Move to tracing package

DaveCTurner · DaveCTurner · commit f73b052ff259 · 2021-11-18T10:05:18.000Z
diff --git a/server/src/main/java/org/elasticsearch/node/Node.java b/server/src/main/java/org/elasticsearch/node/Node.java
@@ -168,9 +168,9 @@
 import org.elasticsearch.tasks.TaskCancellationService;
 import org.elasticsearch.tasks.TaskResultsService;
 import org.elasticsearch.tasks.TaskTracer;
-import org.elasticsearch.tasks.Tracer;
 import org.elasticsearch.threadpool.ExecutorBuilder;
 import org.elasticsearch.threadpool.ThreadPool;
+import org.elasticsearch.tracing.Tracer;
 import org.elasticsearch.transport.Transport;
 import org.elasticsearch.transport.TransportInterceptor;
 import org.elasticsearch.transport.TransportService;
diff --git a/server/src/main/java/org/elasticsearch/tasks/Task.java b/server/src/main/java/org/elasticsearch/tasks/Task.java
@@ -11,6 +11,7 @@
 import org.elasticsearch.action.ActionResponse;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.common.io.stream.NamedWriteable;
+import org.elasticsearch.tracing.Traceable;
 import org.elasticsearch.xcontent.ToXContent;
 import org.elasticsearch.xcontent.ToXContentObject;
 
diff --git a/server/src/main/java/org/elasticsearch/tasks/TaskTracer.java b/server/src/main/java/org/elasticsearch/tasks/TaskTracer.java
@@ -11,6 +11,7 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.message.ParameterizedMessage;
+import org.elasticsearch.tracing.Tracer;
 
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
diff --git a/server/src/main/java/org/elasticsearch/tracing/Traceable.java b/server/src/main/java/org/elasticsearch/tracing/Traceable.java
@@ -6,14 +6,27 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.tasks;
+package org.elasticsearch.tracing;
 
 import java.util.Map;
 
+/**
+ * Something which maps onto a <i>span</i> in a distributed trace.
+ */
 public interface Traceable {
+
+    /**
+     * @return a key which uniquely identifies the span.
+     */
     String getSpanId();
 
+    /**
+     * @return the name of the span as seen by the external tracing system (e.g. the action name for a task)
+     */
     String getSpanName();
 
+    /**
+     * @return extra metadata about the span.
+     */
     Map<String, Object> getAttributes();
 }
diff --git a/server/src/main/java/org/elasticsearch/tracing/Tracer.java b/server/src/main/java/org/elasticsearch/tracing/Tracer.java
@@ -6,10 +6,20 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.tasks;
+package org.elasticsearch.tracing;
 
+/**
+ * Represents a distributed tracing system that keeps track of the start and end of various activities in the cluster.
+ */
 public interface Tracer {
+
+    /**
+     * Called when the {@link Traceable} activity starts.
+     */
     void onTraceStarted(Traceable traceable);
 
+    /**
+     * Called when the {@link Traceable} activity ends.
+     */
     void onTraceStopped(Traceable traceable);
 }
diff --git a/x-pack/plugin/apm-integration/src/main/java/org/elasticsearch/xpack/apm/APMTracer.java b/x-pack/plugin/apm-integration/src/main/java/org/elasticsearch/xpack/apm/APMTracer.java
@@ -39,8 +39,8 @@
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.concurrent.ConcurrentCollections;
 import org.elasticsearch.tasks.Task;
-import org.elasticsearch.tasks.Traceable;
 import org.elasticsearch.threadpool.ThreadPool;
+import org.elasticsearch.tracing.Traceable;
 
 import java.security.AccessController;
 import java.security.PrivilegedAction;
@@ -55,7 +55,7 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-public class APMTracer extends AbstractLifecycleComponent implements org.elasticsearch.tasks.Tracer {
+public class APMTracer extends AbstractLifecycleComponent implements org.elasticsearch.tracing.Tracer {
 
     public static final CapturingSpanExporter CAPTURING_SPAN_EXPORTER = new CapturingSpanExporter();
 
