org.apache.ambari.servicemonitor.probes.DfsListProbe.java Source code

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Here is the source code for org.apache.ambari.servicemonitor.probes.DfsListProbe.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.ambari.servicemonitor.probes;

import org.apache.ambari.servicemonitor.reporting.ProbeStatus;
import org.apache.ambari.servicemonitor.utils.DFSUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.DistributedFileSystem;

import java.io.IOException;
import java.net.URI;

/**
 * Lists a directory
 */
public class DfsListProbe extends Probe {
    private static final Log LOG = LogFactory.getLog(DfsListProbe.class);

    private final String path;
    protected final URI fsURI;

    public DfsListProbe(Configuration conf, String path) throws IOException {
        super("DfsListProbe " + FileSystem.getDefaultUri(conf) + path, conf);
        //make sure the probe doesn't block, regardless of
        //any site configurations
        DFSUtils.makeDfsCallsNonBlocking(conf);
        fsURI = DFSUtils.getHDFSUri(conf);
        LOG.info(getName());
        this.path = path;
    }

    private DistributedFileSystem createDfs() throws IOException {
        return DFSUtils.createUncachedDFS(conf);
    }

    @Override
    public ProbeStatus ping(boolean livePing) {

        ProbeStatus status = new ProbeStatus();
        DistributedFileSystem hdfs = null;
        try {
            hdfs = createDfs();
            Path dfsPath;
            dfsPath = new Path(path);
            if (LOG.isDebugEnabled()) {
                LOG.debug("Listing " + getName());
            }
            FileStatus[] fileStatuses = hdfs.listStatus(dfsPath);
            if (fileStatuses != null) {
                //successful operation
                status.succeed(this);
                status.setMessage(getName() + " contains " + fileStatuses.length + " entries");
            } else {
                //no file
                status.finish(this, false, "Path " + path + " not found", null);
            }
        } catch (IOException e) {
            status.fail(this, new IOException(getName() + " : " + e, e));
            LOG.debug("Failure to probe " + getName());
        } finally {
            DFSUtils.closeDFS(hdfs);
        }
        return status;
    }

}