feat(perf): adapt policy for new classloader system

.circleci/config.yml

@@ -47,17 +47,17 @@ workflows:
       - gravitee/d_pull_requests_secrets:
           context: cicd-orchestrator
           name: pr_secrets_resolution
-            # - gravitee/d_pr_tests_containers_qa:
-            # context: gravitee-qa
-            # name: process_pull_request_qa
-            # requires:
+      # - gravitee/d_pr_tests_containers_qa:
+          # context: gravitee-qa
+          # name: process_pull_request_qa
+          # requires:
             # - pr_secrets_resolution
-            # # "What is the maven ID of the maven profile to use to build and deploy SNAPSHOTS to Prviate Artifactory ?"
-            # maven_profile_id: 'gio-dev'
-            # filters:
+          # # "What is the maven ID of the maven profile to use to build and deploy SNAPSHOTS to Prviate Artifactory ?"
+          # maven_profile_id: 'gio-dev'
+          # filters:
             # branches:
-            # ignore:
-          # - master
+              # ignore:
+                # - master
       - gravitee/d_pull_requests_ce:
           name: process_pull_request
           requires:
@@ -70,10 +70,10 @@ workflows:
           # container_gun_image_name: 'openjdk'
           # container_gun_image_tag: '11.0.3-jdk-stretch'
           container_size: 'medium'
-            # filters:
+          # filters:
             # branches:
-            # ignore:
-          # - master
+              # ignore:
+                # - master
   # ---
   # The 2 Workflows Below are there for the CICD Orchestrator to be able to
   # release Gravitee Kubernetes in an APIM release Process, with Docker executors instead of VMs
@@ -197,13 +197,13 @@ workflows:
       and:
         - equal: [ standalone_release, << pipeline.parameters.gio_action >> ]
         - not: << pipeline.parameters.dry_run >>
-      # ---
-      # Running the nexus staging makes sense only when the
-      # standalone release is being performed with dry run mode off
-      # That is to say, when the maven project is ready to be release to mmaven Staging
-      # Never the less, to test the CICD system, I temporarily git pushed a different configuration
-      # ---
-      # when:
+    # ---
+    # Running the nexus staging makes sense only when the
+    # standalone release is being performed with dry run mode off
+    # That is to say, when the maven project is ready to be release to mmaven Staging
+    # Never the less, to test the CICD system, I temporarily git pushed a different configuration
+    # ---
+    # when:
       # equal: [ standalone_release, << pipeline.parameters.gio_action >> ]
     jobs:
       - gravitee/d_nexus_staging_secrets:
@@ -294,13 +294,13 @@ workflows:
       and:
         - equal: [ standalone_release_replay, << pipeline.parameters.gio_action >> ]
         - not: << pipeline.parameters.dry_run >>
-      # ---
-      # Running the nexus staging makes sense only when the
-      # standalone release is being performed with dry run mode off
-      # That is to say, when the maven project is ready to be release to mmaven Staging
-      # Never the less, to test the CICD system, I temporarily git pushed a different configuration
-      # ---
-      # when:
+    # ---
+    # Running the nexus staging makes sense only when the
+    # standalone release is being performed with dry run mode off
+    # That is to say, when the maven project is ready to be release to mmaven Staging
+    # Never the less, to test the CICD system, I temporarily git pushed a different configuration
+    # ---
+    # when:
       # equal: [ standalone_release, << pipeline.parameters.gio_action >> ]
     jobs:
       - gravitee/d_nexus_staging_secrets:
@@ -353,7 +353,6 @@ workflows:
           maven_profile_id: << pipeline.parameters.maven_profile_id >>
           s3_bucket_name: << pipeline.parameters.s3_bucket_name >>
 
-
   # ---
   # Nighlty for all CE repositories :
   # builds the SNAPSHOT, and deploys
@@ -364,14 +363,14 @@ workflows:
   nightly:
     when:
       equal: [ nightly, << pipeline.parameters.gio_action >> ]
-        # triggers:
-        # - schedule:
-        # cron: "0 0 * * *"
-        # filters:
-        # branches:
-        # only:
-        # - master
-      # - /^[0-999].[0-999].x/
+    # triggers:
+      # - schedule:
+          # cron: "0 0 * * *"
+          # filters:
+            # branches:
+              # only:
+                # - master
+                # - /^[0-999].[0-999].x/
     jobs:
       - gravitee/d_all_nightly_secrets:
           context: cicd-orchestrator
@@ -389,4 +388,4 @@ workflows:
             branches:
               only:
                 - master
-                - /^[0-999].[0-999].x/
+                - /^[0-999].[0-999].x/

pom.xml

@@ -42,6 +42,7 @@
 
         <maven-assembly-plugin.version>2.5.5</maven-assembly-plugin.version>
         <freemarker.version>2.3.31</freemarker.version>
+        <guava.version>30.1.1-jre</guava.version>
 
         <mockito.version>3.5.13</mockito.version>
     </properties>
@@ -110,6 +111,13 @@
             <scope>provided</scope>
         </dependency>
 
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+            <scope>provided</scope>
+        </dependency>
+
         <!-- Test scope -->
         <dependency>
             <groupId>junit</groupId>

src/main/java/io/gravitee/policy/metricsreporter/MetricsReporterPolicy.java

@@ -15,7 +15,6 @@
  */
 package io.gravitee.policy.metricsreporter;
 
-import freemarker.cache.StringTemplateLoader;
 import freemarker.core.TemplateClassResolver;
 import freemarker.template.*;
 import io.gravitee.gateway.api.ExecutionContext;
@@ -24,6 +23,7 @@
 import io.gravitee.gateway.api.stream.ReadWriteStream;
 import io.gravitee.policy.api.annotations.OnResponseContent;
 import io.gravitee.policy.metricsreporter.configuration.MetricsReporterPolicyConfiguration;
+import io.gravitee.policy.metricsreporter.freemarker.CustomTemplateLoader;
 import io.gravitee.policy.metricsreporter.freemarker.LegacyDefaultMemberAccessPolicy;
 import io.gravitee.policy.metricsreporter.metrics.AttributesBasedExecutionContext;
 import io.gravitee.policy.metricsreporter.metrics.RequestMetrics;
@@ -62,7 +62,8 @@ public class MetricsReporterPolicy {
 
   private final MetricsReporterPolicyConfiguration configuration;
 
-  private static final ConcurrentMap<String, HttpClient> clients = new ConcurrentHashMap<>();
+  private HttpClient client;
+  private static final CustomTemplateLoader templateLoader = new CustomTemplateLoader();
   private static final Configuration templateConfiguration = loadConfiguration();
 
   public MetricsReporterPolicy(
@@ -155,10 +156,17 @@ private void reportMetrics(ExecutionContext context) {
   }
 
   private HttpClient getOrCreateClient(ExecutionContext context) {
-    return clients.computeIfAbsent(
-      configuration.getUrl(),
-      url -> createClient(context)
-    );
+    if (client == null) {
+      // Synchronization should not occur more than few times in case of high throughput.
+      synchronized (this) {
+        // Avoid create multiple clients by double checking the client nullability.
+        if (client == null) {
+          client = createClient(context);
+        }
+      }
+    }
+
+    return client;
   }
 
   private HttpClient createClient(ExecutionContext context) {
@@ -204,19 +212,14 @@ private static Configuration loadConfiguration() {
     configuration.setObjectWrapper(objectWrapperBuilder.build());
 
     // Load inline templates
-    configuration.setTemplateLoader(new StringTemplateLoader());
+    configuration.setTemplateLoader(templateLoader);
 
     return configuration;
   }
 
   Template getTemplate(String template) throws IOException {
-    StringTemplateLoader loader = (StringTemplateLoader) templateConfiguration.getTemplateLoader();
     String hash = Sha1.sha1(template);
-    Object source = loader.findTemplateSource(hash);
-    if (source == null) {
-      loader.putTemplate(hash, template);
-    }
-
+    templateLoader.putIfAbsent(hash, template);
     return templateConfiguration.getTemplate(hash);
   }
 

src/main/java/io/gravitee/policy/metricsreporter/freemarker/CustomTemplateLoader.java

@@ -0,0 +1,106 @@
+/**
+ * Copyright (C) 2015 The Gravitee team (http://gravitee.io)
+ *
+ * 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 io.gravitee.policy.metricsreporter.freemarker;
+
+import com.google.common.cache.Cache;
+import com.google.common.cache.CacheBuilder;
+import freemarker.cache.TemplateLoader;
+import java.io.Reader;
+import java.io.StringReader;
+import java.time.Duration;
+import java.util.Objects;
+
+// Duplicated class for now, see https://github.com/gravitee-io/issues/issues/6857
+public class CustomTemplateLoader implements TemplateLoader {
+
+  /**
+   * Number of hours to keep script in cache after the last time it was accessed.
+   */
+  private static final int CACHE_EXPIRATION_HOURS = 1;
+
+  /**
+   * Max number of entries in the cache.
+   */
+  private static final int CACHE_MAXIMUM_SIZE = 1000;
+
+  private final Cache<Object, Object> templates = CacheBuilder
+    .newBuilder()
+    .maximumSize(CACHE_MAXIMUM_SIZE)
+    .expireAfterAccess(Duration.ofHours(CACHE_EXPIRATION_HOURS))
+    .build();
+
+  Cache<Object, Object> getCache() {
+    return templates;
+  }
+
+  @Override
+  public void closeTemplateSource(Object templateSource) {}
+
+  @Override
+  public Object findTemplateSource(String name) {
+    return templates.getIfPresent(name);
+  }
+
+  @Override
+  public long getLastModified(Object templateSource) {
+    return ((TemplateSource) templateSource).lastModified;
+  }
+
+  @Override
+  public Reader getReader(Object templateSource, String encoding) {
+    return new StringReader(((TemplateSource) templateSource).templateContent);
+  }
+
+  public void putIfAbsent(String name, String templateSource) {
+    if (templates.getIfPresent(name) == null) {
+      templates.put(
+        name,
+        new TemplateSource(name, templateSource, System.currentTimeMillis())
+      );
+    }
+  }
+
+  private static class TemplateSource {
+
+    private final String name;
+    private final String templateContent;
+    private final long lastModified;
+
+    TemplateSource(String name, String templateContent, long lastModified) {
+      this.name = name;
+      this.templateContent = templateContent;
+      this.lastModified = lastModified;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      if (this == o) return true;
+      if (o == null || getClass() != o.getClass()) return false;
+      TemplateSource that = (TemplateSource) o;
+      return Objects.equals(name, that.name);
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(name);
+    }
+
+    @Override
+    public String toString() {
+      return name;
+    }
+  }
+}