out.println(requestId + " - " + instance.getDisplayName() + " - " +
                // instance.getId());
            }

            @Override
            public void onError(LaunchInstanceRequest request, Throwable error) {
                error.printStackTrace();
            }
        };

        // Custom client config
        ClientConfiguration clientConfig = ClientConfiguration.builder()
                .connectionTimeoutMillis(3000)
                .readTimeoutMillis(60000)
                .build();
        // Auth provider
        AuthenticationDetailsProvider authenticationDetailsProvider = new ConfigFileAuthenticationDetailsProvider("DEFAULT");

        // Compute client
        ComputeAsyncClient computeClient = ComputeAsyncClient.builder()
                .configuration(clientConfig)
                .build(authenticationDetailsProvider);
        computeClient.setRegion(Region.valueOf(System.getenv("REGION")));

        // Default values
        String availabilityDomain = System.getenv("AD");
        String compartmentId = System.getenv("COMPARTMENT_ID");
        String imageId = System.getenv("IMAGE_ID");
        String subnetId = System.getenv("SUBNET_ID");
        String shape = System.getenv("SHAPE");
        String instanceName = System.getenv("INSTANCE_NAME_PREFIX");

        for (int i = 0; i < numberOfInstances; i++) {
            long startTime1 = System.nanoTime();
            // Set instance details
            LaunchInstanceDetails launchInstanceDetails = LaunchInstanceDetails.builder()
                    .availabilityDomain(availabilityDomain)
                    .compartmentId(compartmentId)
                    .displayName(instanceName + (i + 1))
                    .imageId(imageId)
                    .subnetId(subnetId)
                    .shape(shape)
                    .build();

            // Create request
            LaunchInstanceRequest launchInstanceRequest = LaunchInstanceRequest.builder()
                    .launchInstanceDetails(launchInstanceDetails)
                    .build();

            // Send asynch request
            Future<LaunchInstanceResponse> future = computeClient.launchInstance(launchInstanceRequest, handler);
            futures.add(future);

            long elapsedTime1 = System.nanoTime() - startTime1;
            System.out.println("work requested in " + (elapsedTime1 / 1000000) + " ms");
        }

        // wait for the threads to complete
        int completed = 0;
        while (completed < numberOfInstances) {
            for (Future<LaunchInstanceResponse> f : futures) {
                if (f.isDone()) {
                    LaunchInstanceResponse response = (LaunchInstanceResponse) f.get();
                    String requestId = response.getOpcRequestId();
                    Instance instance = response.getInstance();
                    // System.out.println(requestId);
                    System.out.println(requestId + " - " + instance.getDisplayName() + " - " + instance.getId());
                    instanceIds.add(instance.getId());
                    completed++;
                    futures.remove(f);
                }
            }
        }

        long elapsedTime = System.nanoTime() - startTime;
        System.out.println("Total execution time in seconds: " + TimeUnit.MILLISECONDS.toSeconds(elapsedTime / 1000000));
        System.out.println("-----------------------------------------------------------------------");
        return instanceIds;
    }