diff --git a/src/main/java/com/googlesource/gerrit/plugins/copyright/CheckConfig.java b/src/main/java/com/googlesource/gerrit/plugins/copyright/CheckConfig.java
index d9dd534..14c4e7f 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/copyright/CheckConfig.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/copyright/CheckConfig.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
@@ -18,6 +18,7 @@
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
+import com.google.common.base.Stopwatch;
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
 import com.google.common.flogger.FluentLogger;
@@ -37,6 +38,7 @@
 import java.nio.file.Paths;
 import java.util.Arrays;
 import java.util.Objects;
+import java.util.concurrent.TimeUnit;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import org.eclipse.jgit.errors.ConfigInvalidException;
@@ -57,10 +59,11 @@
   private static final String LABEL = "label";
   private static final String PLUGIN = "plugin";
   private static final int BUFFER_SIZE = 2048;
-  private static final char[] BUFFER = new char[BUFFER_SIZE];
 
   private String pluginName;
+  /** All-Projects project.config contents. */
   private Config configProject;
+  /** Plugin config from All-Projects project.config file. */
   ScannerConfig scannerConfig;
 
   public CheckConfig(String pluginName, String projectConfigContents)
@@ -82,27 +85,6 @@
     this.scannerConfig.readConfigFile(pluginConfig);
   }
 
-  @Override
-  public boolean equals(Object other) {
-    if (this == other) {
-      return true;
-    }
-    if (other == null) {
-      return false;
-    }
-    if (other instanceof CheckConfig) {
-      CheckConfig that = (CheckConfig) other;
-      return Objects.equals(this.pluginName, that.pluginName)
-          && Objects.equals(this.scannerConfig, that.scannerConfig);
-    }
-    return false;
-  }
-
-  @Override
-  public int hashCode() {
-    return Objects.hash(pluginName, scannerConfig);
-  }
-
   /**
    * Validates the final state of {@code trialConfig}.
    *
@@ -111,6 +93,9 @@
    */
   public static void checkProjectConfig(
       CopyrightReviewApi reviewApi, boolean pluginEnabled, CheckConfig trialConfig) {
+    // Warn without blocking project.config pushes when plugin disabled across entire server.
+    ValidationMessage.Type errorWhenActive =
+        pluginEnabled ? ValidationMessage.Type.ERROR : ValidationMessage.Type.WARNING;
     CurrentUser fromUser =
         reviewApi == null
             ? null
@@ -127,7 +112,7 @@
                           ? "the plugin"
                           : fromUser.getLoggableName())
                       + " will vote on"),
-              pluginEnabled ? ValidationMessage.Type.ERROR : ValidationMessage.Type.WARNING));
+              errorWhenActive));
     } else {
       String labelName = trialConfig.scannerConfig.reviewLabel.trim();
       if (!trialConfig.configProject.getSubsections(LABEL).contains(labelName)) {
@@ -137,8 +122,10 @@
                     ScannerConfig.KEY_REVIEW_LABEL,
                     labelName,
                     "no [" + LABEL + " \"" + labelName + "\"] section configured."),
-                pluginEnabled ? ValidationMessage.Type.ERROR : ValidationMessage.Type.WARNING));
+                errorWhenActive));
       }
+
+      // Enforce at least 1 approver exists for the copyright review label for content changes.
       String[] voters =
           trialConfig.configProject.getStringList(
               ACCESS, RefNames.REFS_HEADS + "*", "label-" + labelName);
@@ -160,8 +147,10 @@
                         + " on "
                         + RefNames.REFS_HEADS
                         + "*"),
-                pluginEnabled ? ValidationMessage.Type.ERROR : ValidationMessage.Type.WARNING));
+                errorWhenActive));
       }
+
+      // Enforce an approver exists for the copyright review label for configuration changes.
       voters =
           trialConfig.configProject.getStringList(
               ACCESS, RefNames.REFS_CONFIG, "label-" + labelName);
@@ -179,7 +168,7 @@
                     ScannerConfig.KEY_REVIEW_LABEL,
                     labelName,
                     "no configured approvers for " + labelName + " on " + RefNames.REFS_CONFIG),
-                pluginEnabled ? ValidationMessage.Type.ERROR : ValidationMessage.Type.WARNING));
+                errorWhenActive));
       }
     }
     if (trialConfig.scannerConfig.reviewers.isEmpty()) {
@@ -199,7 +188,7 @@
                       + " non-interactive user with full voting permissions for the review label '"
                       + trialConfig.scannerConfig.reviewLabel
                       + "'"),
-              pluginEnabled ? ValidationMessage.Type.ERROR : ValidationMessage.Type.WARNING));
+              errorWhenActive));
       // TODO: inject ReviewerAdder into reviewApi, and use ReviewerAdder.prepare
       //       a la
       // https://gerrit.googlesource.com/gerrit/+/refs/heads/master/java/com/google/gerrit/server/restapi/change/PostReview.java#265
@@ -252,7 +241,7 @@
    * the output on success into the commit message.
    *
    * <p>This method scans the commit message to find the copied text. If the text was created for
-   * the same pattern signagure, this method returns a single valid finding with the number of
+   * the same pattern signature, this method returns a single valid finding with the number of
    * microseconds it took to scan a large file, which can be used to block patterns that cause
    * excessive backtracking.
    *
@@ -289,7 +278,6 @@
             new CopyrightReviewApi.CommitMessageFinding(
                 commitMessage, m.group(), m.group(1), m.start(), m.end()));
       }
-      logger.atSevere().log("signature for %s is %s", m.group(1), signature);
       builder.add(
           new CopyrightReviewApi.CommitMessageFinding(
               commitMessage, m.group(), m.start(), m.end()));
@@ -329,15 +317,14 @@
 
   /** Checks whether {@code trialConfig} might cause excessive backtracking. */
   private long timeLargeFileInMicros() throws IOException {
-    long startNanos = System.nanoTime();
+    Stopwatch sw = Stopwatch.createStarted();
     try {
       IndexedLineReader file = largeFile();
       scannerConfig.scanner.findMatches("file", -1, file);
     } finally {
-      long elapsedNanos = System.nanoTime() - startNanos;
-      long elapsedMicros = elapsedNanos / 1000;
-      logger.atFine().log("timeLargeFile %dms", elapsedMicros / 1000);
-      return elapsedMicros;
+      sw.stop();
+      logger.atFine().log("timeLargeFile %dms", sw.elapsed(TimeUnit.MILLISECONDS));
+      return sw.elapsed(TimeUnit.MICROSECONDS);
     }
   }
 
@@ -436,7 +423,7 @@
   /** Read the contents of a project.config file from {@code ilr}. */
   private static String readProjectConfigFile(IndexedLineReader ilr) throws IOException {
     StringBuilder sb = new StringBuilder();
-    CharBuffer cb = CharBuffer.wrap(BUFFER);
+    CharBuffer cb = CharBuffer.wrap(new char[BUFFER_SIZE]);
     while (ilr.read(cb) >= 0) {
       cb.flip();
       sb.append(cb);
@@ -459,6 +446,7 @@
     return Hashing.farmHashFingerprint64().hashBytes(sb.toString().getBytes(UTF_8)).toString();
   }
 
+  // TODO: move check from command-line tool to background thread with timeout.
   /** Entry point for command-line tool to check for excessive backtracking. */
   public static void main(String[] args) {
     if (args.length != 2) {
diff --git a/src/main/java/com/googlesource/gerrit/plugins/copyright/CopyrightConfig.java b/src/main/java/com/googlesource/gerrit/plugins/copyright/CopyrightConfig.java
index 5c30033..af45703 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/copyright/CopyrightConfig.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/copyright/CopyrightConfig.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
@@ -16,20 +16,18 @@
 
 import static java.nio.charset.StandardCharsets.UTF_8;
 
-import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
 import com.google.common.flogger.FluentLogger;
+import com.google.gerrit.common.Nullable;
 import com.google.gerrit.extensions.annotations.PluginName;
 import com.google.gerrit.extensions.api.changes.AddReviewerResult;
 import com.google.gerrit.extensions.api.changes.ReviewResult;
 import com.google.gerrit.extensions.events.GitReferenceUpdatedListener;
+import com.google.gerrit.extensions.events.LifecycleListener;
 import com.google.gerrit.extensions.events.RevisionCreatedListener;
 import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.gerrit.extensions.restapi.RestApiException;
-import com.google.gerrit.metrics.Description;
-import com.google.gerrit.metrics.Description.Units;
-import com.google.gerrit.metrics.MetricMaker;
 import com.google.gerrit.metrics.Timer0;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.client.RefNames;
@@ -51,7 +49,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
-import java.util.concurrent.TimeUnit;
 import javax.inject.Inject;
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Constants;
@@ -65,9 +62,13 @@
 /** Listener to manage configuration for enforcing review of copyright declarations and licenses. */
 @Singleton
 class CopyrightConfig
-    implements CommitValidationListener, RevisionCreatedListener, GitReferenceUpdatedListener {
+    implements CommitValidationListener,
+        RevisionCreatedListener,
+        GitReferenceUpdatedListener,
+        LifecycleListener {
   private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
+  /** Default value of timeTestMax configuration parameter for avoiding excessive backtracking. */
   private final long DEFAULT_MAX_ELAPSED_SECONDS = 8;
 
   private final Metrics metrics;
@@ -78,49 +79,21 @@
   private final PluginConfigFactory pluginConfigFactory;
   private final CopyrightReviewApi reviewApi;
 
-  private PluginConfig gerritConfig;
-  private CheckConfig checkConfig;
+  @Nullable private PluginConfig gerritConfig;
+  @Nullable private CheckConfig checkConfig;
 
   static AbstractModule module() {
     return new AbstractModule() {
       @Override
       protected void configure() {
         DynamicSet.bind(binder(), CommitValidationListener.class).to(CopyrightConfig.class);
+        DynamicSet.bind(binder(), LifecycleListener.class).to(CopyrightConfig.class);
         DynamicSet.bind(binder(), RevisionCreatedListener.class).to(CopyrightConfig.class);
         DynamicSet.bind(binder(), GitReferenceUpdatedListener.class).to(CopyrightConfig.class);
       }
     };
   }
 
-  @Singleton
-  private static class Metrics {
-    final Timer0 readConfigTimer;
-    final Timer0 checkConfigTimer;
-    final Timer0 testConfigTimer;
-
-    @Inject
-    Metrics(MetricMaker metricMaker) {
-      readConfigTimer =
-          metricMaker.newTimer(
-              "read_config_latency",
-              new Description("Time spent reading and parsing plugin configurations")
-                  .setCumulative()
-                  .setUnit(Units.MICROSECONDS));
-      checkConfigTimer =
-          metricMaker.newTimer(
-              "check_config_latency",
-              new Description("Time spent testing proposed plugin configurations")
-                  .setCumulative()
-                  .setUnit(Units.MICROSECONDS));
-      testConfigTimer =
-          metricMaker.newTimer(
-              "test_config_latency",
-              new Description("Time spent testing configurations against difficult file pattern")
-                  .setCumulative()
-                  .setUnit(Units.MICROSECONDS));
-    }
-  }
-
   @Inject
   CopyrightConfig(
       Metrics metrics,
@@ -129,8 +102,7 @@
       GitRepositoryManager repoManager,
       ProjectCache projectCache,
       PluginConfigFactory pluginConfigFactory,
-      CopyrightReviewApi reviewApi)
-      throws IOException, ConfigInvalidException {
+      CopyrightReviewApi reviewApi) {
     this.metrics = metrics;
     this.allProjectsName = allProjectsName;
     this.pluginName = pluginName;
@@ -138,40 +110,28 @@
     this.projectCache = projectCache;
     this.pluginConfigFactory = pluginConfigFactory;
     this.reviewApi = reviewApi;
-
-    long nanoStart = System.nanoTime();
-    try {
-      checkConfig = readConfig(projectCache.getAllProjects().getProject().getConfigRefState());
-    } finally {
-      long elapsedMicros = (System.nanoTime() - nanoStart) / 1000;
-      metrics.readConfigTimer.record(elapsedMicros, TimeUnit.MICROSECONDS);
-    }
-  }
-
-  private CopyrightConfig(
-      MetricMaker metricMaker, CopyrightReviewApi reviewApi, String projectConfigContents)
-      throws ConfigInvalidException {
-    metrics = new Metrics(metricMaker);
-    allProjectsName = new AllProjectsName("All-Projects");
-    pluginName = "copyright";
-    repoManager = null;
-    projectCache = null;
-    pluginConfigFactory = null;
-    this.reviewApi = reviewApi;
-    checkConfig = new CheckConfig(pluginName, projectConfigContents);
-  }
-
-  @VisibleForTesting
-  static CopyrightConfig createTestInstance(
-      MetricMaker metricMaker, CopyrightReviewApi reviewApi, String projectConfigContents)
-      throws ConfigInvalidException {
-    return new CopyrightConfig(metricMaker, reviewApi, projectConfigContents);
+    this.checkConfig = null;
   }
 
   ScannerConfig getScannerConfig() {
-    return checkConfig.scannerConfig;
+    return checkConfig == null ? null : checkConfig.scannerConfig;
   }
 
+  @Override
+  public void start() {
+    try (Timer0.Context ctx = metrics.readConfigTimer.start()) {
+      checkConfig = readConfig(projectCache.getAllProjects().getProject().getConfigRefState());
+    } catch (IOException | ConfigInvalidException e) {
+      logger.atSevere().withCause(e).log("unable to load configuration");
+      metrics.configurationErrors.increment(allProjectsName.get());
+      metrics.errors.increment();
+      return;
+    }
+  }
+
+  @Override
+  public void stop() {}
+
   /** Listens for merges to /refs/meta/config on All-Projects to reload plugin configuration. */
   @Override
   public void onGitReferenceUpdated(GitReferenceUpdatedListener.Event event) {
@@ -181,17 +141,13 @@
     if (!event.getProjectName().equals(allProjectsName.get())) {
       return;
     }
-    long nanoStart = System.nanoTime();
-    try {
-      clearConfig();
+    try (Timer0.Context ctx = metrics.readConfigTimer.start()) {
       checkConfig = readConfig(event.getNewObjectId());
     } catch (IOException | ConfigInvalidException e) {
-      logger.atSevere().withCause(e).log("%s plugin unable to load configuration", pluginName);
-      checkConfig = null;
+      logger.atSevere().withCause(e).log("unable to load configuration");
+      metrics.configurationErrors.increment(allProjectsName.get());
+      metrics.errors.increment();
       return;
-    } finally {
-      long elapsedMicros = (System.nanoTime() - nanoStart) / 1000;
-      metrics.readConfigTimer.record(elapsedMicros, TimeUnit.MICROSECONDS);
     }
   }
 
@@ -205,67 +161,56 @@
     if (!event.getProjectNameKey().equals(allProjectsName)) {
       return Collections.emptyList();
     }
-    long readStart = System.nanoTime();
-    long checkStart = -1;
-    long elapsedMicros = -1;
     CheckConfig trialConfig = null;
     try {
-      trialConfig = readConfig(event.commit.getName());
-      elapsedMicros = (System.nanoTime() - readStart) / 1000;
-      metrics.readConfigTimer.record(elapsedMicros, TimeUnit.MICROSECONDS);
-      if (Objects.equals(trialConfig.scannerConfig, checkConfig.scannerConfig)) {
+      try (Timer0.Context ctx = metrics.readConfigTimer.start()) {
+        trialConfig = readConfig(event.commit.getName());
+      }
+      if (Objects.equals(
+          trialConfig.scannerConfig, checkConfig == null ? null : checkConfig.scannerConfig)) {
         return Collections.emptyList();
       }
-      checkStart = System.nanoTime();
-      long maxElapsedSeconds =
-          gerritConfig == null
-              ? DEFAULT_MAX_ELAPSED_SECONDS
-              : gerritConfig.getLong(ScannerConfig.KEY_TIME_TEST_MAX, DEFAULT_MAX_ELAPSED_SECONDS);
-      if (maxElapsedSeconds > 0
-          && CheckConfig.hasScanner(trialConfig)
-          && !CheckConfig.scannersEqual(trialConfig, checkConfig)) {
-        String commitMessage = event.commit.getFullMessage();
-        ImmutableList<CopyrightReviewApi.CommitMessageFinding> findings =
-            trialConfig.checkCommitMessage(commitMessage);
-        if (CheckConfig.mustReportFindings(findings, maxElapsedSeconds)) {
-          throw reviewApi.getCommitMessageException(pluginName, findings, maxElapsedSeconds);
+      try (Timer0.Context ctx = metrics.checkConfigTimer.start()) {
+        long maxElapsedSeconds =
+            gerritConfig == null
+                ? DEFAULT_MAX_ELAPSED_SECONDS
+                : gerritConfig.getLong(
+                    ScannerConfig.KEY_TIME_TEST_MAX, DEFAULT_MAX_ELAPSED_SECONDS);
+        if (maxElapsedSeconds > 0
+            && CheckConfig.hasScanner(trialConfig)
+            && !CheckConfig.scannersEqual(trialConfig, checkConfig)) {
+          String commitMessage = event.commit.getFullMessage();
+          ImmutableList<CopyrightReviewApi.CommitMessageFinding> findings =
+              trialConfig.checkCommitMessage(commitMessage);
+          if (CheckConfig.mustReportFindings(findings, maxElapsedSeconds)) {
+            throw reviewApi.getCommitMessageException(pluginName, findings, maxElapsedSeconds);
+          }
         }
+        boolean pluginEnabled =
+            gerritConfig != null && gerritConfig.getBoolean(ScannerConfig.KEY_ENABLE, false);
+        CheckConfig.checkProjectConfig(reviewApi, pluginEnabled, trialConfig);
+        List<CommitValidationMessage> messages =
+            trialConfig == null || trialConfig.scannerConfig == null
+                ? Collections.emptyList()
+                : trialConfig.scannerConfig.messages;
+        checkForConfigErrors(trialConfig);
+        return messages;
       }
-      boolean pluginEnabled =
-          gerritConfig != null && gerritConfig.getBoolean(ScannerConfig.KEY_ENABLE, false);
-      CheckConfig.checkProjectConfig(reviewApi, pluginEnabled, trialConfig);
-      return trialConfig == null || trialConfig.scannerConfig == null
-          ? Collections.emptyList()
-          : trialConfig.scannerConfig.messages;
     } catch (IOException e) {
-      logger.atSevere().withCause(e).log(
-          "failed to read new project.config for %s plugin", pluginName);
-      throw new CommitValidationException("failed to read new project.config", e);
+      logger.atSevere().withCause(e).log("failed to read new project.config");
+      throw new CommitValidationException(
+          pluginName + "plugin failed to read new project.config", e);
     } catch (ConfigInvalidException e) {
-      logger.atSevere().withCause(e).log("unable to parse %s plugin config", pluginName);
+      logger.atSevere().withCause(e).log("unable to parse plugin config");
       if (trialConfig != null && trialConfig.scannerConfig != null) {
         trialConfig.scannerConfig.messages.add(ScannerConfig.errorMessage(e.getMessage()));
+        metrics.configurationErrors.increment(allProjectsName.get());
+        metrics.errors.increment();
+        checkForConfigErrors(trialConfig);
         return trialConfig.scannerConfig.messages;
       } else {
-        throw new CommitValidationException("unable to parse new project.config", e);
-      }
-    } finally {
-      if (elapsedMicros < 0) {
-        elapsedMicros = (System.nanoTime() - readStart) / 1000;
-        metrics.readConfigTimer.record(elapsedMicros, TimeUnit.MICROSECONDS);
-      } else if (checkStart >= 0) {
-        long elapsedNanos = System.nanoTime() - checkStart;
-        metrics.checkConfigTimer.record(elapsedNanos, TimeUnit.NANOSECONDS);
-      }
-      if (trialConfig != null
-          && trialConfig.scannerConfig != null
-          && trialConfig.scannerConfig.hasErrors()) {
-        StringBuilder sb = new StringBuilder();
-        sb.append("\nerror in ");
-        sb.append(pluginName);
-        sb.append(" plugin configuration");
-        trialConfig.scannerConfig.appendMessages(sb);
-        throw new CommitValidationException(sb.toString());
+        throw new CommitValidationException(
+            pluginName + "plugin unable to parse new project.config", e);
       }
     }
   }
@@ -286,49 +231,49 @@
       return;
     }
     // passed onCommitReceived so expect at worst only warnings here
-    long readStart = System.nanoTime();
-    long checkStart = -1;
-    long elapsedMicros = -1;
     CheckConfig trialConfig = null;
     try {
-      trialConfig = readConfig(event.getChange().currentRevision);
-      elapsedMicros = (System.nanoTime() - readStart) / 1000;
-      metrics.readConfigTimer.record(elapsedMicros, TimeUnit.MICROSECONDS);
-      if (Objects.equals(trialConfig, checkConfig.scannerConfig)) {
+      try (Timer0.Context ctx = metrics.readConfigTimer.start()) {
+        trialConfig = readConfig(event.getChange().currentRevision);
+      }
+      if (Objects.equals(
+          trialConfig.scannerConfig, checkConfig == null ? null : checkConfig.scannerConfig)) {
         return;
       }
 
-      checkStart = System.nanoTime();
-      if (CheckConfig.hasScanner(trialConfig)
-          && !CheckConfig.scannersEqual(trialConfig, checkConfig)) {
-        long maxElapsedSeconds =
-            gerritConfig == null
-                ? DEFAULT_MAX_ELAPSED_SECONDS
-                : gerritConfig.getLong(
-                    ScannerConfig.KEY_TIME_TEST_MAX, DEFAULT_MAX_ELAPSED_SECONDS);
-        if (maxElapsedSeconds > 0) {
-          String commitMessage = event.getRevision().commitWithFooters;
-          ImmutableList<CopyrightReviewApi.CommitMessageFinding> findings =
-              trialConfig.checkCommitMessage(commitMessage);
-          ReviewResult result =
-              reviewApi.reportCommitMessageFindings(
-                  pluginName,
-                  allProjectsName.get(),
-                  checkConfig == null ? null : checkConfig.scannerConfig,
-                  trialConfig.scannerConfig,
-                  event,
-                  findings,
-                  maxElapsedSeconds);
-          logReviewResultErrors(event, result);
+      try (Timer0.Context ctx = metrics.checkConfigTimer.start()) {
+        if (CheckConfig.hasScanner(trialConfig)
+            && !CheckConfig.scannersEqual(trialConfig, checkConfig)) {
+          long maxElapsedSeconds =
+              gerritConfig == null
+                  ? DEFAULT_MAX_ELAPSED_SECONDS
+                  : gerritConfig.getLong(
+                      ScannerConfig.KEY_TIME_TEST_MAX, DEFAULT_MAX_ELAPSED_SECONDS);
+          if (maxElapsedSeconds > 0) {
+            String commitMessage = event.getRevision().commitWithFooters;
+            ImmutableList<CopyrightReviewApi.CommitMessageFinding> findings =
+                trialConfig.checkCommitMessage(commitMessage);
+            ReviewResult result =
+                reviewApi.reportCommitMessageFindings(
+                    pluginName,
+                    allProjectsName.get(),
+                    checkConfig == null ? null : checkConfig.scannerConfig,
+                    trialConfig.scannerConfig,
+                    event,
+                    findings,
+                    maxElapsedSeconds);
+            logReviewResultErrors(event, result);
+          }
         }
+        boolean pluginEnabled =
+            gerritConfig != null && gerritConfig.getBoolean(ScannerConfig.KEY_ENABLE, false);
+        CheckConfig.checkProjectConfig(reviewApi, pluginEnabled, trialConfig);
+        return;
       }
-      boolean pluginEnabled =
-          gerritConfig != null && gerritConfig.getBoolean(ScannerConfig.KEY_ENABLE, false);
-      CheckConfig.checkProjectConfig(reviewApi, pluginEnabled, trialConfig);
-      return;
     } catch (RestApiException | ConfigInvalidException | IOException e) {
-      logger.atSevere().withCause(e).log("%s plugin unable to read new configuration", pluginName);
-      // throw IllegalStateException? RestApiException?
+      logger.atSevere().withCause(e).log("unable to read new configuration");
+      metrics.configurationErrors.increment(project);
+      metrics.errors.increment();
       return;
     } finally {
       if (trialConfig != null
@@ -341,24 +286,17 @@
                   pluginName,
                   project,
                   ProjectConfig.PROJECT_CONFIG,
-                  checkConfig.scannerConfig,
+                  checkConfig == null ? null : checkConfig.scannerConfig,
                   trialConfig.scannerConfig,
                   event);
           logReviewResultErrors(event, result);
         } catch (RestApiException e) {
-          logger.atSevere().withCause(e).log(
-              "%s plugin unable to read new configuration", pluginName);
-          // throw IllegalStateException? RestApiException?
+          logger.atSevere().withCause(e).log("unable to report configuration findings");
+          metrics.postReviewErrors.increment(project);
+          metrics.errors.increment();
           return;
         }
       }
-      if (elapsedMicros < 0) {
-        elapsedMicros = (System.nanoTime() - readStart) / 1000;
-        metrics.readConfigTimer.record(elapsedMicros, TimeUnit.MICROSECONDS);
-      } else if (checkStart >= 0) {
-        long elapsedNanos = System.nanoTime() - checkStart;
-        metrics.checkConfigTimer.record(elapsedNanos, TimeUnit.NANOSECONDS);
-      }
     }
   }
 
@@ -381,18 +319,21 @@
       projectState = projectCache.checkedGet(Project.nameKey(project));
     } catch (IOException e) {
       logger.atSevere().withCause(e).log("error getting project state of %s", project);
-      // throw IllegalStateException? RestApiException?
+      metrics.projectStateErrors.increment(project);
+      metrics.errors.increment();
       return scannerConfig.defaultEnable;
     }
     if (projectState == null) {
       logger.atSevere().log("error getting project state of %s", project);
-      // throw IllegalStateException? RestApiException?
+      metrics.projectStateErrors.increment(project);
+      metrics.errors.increment();
       return scannerConfig.defaultEnable;
     }
     ProjectConfig projectConfig = projectState.getConfig();
     if (projectConfig == null) {
       logger.atWarning().log("error getting project config of %s", project);
-      // throw IllegalStateException? RestApiException? return?
+      metrics.projectConfigErrors.increment(project);
+      metrics.errors.increment();
       return scannerConfig.defaultEnable;
     }
     PluginConfig pluginConfig = projectConfig.getPluginConfig(pluginName);
@@ -403,6 +344,19 @@
     return pluginConfig.getBoolean(ScannerConfig.KEY_ENABLE, scannerConfig.defaultEnable);
   }
 
+  private void checkForConfigErrors(CheckConfig trialConfig) throws CommitValidationException {
+    if (trialConfig != null
+        && trialConfig.scannerConfig != null
+        && trialConfig.scannerConfig.hasErrors()) {
+      StringBuilder sb = new StringBuilder();
+      sb.append("\nerror in ");
+      sb.append(pluginName);
+      sb.append(" plugin configuration");
+      trialConfig.scannerConfig.appendMessages(sb);
+      throw new CommitValidationException(sb.toString());
+    }
+  }
+
   /**
    * Loads and compiles configured patterns from {@code ref/meta/All-Projects/project.config} and
    * {@code gerrit.config}.
@@ -411,6 +365,7 @@
    * @return the new scanner configuration to check
    * @throws IOException if accessing the repository fails
    */
+  @Nullable
   private CheckConfig readConfig(String projectConfigObjectId)
       throws IOException, ConfigInvalidException {
     CheckConfig checkConfig = null;
@@ -425,7 +380,6 @@
     }
     gerritConfig = pluginConfigFactory.getFromGerritConfig(pluginName, true);
     if (gerritConfig == null) {
-      // throw IllegalStateException? RestApiException?
       checkConfig.scannerConfig.messages.add(
           ScannerConfig.hintMessage(
               "missing [plugin \"" + pluginName + "\"] section in gerrit.config"));
@@ -436,32 +390,31 @@
     return checkConfig;
   }
 
-  /** Erases any prior configuration state. */
-  private void clearConfig() {
-    checkConfig = null;
-  }
-
   private void logReviewResultErrors(RevisionCreatedListener.Event event, ReviewResult result) {
     if (!Strings.isNullOrEmpty(result.error)) {
       logger.atSevere().log(
-          "%s plugin revision %s: error posting review: %s",
-          pluginName, event.getChange().currentRevision, result.error);
+          "revision %s: error posting review: %s", event.getChange().currentRevision, result.error);
+      metrics.postReviewErrors.increment(event.getChange().project);
+      metrics.errors.increment();
     }
-    for (Map.Entry<String, AddReviewerResult> entry : result.reviewers.entrySet()) {
-      AddReviewerResult arr = entry.getValue();
-      if (!Strings.isNullOrEmpty(arr.error)) {
-        logger.atSevere().log(
-            "%s plugin revision %s: error adding reviewer %s: %s",
-            pluginName, event.getChange().currentRevision, entry.getKey(), arr.error);
+    if (result.reviewers != null) {
+      for (Map.Entry<String, AddReviewerResult> entry : result.reviewers.entrySet()) {
+        AddReviewerResult arr = entry.getValue();
+        if (!Strings.isNullOrEmpty(arr.error)) {
+          logger.atSevere().log(
+              "revision %s: error adding reviewer %s: %s",
+              event.getChange().currentRevision, entry.getKey(), arr.error);
+          metrics.addReviewerErrors.increment(event.getChange().project);
+          metrics.errors.increment();
+        }
       }
     }
   }
 
   private String readFileContents(Repository repo, ObjectId objectId, String filename)
       throws IOException {
-    RevWalk rw = new RevWalk(repo);
-    RevTree tree = rw.parseTree(objectId);
-    try (TreeWalk tw = TreeWalk.forPath(rw.getObjectReader(), filename, tree)) {
+    try (RevWalk rw = new RevWalk(repo);
+        TreeWalk tw = TreeWalk.forPath(rw.getObjectReader(), filename, rw.parseTree(objectId))) {
       ObjectLoader loader = repo.open(tw.getObjectId(0), Constants.OBJ_BLOB);
       return new String(loader.getCachedBytes(), UTF_8);
     }
diff --git a/src/main/java/com/googlesource/gerrit/plugins/copyright/CopyrightReviewApi.java b/src/main/java/com/googlesource/gerrit/plugins/copyright/CopyrightReviewApi.java
index 0c41d7d..de97d60 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/copyright/CopyrightReviewApi.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/copyright/CopyrightReviewApi.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
@@ -24,9 +24,10 @@
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Strings;
-import com.google.common.base.Throwables;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.gerrit.extensions.api.GerritApi;
+import com.google.gerrit.extensions.api.changes.ChangeApi;
 import com.google.gerrit.extensions.api.changes.ReviewInput;
 import com.google.gerrit.extensions.api.changes.ReviewInput.CommentInput;
 import com.google.gerrit.extensions.api.changes.ReviewResult;
@@ -34,31 +35,17 @@
 import com.google.gerrit.extensions.client.ReviewerState;
 import com.google.gerrit.extensions.common.CommentInfo;
 import com.google.gerrit.extensions.events.RevisionCreatedListener;
-import com.google.gerrit.extensions.restapi.IdString;
-import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
 import com.google.gerrit.extensions.restapi.RestApiException;
-import com.google.gerrit.metrics.Counter0;
-import com.google.gerrit.metrics.Counter1;
-import com.google.gerrit.metrics.Description;
-import com.google.gerrit.metrics.Description.Units;
-import com.google.gerrit.metrics.Field;
-import com.google.gerrit.metrics.MetricMaker;
 import com.google.gerrit.metrics.Timer0;
 import com.google.gerrit.metrics.Timer1;
 import com.google.gerrit.reviewdb.client.Account;
-import com.google.gerrit.reviewdb.client.Change;
-import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
-import com.google.gerrit.server.PatchSetUtil;
 import com.google.gerrit.server.PluginUser;
-import com.google.gerrit.server.change.ChangeResource;
-import com.google.gerrit.server.change.RevisionResource;
 import com.google.gerrit.server.git.validators.CommitValidationException;
 import com.google.gerrit.server.git.validators.CommitValidationMessage;
-import com.google.gerrit.server.notedb.ChangeNotes;
-import com.google.gerrit.server.restapi.change.ListChangeComments;
-import com.google.gerrit.server.restapi.change.PostReview;
+import com.google.gerrit.server.util.ManualRequestContext;
+import com.google.gerrit.server.util.ThreadLocalRequestContext;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import com.googlesource.gerrit.plugins.copyright.lib.CopyrightScanner.Match;
@@ -68,7 +55,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
-import java.util.concurrent.TimeUnit;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import javax.inject.Inject;
@@ -82,61 +68,8 @@
   private final Provider<PluginUser> pluginUserProvider;
   private final Provider<CurrentUser> userProvider;
   private final IdentifiedUser.GenericFactory identifiedUserFactory;
-  private final ChangeNotes.Factory changeNotesFactory;
-  private final ChangeResource.Factory changeResourceFactory;
-  private final PatchSetUtil psUtil;
-  private final PostReview postReview;
-  private final ListChangeComments listChangeComments;
-
-  @Singleton
-  static class Metrics {
-    final Counter0 reviewCount;
-    final Counter0 commentCount;
-    final Timer0 reviewTimer;
-    final Counter1 reviewCountByProject;
-    final Counter1 commentCountByProject;
-    final Timer1 reviewTimerByProject;
-
-    @Inject
-    Metrics(MetricMaker metricMaker) {
-      Field<String> project = Field.ofString("project", "project name");
-      reviewCount =
-          metricMaker.newCounter(
-              "review_count",
-              new Description("Total number of posted reviews").setRate().setUnit("reviews"));
-      commentCount =
-          metricMaker.newCounter(
-              "comment_count",
-              new Description("Total number of posted review comments")
-                  .setRate()
-                  .setUnit("comments"));
-      reviewTimer =
-          metricMaker.newTimer(
-              "review_latency",
-              new Description("Time spent posting reviews to revisions")
-                  .setCumulative()
-                  .setUnit(Units.MICROSECONDS));
-      reviewCountByProject =
-          metricMaker.newCounter(
-              "review_count_by_project",
-              new Description("Total number of posted reviews").setRate().setUnit("reviews"),
-              project);
-      commentCountByProject =
-          metricMaker.newCounter(
-              "comment_count_by_project",
-              new Description("Total number of posted review comments")
-                  .setRate()
-                  .setUnit("comments"),
-              project);
-      reviewTimerByProject =
-          metricMaker.newTimer(
-              "review_latency_by_project",
-              new Description("Time spent posting reviews to revisions")
-                  .setCumulative()
-                  .setUnit(Units.MICROSECONDS),
-              project);
-    }
-  }
+  private final ThreadLocalRequestContext requestContext;
+  private final GerritApi gApi;
 
   @Inject
   CopyrightReviewApi(
@@ -144,20 +77,14 @@
       Provider<PluginUser> pluginUserProvider,
       Provider<CurrentUser> userProvider,
       IdentifiedUser.GenericFactory identifiedUserFactory,
-      ChangeNotes.Factory changeNotesFactory,
-      ChangeResource.Factory changeResourceFactory,
-      PatchSetUtil psUtil,
-      PostReview postReview,
-      ListChangeComments listChangeComments) {
+      ThreadLocalRequestContext requestContext,
+      GerritApi gApi) {
     this.metrics = metrics;
     this.pluginUserProvider = pluginUserProvider;
     this.userProvider = userProvider;
     this.identifiedUserFactory = identifiedUserFactory;
-    this.changeNotesFactory = changeNotesFactory;
-    this.changeResourceFactory = changeResourceFactory;
-    this.psUtil = psUtil;
-    this.postReview = postReview;
-    this.listChangeComments = listChangeComments;
+    this.requestContext = requestContext;
+    this.gApi = gApi;
   }
 
   /**
@@ -199,7 +126,6 @@
     Preconditions.checkArgument(findings.size() != 1 || !findings.get(0).isValid());
     Preconditions.checkArgument(maxElapsedSeconds > 0);
 
-    long startNanos = System.nanoTime();
     metrics.reviewCount.increment();
     metrics.reviewCountByProject.increment(project);
 
@@ -207,41 +133,43 @@
         oldConfig != null && oldConfig.fromAccountId > 0
             ? oldConfig.fromAccountId
             : newConfig.fromAccountId;
-    ChangeResource change = getChange(event, fromAccountId);
-    Map<String, List<CommentInfo>> priorReviewComments = getComments(change);
-    if (priorReviewComments == null) {
-      priorReviewComments = ImmutableMap.of();
-    }
-    HashSet<CommentInfo> priorComments = new HashSet<>();
-    priorComments.addAll(priorReviewComments.get("/COMMIT_MSG"));
-
-    ReviewInput ri = new ReviewInput();
-    ri.message(getCommitMessageMessage(pluginName, findings, maxElapsedSeconds));
-    ImmutableList<CommentInput> comments =
-        ImmutableList.copyOf(
-            getCommitMessageComments(pluginName, findings, maxElapsedSeconds).stream()
-                .filter(ci -> !priorComments.contains(ci))
-                .toArray(i -> new CommentInput[i]));
-    if (!comments.isEmpty()) {
-      ri.comments = ImmutableMap.of("/COMMIT_MSG", comments);
-    }
-    String label = "Code-Review";
-    if (!Strings.isNullOrEmpty(oldConfig.reviewLabel)) {
-      label = oldConfig.reviewLabel;
-    } else if (!Strings.isNullOrEmpty(newConfig.reviewLabel)) {
-      label = newConfig.reviewLabel;
-    }
-    int vote = (findings.size() != 1 || !findings.get(0).isValid()) ? -2 : 2;
-    if (vote == 2) {
-      long elapsedMicros = findings.get(0).elapsedMicros;
-      if (elapsedMicros > maxElapsedSeconds * 1000000) {
-        vote = -2;
-      } else if (elapsedMicros > 2000000) {
-        vote = 1;
+    try (ManualRequestContext ctx = getContext(fromAccountId)) {
+      ChangeApi cApi = gApi.changes().id(event.getChange().id);
+      Map<String, List<CommentInfo>> priorReviewComments = cApi.comments();
+      if (priorReviewComments == null) {
+        priorReviewComments = ImmutableMap.of();
       }
+      HashSet<CommentInfo> priorComments = new HashSet<>();
+      priorComments.addAll(priorReviewComments.get("/COMMIT_MSG"));
+
+      ReviewInput ri = new ReviewInput();
+      ri.message(getCommitMessageMessage(pluginName, findings, maxElapsedSeconds));
+      ImmutableList<CommentInput> comments =
+          ImmutableList.copyOf(
+              getCommitMessageComments(pluginName, findings, maxElapsedSeconds).stream()
+                  .filter(ci -> !priorComments.contains(ci))
+                  .toArray(i -> new CommentInput[i]));
+      if (!comments.isEmpty()) {
+        ri.comments = ImmutableMap.of("/COMMIT_MSG", comments);
+      }
+      String label = "Code-Review";
+      if (!Strings.isNullOrEmpty(oldConfig.reviewLabel)) {
+        label = oldConfig.reviewLabel;
+      } else if (!Strings.isNullOrEmpty(newConfig.reviewLabel)) {
+        label = newConfig.reviewLabel;
+      }
+      int vote = (findings.size() != 1 || !findings.get(0).isValid()) ? -2 : 2;
+      if (vote == 2) {
+        long elapsedMicros = findings.get(0).elapsedMicros;
+        if (elapsedMicros > maxElapsedSeconds * 1000000) {
+          vote = -2;
+        } else if (elapsedMicros > 2000000) {
+          vote = 1;
+        }
+      }
+      ri.label(label, vote);
+      return cApi.current().review(ri);
     }
-    ri.label(label, vote);
-    return review(change, ri);
   }
 
   /**
@@ -308,22 +236,23 @@
     Preconditions.checkNotNull(newConfig.messages);
     Preconditions.checkArgument(!newConfig.messages.isEmpty());
 
-    long startNanos = System.nanoTime();
     metrics.reviewCount.increment();
     metrics.reviewCountByProject.increment(project);
 
-    try {
-      int fromAccountId =
-          oldConfig != null && oldConfig.fromAccountId > 0
-              ? oldConfig.fromAccountId
-              : newConfig.fromAccountId;
-      ChangeResource change = getChange(event, fromAccountId);
+    int fromAccountId =
+        oldConfig != null && oldConfig.fromAccountId > 0
+            ? oldConfig.fromAccountId
+            : newConfig.fromAccountId;
+    try (Timer0.Context t0 = metrics.reviewTimer.start();
+        Timer1.Context t1 = metrics.reviewTimerByProject.start(project);
+        ManualRequestContext ctx = getContext(fromAccountId)) {
+      ChangeApi cApi = gApi.changes().id(event.getChange().id);
       StringBuilder message = new StringBuilder();
       message.append(pluginName);
       message.append(" plugin issues parsing new configuration");
       ReviewInput ri = new ReviewInput().message(message.toString());
 
-      Map<String, List<CommentInfo>> priorComments = getComments(change);
+      Map<String, List<CommentInfo>> priorComments = cApi.comments();
       if (priorComments == null) {
         priorComments = ImmutableMap.of();
       }
@@ -350,11 +279,7 @@
       }
       metrics.commentCount.incrementBy((long) numComments);
       metrics.commentCountByProject.incrementBy(project, (long) numComments);
-      return review(change, ri);
-    } finally {
-      long elapsedMicros = (System.nanoTime() - startNanos) / 1000;
-      metrics.reviewTimer.record(elapsedMicros, TimeUnit.MICROSECONDS);
-      metrics.reviewTimerByProject.record(project, elapsedMicros, TimeUnit.MICROSECONDS);
+      return cApi.current().review(ri);
     }
   }
 
@@ -373,11 +298,12 @@
       RevisionCreatedListener.Event event,
       Map<String, ImmutableList<Match>> findings)
       throws RestApiException {
-    long startNanos = System.nanoTime();
     metrics.reviewCount.increment();
     metrics.reviewCountByProject.increment(project);
 
-    try {
+    try (Timer0.Context t0 = metrics.reviewTimer.start();
+        Timer1.Context t1 = metrics.reviewTimerByProject.start(project);
+        ManualRequestContext ctx = getContext(scannerConfig.fromAccountId)) {
       boolean tpAllowed = scannerConfig.isThirdPartyAllowed(project);
       boolean reviewRequired = false;
       for (Map.Entry<String, ImmutableList<Match>> entry : findings.entrySet()) {
@@ -395,7 +321,7 @@
           break;
         }
       }
-      ChangeResource change = getChange(event, scannerConfig.fromAccountId);
+      ChangeApi cApi = gApi.changes().id(event.getChange().id);
       ReviewInput ri =
           new ReviewInput()
               .message("Copyright scan")
@@ -411,7 +337,7 @@
       } else {
         ri = ri.message("This change appears to comply with copyright requirements.");
       }
-      Map<String, List<CommentInfo>> priorComments = getComments(change);
+      Map<String, List<CommentInfo>> priorComments = cApi.comments();
       if (priorComments == null) {
         priorComments = ImmutableMap.of();
       }
@@ -450,11 +376,7 @@
       }
       metrics.commentCount.incrementBy((long) numCommentsAdded);
       metrics.commentCountByProject.incrementBy(project, (long) numCommentsAdded);
-      return review(change, ri);
-    } finally {
-      long elapsedMicros = (System.nanoTime() - startNanos) / 1000;
-      metrics.reviewTimer.record(elapsedMicros, TimeUnit.MICROSECONDS);
-      metrics.reviewTimerByProject.record(project, elapsedMicros, TimeUnit.MICROSECONDS);
+      return cApi.current().review(ri);
     }
   }
 
@@ -631,26 +553,13 @@
     return sb.toString();
   }
 
-  /**
-   * Constructs a {@link com.google.gerrit.server.change.ChangeResource} from the notes log for the
-   * change onto which a new revision was pushed.
-   *
-   * @param event describes the newly pushed revision
-   * @param fromAccountId identifies the configured user to impersonate when sending review comments
-   * @throws RestApiException if an error occurs looking up the notes log for the change
-   */
-  private ChangeResource getChange(RevisionCreatedListener.Event event, int fromAccountId)
-      throws RestApiException {
-    try {
-      CurrentUser fromUser = getSendingUser(fromAccountId);
-      ChangeNotes notes = changeNotesFactory.createChecked(Change.id(event.getChange()._number));
-      return changeResourceFactory.create(notes, fromUser);
-    } catch (Exception e) {
-      Throwables.throwIfUnchecked(e);
-      throw e instanceof RestApiException
-          ? (RestApiException) e
-          : new RestApiException("Cannot load change", e);
-    }
+  private ManualRequestContext getContext(int fromAccountId) {
+    PluginUser pluginUser = pluginUserProvider.get();
+    CurrentUser user =
+        fromAccountId <= 0
+            ? userProvider.get()
+            : identifiedUserFactory.runAs(null, Account.id(fromAccountId), pluginUser);
+    return new ManualRequestContext(user, requestContext);
   }
 
   /**
@@ -665,44 +574,6 @@
     return ri;
   }
 
-  /**
-   * Retrieves all of the prior review comments already attached to {@code change}.
-   *
-   * @throws RestApiException if an error occurs retrieving the comments
-   */
-  private Map<String, List<CommentInfo>> getComments(ChangeResource change)
-      throws RestApiException {
-    try {
-      return listChangeComments.apply(change);
-    } catch (Exception e) {
-      Throwables.throwIfUnchecked(e);
-      throw e instanceof RestApiException
-          ? (RestApiException) e
-          : new RestApiException("Cannot list comments", e);
-    }
-  }
-
-  /**
-   * Adds the code review described by {@code ri} to the review thread of {@code change}.
-   *
-   * @throws RestApiException if an error occurs updating the review thread
-   */
-  private ReviewResult review(ChangeResource change, ReviewInput ri) throws RestApiException {
-    try {
-      PatchSet ps = psUtil.current(change.getNotes());
-      if (ps == null) {
-        throw new ResourceNotFoundException(IdString.fromDecoded("current"));
-      }
-      RevisionResource revision = RevisionResource.createNonCacheable(change, ps);
-      return postReview.apply(revision, ri).value();
-    } catch (Exception e) {
-      Throwables.throwIfUnchecked(e);
-      throw e instanceof RestApiException
-          ? (RestApiException) e
-          : new RestApiException("Cannot post review", e);
-    }
-  }
-
   /** Returns true if {@code priorComments} already includes a comment identical to {@code ci}. */
   @VisibleForTesting
   boolean containsComment(Iterable<? extends Comment> priorComments, CommentInput ci) {
diff --git a/src/main/java/com/googlesource/gerrit/plugins/copyright/CopyrightValidator.java b/src/main/java/com/googlesource/gerrit/plugins/copyright/CopyrightValidator.java
index 0a77834..7ed50dd 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/copyright/CopyrightValidator.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/copyright/CopyrightValidator.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
@@ -26,12 +26,6 @@
 import com.google.gerrit.extensions.events.RevisionCreatedListener;
 import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.gerrit.extensions.restapi.RestApiException;
-import com.google.gerrit.metrics.Counter0;
-import com.google.gerrit.metrics.Counter1;
-import com.google.gerrit.metrics.Description;
-import com.google.gerrit.metrics.Description.Units;
-import com.google.gerrit.metrics.Field;
-import com.google.gerrit.metrics.MetricMaker;
 import com.google.gerrit.metrics.Timer0;
 import com.google.gerrit.metrics.Timer1;
 import com.google.gerrit.reviewdb.client.Project;
@@ -40,14 +34,12 @@
 import com.google.gerrit.server.config.PluginConfigFactory;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.inject.AbstractModule;
-import com.google.inject.Singleton;
 import com.googlesource.gerrit.plugins.copyright.lib.CopyrightScanner.Match;
 import com.googlesource.gerrit.plugins.copyright.lib.IndexedLineReader;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.concurrent.TimeUnit;
 import javax.inject.Inject;
 import org.eclipse.jgit.lib.FileMode;
 import org.eclipse.jgit.lib.ObjectId;
@@ -81,79 +73,6 @@
     };
   }
 
-  @Singleton
-  private static class Metrics {
-    final Counter0 scanCount;
-    final Timer0 scanRevisionTimer;
-    final Timer0 scanFileTimer;
-    final Counter1 scanCountByProject;
-    final Timer1 scanRevisionTimerByProject;
-    final Timer1 scanFileTimerByProject;
-    final Counter1 scanCountByBranch;
-    final Timer1 scanRevisionTimerByBranch;
-    final Timer1 scanFileTimerByBranch;
-
-    @Inject
-    Metrics(MetricMaker metricMaker) {
-      Field<String> project = Field.ofString("project", "project name");
-      Field<String> branch = Field.ofString("branch", "branch name");
-      scanCount =
-          metricMaker.newCounter(
-              "scan_count",
-              new Description("Total number of copyright scans").setRate().setUnit("scans"));
-      scanRevisionTimer =
-          metricMaker.newTimer(
-              "scan_revision_latency",
-              new Description("Time spent scanning entire revisions")
-                  .setCumulative()
-                  .setUnit(Units.MILLISECONDS));
-      scanFileTimer =
-          metricMaker.newTimer(
-              "scan_file_latency",
-              new Description("Time spent scanning each file")
-                  .setCumulative()
-                  .setUnit(Units.MICROSECONDS));
-      scanCountByProject =
-          metricMaker.newCounter(
-              "scan_count_by_project",
-              new Description("Total number of copyright scans").setRate().setUnit("scans"),
-              project);
-      scanRevisionTimerByProject =
-          metricMaker.newTimer(
-              "scan_revision_latency_by_project",
-              new Description("Time spent scanning entire revisions")
-                  .setCumulative()
-                  .setUnit(Units.MILLISECONDS),
-              project);
-      scanFileTimerByProject =
-          metricMaker.newTimer(
-              "scan_file_latency_by_project",
-              new Description("Time spent scanning each file")
-                  .setCumulative()
-                  .setUnit(Units.MICROSECONDS),
-              project);
-      scanCountByBranch =
-          metricMaker.newCounter(
-              "scan_count_by_branch",
-              new Description("Total number of copyright scans").setRate().setUnit("scans"),
-              branch);
-      scanRevisionTimerByBranch =
-          metricMaker.newTimer(
-              "scan_revision_latency_by_branch",
-              new Description("Time spent scanning entire revisions")
-                  .setCumulative()
-                  .setUnit(Units.MILLISECONDS),
-              branch);
-      scanFileTimerByBranch =
-          metricMaker.newTimer(
-              "scan_file_latency_by_branch",
-              new Description("Time spent scanning each file")
-                  .setCumulative()
-                  .setUnit(Units.MICROSECONDS),
-              branch);
-    }
-  }
-
   @Inject
   CopyrightValidator(
       Metrics metrics,
@@ -189,16 +108,18 @@
     if (scannerConfig == null) {
       // error already reported during configuration load
       logger.atWarning().log(
-          "%s plugin enabled with no configuration -- not scanning revision %s",
-          pluginName, event.getChange().currentRevision);
+          "plugin enabled with no configuration -- not scanning revision %s",
+          event.getChange().currentRevision);
+      metrics.skippedReviewWarnings.increment(project);
       return;
     }
     if (scannerConfig.scanner == null) {
       if (scannerConfig.hasErrors()) {
         // error already reported during configuration load
         logger.atWarning().log(
-            "%s plugin enabled with errors in configuration -- not scanning revision %s",
-            pluginName, event.getChange().currentRevision);
+            "plugin enabled with errors in configuration -- not scanning revision %s",
+            event.getChange().currentRevision);
+        metrics.skippedReviewWarnings.increment(project);
       } // else plugin not enabled
       return;
     }
@@ -210,7 +131,9 @@
       scanRevision(project, branch, event);
     } catch (IOException | RestApiException e) {
       logger.atSevere().withCause(e).log(
-          "%s plugin cannot scan revision %s", pluginName, event.getChange().currentRevision);
+          "cannot scan revision %s", event.getChange().currentRevision);
+      metrics.scanErrors.increment(project);
+      metrics.errors.increment();
       return;
     }
   }
@@ -228,12 +151,13 @@
       throws IOException, RestApiException {
     Map<String, ImmutableList<Match>> findings = new HashMap<>();
     ArrayList<String> containedPaths = new ArrayList<>();
-    long scanStart = System.nanoTime();
-    metrics.scanCount.increment();
     metrics.scanCountByProject.increment(project);
     metrics.scanCountByBranch.increment(branch);
 
-    try (Repository repo = repoManager.openRepository(Project.nameKey(project));
+    try (Timer0.Context t0 = metrics.scanRevisionTimer.start();
+        Timer1.Context t1project = metrics.scanRevisionTimerByProject.start(project);
+        Timer1.Context t1branch = metrics.scanRevisionTimerByBranch.start(branch);
+        Repository repo = repoManager.openRepository(Project.nameKey(project));
         RevWalk revWalk = new RevWalk(repo);
         TreeWalk tw = new TreeWalk(revWalk.getObjectReader())) {
       RevCommit commit = repo.parseCommit(ObjectId.fromString(event.getRevision().commit.commit));
@@ -259,8 +183,10 @@
             && !FileMode.REGULAR_FILE.equals(tw.getFileMode())) {
           continue;
         }
-        long fileStart = System.nanoTime();
-        try (ObjectReader reader = tw.getObjectReader();
+        try (Timer0.Context tf0 = metrics.scanFileTimer.start();
+            Timer1.Context tf1project = metrics.scanFileTimerByProject.start(project);
+            Timer1.Context tf1branch = metrics.scanFileTimerByBranch.start(branch);
+            ObjectReader reader = tw.getObjectReader();
             ObjectStream stream = reader.open(tw.getObjectId(0)).openStream()) {
           IndexedLineReader lineReader = new IndexedLineReader(fullPath, -1, stream);
           ImmutableList<Match> matches =
@@ -268,31 +194,26 @@
           if (!matches.isEmpty()) {
             findings.put(tw.getPathString(), matches);
           }
-          long fileTime = (System.nanoTime() - fileStart) / 1000;
-          metrics.scanFileTimer.record(fileTime, TimeUnit.MICROSECONDS);
-          metrics.scanFileTimerByProject.record(project, fileTime, TimeUnit.MICROSECONDS);
-          metrics.scanFileTimerByBranch.record(branch, fileTime, TimeUnit.MICROSECONDS);
         }
       }
     }
-    long scanTime = (System.nanoTime() - scanStart) / 1000000;
-    metrics.scanRevisionTimer.record(scanTime, TimeUnit.MILLISECONDS);
-    metrics.scanRevisionTimerByProject.record(project, scanTime, TimeUnit.MILLISECONDS);
-    metrics.scanRevisionTimerByBranch.record(branch, scanTime, TimeUnit.MILLISECONDS);
 
     ReviewResult result = reviewApi.reportScanFindings(project, scannerConfig, event, findings);
     if (result != null && result.error != null && !result.error.equals("")) {
       logger.atSevere().log(
-          "%s plugin revision %s: error posting review: %s",
-          pluginName, event.getChange().currentRevision, result.error);
+          "revision %s: error posting review: %s", event.getChange().currentRevision, result.error);
+      metrics.postReviewErrors.increment(project);
+      metrics.errors.increment();
     }
     if (result != null && result.reviewers != null) {
       for (Map.Entry<String, AddReviewerResult> entry : result.reviewers.entrySet()) {
         AddReviewerResult arr = entry.getValue();
         if (arr.error != null && !arr.error.equals("")) {
           logger.atSevere().log(
-              "%s plugin revision %s: error adding reviewer %s: %s",
-              pluginName, event.getChange().currentRevision, entry.getKey(), arr.error);
+              "revision %s: error adding reviewer %s: %s",
+              event.getChange().currentRevision, entry.getKey(), arr.error);
+          metrics.addReviewerErrors.increment(project);
+          metrics.errors.increment();
         }
       }
     }
diff --git a/src/main/java/com/googlesource/gerrit/plugins/copyright/Metrics.java b/src/main/java/com/googlesource/gerrit/plugins/copyright/Metrics.java
new file mode 100644
index 0000000..1e22006
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/copyright/Metrics.java
@@ -0,0 +1,216 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// 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 com.googlesource.gerrit.plugins.copyright;
+
+import com.google.gerrit.metrics.Counter0;
+import com.google.gerrit.metrics.Counter1;
+import com.google.gerrit.metrics.Description;
+import com.google.gerrit.metrics.Description.Units;
+import com.google.gerrit.metrics.Field;
+import com.google.gerrit.metrics.MetricMaker;
+import com.google.gerrit.metrics.Timer0;
+import com.google.gerrit.metrics.Timer1;
+import com.google.inject.Singleton;
+import javax.inject.Inject;
+
+@Singleton
+class Metrics {
+  final Timer0 readConfigTimer;
+  final Timer0 checkConfigTimer;
+  final Timer0 testConfigTimer;
+  final Counter1<String> postReviewErrors;
+  final Counter1<String> addReviewerErrors;
+  final Counter1<String> projectStateErrors;
+  final Counter1<String> projectConfigErrors;
+  final Counter1<String> configurationErrors;
+  final Counter0 reviewCount;
+  final Counter0 commentCount;
+  final Timer0 reviewTimer;
+  final Counter1<String> reviewCountByProject;
+  final Counter1<String> commentCountByProject;
+  final Timer1<String> reviewTimerByProject;
+  final Timer0 scanRevisionTimer;
+  final Timer0 scanFileTimer;
+  final Counter1<String> scanCountByProject;
+  final Timer1<String> scanRevisionTimerByProject;
+  final Timer1<String> scanFileTimerByProject;
+  final Counter1<String> scanCountByBranch;
+  final Timer1<String> scanRevisionTimerByBranch;
+  final Timer1<String> scanFileTimerByBranch;
+  final Counter1<String> skippedReviewWarnings;
+  final Counter1<String> scanErrors;
+  final Counter0 errors;
+
+  @Inject
+  Metrics(MetricMaker metricMaker) {
+    Field<String> project = Field.ofString("project", "project name");
+    Field<String> branch = Field.ofString("branch", "branch name");
+
+    readConfigTimer =
+        metricMaker.newTimer(
+            "read_config_latency",
+            new Description("Time spent reading and parsing plugin configurations")
+                .setCumulative()
+                .setUnit(Units.MICROSECONDS));
+    checkConfigTimer =
+        metricMaker.newTimer(
+            "check_config_latency",
+            new Description("Time spent testing proposed plugin configurations")
+                .setCumulative()
+                .setUnit(Units.MICROSECONDS));
+    testConfigTimer =
+        metricMaker.newTimer(
+            "test_config_latency",
+            new Description("Time spent testing configurations against difficult file pattern")
+                .setCumulative()
+                .setUnit(Units.MICROSECONDS));
+    postReviewErrors =
+        metricMaker.newCounter(
+            "post_review_error_count",
+            new Description("Number of failed attempts to post reviews")
+                .setRate()
+                .setUnit("errors"),
+            project);
+    addReviewerErrors =
+        metricMaker.newCounter(
+            "add_reviewer_error_count",
+            new Description("Number of failed attempts to add a reviewer")
+                .setRate()
+                .setUnit("errors"),
+            project);
+    projectStateErrors =
+        metricMaker.newCounter(
+            "read_project_state_error_count",
+            new Description("Number of failed attempts to read project state")
+                .setRate()
+                .setUnit("errors"),
+            project);
+    projectConfigErrors =
+        metricMaker.newCounter(
+            "get_project_config_error_count",
+            new Description("Number of failed attempts to get config from project state")
+                .setRate()
+                .setUnit("errors"),
+            project);
+    configurationErrors =
+        metricMaker.newCounter(
+            "read_configuration_error_count",
+            new Description("Number of failed attempts to read configuration")
+                .setRate()
+                .setUnit("errors"),
+            project);
+    reviewCount =
+        metricMaker.newCounter(
+            "review_count",
+            new Description("Total number of posted reviews").setRate().setUnit("reviews"));
+    commentCount =
+        metricMaker.newCounter(
+            "comment_count",
+            new Description("Total number of posted review comments")
+                .setRate()
+                .setUnit("comments"));
+    reviewTimer =
+        metricMaker.newTimer(
+            "review_latency",
+            new Description("Time spent posting reviews to revisions")
+                .setCumulative()
+                .setUnit(Units.MICROSECONDS));
+    reviewCountByProject =
+        metricMaker.newCounter(
+            "review_count_by_project",
+            new Description("Total number of posted reviews").setRate().setUnit("reviews"),
+            project);
+    commentCountByProject =
+        metricMaker.newCounter(
+            "comment_count_by_project",
+            new Description("Total number of posted review comments").setRate().setUnit("comments"),
+            project);
+    reviewTimerByProject =
+        metricMaker.newTimer(
+            "review_latency_by_project",
+            new Description("Time spent posting reviews to revisions")
+                .setCumulative()
+                .setUnit(Units.MICROSECONDS),
+            project);
+    scanRevisionTimer =
+        metricMaker.newTimer(
+            "scan_revision_latency",
+            new Description("Time spent scanning entire revisions")
+                .setCumulative()
+                .setUnit(Units.MILLISECONDS));
+    scanFileTimer =
+        metricMaker.newTimer(
+            "scan_file_latency",
+            new Description("Time spent scanning each file")
+                .setCumulative()
+                .setUnit(Units.MICROSECONDS));
+    scanCountByProject =
+        metricMaker.newCounter(
+            "scan_count_by_project",
+            new Description("Total number of copyright scans").setRate().setUnit("scans"),
+            project);
+    scanRevisionTimerByProject =
+        metricMaker.newTimer(
+            "scan_revision_latency_by_project",
+            new Description("Time spent scanning entire revisions")
+                .setCumulative()
+                .setUnit(Units.MILLISECONDS),
+            project);
+    scanFileTimerByProject =
+        metricMaker.newTimer(
+            "scan_file_latency_by_project",
+            new Description("Time spent scanning each file")
+                .setCumulative()
+                .setUnit(Units.MICROSECONDS),
+            project);
+    scanCountByBranch =
+        metricMaker.newCounter(
+            "scan_count_by_branch",
+            new Description("Total number of copyright scans").setRate().setUnit("scans"),
+            branch);
+    scanRevisionTimerByBranch =
+        metricMaker.newTimer(
+            "scan_revision_latency_by_branch",
+            new Description("Time spent scanning entire revisions")
+                .setCumulative()
+                .setUnit(Units.MILLISECONDS),
+            branch);
+    scanFileTimerByBranch =
+        metricMaker.newTimer(
+            "scan_file_latency_by_branch",
+            new Description("Time spent scanning each file")
+                .setCumulative()
+                .setUnit(Units.MICROSECONDS),
+            branch);
+    skippedReviewWarnings =
+        metricMaker.newCounter(
+            "skipped_scan_warning_count",
+            new Description("Number revision scans skipped due to configuration problems")
+                .setRate()
+                .setUnit("warnings"),
+            project);
+    scanErrors =
+        metricMaker.newCounter(
+            "failed_scan_error_count",
+            new Description("Number of failed attempts to scan revisions")
+                .setRate()
+                .setUnit("errors"),
+            project);
+    errors =
+        metricMaker.newCounter(
+            "error_count",
+            new Description("Number of errors of any kind").setRate().setUnit("errors"));
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/copyright/Module.java b/src/main/java/com/googlesource/gerrit/plugins/copyright/Module.java
index af872c7..7f7bd82 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/copyright/Module.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/copyright/Module.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
diff --git a/src/main/java/com/googlesource/gerrit/plugins/copyright/ScannerConfig.java b/src/main/java/com/googlesource/gerrit/plugins/copyright/ScannerConfig.java
index 815b28c..c53ee1f 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/copyright/ScannerConfig.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/copyright/ScannerConfig.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
@@ -33,7 +33,7 @@
 import java.util.regex.Pattern;
 import java.util.regex.PatternSyntaxException;
 
-/** Configuration state for {@link CopyrightValidator}. */
+/** Configuration state for {@link CopyrightValidator} from All-Projects project.config file. */
 class ScannerConfig {
   private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
@@ -88,6 +88,7 @@
     this.fromAccountId = 0;
   }
 
+  /** True when {@link CopyrightValidator} will behave the same with either config. */
   @Override
   public boolean equals(Object other) {
     if (this == other) {
@@ -99,6 +100,7 @@
     if (other instanceof ScannerConfig) {
       ScannerConfig otherConfig = (ScannerConfig) other;
       return defaultEnable == otherConfig.defaultEnable
+          && fromAccountId == otherConfig.fromAccountId
           && messages.equals(otherConfig.messages)
           && alwaysReviewPath.equals(otherConfig.alwaysReviewPath)
           && matchProjects.equals(otherConfig.matchProjects)
@@ -116,6 +118,7 @@
   public int hashCode() {
     return Objects.hash(
         defaultEnable,
+        fromAccountId,
         messages,
         alwaysReviewPath,
         matchProjects,
diff --git a/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/Archive.java b/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/Archive.java
index 8d6ed0b..8d8fab7 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/Archive.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/Archive.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
diff --git a/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightPatterns.java b/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightPatterns.java
index 060dffc..d2bf243 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightPatterns.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightPatterns.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
diff --git a/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightScanner.java b/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightScanner.java
index ddc5f78..736a537 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightScanner.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightScanner.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
diff --git a/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/IndexedLineReader.java b/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/IndexedLineReader.java
index 015863c..f4749fc 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/IndexedLineReader.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/copyright/lib/IndexedLineReader.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
diff --git a/src/main/java/com/googlesource/gerrit/plugins/copyright/tools/AndroidScan.java b/src/main/java/com/googlesource/gerrit/plugins/copyright/tools/AndroidScan.java
index b5591a4..37fed5e 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/copyright/tools/AndroidScan.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/copyright/tools/AndroidScan.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
diff --git a/src/main/java/com/googlesource/gerrit/plugins/copyright/tools/ScanTool.java b/src/main/java/com/googlesource/gerrit/plugins/copyright/tools/ScanTool.java
index 0a4bb04..087f2c3 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/copyright/tools/ScanTool.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/copyright/tools/ScanTool.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
diff --git a/src/main/resources/Documentation/about.md b/src/main/resources/Documentation/about.md
index e700891..a165149 100644
--- a/src/main/resources/Documentation/about.md
+++ b/src/main/resources/Documentation/about.md
@@ -14,6 +14,7 @@
 It will have false-positives--especially in the unknown category. It may also
 have false negatives.
 
+
 ## First-party
 
 Licensed or owned by the owner of the gerrit repository.
diff --git a/src/main/resources/Documentation/build.md b/src/main/resources/Documentation/build.md
index 81eec27..b682c71 100644
--- a/src/main/resources/Documentation/build.md
+++ b/src/main/resources/Documentation/build.md
@@ -84,6 +84,7 @@
   bazel test --test_tag_filters=@PLUGIN@ //...
 ````
 
+
 This project can be imported into the Eclipse IDE.
 Add the plugin name to the `CUSTOM_PLUGINS` set in
 Gerrit core in `tools/bzl/plugins.bzl`, and execute:
diff --git a/src/main/resources/Documentation/config.md b/src/main/resources/Documentation/config.md
index 32b4ef9..5163a2d 100644
--- a/src/main/resources/Documentation/config.md
+++ b/src/main/resources/Documentation/config.md
@@ -43,6 +43,7 @@
     the command-line tool, to take heed of any warnings or errors it prints, and
     to copy+paste the token.
 
+
 ## Project Configuration
 
 Each project's `project.config` has a configuration parameter to enable or to
@@ -216,7 +217,8 @@
 
     Review comments will appear to come from the given account. Recommend
     creating a non-interactive user with a descriptive name like
-    "Copyright Scanner".
+    "Copyright Scanner". Must have read access to refs/heads/* and to
+    refs/meta/config in all repositories.
 
 plugin.@PLUGIN@.matchProjects
 :    List of Project Patterns to Scan
diff --git a/src/main/resources/Documentation/known-patterns.md b/src/main/resources/Documentation/known-patterns.md
index fae7a2d..9499a1e 100644
--- a/src/main/resources/Documentation/known-patterns.md
+++ b/src/main/resources/Documentation/known-patterns.md
@@ -15,3 +15,4 @@
 The names do not have to match an exact license or entity per se. For example,
 the Creative Commons folks do not define a CC_BY_C license. The named pattern
 matches any of several Creative Commons licenses that allow commercial use.
+
diff --git a/src/main/resources/Documentation/modified-regex.md b/src/main/resources/Documentation/modified-regex.md
index 9e1bd9e..8abc2df 100644
--- a/src/main/resources/Documentation/modified-regex.md
+++ b/src/main/resources/Documentation/modified-regex.md
@@ -10,6 +10,7 @@
 expressions](https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html)
 with modifications to assist the 3 requirements above.
 
+
 ## Unlimited Wildcards
 
 If you run the ScanTool.java command-line tool against the files in your
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/CopyrightConfigIT.java b/src/test/java/com/googlesource/gerrit/plugins/copyright/CopyrightConfigIT.java
index 7a31f07..af7278a 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/CopyrightConfigIT.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/CopyrightConfigIT.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
@@ -25,6 +25,7 @@
 import static com.googlesource.gerrit.plugins.copyright.TestConfig.LOCAL_BRANCH;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.flogger.FluentLogger;
 import com.google.common.truth.Correspondence;
 import com.google.gerrit.acceptance.GerritConfig;
 import com.google.gerrit.acceptance.GerritConfigs;
@@ -47,6 +48,8 @@
 
 @TestPlugin(name = "copyright", sysModule = "com.googlesource.gerrit.plugins.copyright.Module")
 public class CopyrightConfigIT extends LightweightPluginDaemonTest {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
   @Test
   @GerritConfigs({
     @GerritConfig(name = "plugin.copyright.enable", value = "true"),
@@ -99,7 +102,9 @@
   })
   public void testCopyrightConfig_pushWithSenderNoName() throws Exception {
     TestAccount anonymous =
-        accountCreator.create("copyright-scan", "", "", "Non-Interactive Users", expertGroup.name);
+        accountCreator.create(
+            "copyright-scan", "", "", "Administrators", "Non-Interactive Users", expertGroup.name);
+
     testConfig.updatePlugin(
         cfg -> {
           cfg.setInt(KEY_FROM, anonymous.id().get());
@@ -317,6 +322,7 @@
             "copyright-scanner",
             "copyright-scanner@example.com",
             "Copyright Scanner",
+            "Administrators",
             "Non-Interactive Users",
             expertGroup.name);
     reviewer =
@@ -360,16 +366,9 @@
   }
 
   private static Correspondence<Comment, String> warningContains() {
-    return new Correspondence<Comment, String>() {
-      @Override
-      public boolean compare(Comment actual, String expected) {
-        return actual.message.startsWith("WARNING ") && actual.message.contains(expected);
-      }
-
-      @Override
-      public String toString() {
-        return "matches regex";
-      }
-    };
+    return Correspondence.from(
+        (actual, expected) ->
+            actual.message.startsWith("WARNING ") && actual.message.contains(expected),
+        "matches regex");
   }
 }
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/CopyrightReviewApiTest.java b/src/test/java/com/googlesource/gerrit/plugins/copyright/CopyrightReviewApiTest.java
index f71ea0f..efea843 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/CopyrightReviewApiTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/CopyrightReviewApiTest.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
@@ -39,6 +39,7 @@
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.PluginUser;
 import com.google.gerrit.server.account.GroupMembership;
+import com.google.gerrit.server.util.ThreadLocalRequestContext;
 import com.googlesource.gerrit.plugins.copyright.lib.CopyrightScanner.Match;
 import org.junit.Before;
 import org.junit.Test;
@@ -53,21 +54,15 @@
   private IdentifiedUser.GenericFactory identifiedUserFactory =
       createMock(IdentifiedUser.GenericFactory.class);
 
+  private ThreadLocalRequestContext requestContext = createMock(ThreadLocalRequestContext.class);
+
   private CopyrightReviewApi reviewApi;
 
   @Before
   public void setUp() throws Exception {
     reviewApi =
         new CopyrightReviewApi(
-            null,
-            () -> pluginUser,
-            () -> currentUser,
-            identifiedUserFactory,
-            null,
-            null,
-            null,
-            null,
-            null);
+            null, () -> pluginUser, () -> currentUser, identifiedUserFactory, requestContext, null);
   }
 
   @Test
@@ -90,7 +85,7 @@
     CurrentUser from = reviewApi.getSendingUser(0);
 
     verify(identifiedUserFactory);
-    assertThat(from).isSameAs(currentUser);
+    assertThat(from).isSameInstanceAs(currentUser);
   }
 
   @Test
@@ -353,33 +348,18 @@
   }
 
   private static Correspondence<CommentInput, CommentInput> startsWithAndRangesMatch() {
-    return new Correspondence<CommentInput, CommentInput>() {
-      @Override
-      public boolean compare(CommentInput actual, CommentInput expected) {
-        return actual.range.startLine == expected.range.startLine
-            && actual.range.endLine == expected.range.endLine
-            && actual.message.startsWith(expected.message);
-      }
-
-      @Override
-      public String toString() {
-        return "starts with and ranges match";
-      }
-    };
+    return Correspondence.from(
+        (actual, expected) ->
+            actual.range.startLine == expected.range.startLine
+                && actual.range.endLine == expected.range.endLine
+                && actual.message.startsWith(expected.message),
+        "starts with and ranges match");
   }
 
   private static Correspondence<AddReviewerInput, String> addressedTo() {
-    return new Correspondence<AddReviewerInput, String>() {
-      @Override
-      public boolean compare(AddReviewerInput actual, String expected) {
-        return expected.equals(actual.state().toString() + ":" + actual.reviewer);
-      }
-
-      @Override
-      public String toString() {
-        return "addressed to";
-      }
-    };
+    return Correspondence.from(
+        (actual, expected) -> expected.equals(actual.state().toString() + ":" + actual.reviewer),
+        "addressed to");
   }
 
   /** Comment input {@code text} from {@code start} line to {@code end} line. */
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/CopyrightValidatorIT.java b/src/test/java/com/googlesource/gerrit/plugins/copyright/CopyrightValidatorIT.java
index 304e87f..a629e9f 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/CopyrightValidatorIT.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/CopyrightValidatorIT.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
@@ -434,17 +434,10 @@
   }
 
   private static Correspondence<Comment, CommentMatch> commentContains() {
-    return new Correspondence<Comment, CommentMatch>() {
-      @Override
-      public boolean compare(Comment actual, CommentMatch expected) {
-        return actual.unresolved != expected.resolved && actual.message.contains(expected.content);
-      }
-
-      @Override
-      public String toString() {
-        return "comment resolution status and content matches";
-      }
-    };
+    return Correspondence.from(
+        (actual, expected) ->
+            actual.unresolved != expected.resolved && actual.message.contains(expected.content),
+        "comment resolution status and content matches");
   }
 
   private static class CommentMatch {
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/TestConfig.java b/src/test/java/com/googlesource/gerrit/plugins/copyright/TestConfig.java
index f35cbc0..346c53b 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/TestConfig.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/TestConfig.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/ArchiveTest.java b/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/ArchiveTest.java
index c5aeb8d..87e4023 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/ArchiveTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/ArchiveTest.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightPatternsTest.java b/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightPatternsTest.java
index a7bd486..394eb76 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightPatternsTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightPatternsTest.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightScannerTest.java b/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightScannerTest.java
index 3aa379b..6966975 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightScannerTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/CopyrightScannerTest.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
@@ -36,17 +36,7 @@
 public class CopyrightScannerTest {
 
   private static final Correspondence<String, String> CONTAINS_STRING =
-      new Correspondence<String, String>() {
-        @Override
-        public boolean compare(String actual, String expected) {
-          return actual.contains(expected);
-        }
-
-        @Override
-        public String toString() {
-          return "contains";
-        }
-      };
+      Correspondence.from((actual, expected) -> actual.contains(expected), "contains");
 
   private CopyrightPatterns.RuleSet.Builder builder;
 
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/IndexedLineReaderTest.java b/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/IndexedLineReaderTest.java
index a337027..cdbe089 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/IndexedLineReaderTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/lib/IndexedLineReaderTest.java
@@ -4,7 +4,7 @@
 // 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
+//  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,
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/ANDROID.txt b/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/ANDROID.txt
index 71a183b..8ae0bfd 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/ANDROID.txt
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/ANDROID.txt
@@ -1,3 +1,3 @@
 /*
- * Copyright (C) 2019 Android Open-Source Project
+ *  Copyright (C) 2019 Android Open-Source Project
  */
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/APACHE2.txt b/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/APACHE2.txt
index d645695..cb12cf1 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/APACHE2.txt
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/APACHE2.txt
@@ -176,6 +176,7 @@
 
    END OF TERMS AND CONDITIONS
 
+
    APPENDIX: How to apply the Apache License to your work.
 
       To apply the Apache License to your work, attach the following
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/BSD2.txt b/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/BSD2.txt
index 453967f..5b4d707 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/BSD2.txt
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/BSD2.txt
@@ -4,6 +4,7 @@
 Copyright (c) 2019, Jane Doe <jdoe@example.com>
 All rights reserved.
 
+
 Redistribution and use in source and binary forms, with or without modification,
 are permitted provided that the following conditions are met:
 
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/MIT.txt b/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/MIT.txt
index af63709..2a1d858 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/MIT.txt
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/MIT.txt
@@ -12,6 +12,7 @@
 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.
 
+
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/UNKNOWN.txt b/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/UNKNOWN.txt
index 67a5ebe..87124eb 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/UNKNOWN.txt
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/testdata/licenses/UNKNOWN.txt
@@ -1,4 +1,4 @@
 #!/bin/sh
 # Copyright (C) 2019
-# Jane Doe <jdoe@example.com>
+#  Jane Doe <jdoe@example.com>
 exit 0
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/tools/AndroidScanTest.sh b/src/test/java/com/googlesource/gerrit/plugins/copyright/tools/AndroidScanTest.sh
index cb3a3eb..0e8e5d0 100755
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/tools/AndroidScanTest.sh
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/tools/AndroidScanTest.sh
@@ -6,7 +6,7 @@
 # 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
+#  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,
diff --git a/src/test/java/com/googlesource/gerrit/plugins/copyright/tools/ScanToolTest.sh b/src/test/java/com/googlesource/gerrit/plugins/copyright/tools/ScanToolTest.sh
index 89ab77e..1db9039 100755
--- a/src/test/java/com/googlesource/gerrit/plugins/copyright/tools/ScanToolTest.sh
+++ b/src/test/java/com/googlesource/gerrit/plugins/copyright/tools/ScanToolTest.sh
@@ -6,7 +6,7 @@
 # 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
+#  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,
diff --git a/tools/android_scan.sh b/tools/android_scan.sh
index a3a51b2..1771f97 100755
--- a/tools/android_scan.sh
+++ b/tools/android_scan.sh
@@ -6,7 +6,7 @@
 # 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
+#  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,
diff --git a/tools/check_new_config.sh b/tools/check_new_config.sh
index 01cb7a4..29a7b27 100755
--- a/tools/check_new_config.sh
+++ b/tools/check_new_config.sh
@@ -6,7 +6,7 @@
 # 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
+#  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,
@@ -34,7 +34,7 @@
       echo
     else
       echo "The project.config full path must end with project.config -- not $(basename $2)"
-      ehco
+      echo
     fi
   fi
 }