ThrottledAgent.java

/*******************************************************************************
 * Copyright 2013 Michael Marconi
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/
package oncue.agent;

import java.util.Set;

import oncue.common.messages.ThrottledWorkRequest;

import com.typesafe.config.Config;

/**
 * This agent will work on the configured maximum number of jobs at any one
 * time, before asking for more work.
 */
public class ThrottledAgent extends AbstractAgent {

	// The maximum number of concurrent workers
	private final Integer MAX_WORKERS;

	public ThrottledAgent(Set<String> workerTypes) {
		super(workerTypes);
		Config config = getContext().system().settings().config();
		if (!config.hasPath("oncue.agent.throttled-agent.max-jobs")) {
			throw new RuntimeException(
					"Configuration is missing the maximum concurrent jobs configuration for the throttled agent.");
		}
		MAX_WORKERS = config.getInt("oncue.agent.throttled-agent.max-jobs");
		log.info("The throttled agent will process a maximum of {} jobs in parallel", MAX_WORKERS);
	}

	@Override
	protected void requestWork() {
		/*
		 * Don't request work if this agent is already dealing with all the jobs
		 * it can manage
		 */
		if (jobsInProgress.size() < MAX_WORKERS) {
			int jobsToRequest = MAX_WORKERS - jobsInProgress.size();
			log.debug("Requesting {} new jobs", jobsToRequest);
			getScheduler().tell(new ThrottledWorkRequest(getSelf(), getWorkerTypes(), jobsToRequest), getSelf());
		} else {
			log.debug("Not requesting work because {} jobs in progress and limited to {} workers",
					jobsInProgress.size(), MAX_WORKERS);
		}
	}
}