modules/airavata-metascheduler/process-scheduler/src/main/java/org/apache/airavata/metascheduler/process/scheduling/engine/cr/selection/DefaultComputeResourceSelectionPolicy.java

package org.apache.airavata.metascheduler.process.scheduling.engine.cr.selection;

import org.apache.airavata.model.appcatalog.computeresource.ComputeResourceDescription;
import org.apache.airavata.model.appcatalog.groupresourceprofile.GroupComputeResourcePreference;
import org.apache.airavata.model.experiment.ExperimentModel;
import org.apache.airavata.model.experiment.UserConfigurationDataModel;
import org.apache.airavata.model.process.ProcessModel;
import org.apache.airavata.model.scheduling.ComputationalResourceSchedulingModel;
import org.apache.airavata.model.status.QueueStatusModel;
import org.apache.airavata.registry.api.RegistryService;
import org.apache.airavata.registry.api.RegistryService.Client;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Optional;

/**
 * This class implements selecting compute resource defined in USER_CONFIGURATION_DATA and assumes only one
 * compute resource is selected for experiment.
 * This checks whether defined CR is live
 */
public class DefaultComputeResourceSelectionPolicy extends ComputeResourceSelectionPolicyImpl {

    private static final Logger LOGGER = LoggerFactory.getLogger(DefaultComputeResourceSelectionPolicy.class);

    @Override
    public Optional<ComputationalResourceSchedulingModel> selectComputeResource(String processId) {
        RegistryService.Client registryClient = this.registryClientPool.getResource();
        try {
            ProcessModel processModel = registryClient.getProcess(processId);

            ExperimentModel experiment = registryClient.getExperiment(processModel.getExperimentId());


            UserConfigurationDataModel userConfigurationDataModel = experiment.getUserConfigurationData();

            // Assume scheduling data is populated in USER_CONFIGURATION_DATA_MODEL
            ComputationalResourceSchedulingModel computationalResourceSchedulingModel = userConfigurationDataModel
                    .getComputationalResourceScheduling();

            String computeResourceId = computationalResourceSchedulingModel.getResourceHostId();

            ComputeResourceDescription comResourceDes = registryClient.getComputeResource(computeResourceId);

            GroupComputeResourcePreference computeResourcePreference = getGroupComputeResourcePreference(computeResourceId,
                    processModel.getGroupResourceProfileId());

            String hostName = comResourceDes.getHostName();
            String queueName = computationalResourceSchedulingModel.getQueueName();

            QueueStatusModel queueStatusModel = registryClient.getQueueStatus(hostName, queueName);
            if (queueStatusModel.isQueueUp()) {
              return  Optional.of(computationalResourceSchedulingModel);
            }
        } catch (Exception exception) {
            LOGGER.error(" Exception occurred while scheduling Process with Id {}", processId, exception);
            this.registryClientPool.returnBrokenResource(registryClient);
            registryClient = null;
        } finally {
            if(registryClient != null) {
                this.registryClientPool.returnResource(registryClient);
            }
        }
        return Optional.empty();
    }

    public static void main(String[] args) {
        DefaultComputeResourceSelectionPolicy defaultComputeResourceSelectionPolicy = new DefaultComputeResourceSelectionPolicy();
        defaultComputeResourceSelectionPolicy.selectComputeResource("PROCESS_5dd4f56b-f0fd-41d0-9437-693ad25f4a1d");
    }
}