Core metrics (#1586)

Expose metrics for http requests and executor services.

scm-webapp/src/main/java/sonia/scm/admin/ReleaseFeedParser.java

@@ -26,8 +26,11 @@ package sonia.scm.admin;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Strings;
+import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import io.micrometer.core.instrument.MeterRegistry;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import sonia.scm.metrics.Metrics;
 import sonia.scm.net.ahc.AdvancedHttpClient;
 import sonia.scm.version.Version;
 
@@ -46,7 +49,7 @@ public class ReleaseFeedParser {
   public static final int DEFAULT_TIMEOUT_IN_MILLIS = 5000;
 
   private static final Logger LOG = LoggerFactory.getLogger(ReleaseFeedParser.class);
-  
+
   @VisibleForTesting
   static final String SPAN_KIND = "Release Feed";
 
@@ -56,14 +59,24 @@ public class ReleaseFeedParser {
   private Future<Optional<UpdateInfo>> updateInfoFuture;
 
   @Inject
-  public ReleaseFeedParser(AdvancedHttpClient client) {
-    this(client, DEFAULT_TIMEOUT_IN_MILLIS);
+  public ReleaseFeedParser(AdvancedHttpClient client, MeterRegistry registry) {
+    this(client, registry, DEFAULT_TIMEOUT_IN_MILLIS);
   }
 
-  public ReleaseFeedParser(AdvancedHttpClient client, long timeoutInMillis) {
+  public ReleaseFeedParser(AdvancedHttpClient client, MeterRegistry registry, long timeoutInMillis) {
     this.client = client;
     this.timeoutInMillis = timeoutInMillis;
-    this.executorService = Executors.newSingleThreadExecutor();
+    this.executorService = createExecutorService(registry);
+  }
+
+  private ExecutorService createExecutorService(MeterRegistry registry) {
+    ExecutorService executor = Executors.newSingleThreadExecutor(
+      new ThreadFactoryBuilder()
+        .setNameFormat("ReleaseFeedParser")
+        .build()
+    );
+    Metrics.executor(registry, executor, "ReleaseFeedParser", "single");
+    return executor;
   }
 
   Optional<UpdateInfo> findLatestRelease(String url) {

scm-webapp/src/main/java/sonia/scm/api/v2/resources/RepositoryExportResource.java

@@ -27,6 +27,7 @@ package sonia.scm.api.v2.resources;
 import com.google.common.base.Strings;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import com.google.inject.Inject;
+import io.micrometer.core.instrument.MeterRegistry;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.media.Content;
 import io.swagger.v3.oas.annotations.media.Schema;
@@ -43,6 +44,7 @@ import sonia.scm.importexport.ExportFileExtensionResolver;
 import sonia.scm.importexport.ExportService;
 import sonia.scm.importexport.FullScmRepositoryExporter;
 import sonia.scm.importexport.RepositoryImportExportEncryption;
+import sonia.scm.metrics.Metrics;
 import sonia.scm.repository.NamespaceAndName;
 import sonia.scm.repository.Repository;
 import sonia.scm.repository.RepositoryManager;
@@ -104,7 +106,10 @@ public class RepositoryExportResource {
                                   RepositoryImportExportEncryption repositoryImportExportEncryption,
                                   ExportService exportService,
                                   RepositoryExportInformationToDtoMapper informationToDtoMapper,
-                                  ExportFileExtensionResolver fileExtensionResolver, ResourceLinks resourceLinks) {
+                                  ExportFileExtensionResolver fileExtensionResolver,
+                                  ResourceLinks resourceLinks,
+                                  MeterRegistry registry
+  ) {
     this.manager = manager;
     this.serviceFactory = serviceFactory;
     this.fullScmRepositoryExporter = fullScmRepositoryExporter;
@@ -113,7 +118,7 @@ public class RepositoryExportResource {
     this.informationToDtoMapper = informationToDtoMapper;
     this.fileExtensionResolver = fileExtensionResolver;
     this.resourceLinks = resourceLinks;
-    this.repositoryExportHandler = this.createExportHandlerPool();
+    this.repositoryExportHandler = this.createExportHandlerPool(registry);
   }
 
   /**
@@ -518,12 +523,14 @@ public class RepositoryExportResource {
     return Instant.now().toString().replace(":", "-").split("\\.")[0];
   }
 
-  private ExecutorService createExportHandlerPool() {
-    return Executors.newCachedThreadPool(
+  private ExecutorService createExportHandlerPool(MeterRegistry registry) {
+    ExecutorService executorService = Executors.newCachedThreadPool(
       new ThreadFactoryBuilder()
         .setNameFormat("RepositoryExportHandler-%d")
         .build()
     );
+    Metrics.executor(registry, executorService, "RepositoryExport", "cached");
+    return executorService;
   }
 
 

scm-webapp/src/main/java/sonia/scm/metrics/HttpMetricsFilter.java

@@ -0,0 +1,86 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * 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
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.metrics;
+
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.Tag;
+import io.micrometer.core.instrument.Tags;
+import io.micrometer.core.instrument.Timer;
+import io.micrometer.core.instrument.binder.http.DefaultHttpServletRequestTagsProvider;
+import io.micrometer.core.instrument.binder.http.HttpServletRequestTagsProvider;
+import sonia.scm.Priority;
+import sonia.scm.filter.Filters;
+import sonia.scm.filter.WebElement;
+import sonia.scm.web.filter.HttpFilter;
+
+import javax.inject.Inject;
+import javax.inject.Provider;
+import javax.servlet.FilterChain;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+@WebElement(Filters.PATTERN_ALL)
+@Priority(Filters.PRIORITY_PRE_BASEURL)
+public class HttpMetricsFilter extends HttpFilter {
+
+  static final String METRIC_DURATION = "scm.http.requests";
+
+  private final HttpServletRequestTagsProvider tagsProvider = new DefaultHttpServletRequestTagsProvider();
+
+  private final Provider<MeterRegistry> registryProvider;
+  private final RequestCategoryDetector detector;
+
+  @Inject
+  public HttpMetricsFilter(Provider<MeterRegistry> registryProvider, RequestCategoryDetector detector) {
+    this.registryProvider = registryProvider;
+    this.detector = detector;
+  }
+
+  @Override
+  protected void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException {
+    MeterRegistry registry = registryProvider.get();
+    Timer.Sample sample = Timer.start(registry);
+    try {
+      chain.doFilter(request, response);
+    } finally {
+      Tags tags = tags(request, response);
+      sample.stop(timer(registry, tags));
+    }
+  }
+
+  private Timer timer(MeterRegistry registry, Tags tags) {
+    return Timer.builder(METRIC_DURATION)
+      .description("Duration of an http request")
+      .tags(tags)
+      .register(registry);
+  }
+
+  private Tags tags(HttpServletRequest request, HttpServletResponse response) {
+    Iterable<Tag> tags = tagsProvider.getTags(request, response);
+    return Tags.concat(tags, "category", detector.detect(request).name());
+  }
+}

scm-webapp/src/main/java/sonia/scm/metrics/MeterRegistryProvider.java

@@ -31,6 +31,8 @@ import io.micrometer.core.instrument.binder.jvm.JvmMemoryMetrics;
 import io.micrometer.core.instrument.binder.jvm.JvmThreadMetrics;
 import io.micrometer.core.instrument.binder.system.ProcessorMetrics;
 import io.micrometer.core.instrument.composite.CompositeMeterRegistry;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import javax.inject.Inject;
 import javax.inject.Provider;
@@ -40,6 +42,8 @@ import java.util.Set;
 @Singleton
 public class MeterRegistryProvider implements Provider<MeterRegistry> {
 
+  private static final Logger LOG = LoggerFactory.getLogger(MeterRegistryProvider.class);
+
   private final Set<MonitoringSystem> providerSet;
 
   @Inject
@@ -58,15 +62,20 @@ public class MeterRegistryProvider implements Provider<MeterRegistry> {
 
   private MeterRegistry createRegistry() {
     if (providerSet.size() == 1) {
-      return providerSet.iterator().next().getRegistry();
+      MeterRegistry registry = providerSet.iterator().next().getRegistry();
+      LOG.debug("create meter registry from single registration: {}", registry.getClass());
+      return registry;
     }
     return createCompositeRegistry();
   }
 
   private CompositeMeterRegistry createCompositeRegistry() {
+    LOG.debug("create composite meter registry");
     CompositeMeterRegistry registry = new CompositeMeterRegistry();
     for (MonitoringSystem provider : providerSet) {
-      registry.add(provider.getRegistry());
+      MeterRegistry subRegistry = provider.getRegistry();
+      LOG.debug("register {} as part of composite meter registry", subRegistry.getClass());
+      registry.add(subRegistry);
     }
     return registry;
   }

scm-webapp/src/main/java/sonia/scm/metrics/RequestCategory.java

@@ -0,0 +1,32 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * 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
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.metrics;
+
+
+public enum RequestCategory {
+
+  UI, API, PROTOCOL, STATIC, UNKNOWN
+
+}

scm-webapp/src/main/java/sonia/scm/metrics/RequestCategoryDetector.java

@@ -0,0 +1,74 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * 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
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.metrics;
+
+import sonia.scm.util.HttpUtil;
+import sonia.scm.web.UserAgent;
+import sonia.scm.web.UserAgentParser;
+
+import javax.inject.Inject;
+import javax.servlet.http.HttpServletRequest;
+
+public final class RequestCategoryDetector {
+
+  private final UserAgentParser userAgentParser;
+
+  @Inject
+  public RequestCategoryDetector(UserAgentParser userAgentParser) {
+    this.userAgentParser = userAgentParser;
+  }
+
+  public RequestCategory detect(HttpServletRequest request) {
+    String uri = HttpUtil.getStrippedURI(request);
+    if (isStatic(uri)) {
+      return RequestCategory.STATIC;
+    } else if (HttpUtil.isWUIRequest(request)) {
+      return RequestCategory.UI;
+    } else if (uri.startsWith("/api/")) {
+      return RequestCategory.API;
+    } else if (uri.startsWith("/repo/") && isScmClient(request)) {
+      return RequestCategory.PROTOCOL;
+    }
+    return RequestCategory.UNKNOWN;
+  }
+
+  private boolean isStatic(String uri) {
+    return uri.startsWith("/assets")
+      || uri.endsWith(".js")
+      || uri.endsWith(".css")
+      || uri.endsWith(".jpg")
+      || uri.endsWith(".jpeg")
+      || uri.endsWith(".png")
+      || uri.endsWith(".gif")
+      || uri.endsWith(".svg")
+      || uri.endsWith(".html");
+  }
+
+  private boolean isScmClient(HttpServletRequest request) {
+    UserAgent agent = userAgentParser.parse(request);
+    return agent != null && agent.isScmClient();
+  }
+
+}

scm-webapp/src/main/java/sonia/scm/repository/DefaultRepositoryManager.java

@@ -26,10 +26,8 @@ package sonia.scm.repository;
 
 import com.google.common.base.Strings;
 import com.google.common.collect.Lists;
-import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
-import org.apache.shiro.concurrent.SubjectAwareExecutorService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import sonia.scm.ConfigurationException;
@@ -56,9 +54,6 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.ThreadFactory;
 import java.util.function.Consumer;
 import java.util.function.Predicate;
 
@@ -75,10 +70,7 @@ import static sonia.scm.NotFoundException.notFound;
 @Singleton
 public class DefaultRepositoryManager extends AbstractRepositoryManager {
 
-  private static final String THREAD_NAME = "Hook-%s";
-  private static final Logger logger =
-    LoggerFactory.getLogger(DefaultRepositoryManager.class);
-  private final ExecutorService executorService;
+  private static final Logger logger = LoggerFactory.getLogger(DefaultRepositoryManager.class);
   private final Map<String, RepositoryHandler> handlerMap;
   private final KeyGenerator keyGenerator;
   private final RepositoryDAO repositoryDAO;
@@ -94,12 +86,6 @@ public class DefaultRepositoryManager extends AbstractRepositoryManager {
     this.repositoryDAO = repositoryDAO;
     this.namespaceStrategyProvider = namespaceStrategyProvider;
 
-    ThreadFactory factory = new ThreadFactoryBuilder()
-      .setNameFormat(THREAD_NAME).build();
-    this.executorService = new SubjectAwareExecutorService(
-      Executors.newCachedThreadPool(factory)
-    );
-
     handlerMap = new HashMap<>();
     types = new HashSet<>();
 
@@ -109,11 +95,8 @@ public class DefaultRepositoryManager extends AbstractRepositoryManager {
     managerDaoAdapter = new ManagerDaoAdapter<>(repositoryDAO);
   }
 
-
   @Override
   public void close() {
-    executorService.shutdown();
-
     for (RepositoryHandler handler : handlerMap.values()) {
       IOUtil.close(handler);
     }

scm-webapp/src/main/java/sonia/scm/repository/DefaultSyncAsyncExecutorProvider.java

@@ -21,9 +21,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.repository;
 
+import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import io.micrometer.core.instrument.MeterRegistry;
+import sonia.scm.metrics.Metrics;
 import sonia.scm.repository.spi.SyncAsyncExecutor;
 import sonia.scm.repository.spi.SyncAsyncExecutorProvider;
 
@@ -48,8 +51,19 @@ public class DefaultSyncAsyncExecutorProvider implements SyncAsyncExecutorProvid
   private final int defaultMaxAsyncAbortSeconds;
 
   @Inject
-  public DefaultSyncAsyncExecutorProvider() {
-    this(Executors.newFixedThreadPool(getProperty(NUMBER_OF_THREADS_PROPERTY, DEFAULT_NUMBER_OF_THREADS)));
+  public DefaultSyncAsyncExecutorProvider(MeterRegistry registry) {
+    this(createExecutorService(registry, getProperty(NUMBER_OF_THREADS_PROPERTY, DEFAULT_NUMBER_OF_THREADS)));
+  }
+
+  private static ExecutorService createExecutorService(MeterRegistry registry, int fixed) {
+    ExecutorService executorService = Executors.newFixedThreadPool(
+      fixed,
+      new ThreadFactoryBuilder()
+        .setNameFormat("SyncAsyncExecutorProvider-%d")
+        .build()
+    );
+    Metrics.executor(registry, executorService, "SyncAsyncExecutorProvider", "fixed");
+    return executorService;
   }
 
   public DefaultSyncAsyncExecutorProvider(ExecutorService executor) {

scm-webapp/src/main/java/sonia/scm/schedule/CronScheduler.java

@@ -21,11 +21,13 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.schedule;
 
+import io.micrometer.core.instrument.MeterRegistry;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import sonia.scm.metrics.Metrics;
 
 import javax.inject.Inject;
 import javax.inject.Singleton;
@@ -44,14 +46,16 @@ public class CronScheduler implements Scheduler {
   private final CronThreadFactory threadFactory;
 
   @Inject
-  public CronScheduler(CronTaskFactory taskFactory) {
+  public CronScheduler(CronTaskFactory taskFactory, MeterRegistry registry) {
     this.taskFactory = taskFactory;
     this.threadFactory = new CronThreadFactory();
-    this.executorService = createExecutor();
+    this.executorService = createExecutor(registry);
   }
 
-  private ScheduledExecutorService createExecutor() {
-    return Executors.newScheduledThreadPool(2, threadFactory);
+  private ScheduledExecutorService createExecutor(MeterRegistry registry) {
+    ScheduledExecutorService executor = Executors.newScheduledThreadPool(2, threadFactory);
+    Metrics.executor(registry, executor, "Cron", "scheduled");
+    return executor;
   }
 
   @Override

scm-webapp/src/main/java/sonia/scm/template/MustacheTemplateEngine.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.template;
 
 //~--- non-JDK imports --------------------------------------------------------
@@ -32,16 +32,19 @@ import com.google.common.base.Throwables;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import com.google.common.util.concurrent.UncheckedExecutionException;
 import com.google.inject.Inject;
+import io.micrometer.core.instrument.MeterRegistry;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import sonia.scm.Default;
+import sonia.scm.metrics.Metrics;
 import sonia.scm.plugin.PluginLoader;
 
+import javax.annotation.Nullable;
 import javax.servlet.ServletContext;
 import java.io.IOException;
 import java.io.Reader;
+import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
-import java.util.concurrent.ThreadFactory;
 
 //~--- JDK imports ------------------------------------------------------------
 
@@ -61,37 +64,43 @@ public class MustacheTemplateEngine implements TemplateEngine
     @Inject(optional = true) PluginLoader pluginLoader;
   }
 
+  /**
+   * Used to implement optional injection for the MeterRegistry.
+   * @see <a href="https://github.com/google/guice/wiki/FrequentlyAskedQuestions#how-can-i-inject-optional-parameters-into-a-constructor">Optional Injection</a>
+   */
+  static class MeterRegistryHolder {
+    @Inject(optional = true) MeterRegistry registry;
+  }
+
   /** Field description */
   public static final TemplateType TYPE = new TemplateType("mustache",
                                             "Mustache", "mustache");
 
-  /** Field description */
-  private static final String THREAD_NAME = "Mustache-%s";
-
   /**
    * the logger for MustacheTemplateEngine
    */
   private static final Logger logger =
     LoggerFactory.getLogger(MustacheTemplateEngine.class);
 
-  //~--- constructors ---------------------------------------------------------
-
-  /**
-   * Constructs ...
-   *
-   *
-   * @param context
-   * @param pluginLoaderHolder
-   */
   @Inject
-  public MustacheTemplateEngine(@Default ServletContext context, PluginLoaderHolder pluginLoaderHolder)
+  public MustacheTemplateEngine(@Default ServletContext context, PluginLoaderHolder pluginLoaderHolder, MeterRegistryHolder registryHolder)
   {
     factory = new ServletMustacheFactory(context, createClassLoader(pluginLoaderHolder.pluginLoader));
+    factory.setExecutorService(createExecutorService(registryHolder.registry));
+  }
 
-    ThreadFactory threadFactory =
-      new ThreadFactoryBuilder().setNameFormat(THREAD_NAME).build();
+  private static ExecutorService createExecutorService(@Nullable MeterRegistry registry) {
+    ExecutorService executorService = Executors.newCachedThreadPool(
+      new ThreadFactoryBuilder()
+        .setNameFormat("MustacheTemplateEngine-%d")
+        .build()
+    );
 
-    factory.setExecutorService(Executors.newCachedThreadPool(threadFactory));
+    if (registry != null) {
+      Metrics.executor(registry, executorService,"MustacheTemplateEngine", "cached" );
+    }
+
+    return executorService;
   }
 
   private ClassLoader createClassLoader(PluginLoader pluginLoader) {

scm-webapp/src/main/java/sonia/scm/web/cgi/DefaultCGIExecutorFactory.java

@@ -21,23 +21,24 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.web.cgi;
 
 //~--- non-JDK imports --------------------------------------------------------
 
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
-
+import io.micrometer.core.instrument.MeterRegistry;
 import sonia.scm.config.ScmConfiguration;
+import sonia.scm.metrics.Metrics;
 
-//~--- JDK imports ------------------------------------------------------------
-
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-
+import javax.inject.Inject;
 import javax.servlet.ServletContext;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+//~--- JDK imports ------------------------------------------------------------
 
 /**
  *
@@ -50,13 +51,19 @@ public class DefaultCGIExecutorFactory implements CGIExecutorFactory, AutoClosea
    * Constructs ...
    *
    */
-  public DefaultCGIExecutorFactory()
-  {
-    //J-
-    this.executor = Executors.newCachedThreadPool(
-      new ThreadFactoryBuilder().setNameFormat("cgi-pool-%d").build()
+  @Inject
+  public DefaultCGIExecutorFactory(MeterRegistry registry) {
+    this.executor = createExecutor(registry);
+  }
+
+  private ExecutorService createExecutor(MeterRegistry registry) {
+    ExecutorService executorService = Executors.newCachedThreadPool(
+      new ThreadFactoryBuilder()
+        .setNameFormat("cgi-pool-%d")
+        .build()
     );
-    //J+
+    Metrics.executor(registry, executorService, "CGI", "cached");
+    return executorService;
   }
 
   //~--- methods --------------------------------------------------------------