Exporter/Instana: Use configurations and add deadline option.

CHANGELOG.md

@@ -5,10 +5,8 @@ break behaviors for applications that rely on this to be always enabled.
 - Provide a `Deadline` option to Stackdriver Stats exporter. Default value is 10 seconds.
 Also provide a `MetricServiceStub` option so that advanced users can use a custom Stackdriver
 Monitoring client to make RPCs.
-- Use `JaegerExporterConfiguration` for creating `JaegerTraceExporter`. Provide a `Deadline` option
-with default value 10 seconds.
-- Use `ZipkinExporterConfiguration` for creating `ZipkinTraceExporter`. Provide a `Deadline` option
-with default value 10 seconds.
+- Use `Configuration` builder pattern for creating `JaegerTraceExporter`, `ZipkinTraceExporter` and
+`InstanaTraceExporter`. Provide a `Deadline` option with default value 10 seconds.
 - Provide a `Deadline` option to Datadog and Elasticsearch exporter. Default value is 10 seconds.
 - Extract the common timeout logic of Trace exporters to `opencensus-exporter-trace-util`.
 

exporters/trace/instana/build.gradle

@@ -6,6 +6,8 @@ description = 'OpenCensus Trace Instana Exporter'
 }
 
 dependencies {
+    compileOnly libraries.auto_value
+
     compile project(':opencensus-api'),
             project(':opencensus-exporter-trace-util'),
             libraries.guava

exporters/trace/instana/src/main/java/io/opencensus/exporter/trace/instana/InstanaExporterConfiguration.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright 2019, OpenCensus 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 io.opencensus.exporter.trace.instana;
+
+import com.google.auto.value.AutoValue;
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Preconditions;
+import io.opencensus.common.Duration;
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * Configuration for {@link InstanaTraceExporter}.
+ *
+ * @since 0.22
+ */
+@AutoValue
+@Immutable
+public abstract class InstanaExporterConfiguration {
+
+  @VisibleForTesting static final Duration DEFAULT_DEADLINE = Duration.create(10, 0);
+  @VisibleForTesting static final Duration ZERO = Duration.fromMillis(0);
+
+  InstanaExporterConfiguration() {}
+
+  /**
+   * Returns the endpoint of the Instana agent.
+   *
+   * @return the endpoint of the Instana agent.
+   * @since 0.22
+   */
+  public abstract String getAgentEndpoint();
+
+  /**
+   * Returns the deadline for exporting to Instana.
+   *
+   * <p>Default value is 10 seconds.
+   *
+   * @return the export deadline.
+   * @since 0.22
+   */
+  public abstract Duration getDeadline();
+
+  /**
+   * Return a new {@link Builder}.
+   *
+   * @return a {@code Builder}
+   * @since 0.22
+   */
+  public static Builder builder() {
+    return new AutoValue_InstanaExporterConfiguration.Builder().setDeadline(DEFAULT_DEADLINE);
+  }
+
+  /**
+   * Builder for {@link InstanaExporterConfiguration}.
+   *
+   * @since 0.22
+   */
+  @AutoValue.Builder
+  public abstract static class Builder {
+
+    Builder() {}
+
+    /**
+     * Sets the endpoint of Instana agent to send traces to. E.g
+     * http://localhost:42699/com.instana.plugin.generic.trace
+     *
+     * @param agentEndpoint the endpoint of the agent.
+     * @return this.
+     * @since 0.22
+     */
+    public abstract Builder setAgentEndpoint(String agentEndpoint);
+
+    /**
+     * Sets the deadline for exporting to Instana.
+     *
+     * @param deadline the export deadline.
+     * @return this
+     * @since 0.22
+     */
+    public abstract Builder setDeadline(Duration deadline);
+
+    abstract Duration getDeadline();
+
+    abstract InstanaExporterConfiguration autoBuild();
+
+    /**
+     * Builds a {@link InstanaExporterConfiguration}.
+     *
+     * @return a {@code InstanaExporterConfiguration}.
+     * @since 0.22
+     */
+    public InstanaExporterConfiguration build() {
+      Preconditions.checkArgument(getDeadline().compareTo(ZERO) > 0, "Deadline must be positive.");
+      return autoBuild();
+    }
+  }
+}

exporters/trace/instana/src/main/java/io/opencensus/exporter/trace/instana/InstanaExporterHandler.java

@@ -23,20 +23,16 @@
 import io.opencensus.common.Duration;
 import io.opencensus.common.Function;
 import io.opencensus.common.Functions;
-import io.opencensus.common.Scope;
 import io.opencensus.common.Timestamp;
+import io.opencensus.exporter.trace.util.TimeLimitedHandler;
 import io.opencensus.trace.AttributeValue;
-import io.opencensus.trace.Sampler;
 import io.opencensus.trace.Span.Kind;
 import io.opencensus.trace.SpanContext;
 import io.opencensus.trace.SpanId;
 import io.opencensus.trace.Status;
 import io.opencensus.trace.TraceId;
-import io.opencensus.trace.Tracer;
-import io.opencensus.trace.Tracing;
 import io.opencensus.trace.export.SpanData;
-import io.opencensus.trace.export.SpanExporter;
-import io.opencensus.trace.samplers.Samplers;
+import java.io.Closeable;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
@@ -63,13 +59,13 @@
  * Major TODO is the limitation of Instana to only suport 64bit trace ids, which will be resolved.
  * Until then it is crossing fingers and treating it as 50% sampler :).
  */
-final class InstanaExporterHandler extends SpanExporter.Handler {
+final class InstanaExporterHandler extends TimeLimitedHandler {
 
-  private static final Tracer tracer = Tracing.getTracer();
-  private static final Sampler probabilitySpampler = Samplers.probabilitySampler(0.0001);
+  private static final String EXPORT_SPAN_NAME = "ExportInstanaTraces";
   private final URL agentEndpoint;
 
-  InstanaExporterHandler(URL agentEndpoint) {
+  InstanaExporterHandler(URL agentEndpoint, Duration deadline) {
+    super(deadline, EXPORT_SPAN_NAME);
     this.agentEndpoint = agentEndpoint;
   }
 
@@ -180,56 +176,36 @@ static String convertToJson(Collection<SpanData> spanDataList) {
   }
 
   @Override
-  public void export(Collection<SpanData> spanDataList) {
-    // Start a new span with explicit 1/10000 sampling probability to avoid the case when user
-    // sets the default sampler to always sample and we get the gRPC span of the instana
-    // export call always sampled and go to an infinite loop.
-    Scope scope =
-        tracer.spanBuilder("ExportInstanaTraces").setSampler(probabilitySpampler).startScopedSpan();
+  public void timeLimitedExport(Collection<SpanData> spanDataList) throws Exception {
+    String json = convertToJson(spanDataList);
+
+    OutputStream outputStream = null;
+    InputStream inputStream = null;
     try {
-      String json = convertToJson(spanDataList);
+      HttpURLConnection connection = (HttpURLConnection) agentEndpoint.openConnection();
+      connection.setRequestMethod("POST");
+      connection.setDoOutput(true);
+      outputStream = connection.getOutputStream();
+      outputStream.write(json.getBytes(Charset.defaultCharset()));
+      outputStream.flush();
+      inputStream = connection.getInputStream();
+      if (connection.getResponseCode() != 200) {
+        throw new Exception("Response " + connection.getResponseCode());
+      }
+    } finally {
+      closeStream(inputStream);
+      closeStream(outputStream);
+    }
+  }
 
-      OutputStream outputStream = null;
-      InputStream inputStream = null;
+  // Closes an input or output stream and ignores potential IOException.
+  private static void closeStream(@javax.annotation.Nullable Closeable stream) {
+    if (stream != null) {
       try {
-        HttpURLConnection connection = (HttpURLConnection) agentEndpoint.openConnection();
-        connection.setRequestMethod("POST");
-        connection.setDoOutput(true);
-        outputStream = connection.getOutputStream();
-        outputStream.write(json.getBytes(Charset.defaultCharset()));
-        outputStream.flush();
-        inputStream = connection.getInputStream();
-        if (connection.getResponseCode() != 200) {
-          tracer
-              .getCurrentSpan()
-              .setStatus(
-                  Status.UNKNOWN.withDescription("Response " + connection.getResponseCode()));
-        }
+        stream.close();
       } catch (IOException e) {
-        tracer
-            .getCurrentSpan()
-            .setStatus(
-                Status.UNKNOWN.withDescription(
-                    e.getMessage() == null ? e.getClass().getSimpleName() : e.getMessage()));
-        // dropping span batch
-      } finally {
-        if (inputStream != null) {
-          try {
-            inputStream.close();
-          } catch (IOException e) {
-            // ignore
-          }
-        }
-        if (outputStream != null) {
-          try {
-            outputStream.close();
-          } catch (IOException e) {
-            // ignore
-          }
-        }
+        // ignore
       }
-    } finally {
-      scope.close();
     }
   }
 }

exporters/trace/instana/src/main/java/io/opencensus/exporter/trace/instana/InstanaTraceExporter.java

@@ -34,7 +34,9 @@
  *
  * <pre>{@code
  * public static void main(String[] args) {
- *   InstanaTraceExporter.createAndRegister("http://localhost:42699/com.instana.plugin.generic.trace");
+ *   String agentEndpoint = "http://localhost:42699/com.instana.plugin.generic.trace";
+ *   InstanaTraceExporter.createAndRegister(
+ *     InstanaExporterConfiguration.builder().setAgentEndpoint(agentEndpoint).build());
  *   ... // Do work.
  * }
  * }</pre>
@@ -56,20 +58,39 @@ private InstanaTraceExporter() {}
    * Creates and registers the Instana Trace exporter to the OpenCensus library. Only one Instana
    * exporter can be registered at any point.
    *
-   * @param agentEndpoint Ex http://localhost:42699/com.instana.plugin.generic.trace
+   * @param configuration Configuration for InstanaTraceExporter.
    * @throws MalformedURLException if the agentEndpoint is not a valid http url.
    * @throws IllegalStateException if a Instana exporter is already registered.
-   * @since 0.12
+   * @since 0.22
    */
-  public static void createAndRegister(String agentEndpoint) throws MalformedURLException {
+  public static void createAndRegister(InstanaExporterConfiguration configuration)
+      throws MalformedURLException {
     synchronized (monitor) {
       checkState(handler == null, "Instana exporter is already registered.");
-      Handler newHandler = new InstanaExporterHandler(new URL(agentEndpoint));
+      Handler newHandler =
+          new InstanaExporterHandler(
+              new URL(configuration.getAgentEndpoint()), configuration.getDeadline());
       handler = newHandler;
       register(Tracing.getExportComponent().getSpanExporter(), newHandler);
     }
   }
 
+  /**
+   * Creates and registers the Instana Trace exporter to the OpenCensus library. Only one Instana
+   * exporter can be registered at any point.
+   *
+   * @param agentEndpoint Ex http://localhost:42699/com.instana.plugin.generic.trace
+   * @throws MalformedURLException if the agentEndpoint is not a valid http url.
+   * @throws IllegalStateException if a Instana exporter is already registered.
+   * @since 0.12
+   * @deprecated in favor of {@link #createAndRegister(InstanaExporterConfiguration)}.
+   */
+  @Deprecated
+  public static void createAndRegister(String agentEndpoint) throws MalformedURLException {
+    createAndRegister(
+        InstanaExporterConfiguration.builder().setAgentEndpoint(agentEndpoint).build());
+  }
+
   /**
    * Registers the {@code InstanaTraceExporter}.
    *