feat: Open telemetry implementation (#2770)

This PR adds support for [OpenTelemetry](https://opentelemetry.io/) Instrumentation for Traces and Metrics. 

Add dependency for [OpenTelemetrySDK](https://opentelemetry.io/docs/instrumentation/java/manual/#initialize-the-sdk) and required [exporters](https://opentelemetry.io/docs/instrumentation/java/exporters/).

Create OpenTelemetry object with required MeterProvider and TracerProvider exporter . Inject OpenTelemetry object via SpannerOptions or register as Global

`
OpenTelemetry openTelemetry = OpenTelemetrySdk.builder()
              .setPropagators(ContextPropagators.create(W3CTraceContextPropagator.getInstance()))
              .setTracerProvider(tracerProvider)
              .setMeterProvider(sdkMeterProvider)
              .build;

SpannerOptions options = SpannerOptions.newBuilder().setOpenTelemetry(openTelemetry).build();
`

 By default, OpenTelemetry traces are not enabled. To enable OpenTelemetry traces , call `SpannerOptions.enableOpenTelemetryTraces()` in startup of your application. Enabling OpenTelemetry traces will disable OpenCensus traces. Both OpenCensus and OpenTelemetry traces can not be enabled at the same time.

Author: surbhigarg92

.gitignore

@@ -22,6 +22,7 @@ nosetests.xml
 .settings
 .DS_Store
 .classpath
+.tool-versions
 
 # Built documentation
 docs/

google-cloud-spanner/clirr-ignored-differences.xml

@@ -426,7 +426,6 @@
     <className>com/google/cloud/spanner/connection/Connection</className>
     <method>void rollbackToSavepoint(java.lang.String)</method>
   </difference>
-  
   <!-- Delay start transaction -->
   <difference>
     <differenceType>7012</differenceType>
@@ -540,6 +539,12 @@
     <className>com/google/cloud/spanner/Dialect</className>
     <method>java.lang.String getDefaultSchema()</method>
   </difference>
+  <difference>
+    <differenceType>7005</differenceType>
+    <className>com/google/cloud/spanner/PartitionedDmlTransaction</className>
+    <method>void setSpan(io.opencensus.trace.Span)</method>
+    <to>void setSpan(com.google.cloud.spanner.ISpan)</to>
+  </difference>
 
   <!-- Added DirectedReadOptions -->
   <difference>

google-cloud-spanner/pom.xml

@@ -247,6 +247,14 @@
       <artifactId>opencensus-impl</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>io.opentelemetry</groupId>
+      <artifactId>opentelemetry-api</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>io.opentelemetry</groupId>
+      <artifactId>opentelemetry-context</artifactId>
+    </dependency>
     <dependency>
       <groupId>com.google.auth</groupId>
       <artifactId>google-auth-library-oauth2-http</artifactId>
@@ -393,7 +401,6 @@
       <version>2.2</version>
       <scope>test</scope>
     </dependency>
-    
     <!-- Benchmarking dependencies -->
     <dependency>
       <groupId>org.openjdk.jmh</groupId>
@@ -407,9 +414,28 @@
       <version>1.37</version>
       <scope>test</scope>
     </dependency>
-
+    <!-- OpenTelemetry test dependencies -->
+    <dependency>
+      <groupId>io.opentelemetry</groupId>
+      <artifactId>opentelemetry-sdk</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>io.opentelemetry</groupId>
+      <artifactId>opentelemetry-sdk-metrics</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>io.opentelemetry</groupId>
+      <artifactId>opentelemetry-sdk-trace</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>io.opentelemetry</groupId>
+      <artifactId>opentelemetry-sdk-testing</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
-
   <profiles>
     <profile>
       <id>java9</id>

google-cloud-spanner/src/main/java/com/google/cloud/spanner/AbstractReadContext.java

@@ -39,6 +39,7 @@
 import com.google.cloud.spanner.spi.v1.SpannerRpc;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.util.concurrent.MoreExecutors;
 import com.google.protobuf.ByteString;
 import com.google.spanner.v1.BeginTransactionRequest;
@@ -53,8 +54,6 @@
 import com.google.spanner.v1.Transaction;
 import com.google.spanner.v1.TransactionOptions;
 import com.google.spanner.v1.TransactionSelector;
-import io.opencensus.trace.Span;
-import io.opencensus.trace.Tracing;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicLong;
 import javax.annotation.Nullable;
@@ -70,7 +69,8 @@ abstract class AbstractReadContext
   abstract static class Builder<B extends Builder<?, T>, T extends AbstractReadContext> {
     private SessionImpl session;
     private SpannerRpc rpc;
-    private Span span = Tracing.getTracer().getCurrentSpan();
+    private ISpan span;
+    private TraceWrapper tracer;
     private int defaultPrefetchChunks = SpannerOptions.Builder.DEFAULT_PREFETCH_CHUNKS;
     private QueryOptions defaultQueryOptions = SpannerOptions.Builder.DEFAULT_QUERY_OPTIONS;
     private DirectedReadOptions defaultDirectedReadOption;
@@ -94,11 +94,16 @@ B setRpc(SpannerRpc rpc) {
       return self();
     }
 
-    B setSpan(Span span) {
+    B setSpan(ISpan span) {
       this.span = span;
       return self();
     }
 
+    B setTracer(TraceWrapper tracer) {
+      this.tracer = tracer;
+      return self();
+    }
+
     B setDefaultPrefetchChunks(int defaultPrefetchChunks) {
       this.defaultPrefetchChunks = defaultPrefetchChunks;
       return self();
@@ -389,9 +394,12 @@ void initTransaction() {
           }
           transactionId = transaction.getId();
           span.addAnnotation(
-              "Transaction Creation Done", TraceUtil.getTransactionAnnotations(transaction));
+              "Transaction Creation Done",
+              ImmutableMap.of(
+                  "Id", transaction.getId().toStringUtf8(), "Timestamp", timestamp.toString()));
+
         } catch (SpannerException e) {
-          span.addAnnotation("Transaction Creation Failed", TraceUtil.getExceptionAnnotations(e));
+          span.addAnnotation("Transaction Creation Failed", e);
           throw e;
         }
       }
@@ -402,7 +410,8 @@ void initTransaction() {
   final SessionImpl session;
   final SpannerRpc rpc;
   final ExecutorProvider executorProvider;
-  Span span;
+  ISpan span;
+  TraceWrapper tracer;
   private final int defaultPrefetchChunks;
   private final QueryOptions defaultQueryOptions;
 
@@ -435,10 +444,11 @@ void initTransaction() {
     this.span = builder.span;
     this.executorProvider = builder.executorProvider;
     this.clock = builder.clock;
+    this.tracer = builder.tracer;
   }
 
   @Override
-  public void setSpan(Span span) {
+  public void setSpan(ISpan span) {
     this.span = span;
   }
 
@@ -692,6 +702,7 @@ ResultSet executeQueryInternalWithOptions(
             MAX_BUFFERED_CHUNKS,
             SpannerImpl.QUERY,
             span,
+            tracer,
             rpc.getExecuteQueryRetrySettings(),
             rpc.getExecuteQueryRetryableCodes()) {
           @Override
@@ -752,7 +763,7 @@ public final void invalidate() {
 
   @Override
   public void close() {
-    span.end(TraceUtil.END_SPAN_OPTIONS);
+    span.end();
     synchronized (lock) {
       isClosed = true;
     }
@@ -837,6 +848,7 @@ ResultSet readInternalWithOptions(
             MAX_BUFFERED_CHUNKS,
             SpannerImpl.READ,
             span,
+            tracer,
             rpc.getReadRetrySettings(),
             rpc.getReadRetryableCodes()) {
           @Override

google-cloud-spanner/src/main/java/com/google/cloud/spanner/AbstractResultSet.java

@@ -37,7 +37,6 @@
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.AbstractIterator;
-import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Lists;
 import com.google.common.io.CharSource;
 import com.google.common.util.concurrent.Uninterruptibles;
@@ -53,11 +52,6 @@
 import com.google.spanner.v1.Transaction;
 import com.google.spanner.v1.TypeCode;
 import io.grpc.Context;
-import io.opencensus.common.Scope;
-import io.opencensus.trace.AttributeValue;
-import io.opencensus.trace.Span;
-import io.opencensus.trace.Tracer;
-import io.opencensus.trace.Tracing;
 import java.io.IOException;
 import java.io.Serializable;
 import java.math.BigDecimal;
@@ -87,7 +81,6 @@
 
 /** Implementation of {@link ResultSet}. */
 abstract class AbstractResultSet<R> extends AbstractStructReader implements ResultSet {
-  private static final Tracer tracer = Tracing.getTracer();
   private static final com.google.protobuf.Value NULL_VALUE =
       com.google.protobuf.Value.newBuilder().setNullValue(NullValue.NULL_VALUE).build();
 
@@ -1206,7 +1199,8 @@ abstract static class ResumableStreamIterator extends AbstractIterator<PartialRe
     private final BackOff backOff;
     private final LinkedList<PartialResultSet> buffer = new LinkedList<>();
     private final int maxBufferSize;
-    private final Span span;
+    private final ISpan span;
+    private final TraceWrapper tracer;
     private CloseableIterator<PartialResultSet> stream;
     private ByteString resumeToken;
     private boolean finished;
@@ -1220,12 +1214,14 @@ abstract static class ResumableStreamIterator extends AbstractIterator<PartialRe
     protected ResumableStreamIterator(
         int maxBufferSize,
         String streamName,
-        Span parent,
+        ISpan parent,
+        TraceWrapper tracer,
         RetrySettings streamingRetrySettings,
         Set<Code> retryableCodes) {
       checkArgument(maxBufferSize >= 0);
       this.maxBufferSize = maxBufferSize;
-      this.span = tracer.spanBuilderWithExplicitParent(streamName, parent).startSpan();
+      this.tracer = tracer;
+      this.span = tracer.spanBuilderWithExplicitParent(streamName, parent);
       this.streamingRetrySettings = Preconditions.checkNotNull(streamingRetrySettings);
       this.retryableCodes = Preconditions.checkNotNull(retryableCodes);
       this.backOff = newBackOff();
@@ -1281,11 +1277,7 @@ private static long nextBackOffMillis(BackOff backoff) throws SpannerException {
     }
 
     private void backoffSleep(Context context, long backoffMillis) throws SpannerException {
-      tracer
-          .getCurrentSpan()
-          .addAnnotation(
-              "Backing off",
-              ImmutableMap.of("Delay", AttributeValue.longAttributeValue(backoffMillis)));
+      tracer.getCurrentSpan().addAnnotation("Backing off", "Delay", backoffMillis);
       final CountDownLatch latch = new CountDownLatch(1);
       final Context.CancellationListener listener =
           ignored -> {
@@ -1325,7 +1317,7 @@ public void execute(Runnable command) {
     public void close(@Nullable String message) {
       if (stream != null) {
         stream.close(message);
-        span.end(TraceUtil.END_SPAN_OPTIONS);
+        span.end();
         stream = null;
       }
     }
@@ -1343,11 +1335,9 @@ protected PartialResultSet computeNext() {
         if (stream == null) {
           span.addAnnotation(
               "Starting/Resuming stream",
-              ImmutableMap.of(
-                  "ResumeToken",
-                  AttributeValue.stringAttributeValue(
-                      resumeToken == null ? "null" : resumeToken.toStringUtf8())));
-          try (Scope s = tracer.withSpan(span)) {
+              "ResumeToken",
+              resumeToken == null ? "null" : resumeToken.toStringUtf8());
+          try (IScope scope = tracer.withSpan(span)) {
             // When start a new stream set the Span as current to make the gRPC Span a child of
             // this Span.
             stream = checkNotNull(startStream(resumeToken));
@@ -1387,17 +1377,15 @@ protected PartialResultSet computeNext() {
           }
         } catch (SpannerException spannerException) {
           if (safeToRetry && isRetryable(spannerException)) {
-            span.addAnnotation(
-                "Stream broken. Safe to retry",
-                TraceUtil.getExceptionAnnotations(spannerException));
+            span.addAnnotation("Stream broken. Safe to retry", spannerException);
             logger.log(Level.FINE, "Retryable exception, will sleep and retry", spannerException);
             // Truncate any items in the buffer before the last retry token.
             while (!buffer.isEmpty() && buffer.getLast().getResumeToken().isEmpty()) {
               buffer.removeLast();
             }
             assert buffer.isEmpty() || buffer.getLast().getResumeToken().equals(resumeToken);
             stream = null;
-            try (Scope s = tracer.withSpan(span)) {
+            try (IScope s = tracer.withSpan(span)) {
               long delay = spannerException.getRetryDelayInMillis();
               if (delay != -1) {
                 backoffSleep(context, delay);
@@ -1408,12 +1396,12 @@ protected PartialResultSet computeNext() {
 
             continue;
           }
-          span.addAnnotation("Stream broken. Not safe to retry");
-          TraceUtil.setWithFailure(span, spannerException);
+          span.addAnnotation("Stream broken. Not safe to retry", spannerException);
+          span.setStatus(spannerException);
           throw spannerException;
         } catch (RuntimeException e) {
-          span.addAnnotation("Stream broken. Not safe to retry");
-          TraceUtil.setWithFailure(span, e);
+          span.addAnnotation("Stream broken. Not safe to retry", e);
+          span.setStatus(e);
           throw e;
         }
       }

google-cloud-spanner/src/main/java/com/google/cloud/spanner/AsyncTransactionManagerImpl.java

@@ -28,31 +28,27 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Preconditions;
 import com.google.common.util.concurrent.MoreExecutors;
-import io.opencensus.trace.Span;
-import io.opencensus.trace.Tracer;
-import io.opencensus.trace.Tracing;
 
 /** Implementation of {@link AsyncTransactionManager}. */
 final class AsyncTransactionManagerImpl
     implements CommittableAsyncTransactionManager, SessionTransaction {
-  private static final Tracer tracer = Tracing.getTracer();
 
   private final SessionImpl session;
-  private Span span;
+  private ISpan span;
   private final Options options;
 
   private TransactionRunnerImpl.TransactionContextImpl txn;
   private TransactionState txnState;
   private final SettableApiFuture<CommitResponse> commitResponse = SettableApiFuture.create();
 
-  AsyncTransactionManagerImpl(SessionImpl session, Span span, TransactionOption... options) {
+  AsyncTransactionManagerImpl(SessionImpl session, ISpan span, TransactionOption... options) {
     this.session = session;
     this.span = span;
     this.options = Options.fromTransactionOptions(options);
   }
 
   @Override
-  public void setSpan(Span span) {
+  public void setSpan(ISpan span) {
     this.span = span;
   }