[6.2.0]Automatically retry the build if encountered remote cache eviction error

src/main/java/com/google/devtools/build/lib/exec/AbstractSpawnStrategy.java

@@ -243,14 +243,36 @@ public int getId() {
     public ListenableFuture<Void> prefetchInputs()
         throws IOException, ForbiddenActionInputException {
       if (Spawns.shouldPrefetchInputsForLocalExecution(spawn)) {
-        return actionExecutionContext
-            .getActionInputPrefetcher()
-            .prefetchFiles(
-                getInputMapping(PathFragment.EMPTY_FRAGMENT, /* willAccessRepeatedly= */ true)
-                    .values(),
-                getMetadataProvider());
+        return Futures.catchingAsync(
+            actionExecutionContext
+                .getActionInputPrefetcher()
+                .prefetchFiles(
+                    getInputMapping(PathFragment.EMPTY_FRAGMENT, /* willAccessRepeatedly= */ true)
+                        .values(),
+                    getMetadataProvider(),
+                    Priority.MEDIUM),
+            BulkTransferException.class,
+            (BulkTransferException e) -> {
+              if (BulkTransferException.allCausedByCacheNotFoundException(e)) {
+                var code =
+                    (executionOptions.useNewExitCodeForLostInputs
+                            || executionOptions.remoteRetryOnCacheEviction > 0)
+                        ? Code.REMOTE_CACHE_EVICTED
+                        : Code.REMOTE_CACHE_FAILED;
+                throw new EnvironmentalExecException(
+                    e,
+                    FailureDetail.newBuilder()
+                        .setMessage("Failed to fetch blobs because they do not exist remotely.")
+                        .setSpawn(FailureDetails.Spawn.newBuilder().setCode(code))
+                        .build());
+              } else {
+                throw e;
+              }
+            },
+            directExecutor());
       }
 
+
       return immediateVoidFuture();
     }
 

src/main/java/com/google/devtools/build/lib/exec/ExecutionOptions.java

@@ -494,6 +494,28 @@ public boolean usingLocalTestJobs() {
               + "test log. Otherwise, Bazel generates a test.xml as part of the test action.")
   public boolean splitXmlGeneration;
 
+  @Option(
+      name = "incompatible_remote_use_new_exit_code_for_lost_inputs",
+      defaultValue = "true",
+      documentationCategory = OptionDocumentationCategory.REMOTE,
+      effectTags = {OptionEffectTag.UNKNOWN},
+      metadataTags = {OptionMetadataTag.INCOMPATIBLE_CHANGE},
+      help =
+          "If set to true, Bazel will use new exit code 39 instead of 34 if remote cache evicts"
+              + " blobs during the build.")
+  public boolean useNewExitCodeForLostInputs;
+
+  @Option(
+      name = "experimental_remote_cache_eviction_retries",
+      defaultValue = "0",
+      documentationCategory = OptionDocumentationCategory.REMOTE,
+      effectTags = {OptionEffectTag.EXECUTION},
+      help =
+          "The maximum number of attempts to retry if the build encountered remote cache eviction"
+              + " error. A non-zero value will implicitly set"
+              + " --incompatible_remote_use_new_exit_code_for_lost_inputs to true.")
+  public int remoteRetryOnCacheEviction;
+
   /** An enum for specifying different formats of test output. */
   public enum TestOutputFormat {
     SUMMARY, // Provide summary output only.

src/main/java/com/google/devtools/build/lib/remote/RemoteSpawnRunner.java

@@ -557,7 +557,8 @@ private SpawnResult handleError(
       catastrophe = true;
     } else if (remoteCacheFailed) {
       status = Status.REMOTE_CACHE_FAILED;
-      if (remoteOptions.useNewExitCodeForLostInputs) {
+      if (executionOptions.useNewExitCodeForLostInputs
+          || executionOptions.remoteRetryOnCacheEviction > 0) {
         detailedCode = FailureDetails.Spawn.Code.REMOTE_CACHE_EVICTED;
       } else {
         detailedCode = FailureDetails.Spawn.Code.REMOTE_CACHE_FAILED;

src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java

@@ -43,6 +43,7 @@
 import com.google.devtools.build.lib.events.PrintingEventHandler;
 import com.google.devtools.build.lib.events.Reporter;
 import com.google.devtools.build.lib.events.StoredEventHandler;
+import com.google.devtools.build.lib.exec.ExecutionOptions;
 import com.google.devtools.build.lib.profiler.MemoryProfiler;
 import com.google.devtools.build.lib.profiler.Profiler;
 import com.google.devtools.build.lib.profiler.SilentCloseable;
@@ -54,6 +55,7 @@
 import com.google.devtools.build.lib.util.AnsiStrippingOutputStream;
 import com.google.devtools.build.lib.util.DebugLoggerConfigurator;
 import com.google.devtools.build.lib.util.DetailedExitCode;
+import com.google.devtools.build.lib.util.ExitCode;
 import com.google.devtools.build.lib.util.InterruptedFailureDetails;
 import com.google.devtools.build.lib.util.LoggingUtil;
 import com.google.devtools.build.lib.util.Pair;
@@ -230,18 +232,29 @@ public BlazeCommandResult exec(
         return createDetailedCommandResult(
             retrievedShutdownReason, FailureDetails.Command.Code.PREVIOUSLY_SHUTDOWN);
       }
-      BlazeCommandResult result =
-          execExclusively(
-              originalCommandLine,
-              invocationPolicy,
-              args,
-              outErr,
-              firstContactTimeMillis,
-              commandName,
-              command,
-              waitTimeInMs,
-              startupOptionsTaggedWithBazelRc,
-              commandExtensions);
+      BlazeCommandResult result;
+      int attempt = 0;
+      while (true) {
+        try {
+          result =
+              execExclusively(
+                  originalCommandLine,
+                  invocationPolicy,
+                  args,
+                  outErr,
+                  firstContactTimeMillis,
+                  commandName,
+                  command,
+                  waitTimeInMs,
+                  startupOptionsTaggedWithBazelRc,
+                  commandExtensions,
+                  attempt);
+          break;
+        } catch (RemoteCacheEvictedException e) {
+          outErr.printErrLn("Found remote cache eviction error, retrying the build...");
+          attempt += 1;
+        }
+      }
       if (result.shutdown()) {
         setShutdownReason(
             "Server shut down "
@@ -289,7 +302,9 @@ private BlazeCommandResult execExclusively(
       BlazeCommand command,
       long waitTimeInMs,
       Optional<List<Pair<String, String>>> startupOptionsTaggedWithBazelRc,
-      List<Any> commandExtensions) {
+      List<Any> commandExtensions,
+      int attempt)
+      throws RemoteCacheEvictedException {
     // Record the start time for the profiler. Do not put anything before this!
     long execStartTimeNanos = runtime.getClock().nanoTime();
 
@@ -631,7 +646,18 @@ private BlazeCommandResult execExclusively(
       }
 
       needToCallAfterCommand = false;
-      return runtime.afterCommand(env, result);
+      var newResult = runtime.afterCommand(env, result);
+      if (newResult.getExitCode().equals(ExitCode.REMOTE_CACHE_EVICTED)) {
+        var executionOptions =
+            Preconditions.checkNotNull(options.getOptions(ExecutionOptions.class));
+        if (attempt < executionOptions.remoteRetryOnCacheEviction) {
+          throw new RemoteCacheEvictedException();
+        }
+      }
+
+      return newResult;
+    } catch (RemoteCacheEvictedException e) {
+      throw e;
     } catch (Throwable e) {
       logger.atSevere().withCause(e).log("Shutting down due to exception");
       Crash crash = Crash.from(e);
@@ -665,6 +691,8 @@ private BlazeCommandResult execExclusively(
     }
   }
 
+  private static class RemoteCacheEvictedException extends IOException {}
+
   private static void replayEarlyExitEvents(
       OutErr outErr,
       BlazeOptionHandler optionHandler,

src/test/java/com/google/devtools/build/lib/remote/BuildWithoutTheBytesIntegrationTest.java

@@ -466,9 +466,7 @@ public void remoteCacheEvictBlobs_whenPrefetchingInput_exitWithCode39() throws E
     // Assert: Exit code is 39
     assertThat(error)
         .hasMessageThat()
-        .contains(
-            "Build without the Bytes does not work if your remote cache evicts blobs"
-                + " during builds");
+        .contains("Failed to fetch blobs because they do not exist remotely");
     assertThat(error).hasMessageThat().contains(String.format("%s/%s", hashCode, bytes.length));
     assertThat(error.getDetailedExitCode().getExitCode().getNumericExitCode()).isEqualTo(39);
   }

src/test/shell/bazel/remote/build_without_the_bytes_test.sh

@@ -1627,4 +1627,63 @@ end_of_record"
   expect_log "$expected_result"
 }
 
+function test_remote_cache_eviction_retries() {
+  mkdir -p a
+
+  cat > a/BUILD <<'EOF'
+genrule(
+  name = 'foo',
+  srcs = ['foo.in'],
+  outs = ['foo.out'],
+  cmd = 'cat $(SRCS) > $@',
+)
+
+genrule(
+  name = 'bar',
+  srcs = ['foo.out', 'bar.in'],
+  outs = ['bar.out'],
+  cmd = 'cat $(SRCS) > $@',
+  tags = ['no-remote-exec'],
+)
+EOF
+
+  echo foo > a/foo.in
+  echo bar > a/bar.in
+
+  # Populate remote cache
+  bazel build \
+      --remote_executor=grpc://localhost:${worker_port} \
+      --remote_download_minimal \
+      //a:bar >& $TEST_log || fail "Failed to build"
+
+  bazel clean
+
+  # Clean build, foo.out isn't downloaded
+  bazel build \
+      --remote_executor=grpc://localhost:${worker_port} \
+      --remote_download_minimal \
+      //a:bar >& $TEST_log || fail "Failed to build"
+
+  if [[ -f bazel-bin/a/foo.out ]]; then
+    fail "Expected intermediate output bazel-bin/a/foo.out to not be downloaded"
+  fi
+
+  # Evict blobs from remote cache
+  stop_worker
+  start_worker
+
+  echo "updated bar" > a/bar.in
+
+  # Incremental build triggers remote cache eviction error but Bazel
+  # automatically retries the build and reruns the generating actions for
+  # missing blobs
+  bazel build \
+      --remote_executor=grpc://localhost:${worker_port} \
+      --remote_download_minimal \
+      --experimental_remote_cache_eviction_retries=5 \
+      //a:bar >& $TEST_log || fail "Failed to build"
+
+  expect_log "Found remote cache eviction error, retrying the build..."
+}
+
 run_suite "Build without the Bytes tests"