co.cask.cdap.operations.hdfs.HDFSNodes.java Source code

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Here is the source code for co.cask.cdap.operations.hdfs.HDFSNodes.java

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/*
 * Copyright  2016 Cask Data, Inc.
 *
 * 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 co.cask.cdap.operations.hdfs;

import co.cask.cdap.operations.OperationalStats;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.Iterables;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.DFSUtil;
import org.apache.hadoop.hdfs.HAUtil;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import javax.annotation.Nullable;

/**
 * {@link OperationalStats} for HDFS nodes.
 */
@SuppressWarnings("unused")
public class HDFSNodes extends AbstractHDFSStats implements HDFSNodesMXBean {
    @VisibleForTesting
    static final String STAT_TYPE = "nodes";

    private int namenodes;

    public HDFSNodes() {
        this(new Configuration());
    }

    @VisibleForTesting
    HDFSNodes(Configuration conf) {
        super(conf);
    }

    @Override
    public String getStatType() {
        return "nodes";
    }

    @Override
    public int getNamenodes() {
        return namenodes;
    }

    @Override
    public void collect() throws IOException {
        namenodes = getNameNodes().size();
    }

    private List<String> getNameNodes() throws IOException {
        List<String> namenodes = new ArrayList<>();
        if (!HAUtil.isHAEnabled(conf, getNameService())) {
            try (FileSystem fs = FileSystem.get(conf)) {
                return Collections.singletonList(fs.getUri().toString());
            }
        }
        String nameService = getNameService();
        for (String nnId : DFSUtil.getNameNodeIds(conf, nameService)) {
            namenodes.add(DFSUtil.getNamenodeServiceAddr(conf, nameService, nnId));
        }
        return namenodes;
    }

    @Nullable
    private String getNameService() {
        Collection<String> nameservices = conf.getTrimmedStringCollection(DFSConfigKeys.DFS_NAMESERVICES);
        if (nameservices.isEmpty()) {
            return null;
        }
        if (1 == nameservices.size()) {
            return Iterables.getOnlyElement(nameservices);
        }
        throw new IllegalStateException(
                "Found multiple nameservices configured in HDFS. CDAP currently does not support "
                        + "HDFS Federation.");
    }
}