Merge branch 'master' of github.com:grpc/grpc-java into impl/clean_up…

…_io_grpc_services

README.md

@@ -31,8 +31,8 @@ For a guided tour, take a look at the [quick start
 guide](https://grpc.io/docs/languages/java/quickstart) or the more explanatory [gRPC
 basics](https://grpc.io/docs/languages/java/basics).
 
-The [examples](https://github.com/grpc/grpc-java/tree/v1.36.0/examples) and the
-[Android example](https://github.com/grpc/grpc-java/tree/v1.36.0/examples/android)
+The [examples](https://github.com/grpc/grpc-java/tree/v1.37.0/examples) and the
+[Android example](https://github.com/grpc/grpc-java/tree/v1.37.0/examples/android)
 are standalone projects that showcase the usage of gRPC.
 
 Download
@@ -43,17 +43,17 @@ Download [the JARs][]. Or for Maven with non-Android, add to your `pom.xml`:
 <dependency>
   <groupId>io.grpc</groupId>
   <artifactId>grpc-netty-shaded</artifactId>
-  <version>1.36.0</version>
+  <version>1.37.0</version>
 </dependency>
 <dependency>
   <groupId>io.grpc</groupId>
   <artifactId>grpc-protobuf</artifactId>
-  <version>1.36.0</version>
+  <version>1.37.0</version>
 </dependency>
 <dependency>
   <groupId>io.grpc</groupId>
   <artifactId>grpc-stub</artifactId>
-  <version>1.36.0</version>
+  <version>1.37.0</version>
 </dependency>
 <dependency> <!-- necessary for Java 9+ -->
   <groupId>org.apache.tomcat</groupId>
@@ -65,23 +65,23 @@ Download [the JARs][]. Or for Maven with non-Android, add to your `pom.xml`:
 
 Or for Gradle with non-Android, add to your dependencies:
 ```gradle
-implementation 'io.grpc:grpc-netty-shaded:1.36.0'
-implementation 'io.grpc:grpc-protobuf:1.36.0'
-implementation 'io.grpc:grpc-stub:1.36.0'
+implementation 'io.grpc:grpc-netty-shaded:1.37.0'
+implementation 'io.grpc:grpc-protobuf:1.37.0'
+implementation 'io.grpc:grpc-stub:1.37.0'
 compileOnly 'org.apache.tomcat:annotations-api:6.0.53' // necessary for Java 9+
 ```
 
 For Android client, use `grpc-okhttp` instead of `grpc-netty-shaded` and
 `grpc-protobuf-lite` instead of `grpc-protobuf`:
 ```gradle
-implementation 'io.grpc:grpc-okhttp:1.36.0'
-implementation 'io.grpc:grpc-protobuf-lite:1.36.0'
-implementation 'io.grpc:grpc-stub:1.36.0'
+implementation 'io.grpc:grpc-okhttp:1.37.0'
+implementation 'io.grpc:grpc-protobuf-lite:1.37.0'
+implementation 'io.grpc:grpc-stub:1.37.0'
 compileOnly 'org.apache.tomcat:annotations-api:6.0.53' // necessary for Java 9+
 ```
 
 [the JARs]:
-https://search.maven.org/search?q=g:io.grpc%20AND%20v:1.36.0
+https://search.maven.org/search?q=g:io.grpc%20AND%20v:1.37.0
 
 Development snapshots are available in [Sonatypes's snapshot
 repository](https://oss.sonatype.org/content/repositories/snapshots/).
@@ -113,7 +113,7 @@ For protobuf-based codegen integrated with the Maven build system, you can use
       <configuration>
         <protocArtifact>com.google.protobuf:protoc:3.12.0:exe:${os.detected.classifier}</protocArtifact>
         <pluginId>grpc-java</pluginId>
-        <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.36.0:exe:${os.detected.classifier}</pluginArtifact>
+        <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.37.0:exe:${os.detected.classifier}</pluginArtifact>
       </configuration>
       <executions>
         <execution>
@@ -143,7 +143,7 @@ protobuf {
   }
   plugins {
     grpc {
-      artifact = 'io.grpc:protoc-gen-grpc-java:1.36.0'
+      artifact = 'io.grpc:protoc-gen-grpc-java:1.37.0'
     }
   }
   generateProtoTasks {
@@ -176,7 +176,7 @@ protobuf {
   }
   plugins {
     grpc {
-      artifact = 'io.grpc:protoc-gen-grpc-java:1.36.0'
+      artifact = 'io.grpc:protoc-gen-grpc-java:1.37.0'
     }
   }
   generateProtoTasks {

RELEASING.md

@@ -108,7 +108,8 @@ Tagging the Release
 
 1. Verify there are no open issues in the release milestone. Open issues should
    either be deferred or resolved and the fix backported.
-2. For vMajor.Minor.x branch, change `README.md` to refer to the next release
+2. Ensure that Google-internal steps completed at go/grpc/java/releasing#before-tagging-a-release.
+3. For vMajor.Minor.x branch, change `README.md` to refer to the next release
    version. _Also_ update the version numbers for protoc if the protobuf library
    version was updated since the last release.
 
@@ -122,7 +123,7 @@ Tagging the Release
    $ ${EDITOR:-nano -w} cronet/README.md
    $ git commit -a -m "Update README etc to reference $MAJOR.$MINOR.$PATCH"
    ```
-3. Change root build files to remove "-SNAPSHOT" for the next release version
+4. Change root build files to remove "-SNAPSHOT" for the next release version
    (e.g. `0.7.0`). Commit the result and make a tag:
 
    ```bash
@@ -133,7 +134,7 @@ Tagging the Release
    $ git commit -a -m "Bump version to $MAJOR.$MINOR.$PATCH"
    $ git tag -a v$MAJOR.$MINOR.$PATCH -m "Version $MAJOR.$MINOR.$PATCH"
    ```
-4. Change root build files to the next snapshot version (e.g. `0.7.1-SNAPSHOT`).
+5. Change root build files to the next snapshot version (e.g. `0.7.1-SNAPSHOT`).
    Commit the result:
 
    ```bash
@@ -145,7 +146,7 @@ Tagging the Release
    $ ./gradlew build
    $ git commit -a -m "Bump version to $MAJOR.$MINOR.$((PATCH+1))-SNAPSHOT"
    ```
-5. Go through PR review and push the release tag and updated release branch to
+6. Go through PR review and push the release tag and updated release branch to
    GitHub:
 
    ```bash
@@ -154,7 +155,7 @@ Tagging the Release
    $ git push upstream v$MAJOR.$MINOR.x
    $ git push upstream v$MAJOR.$MINOR.$PATCH
    ```
-6. Close the release milestone.
+7. Close the release milestone.
 
 Build Artifacts
 ---------------
@@ -214,9 +215,6 @@ Finally, document and publicize the release.
 2. Post a release announcement to [grpc-io](https://groups.google.com/forum/#!forum/grpc-io)
    (`grpc-io@googlegroups.com`). The title should be something that clearly identifies
    the release (e.g.`GRPC-Java <tag> Released`).
-    1. Check if JCenter has picked up the new release (https://jcenter.bintray.com/io/grpc/)
-       and include its availability in the release announcement email. JCenter should mirror
-       everything on Maven Central, but users have reported delays.
 
 Update Hosted Javadoc
 ---------------------

buildscripts/kokoro/xds-k8s.cfg

@@ -2,7 +2,7 @@
 
 # Location of the continuous shell script in repository.
 build_file: "grpc-java/buildscripts/kokoro/xds-k8s.sh"
-timeout_mins: 90
+timeout_mins: 120
 
 action {
   define_artifacts {

buildscripts/kokoro/xds-k8s.sh

@@ -4,8 +4,9 @@ set -eo pipefail
 # Constants
 readonly GITHUB_REPOSITORY_NAME="grpc-java"
 # GKE Cluster
-readonly GKE_CLUSTER_NAME="interop-test-psm-sec1-us-central1"
-readonly GKE_CLUSTER_ZONE="us-central1-a"
+readonly GKE_CLUSTER_NAME="interop-test-psm-sec-testing-api"
+readonly GKE_CLUSTER_ZONE="us-west1-b"
+export CLOUDSDK_API_ENDPOINT_OVERRIDES_CONTAINER="https://test-container.sandbox.googleapis.com/"
 ## xDS test server/client Docker images
 readonly SERVER_IMAGE_NAME="gcr.io/grpc-testing/xds-interop/java-server"
 readonly CLIENT_IMAGE_NAME="gcr.io/grpc-testing/xds-interop/java-client"

cronet/README.md

@@ -26,7 +26,7 @@ In your app module's `build.gradle` file, include a dependency on both `grpc-cro
 Google Play Services Client Library for Cronet
 
 ```
-implementation 'io.grpc:grpc-cronet:1.36.0'
+implementation 'io.grpc:grpc-cronet:1.37.0'
 implementation 'com.google.android.gms:play-services-cronet:16.0.0'
 ```
 

documentation/android-channel-builder.md

@@ -36,8 +36,8 @@ In your `build.gradle` file, include a dependency on both `grpc-android` and
 `grpc-okhttp`:
 
 ```
-implementation 'io.grpc:grpc-android:1.36.0'
-implementation 'io.grpc:grpc-okhttp:1.36.0'
+implementation 'io.grpc:grpc-android:1.37.0'
+implementation 'io.grpc:grpc-okhttp:1.37.0'
 ```
 
 You also need permission to access the device's network state in your

grpclb/src/main/java/io/grpc/grpclb/GrpclbState.java

@@ -95,8 +95,20 @@ final class GrpclbState {
   static final Status NO_AVAILABLE_BACKENDS_STATUS =
       Status.UNAVAILABLE.withDescription("LoadBalancer responded without any backends");
   @VisibleForTesting
-  static final Status NO_FALLBACK_BACKENDS_FOUND_STATUS =
+  static final Status BALANCER_TIMEOUT_STATUS =
+      Status.UNAVAILABLE.withDescription("Timeout waiting for remote balancer");
+  @VisibleForTesting
+  static final Status BALANCER_REQUESTED_FALLBACK_STATUS =
+      Status.UNAVAILABLE.withDescription("Fallback requested by balancer");
+  @VisibleForTesting
+  static final Status NO_FALLBACK_BACKENDS_STATUS =
       Status.UNAVAILABLE.withDescription("Unable to fallback, no fallback addresses found");
+  // This error status should never be propagated to RPC failures, as "no backend or balancer
+  // addresses found" should be directly handled as a name resolution error. So in cases of no
+  // balancer address, fallback should never fail.
+  private static final Status NO_LB_ADDRESS_PROVIDED_STATUS =
+      Status.UNAVAILABLE.withDescription("No balancer address found");
+
 
   @VisibleForTesting
   static final RoundRobinEntry BUFFER_ENTRY = new RoundRobinEntry() {
@@ -137,6 +149,10 @@ enum Mode {
   private ScheduledHandle fallbackTimer;
   private List<EquivalentAddressGroup> fallbackBackendList = Collections.emptyList();
   private boolean usingFallbackBackends;
+  // Reason to fallback, will be used as RPC's error message if fail to fallback (e.g., no
+  // fallback addresses found).
+  @Nullable
+  private Status fallbackReason;
   // True if the current balancer has returned a serverlist.  Will be reset to false when lost
   // connection to a balancer.
   private boolean balancerWorking;
@@ -239,7 +255,7 @@ void handleAddresses(
       // No balancer address: close existing balancer connection and enter fallback mode
       // immediately.
       shutdownLbComm();
-      syncContext.execute(new FallbackModeTask());
+      syncContext.execute(new FallbackModeTask(NO_LB_ADDRESS_PROVIDED_STATUS));
     } else {
       startLbComm(newLbAddressGroups);
       // Avoid creating a new RPC just because the addresses were updated, as it can cause a
@@ -253,7 +269,8 @@ void handleAddresses(
       // Start the fallback timer if it's never started
       if (fallbackTimer == null) {
         fallbackTimer = syncContext.schedule(
-            new FallbackModeTask(), FALLBACK_TIMEOUT_MS, TimeUnit.MILLISECONDS, timerService);
+            new FallbackModeTask(BALANCER_TIMEOUT_STATUS), FALLBACK_TIMEOUT_MS,
+            TimeUnit.MILLISECONDS, timerService);
       }
     }
     fallbackBackendList = newBackendServers;
@@ -275,16 +292,21 @@ void requestConnection() {
   }
 
   private void maybeUseFallbackBackends() {
-    if (balancerWorking) {
-      return;
-    }
-    if (usingFallbackBackends) {
+    if (balancerWorking || usingFallbackBackends) {
       return;
     }
+    // Balancer RPC should have either been broken or timed out.
+    checkState(fallbackReason != null, "no reason to fallback");
     for (Subchannel subchannel : subchannels.values()) {
-      if (subchannel.getAttributes().get(STATE_INFO).get().getState() == READY) {
+      ConnectivityStateInfo stateInfo = subchannel.getAttributes().get(STATE_INFO).get();
+      if (stateInfo.getState() == READY) {
         return;
       }
+      // If we do have balancer-provided backends, use one of its error in the error message if
+      // fail to fallback.
+      if (stateInfo.getState() == TRANSIENT_FAILURE) {
+        fallbackReason = stateInfo.getStatus();
+      }
     }
     // Fallback conditions met
     useFallbackBackends();
@@ -401,8 +423,10 @@ void shutdown() {
   void propagateError(Status status) {
     logger.log(ChannelLogLevel.DEBUG, "[grpclb-<{0}>] Error: {1}", serviceName, status);
     if (backendList.isEmpty()) {
+      Status error =
+          Status.UNAVAILABLE.withCause(status.getCause()).withDescription(status.getDescription());
       maybeUpdatePicker(
-          TRANSIENT_FAILURE, new RoundRobinPicker(dropList, Arrays.asList(new ErrorEntry(status))));
+          TRANSIENT_FAILURE, new RoundRobinPicker(dropList, Arrays.asList(new ErrorEntry(error))));
     }
   }
 
@@ -528,8 +552,17 @@ public void onSubchannelState(ConnectivityStateInfo newState) {
 
   @VisibleForTesting
   class FallbackModeTask implements Runnable {
+    private final Status reason;
+
+    private FallbackModeTask(Status reason) {
+      this.reason = reason;
+    }
+
     @Override
     public void run() {
+      // Timer should have been cancelled if entered fallback early.
+      checkState(!usingFallbackBackends, "already in fallback");
+      fallbackReason = reason;
       maybeUseFallbackBackends();
       maybeUpdatePicker();
     }
@@ -658,7 +691,9 @@ private void handleResponse(LoadBalanceResponse response) {
       }
 
       if (typeCase == LoadBalanceResponseTypeCase.FALLBACK_RESPONSE) {
+        // Force entering fallback requested by balancer.
         cancelFallbackTimer();
+        fallbackReason = BALANCER_REQUESTED_FALLBACK_STATUS;
         useFallbackBackends();
         maybeUpdatePicker();
         return;
@@ -690,7 +725,7 @@ private void handleResponse(LoadBalanceResponse response) {
           } catch (UnknownHostException e) {
             propagateError(
                 Status.UNAVAILABLE
-                    .withDescription("Host for server not found: " + server)
+                    .withDescription("Invalid backend address: " + server)
                     .withCause(e));
             continue;
           }
@@ -701,8 +736,9 @@ private void handleResponse(LoadBalanceResponse response) {
           newBackendAddrList.add(new BackendAddressGroup(eag, token));
         }
       }
-      // Stop using fallback backends as soon as a new server list is received from the balancer.
+      // Exit fallback as soon as a new server list is received from the balancer.
       usingFallbackBackends = false;
+      fallbackReason = null;
       cancelFallbackTimer();
       updateServerList(newDropList, newBackendAddrList, loadRecorder);
       maybeUpdatePicker();
@@ -717,6 +753,8 @@ private void handleStreamClosed(Status error) {
       cleanUp();
       propagateError(error);
       balancerWorking = false;
+      fallbackReason = error;
+      cancelFallbackTimer();
       maybeUseFallbackBackends();
       maybeUpdatePicker();
 
@@ -773,15 +811,19 @@ private void maybeUpdatePicker() {
     List<RoundRobinEntry> pickList;
     ConnectivityState state;
     if (backendList.isEmpty()) {
-      if (balancerWorking)  {
-        pickList =
-            Collections.<RoundRobinEntry>singletonList(
-                new ErrorEntry(NO_AVAILABLE_BACKENDS_STATUS));
+      // Note balancer (is working) may enforce using fallback backends, and that fallback may
+      // fail. So we should check if currently in fallback first.
+      if (usingFallbackBackends) {
+        Status error =
+            NO_FALLBACK_BACKENDS_STATUS
+                .withCause(fallbackReason.getCause())
+                .augmentDescription(fallbackReason.getDescription());
+        pickList = Collections.<RoundRobinEntry>singletonList(new ErrorEntry(error));
         state = TRANSIENT_FAILURE;
-      } else if (usingFallbackBackends) {
+      } else if (balancerWorking)  {
         pickList =
             Collections.<RoundRobinEntry>singletonList(
-                new ErrorEntry(NO_FALLBACK_BACKENDS_FOUND_STATUS));
+                new ErrorEntry(NO_AVAILABLE_BACKENDS_STATUS));
         state = TRANSIENT_FAILURE;
       } else {  // still waiting for balancer
         pickList = Collections.singletonList(BUFFER_ENTRY);