org.openscore.engine.queue.services.assigner.ExecutionAssignerServiceImpl.java Source code

Introduction

Here is the source code for org.openscore.engine.queue.services.assigner.ExecutionAssignerServiceImpl.java

Source

/*******************************************************************************
* (c) Copyright 2014 Hewlett-Packard Development Company, L.P.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Apache License v2.0 which accompany this distribution.
*
* The Apache License is available at
* http://www.apache.org/licenses/LICENSE-2.0
*
*******************************************************************************/

package org.openscore.engine.queue.services.assigner;

import com.google.common.collect.Multimap;
import org.openscore.engine.node.services.WorkerNodeService;
import org.openscore.engine.queue.entities.ExecStatus;
import org.openscore.engine.queue.entities.ExecutionMessage;
import org.openscore.engine.queue.entities.ExecutionMessageConverter;
import org.openscore.engine.queue.entities.Payload;
import org.openscore.engine.queue.services.ExecutionQueueService;
import org.openscore.facade.entities.Execution;
import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.CollectionUtils;

import java.io.IOException;
import java.util.*;

/**
 * Created by IntelliJ IDEA.
 * User:
 * Date: 19/11/12
 */
final public class ExecutionAssignerServiceImpl implements ExecutionAssignerService {

    private Logger logger = Logger.getLogger(getClass());

    @Autowired
    private ExecutionQueueService executionQueueService;

    @Autowired
    private WorkerNodeService workerNodeService;

    @Autowired
    private ExecutionMessageConverter converter;

    private void addErrorMessage(ExecutionMessage message) {
        try {
            String group = message.getWorkerGroup();
            Execution execution = converter.extractExecution(message.getPayload());
            execution.getSystemContext().setNoWorkerInGroup(group);

            Payload payload = converter.createPayload(execution);
            message.setPayload(payload);

        } catch (IOException e) {
            logger.error("Failed to add error message to execution message!", e);
        }
    }

    private void fillPayload(ExecutionMessage msg) {
        if (msg.getPayload() == null) {
            Map<Long, Payload> payloadMap = executionQueueService.readPayloadByExecutionIds(msg.getExecStateId());
            Payload payload = payloadMap.get(msg.getExecStateId());
            msg.setPayload(payload);
        }
    }

    private String chooseWorker(String groupName, Multimap<String, String> groupWorkersMap,
            Random randIntGenerator) {
        Collection<String> workerNames = groupWorkersMap.get(groupName);

        if (workerNames == null || workerNames.size() == 0) {
            // this returns a worker UUID in case of the group defined on specific worker (private group)
            if (groupName.startsWith("Worker_")) {
                return groupName.substring("Worker_".length());
            } else {
                return null;
            }
        }

        Object[] workerArr = workerNames.toArray();

        // we assign the worker using random algorithm
        int groupIndex = randIntGenerator.nextInt(workerArr.length);
        groupIndex = groupIndex % workerArr.length;

        return (String) workerArr[groupIndex];
    }

    @Override
    @Transactional
    public List<ExecutionMessage> assignWorkers(List<ExecutionMessage> messages) {
        if (logger.isDebugEnabled())
            logger.debug("Assigner iteration started");
        if (CollectionUtils.isEmpty(messages)) {
            if (logger.isDebugEnabled())
                logger.debug("Assigner iteration finished");
            return messages;

        }
        List<ExecutionMessage> assignMessages = new ArrayList<>(messages.size());
        Multimap<String, String> groupWorkersMap = null;
        Random randIntGenerator = new Random(System.currentTimeMillis());

        for (ExecutionMessage msg : messages) {

            if (msg.getWorkerId().equals(ExecutionMessage.EMPTY_WORKER) && msg.getStatus() == ExecStatus.PENDING) {
                if (groupWorkersMap == null) {
                    groupWorkersMap = workerNodeService.readGroupWorkersMapActiveAndRunning();
                }
                String workerId = chooseWorker(msg.getWorkerGroup(), groupWorkersMap, randIntGenerator);
                if (workerId == null) {
                    // error on assigning worker, no available worker
                    logger.warn("Can't assign worker for group name: " + msg.getWorkerGroup()
                            + " , because there are no available workers for that group.");

                    //We need to extract the payload in case of FAILED
                    fillPayload(msg);

                    // send step finish event
                    ExecutionMessage stepFinishMessage = (ExecutionMessage) msg.clone();
                    stepFinishMessage.setStatus(ExecStatus.FINISHED);
                    stepFinishMessage.incMsgSeqId();
                    assignMessages.add(stepFinishMessage);

                    // send step finish event
                    ExecutionMessage flowFailedMessage = (ExecutionMessage) stepFinishMessage.clone();
                    flowFailedMessage.setStatus(ExecStatus.FAILED);
                    addErrorMessage(flowFailedMessage);
                    flowFailedMessage.incMsgSeqId();
                    assignMessages.add(flowFailedMessage);
                } else {
                    // assign worker
                    assignMessages.add(msg);
                    msg.setStatus(ExecStatus.ASSIGNED);
                    msg.incMsgSeqId();
                    msg.setWorkerId(workerId);
                }
            } else {
                // msg that was already assigned or non pending status
                assignMessages.add(msg);
            }
        } // end for

        if (logger.isDebugEnabled())
            logger.debug("Assigner iteration finished");
        return assignMessages;
    }

}