org.springframework.yarn.rpc.YarnRpcAccessor.java Source code

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Here is the source code for org.springframework.yarn.rpc.YarnRpcAccessor.java

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/*
 * Copyright 2013 the original author or authors.
 *
 * 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 org.springframework.yarn.rpc;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.security.PrivilegedAction;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.ipc.RPC;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.yarn.exceptions.YarnException;
import org.apache.hadoop.yarn.exceptions.YarnRuntimeException;
import org.apache.hadoop.yarn.ipc.YarnRPC;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.dao.DataAccessException;
import org.springframework.util.Assert;
import org.springframework.yarn.support.YarnUtils;

/**
 * Base implementation for accessing yarn components over
 * protocol buffer rpc system.
 *
 * @author Janne Valkealahti
 *
 * @param <P> Type of the protocol buffer implementation
 */
public abstract class YarnRpcAccessor<P> implements InitializingBean, DisposableBean {

    /** Protocol class used to create rpc connection */
    private Class<P> protocolClazz;

    /** Yarn configuration */
    private Configuration configuration;

    /** Address for rpc end point */
    private InetSocketAddress address;

    /** Created proxy */
    private P proxy;

    /**
     * Instantiates a new yarn rpc accessor with a protocol class
     * and Yarn configuration.
     *
     * @param protocolClazz the protocol clazz
     * @param config the yarn configuration
     */
    public YarnRpcAccessor(Class<P> protocolClazz, Configuration config) {
        this.protocolClazz = protocolClazz;
        this.configuration = config;
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        Assert.notNull(configuration, "Yarn configuration must be set");
        Assert.notNull(protocolClazz, "Rpc protocol class must be set");
        if (UserGroupInformation.isSecurityEnabled()) {
            UserGroupInformation.setConfiguration(configuration);
        }
        address = getRpcAddress(configuration);
        proxy = createProxy();
    }

    @Override
    public void destroy() {
        RPC.stopProxy(proxy);
    }

    /**
     * Gets the proxy handled by this accessor.
     *
     * @return the proxy
     */
    public P getProxy() {
        return proxy;
    }

    /**
     * Execute given action callback on the rpc proxy.
     *
     * @param <T> the return type
     * @param <S> the proxy type
     * @param action the action
     * @return the result from a callback execution
     * @throws DataAccessException the data access exception
     */
    public <T, S extends P> T execute(YarnRpcCallback<T, S> action) throws DataAccessException {
        @SuppressWarnings("unchecked")
        S proxy = (S) getProxy();
        try {
            T result = action.doInYarn(proxy);
            return result;
        } catch (YarnException e) {
            throw YarnUtils.convertYarnAccessException(e);
        } catch (YarnRuntimeException e) {
            throw YarnUtils.convertYarnAccessException(e);
        } catch (IOException e) {
            throw YarnUtils.convertYarnAccessException(e);
        } catch (RuntimeException e) {
            throw e;
        }
    }

    /**
     * Gets the Yarn configuration.
     *
     * @return the Yarn configuration
     */
    public Configuration getConfiguration() {
        return configuration;
    }

    /**
     * Creates the proxy. If {@link #getUser()} returns
     * a non null {@link UserGroupInformation user}, that
     * will be used to request the proxy with
     * a {@link PrivilegedAction}.
     *
     * @return the proxy
     * @throws IOException
     */
    @SuppressWarnings("unchecked")
    protected P createProxy() throws IOException {
        return getUser().doAs(new PrivilegedAction<P>() {
            @Override
            public P run() {
                return (P) YarnRPC.create(configuration).getProxy(protocolClazz, address, configuration);
            }
        });
    }

    /**
     * Gets the {@link UserGroupInformation user} used to
     * create the proxy. Default implementation delegates into
     * {@link UserGroupInformation#getCurrentUser()}.
     *
     * @return the user
     * @throws IOException if login fails
     * @see #createProxy()
     */
    protected UserGroupInformation getUser() throws IOException {
        return UserGroupInformation.getCurrentUser();
    }

    /**
     * Gets the {@link InetSocketAddress} where this accessor should connect.
     *
     * @param configuration the yarn configuration
     * @return address of rpc endpoint
     */
    protected abstract InetSocketAddress getRpcAddress(Configuration configuration);

}