HADOOP-17804. Expose prometheus metrics only after a flush and dedupe with tag values (#3369)

Signed-off-by: Akira Ajisaka <aajisaka@apache.org>
This commit is contained in:
Adam Binford 2021-09-09 03:49:40 -04:00 committed by GitHub
parent e708836641
commit 4ced012f33
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2 changed files with 168 additions and 40 deletions

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@ -26,6 +26,7 @@ import org.apache.hadoop.metrics2.MetricsTag;
import java.io.IOException;
import java.io.Writer;
import java.util.Collection;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.regex.Pattern;
@ -42,7 +43,10 @@ public class PrometheusMetricsSink implements MetricsSink {
/**
* Cached output lines for each metrics.
*/
private final Map<String, String> metricLines = new ConcurrentHashMap<>();
private Map<String, Map<Collection<MetricsTag>, AbstractMetric>> promMetrics =
new ConcurrentHashMap<>();
private Map<String, Map<Collection<MetricsTag>, AbstractMetric>> nextPromMetrics =
new ConcurrentHashMap<>();
private static final Pattern SPLIT_PATTERN =
Pattern.compile("(?<!(^|[A-Z_]))(?=[A-Z])|(?<!^)(?=[A-Z][a-z])");
@ -53,42 +57,16 @@ public class PrometheusMetricsSink implements MetricsSink {
@Override
public void putMetrics(MetricsRecord metricsRecord) {
for (AbstractMetric metrics : metricsRecord.metrics()) {
if (metrics.type() == MetricType.COUNTER
|| metrics.type() == MetricType.GAUGE) {
for (AbstractMetric metric : metricsRecord.metrics()) {
if (metric.type() == MetricType.COUNTER
|| metric.type() == MetricType.GAUGE) {
String key = prometheusName(
metricsRecord.name(), metrics.name());
StringBuilder builder = new StringBuilder();
builder.append("# TYPE ")
.append(key)
.append(" ")
.append(metrics.type().toString().toLowerCase())
.append("\n")
.append(key)
.append("{");
String sep = "";
//add tags
for (MetricsTag tag : metricsRecord.tags()) {
String tagName = tag.name().toLowerCase();
//ignore specific tag which includes sub-hierarchy
if (!tagName.equals("numopenconnectionsperuser")) {
builder.append(sep)
.append(tagName)
.append("=\"")
.append(tag.value())
.append("\"");
sep = ",";
}
}
builder.append("} ");
builder.append(metrics.value());
builder.append("\n");
metricLines.put(key, builder.toString());
metricsRecord.name(), metric.name());
nextPromMetrics.computeIfAbsent(key,
any -> new ConcurrentHashMap<>())
.put(metricsRecord.tags(), metric);
}
}
}
@ -108,17 +86,55 @@ public class PrometheusMetricsSink implements MetricsSink {
@Override
public void flush() {
promMetrics = nextPromMetrics;
nextPromMetrics = new ConcurrentHashMap<>();
}
@Override
public void init(SubsetConfiguration subsetConfiguration) {
public void init(SubsetConfiguration conf) {
}
public void writeMetrics(Writer writer) throws IOException {
for (String line : metricLines.values()) {
writer.write(line);
for (Map.Entry<String, Map<Collection<MetricsTag>, AbstractMetric>> promMetric :
promMetrics.entrySet()) {
AbstractMetric firstMetric = promMetric.getValue().values().iterator().next();
StringBuilder builder = new StringBuilder();
builder.append("# HELP ")
.append(promMetric.getKey())
.append(" ")
.append(firstMetric.description())
.append("\n")
.append("# TYPE ")
.append(promMetric.getKey())
.append(" ")
.append(firstMetric.type().toString().toLowerCase())
.append("\n");
for (Map.Entry<Collection<MetricsTag>, AbstractMetric> metric :
promMetric.getValue().entrySet()) {
builder.append(promMetric.getKey())
.append("{");
String sep = "";
for (MetricsTag tag : metric.getKey()) {
String tagName = tag.name().toLowerCase();
if (!tagName.equals("numopenconnectionsperuser")) {
builder.append(sep)
.append(tagName)
.append("=\"")
.append(tag.value())
.append("\"");
sep = ",";
}
}
builder.append("} ");
builder.append(metric.getValue().value());
builder.append("\n");
}
writer.write(builder.toString());
}
}
}

View File

@ -24,6 +24,7 @@ import java.io.OutputStreamWriter;
import org.apache.hadoop.metrics2.MetricsSystem;
import org.apache.hadoop.metrics2.annotation.Metric;
import org.apache.hadoop.metrics2.annotation.Metrics;
import org.apache.hadoop.metrics2.annotation.Metric.Type;
import org.apache.hadoop.metrics2.lib.DefaultMetricsSystem;
import org.apache.hadoop.metrics2.lib.MutableCounterLong;
@ -48,7 +49,6 @@ public class TestPrometheusMetricsSink {
TestMetrics testMetrics = metrics
.register("TestMetrics", "Testing metrics", new TestMetrics());
metrics.start();
testMetrics.numBucketCreateFails.incr();
metrics.publishMetricsNow();
ByteArrayOutputStream stream = new ByteArrayOutputStream();
@ -67,6 +67,104 @@ public class TestPrometheusMetricsSink {
"test_metrics_num_bucket_create_fails{context=\"dfs\"")
);
metrics.unregisterSource("TestMetrics");
metrics.stop();
metrics.shutdown();
}
/**
* Fix for HADOOP-17804, make sure Prometheus metrics get deduped based on metric
* and tags, not just the metric.
*/
@Test
public void testPublishMultiple() throws IOException {
//GIVEN
MetricsSystem metrics = DefaultMetricsSystem.instance();
metrics.init("test");
PrometheusMetricsSink sink = new PrometheusMetricsSink();
metrics.register("Prometheus", "Prometheus", sink);
TestMetrics testMetrics1 = metrics
.register("TestMetrics1", "Testing metrics", new TestMetrics("1"));
TestMetrics testMetrics2 = metrics
.register("TestMetrics2", "Testing metrics", new TestMetrics("2"));
testMetrics1.numBucketCreateFails.incr();
testMetrics2.numBucketCreateFails.incr();
metrics.publishMetricsNow();
ByteArrayOutputStream stream = new ByteArrayOutputStream();
OutputStreamWriter writer = new OutputStreamWriter(stream, UTF_8);
//WHEN
sink.writeMetrics(writer);
writer.flush();
//THEN
String writtenMetrics = stream.toString(UTF_8.name());
System.out.println(writtenMetrics);
Assert.assertTrue(
"The expected first metric line is missing from prometheus metrics output",
writtenMetrics.contains(
"test_metrics_num_bucket_create_fails{context=\"dfs\",testtag=\"testTagValue1\"")
);
Assert.assertTrue(
"The expected second metric line is missing from prometheus metrics output",
writtenMetrics.contains(
"test_metrics_num_bucket_create_fails{context=\"dfs\",testtag=\"testTagValue2\"")
);
metrics.unregisterSource("TestMetrics1");
metrics.unregisterSource("TestMetrics2");
metrics.stop();
metrics.shutdown();
}
/**
* Fix for HADOOP-17804, make sure Prometheus metrics start fresh after each flush.
*/
@Test
public void testPublishFlush() throws IOException {
//GIVEN
MetricsSystem metrics = DefaultMetricsSystem.instance();
metrics.init("test");
PrometheusMetricsSink sink = new PrometheusMetricsSink();
metrics.register("Prometheus", "Prometheus", sink);
TestMetrics testMetrics = metrics
.register("TestMetrics", "Testing metrics", new TestMetrics("1"));
testMetrics.numBucketCreateFails.incr();
metrics.publishMetricsNow();
metrics.unregisterSource("TestMetrics");
testMetrics = metrics
.register("TestMetrics", "Testing metrics", new TestMetrics("2"));
testMetrics.numBucketCreateFails.incr();
metrics.publishMetricsNow();
ByteArrayOutputStream stream = new ByteArrayOutputStream();
OutputStreamWriter writer = new OutputStreamWriter(stream, UTF_8);
//WHEN
sink.writeMetrics(writer);
writer.flush();
//THEN
String writtenMetrics = stream.toString(UTF_8.name());
System.out.println(writtenMetrics);
Assert.assertFalse(
"The first metric should not exist after flushing",
writtenMetrics.contains(
"test_metrics_num_bucket_create_fails{context=\"dfs\",testtag=\"testTagValue1\"")
);
Assert.assertTrue(
"The expected metric line is missing from prometheus metrics output",
writtenMetrics.contains(
"test_metrics_num_bucket_create_fails{context=\"dfs\",testtag=\"testTagValue2\"")
);
metrics.unregisterSource("TestMetrics");
metrics.stop();
metrics.shutdown();
}
@ -126,6 +224,20 @@ public class TestPrometheusMetricsSink {
*/
@Metrics(about = "Test Metrics", context = "dfs")
private static class TestMetrics {
private String id;
TestMetrics() {
this("1");
}
TestMetrics(String id) {
this.id = id;
}
@Metric(value={"testTag", ""}, type=Type.TAG)
String testTag1() {
return "testTagValue" + id;
}
@Metric
private MutableCounterLong numBucketCreateFails;