org.apache.slider.server.services.utility.AbstractSliderLaunchedService.java Source code

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Here is the source code for org.apache.slider.server.services.utility.AbstractSliderLaunchedService.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.slider.server.services.utility;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.yarn.conf.YarnConfiguration;
import org.apache.hadoop.registry.client.api.RegistryConstants;
import org.apache.hadoop.registry.client.api.RegistryOperations;
import org.apache.hadoop.registry.client.api.RegistryOperationsFactory;
import org.apache.slider.common.SliderXmlConfKeys;
import org.apache.slider.common.tools.ConfigHelper;
import org.apache.slider.common.tools.SliderUtils;
import org.apache.slider.core.exceptions.BadCommandArgumentsException;
import org.apache.slider.core.exceptions.BadConfigException;
import org.apache.slider.core.zk.ZookeeperUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Base service for the standard slider client/server services
 */
public abstract class AbstractSliderLaunchedService extends LaunchedWorkflowCompositeService {
    private static final Logger log = LoggerFactory.getLogger(AbstractSliderLaunchedService.class);

    public AbstractSliderLaunchedService(String name) {
        super(name);
        // make sure all the yarn configs get loaded
        YarnConfiguration conf = new YarnConfiguration();
        ConfigHelper.registerDeprecatedConfigItems();
    }

    /**
     * look up the registry quorum from the config
     * @return the quorum string
     * @throws BadConfigException if it is not there or invalid
     */
    public String lookupZKQuorum() throws BadConfigException {

        String registryQuorum = getConfig().get(RegistryConstants.KEY_REGISTRY_ZK_QUORUM);

        // though if neither is set: trouble
        if (SliderUtils.isUnset(registryQuorum)) {
            throw new BadConfigException("No Zookeeper quorum provided in the" + " configuration property "
                    + RegistryConstants.KEY_REGISTRY_ZK_QUORUM);
        }
        ZookeeperUtils.splitToHostsAndPortsStrictly(registryQuorum);
        return registryQuorum;
    }

    /**
     * Create, adopt ,and start the YARN registration service
     * @return the registry operations service, already deployed as a child
     * of the AbstractSliderLaunchedService instance.
     */
    public RegistryOperations startRegistryOperationsService() throws BadConfigException {

        // push back the slider registry entry if needed
        String quorum = lookupZKQuorum();
        RegistryOperations registryWriterService = createRegistryOperationsInstance();
        deployChildService(registryWriterService);
        return registryWriterService;
    }

    /**
     * Create the registry operations instance. This is to allow
     * subclasses to instantiate a subclass service
     * @return an instance to match to the lifecycle of this service
     */
    protected RegistryOperations createRegistryOperationsInstance() {
        return RegistryOperationsFactory.createInstance("YarnRegistry", getConfig());
    }

    /**
     * Utility method to require an argument to be set (non null, non-empty)
     * @param argname argument name
     * @param value value
     * @throws BadCommandArgumentsException if the condition is not met
     */
    protected static void requireArgumentSet(String argname, String value) throws BadCommandArgumentsException {
        if (isUnset(value)) {
            throw new BadCommandArgumentsException("Required argument " + argname + " missing");
        }
    }

}