/**
* 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.hadoop.hdfs.server.datanode;
import static org.apache.hadoop.test.MetricsAsserts.assertCounter;
import static org.apache.hadoop.test.MetricsAsserts.assertQuantileGauges;
import static org.apache.hadoop.test.MetricsAsserts.getLongCounter;
import static org.apache.hadoop.test.MetricsAsserts.getMetrics;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import java.util.List;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.DFSOutputStream;
import org.apache.hadoop.hdfs.DFSTestUtil;
import org.apache.hadoop.hdfs.DistributedFileSystem;
import org.apache.hadoop.hdfs.HdfsConfiguration;
import org.apache.hadoop.hdfs.MiniDFSCluster;
import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
import org.apache.hadoop.metrics2.MetricsRecordBuilder;
import org.junit.Test;
public class TestDataNodeMetrics {
@Test
public void testDataNodeMetrics() throws Exception {
Configuration conf = new HdfsConfiguration();
SimulatedFSDataset.setFactory(conf);
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
try {
FileSystem fs = cluster.getFileSystem();
final long LONG_FILE_LEN = Integer.MAX_VALUE+1L;
DFSTestUtil.createFile(fs, new Path("/tmp.txt"),
LONG_FILE_LEN, (short)1, 1L);
List<DataNode> datanodes = cluster.getDataNodes();
assertEquals(datanodes.size(), 1);
DataNode datanode = datanodes.get(0);
MetricsRecordBuilder rb = getMetrics(datanode.getMetrics().name());
assertCounter("BytesWritten", LONG_FILE_LEN, rb);
} finally {
if (cluster != null) {cluster.shutdown();}
}
}
@Test
public void testSendDataPacketMetrics() throws Exception {
Configuration conf = new HdfsConfiguration();
final int interval = 1;
conf.set(DFSConfigKeys.DFS_METRICS_PERCENTILES_INTERVALS_KEY, "" + interval);
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
try {
FileSystem fs = cluster.getFileSystem();
// Create and read a 1 byte file
Path tmpfile = new Path("/tmp.txt");
DFSTestUtil.createFile(fs, tmpfile,
(long)1, (short)1, 1L);
DFSTestUtil.readFile(fs, tmpfile);
List<DataNode> datanodes = cluster.getDataNodes();
assertEquals(datanodes.size(), 1);
DataNode datanode = datanodes.get(0);
MetricsRecordBuilder rb = getMetrics(datanode.getMetrics().name());
// Expect 2 packets, 1 for the 1 byte read, 1 for the empty packet
// signaling the end of the block
assertCounter("SendDataPacketTransferNanosNumOps", (long)2, rb);
assertCounter("SendDataPacketBlockedOnNetworkNanosNumOps", (long)2, rb);
// Wait for at least 1 rollover
Thread.sleep((interval + 1) * 1000);
// Check that the sendPacket percentiles rolled to non-zero values
String sec = interval + "s";
assertQuantileGauges("SendDataPacketBlockedOnNetworkNanos" + sec, rb);
assertQuantileGauges("SendDataPacketTransferNanos" + sec, rb);
} finally {
if (cluster != null) {cluster.shutdown();}
}
}
@Test
public void testReceivePacketMetrics() throws Exception {
Configuration conf = new HdfsConfiguration();
final int interval = 1;
conf.set(DFSConfigKeys.DFS_METRICS_PERCENTILES_INTERVALS_KEY, "" + interval);
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
try {
cluster.waitActive();
DistributedFileSystem fs = cluster.getFileSystem();
Path testFile = new Path("/testFlushNanosMetric.txt");
FSDataOutputStream fout = fs.create(testFile);
fout.write(new byte[1]);
fout.hsync();
fout.close();
List<DataNode> datanodes = cluster.getDataNodes();
DataNode datanode = datanodes.get(0);
MetricsRecordBuilder dnMetrics = getMetrics(datanode.getMetrics().name());
// Expect two flushes, 1 for the flush that occurs after writing,
// 1 that occurs on closing the data and metadata files.
assertCounter("FlushNanosNumOps", 2L, dnMetrics);
// Expect two syncs, one from the hsync, one on close.
assertCounter("FsyncNanosNumOps", 2L, dnMetrics);
// Wait for at least 1 rollover
Thread.sleep((interval + 1) * 1000);
// Check the receivePacket percentiles that should be non-zero
String sec = interval + "s";
assertQuantileGauges("FlushNanos" + sec, dnMetrics);
assertQuantileGauges("FsyncNanos" + sec, dnMetrics);
} finally {
if (cluster != null) {cluster.shutdown();}
}
}
/**
* Tests that round-trip acks in a datanode write pipeline are correctly
* measured.
*/
@Test
public void testRoundTripAckMetric() throws Exception {
final int datanodeCount = 2;
final int interval = 1;
Configuration conf = new HdfsConfiguration();
conf.set(DFSConfigKeys.DFS_METRICS_PERCENTILES_INTERVALS_KEY, "" + interval);
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).numDataNodes(
datanodeCount).build();
try {
cluster.waitActive();
FileSystem fs = cluster.getFileSystem();
// Open a file and get the head of the pipeline
Path testFile = new Path("/testRoundTripAckMetric.txt");
FSDataOutputStream fsout = fs.create(testFile, (short) datanodeCount);
DFSOutputStream dout = (DFSOutputStream) fsout.getWrappedStream();
// Slow down the writes to catch the write pipeline
dout.setChunksPerPacket(5);
dout.setArtificialSlowdown(3000);
fsout.write(new byte[10000]);
DatanodeInfo[] pipeline = null;
int count = 0;
while (pipeline == null && count < 5) {
pipeline = dout.getPipeline();
System.out.println("Waiting for pipeline to be created.");
Thread.sleep(1000);
count++;
}
// Get the head node that should be receiving downstream acks
DatanodeInfo headInfo = pipeline[0];
DataNode headNode = null;
for (DataNode datanode : cluster.getDataNodes()) {
if (datanode.getDatanodeId().equals(headInfo)) {
headNode = datanode;
break;
}
}
assertNotNull("Could not find the head of the datanode write pipeline",
headNode);
// Close the file and wait for the metrics to rollover
Thread.sleep((interval + 1) * 1000);
// Check the ack was received
MetricsRecordBuilder dnMetrics = getMetrics(headNode.getMetrics()
.name());
assertTrue("Expected non-zero number of acks",
getLongCounter("PacketAckRoundTripTimeNanosNumOps", dnMetrics) > 0);
assertQuantileGauges("PacketAckRoundTripTimeNanos" + interval
+ "s", dnMetrics);
} finally {
if (cluster != null) {
cluster.shutdown();
}
}
}
}