Starts 128-bit traces when spring.sleuth.traceId128=true (#455)

This adds autoconfiguration to create 128-bit traces when
`spring.sleuth.traceId128=true`.

Author: adriancole

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/autoconfig/SleuthProperties.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2013-2015 the original author or authors.
+ *
+ * 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 org.springframework.cloud.sleuth.autoconfig;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+/**
+ * Sleuth settings
+ *
+ * @since 1.0.11
+ */
+@ConfigurationProperties("spring.sleuth")
+public class SleuthProperties {
+	/** When true, generate 128-bit trace IDs instead of 64-bit ones. */
+	private boolean traceId128 = false;
+
+	public boolean isTraceId128() {
+		return this.traceId128;
+	}
+
+	public void setTraceId128(boolean traceId128) {
+		this.traceId128 = traceId128;
+	}
+}

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/autoconfig/TraceAutoConfiguration.java

@@ -18,6 +18,7 @@
 
 import java.util.Random;
 
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
@@ -44,8 +45,10 @@
  */
 @Configuration
 @ConditionalOnProperty(value="spring.sleuth.enabled", matchIfMissing=true)
-@EnableConfigurationProperties(TraceKeys.class)
+@EnableConfigurationProperties({TraceKeys.class, SleuthProperties.class})
 public class TraceAutoConfiguration {
+	@Autowired
+	SleuthProperties properties;
 
 	@Bean
 	@ConditionalOnMissingBean
@@ -65,7 +68,7 @@ public DefaultTracer sleuthTracer(Sampler sampler, Random random,
 			SpanNamer spanNamer, SpanLogger spanLogger,
 			SpanReporter spanReporter) {
 		return new DefaultTracer(sampler, random, spanNamer, spanLogger,
-				spanReporter);
+				spanReporter, this.properties.isTraceId128());
 	}
 
 	@Bean

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/DefaultTracer.java

@@ -18,7 +18,6 @@
 
 import java.util.Random;
 import java.util.concurrent.Callable;
-
 import org.springframework.cloud.sleuth.Sampler;
 import org.springframework.cloud.sleuth.Span;
 import org.springframework.cloud.sleuth.SpanNamer;
@@ -47,13 +46,21 @@ public class DefaultTracer implements Tracer {
 
 	private final SpanReporter spanReporter;
 
+	private final boolean traceId128;
+
 	public DefaultTracer(Sampler defaultSampler, Random random, SpanNamer spanNamer,
 			SpanLogger spanLogger, SpanReporter spanReporter) {
+		this(defaultSampler, random, spanNamer, spanLogger, spanReporter, false);
+	}
+
+	public DefaultTracer(Sampler defaultSampler, Random random, SpanNamer spanNamer,
+				SpanLogger spanLogger, SpanReporter spanReporter, boolean traceId128) {
 		this.defaultSampler = defaultSampler;
 		this.random = random;
 		this.spanNamer = spanNamer;
 		this.spanLogger = spanLogger;
 		this.spanReporter = spanReporter;
+		this.traceId128 = traceId128;
 	}
 
 	@Override
@@ -77,12 +84,14 @@ public Span createSpan(String name, Sampler sampler) {
 		}
 		else {
 			long id = createId();
-			span = Span.builder().name(name).traceId(id)
+			span = Span.builder().name(name)
+					.traceIdHigh(this.traceId128 ? createId() : 0L)
+					.traceId(id)
 					.spanId(id).build();
-			if (sampler==null) {
+			if (sampler == null) {
 				sampler = this.defaultSampler;
 			}
-			span = sampledSpan(name, id, span, sampler);
+			span = sampledSpan(span, sampler);
 			this.spanLogger.logStartedSpan(null, span);
 		}
 		return continueSpan(span);
@@ -142,8 +151,10 @@ protected Span createChild(Span parent, String name) {
 		long id = createId();
 		if (parent == null) {
 			Span span = Span.builder().name(name)
-					.traceId(id).spanId(id).build();
-			span = sampledSpan(name, id, span, this.defaultSampler);
+					.traceIdHigh(this.traceId128 ? createId() : 0L)
+					.traceId(id)
+					.spanId(id).build();
+			span = sampledSpan(span, this.defaultSampler);
 			this.spanLogger.logStartedSpan(null, span);
 			return span;
 		}
@@ -152,6 +163,7 @@ protected Span createChild(Span parent, String name) {
 				SpanContextHolder.push(parent, true);
 			}
 			Span span = Span.builder().name(name)
+					.traceIdHigh(parent.getTraceIdHigh())
 					.traceId(parent.getTraceId()).parent(parent.getSpanId()).spanId(id)
 					.processId(parent.getProcessId()).savedSpan(parent)
 					.exportable(parent.isExportable()).build();
@@ -160,11 +172,16 @@ protected Span createChild(Span parent, String name) {
 		}
 	}
 
-	private Span sampledSpan(String name, long id, Span span, Sampler sampler) {
+	private Span sampledSpan(Span span, Sampler sampler) {
 		if (!sampler.isSampled(span)) {
-			// Non-exportable so we keep the trace but not other data
-			return Span.builder().begin(span.getBegin()).name(name).traceId(id)
-					.spanId(id).exportable(false).build();
+			// Copy everything, except set exportable to false
+			return Span.builder()
+					.begin(span.getBegin())
+					.traceIdHigh(span.getTraceIdHigh())
+					.traceId(span.getTraceId())
+					.spanId(span.getSpanId())
+					.name(span.getName())
+					.exportable(false).build();
 		}
 		return span;
 	}

spring-cloud-sleuth-core/src/test/java/org/springframework/cloud/sleuth/autoconfig/TraceAutoConfigurationTest.java

@@ -0,0 +1,82 @@
+/**
+ * Copyright 2015-2016 The OpenZipkin Authors
+ *
+ * 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 org.springframework.cloud.sleuth.autoconfig;
+
+import org.junit.After;
+import org.junit.Test;
+import org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfiguration;
+import org.springframework.cloud.sleuth.Span;
+import org.springframework.cloud.sleuth.Tracer;
+import org.springframework.cloud.sleuth.log.SleuthLogAutoConfiguration;
+import org.springframework.cloud.sleuth.sampler.NeverSampler;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.boot.test.util.EnvironmentTestUtils.addEnvironment;
+
+public class TraceAutoConfigurationTest {
+
+  AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+
+  @After
+  public void close() {
+    context.close();
+  }
+
+  @Test
+  public void defaultsTo64BitTraceId() {
+    context = new AnnotationConfigApplicationContext();
+    context.register(
+        PropertyPlaceholderAutoConfiguration.class,
+        SleuthLogAutoConfiguration.class,
+        TraceAutoConfiguration.class
+    );
+    context.refresh();
+    Tracer tracer = context.getBean(Tracer.class);
+
+    Span span = null;
+    try {
+      span = tracer.createSpan("foo", NeverSampler.INSTANCE);
+      assertThat(span.getTraceIdHigh()).isEqualTo(0L);
+      assertThat(span.getTraceId()).isNotEqualTo(0L);
+    } finally {
+      if (span != null){
+        tracer.close(span);
+      }
+    }
+  }
+
+  @Test
+  public void optInto128BitTraceId() {
+    addEnvironment(context, "spring.sleuth.traceId128:true");
+    context.register(
+        PropertyPlaceholderAutoConfiguration.class,
+        SleuthLogAutoConfiguration.class,
+        TraceAutoConfiguration.class
+    );
+    context.refresh();
+    Tracer tracer = context.getBean(Tracer.class);
+
+    Span span = null;
+    try {
+      span = tracer.createSpan("foo", NeverSampler.INSTANCE);
+      assertThat(span.getTraceIdHigh()).isNotEqualTo(0L);
+      assertThat(span.getTraceId()).isNotEqualTo(0L);
+    } finally {
+      if (span != null){
+        tracer.close(span);
+      }
+    }
+  }
+}