001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.http.prometheus;
019
020import static java.nio.charset.StandardCharsets.UTF_8;
021
022import java.io.ByteArrayOutputStream;
023import java.io.IOException;
024import java.io.OutputStreamWriter;
025import org.apache.hadoop.hbase.HBaseClassTestRule;
026import org.apache.hadoop.hbase.testclassification.MiscTests;
027import org.apache.hadoop.hbase.testclassification.SmallTests;
028import org.apache.hadoop.metrics2.MetricsSystem;
029import org.apache.hadoop.metrics2.annotation.Metric;
030import org.apache.hadoop.metrics2.annotation.Metrics;
031import org.apache.hadoop.metrics2.lib.DefaultMetricsSystem;
032import org.apache.hadoop.metrics2.lib.MutableCounterLong;
033import org.junit.Assert;
034import org.junit.ClassRule;
035import org.junit.Test;
036import org.junit.experimental.categories.Category;
037
038/**
039 * Test prometheus Sink.
040 */
041@Category({ SmallTests.class, MiscTests.class })
042public class TestPrometheusServlet {
043
044  @ClassRule
045  public static final HBaseClassTestRule CLASS_TEST_RULE =
046    HBaseClassTestRule.forClass(TestPrometheusServlet.class);
047
048  @Test
049  public void testPublish() throws IOException {
050    // GIVEN
051    MetricsSystem metrics = DefaultMetricsSystem.instance();
052    metrics.init("test");
053    TestMetrics testMetrics = metrics.register("TestMetrics", "Testing metrics", new TestMetrics());
054    metrics.start();
055
056    testMetrics.numBucketCreateFails.incr();
057    metrics.publishMetricsNow();
058    ByteArrayOutputStream stream = new ByteArrayOutputStream();
059    OutputStreamWriter writer = new OutputStreamWriter(stream, UTF_8);
060
061    // WHEN
062    PrometheusHadoopServlet prom2Servlet = new PrometheusHadoopServlet();
063    // Test with no description
064    prom2Servlet.writeMetrics(writer, false, null);
065
066    // THEN
067    String writtenMetrics = stream.toString(UTF_8.name());
068    System.out.println(writtenMetrics);
069    Assert.assertTrue("The expected metric line is missing from prometheus metrics output",
070      writtenMetrics.contains("test_metrics_num_bucket_create_fails{context=\"dfs\""));
071
072    metrics.stop();
073    metrics.shutdown();
074  }
075
076  /**
077   * Example metric pojo.
078   */
079  @Metrics(about = "Test Metrics", context = "dfs")
080  private static class TestMetrics {
081
082    @Metric
083    private MutableCounterLong numBucketCreateFails;
084  }
085}