[Rejected] Add support for Java Extension Class Loader.

.github/workflows/plugins-jdk14-test.0.yaml

@@ -62,8 +62,9 @@ jobs:
       - uses: actions/checkout@v2
         with:
           submodules: true
-      - uses: actions/setup-java@v1
+      - uses: actions/setup-java@v2
         with:
+          distribution: 'temurin'
           java-version: 14
       - name: Run Test
         uses: ./.github/actions/run

.github/workflows/plugins-test.0.yaml

@@ -90,8 +90,9 @@ jobs:
       - uses: actions/checkout@v2
         with:
           submodules: true
-      - uses: actions/setup-java@v1
+      - uses: actions/setup-java@v2
         with:
+          distribution: 'temurin'
           java-version: 8
       - name: Run Plugin Test
         uses: ./.github/actions/run

.github/workflows/plugins-test.1.yaml

@@ -81,8 +81,9 @@ jobs:
       - uses: actions/checkout@v2
         with:
           submodules: true
-      - uses: actions/setup-java@v1
+      - uses: actions/setup-java@v2
         with:
+          distribution: 'temurin'
           java-version: 8
       - name: Run Plugin Test
         uses: ./.github/actions/run

.github/workflows/plugins-test.2.yaml

@@ -83,8 +83,9 @@ jobs:
       - uses: actions/checkout@v2
         with:
           submodules: true
-      - uses: actions/setup-java@v1
+      - uses: actions/setup-java@v2
         with:
+          distribution: 'temurin'
           java-version: 8
       - name: Run Plugin Test
         uses: ./.github/actions/run

.github/workflows/plugins-test.3.yaml

@@ -92,13 +92,15 @@ jobs:
           - hikaricp-scenario
           - clickhouse-0.3.x-scenario
           - kylin-jdbc-2.6.x-3.x-4.x-scenario
+          - extclassloader-scenario
     steps:
       - uses: actions/checkout@v2
         with:
           submodules: true
-      - uses: actions/setup-java@v1
+      - uses: actions/setup-java@v2
         with:
           java-version: 8
+          distribution: 'temurin'
       - name: Install Oracle Libs
         if: matrix.case == 'oracle-scenario'
         run: |

CHANGES.md

@@ -5,6 +5,7 @@ Release Notes.
 8.9.0
 ------------------
 
+* Add support for Java Extension Class Loader.
 * Support `Transaction` and fix duplicated methods enhancements for `jedis-2.x` plugin.
 
 #### Documentation

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/Config.java

@@ -18,10 +18,6 @@
 
 package org.apache.skywalking.apm.agent.core.conf;
 
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
 import org.apache.skywalking.apm.agent.core.context.trace.TraceSegment;
 import org.apache.skywalking.apm.agent.core.logging.core.LogLevel;
 import org.apache.skywalking.apm.agent.core.logging.core.LogOutput;
@@ -30,6 +26,11 @@
 import org.apache.skywalking.apm.agent.core.plugin.bytebuddy.ClassCacheMode;
 import org.apache.skywalking.apm.util.Length;
 
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
 /**
  * This is the core config in sniffer agent.
  */
@@ -342,6 +343,13 @@ public static class Plugin {
          * Mount the folders of the plugins. The folder path is relative to agent.jar.
          */
         public static List<String> MOUNT = Arrays.asList("plugins", "activations");
+
+
+        /**
+         * Multiple values should be separated by `,`.
+         * Support wildcard "*",like "ehcache*"
+         */
+        public static String PLUGINS_IN_EXT_CLASS_LOADER = "";
     }
 
     public static class Correlation {

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/AbstractClassEnhancePluginDefine.java

@@ -48,6 +48,8 @@ public abstract class AbstractClassEnhancePluginDefine {
      */
     public static final String CONTEXT_ATTR_NAME = "_$EnhancedClassField_ws";
 
+    private boolean isExtClassLoaderLoaded = false;
+
     /**
      * Main entrance of enhancing the class.
      *
@@ -166,6 +168,14 @@ public boolean isBootstrapInstrumentation() {
         return false;
     }
 
+    public boolean isExtClassLoaderLoaded() {
+        return isExtClassLoaderLoaded;
+    }
+
+    public void setExtClassLoaderLoaded(boolean isExtClassLoaderLoaded) {
+        this.isExtClassLoaderLoaded = isExtClassLoaderLoaded;
+    }
+
     /**
      * Constructor methods intercept point. See {@link ConstructorInterceptPoint}
      *

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginBootstrap.java

@@ -18,13 +18,14 @@
 
 package org.apache.skywalking.apm.agent.core.plugin;
 
-import java.net.URL;
-import java.util.ArrayList;
-import java.util.List;
 import org.apache.skywalking.apm.agent.core.boot.AgentPackageNotFoundException;
-import org.apache.skywalking.apm.agent.core.plugin.loader.AgentClassLoader;
 import org.apache.skywalking.apm.agent.core.logging.api.ILog;
 import org.apache.skywalking.apm.agent.core.logging.api.LogManager;
+import org.apache.skywalking.apm.agent.core.plugin.loader.AgentClassLoader;
+
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Plugins finder. Use {@link PluginResourcesResolver} to find all plugins, and ask {@link PluginCfg} to load all plugin
@@ -59,17 +60,7 @@ public List<AbstractClassEnhancePluginDefine> loadPlugins() throws AgentPackageN
 
         List<PluginDefine> pluginClassList = PluginCfg.INSTANCE.getPluginClassList();
 
-        List<AbstractClassEnhancePluginDefine> plugins = new ArrayList<AbstractClassEnhancePluginDefine>();
-        for (PluginDefine pluginDefine : pluginClassList) {
-            try {
-                LOGGER.debug("loading plugin class {}.", pluginDefine.getDefineClass());
-                AbstractClassEnhancePluginDefine plugin = (AbstractClassEnhancePluginDefine) Class.forName(pluginDefine.getDefineClass(), true, AgentClassLoader
-                    .getDefault()).newInstance();
-                plugins.add(plugin);
-            } catch (Throwable t) {
-                LOGGER.error(t, "load plugin [{}] failure.", pluginDefine.getDefineClass());
-            }
-        }
+        List<AbstractClassEnhancePluginDefine> plugins = PluginCreator.create(pluginClassList);
 
         plugins.addAll(DynamicPluginLoader.INSTANCE.load(AgentClassLoader.getDefault()));
 

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginCreator.java

@@ -0,0 +1,64 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.skywalking.apm.agent.core.plugin;
+
+import org.apache.skywalking.apm.agent.core.conf.Config;
+import org.apache.skywalking.apm.agent.core.logging.api.ILog;
+import org.apache.skywalking.apm.agent.core.logging.api.LogManager;
+import org.apache.skywalking.apm.agent.core.plugin.loader.AgentClassLoader;
+import org.apache.skywalking.apm.util.StringUtil;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Pattern;
+
+/**
+ * The creator of AbstractClassEnhancePluginDefine instance according to {@link PluginDefine} and agent.config
+ */
+public class PluginCreator {
+
+    private static final ILog LOGGER = LogManager.getLogger(PluginCreator.class);
+
+    public static List<AbstractClassEnhancePluginDefine> create(List<PluginDefine> pluginDefines) {
+        String pluginMatchRule = Config.Plugin.PLUGINS_IN_EXT_CLASS_LOADER;
+        Pattern extLoadPluginMatchPattern = null;
+        if (StringUtil.isNotEmpty(pluginMatchRule)) {
+            extLoadPluginMatchPattern = Pattern.compile(pluginMatchRule.replace(",", "|")
+                                                                       .replace("*", ".*"));
+        }
+        List<AbstractClassEnhancePluginDefine> plugins = new ArrayList<>();
+        for (PluginDefine pluginDefine : pluginDefines) {
+            LOGGER.debug("loading plugin class {}.", pluginDefine.getDefineClass());
+            try {
+                AbstractClassEnhancePluginDefine pluginDefineInstance =
+                    (AbstractClassEnhancePluginDefine) Class.forName(
+                        pluginDefine.getDefineClass(), true, AgentClassLoader.getDefault()).newInstance();
+                if (extLoadPluginMatchPattern != null && extLoadPluginMatchPattern.matcher(pluginDefine.getName())
+                                                                                  .matches()) {
+                    pluginDefineInstance.setExtClassLoaderLoaded(true);
+                }
+                plugins.add(pluginDefineInstance);
+            } catch (Throwable t) {
+                LOGGER.error(t, "load plugin [{}] failure.", pluginDefine.getDefineClass());
+            }
+        }
+
+        return plugins;
+    }
+}

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginFinder.java

@@ -42,7 +42,7 @@
 public class PluginFinder {
     private final Map<String, LinkedList<AbstractClassEnhancePluginDefine>> nameMatchDefine = new HashMap<String, LinkedList<AbstractClassEnhancePluginDefine>>();
     private final List<AbstractClassEnhancePluginDefine> signatureMatchDefine = new ArrayList<AbstractClassEnhancePluginDefine>();
-    private final List<AbstractClassEnhancePluginDefine> bootstrapClassMatchDefine = new ArrayList<AbstractClassEnhancePluginDefine>();
+    private final List<AbstractClassEnhancePluginDefine> bootstrapClassAndExtClassMatchDefine = new ArrayList<AbstractClassEnhancePluginDefine>();
 
     public PluginFinder(List<AbstractClassEnhancePluginDefine> plugins) {
         for (AbstractClassEnhancePluginDefine plugin : plugins) {
@@ -64,8 +64,8 @@ public PluginFinder(List<AbstractClassEnhancePluginDefine> plugins) {
                 signatureMatchDefine.add(plugin);
             }
 
-            if (plugin.isBootstrapInstrumentation()) {
-                bootstrapClassMatchDefine.add(plugin);
+            if (plugin.isBootstrapInstrumentation() || plugin.isExtClassLoaderLoaded()) {
+                bootstrapClassAndExtClassMatchDefine.add(plugin);
             }
         }
     }
@@ -104,7 +104,7 @@ public boolean matches(NamedElement target) {
         return new ProtectiveShieldMatcher(judge);
     }
 
-    public List<AbstractClassEnhancePluginDefine> getBootstrapClassMatchDefine() {
-        return bootstrapClassMatchDefine;
+    public List<AbstractClassEnhancePluginDefine> getBootstrapClassAndExtClassMatchDefine() {
+        return bootstrapClassAndExtClassMatchDefine;
     }
 }

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/bootstrap/BootstrapInstrumentBoost.java

@@ -156,7 +156,7 @@ public static Class forInternalDelegateClass(String methodsInterceptor) {
     private static boolean prepareJREInstrumentation(PluginFinder pluginFinder,
         Map<String, byte[]> classesTypeMap) throws PluginException {
         TypePool typePool = TypePool.Default.of(BootstrapInstrumentBoost.class.getClassLoader());
-        List<AbstractClassEnhancePluginDefine> bootstrapClassMatchDefines = pluginFinder.getBootstrapClassMatchDefine();
+        List<AbstractClassEnhancePluginDefine> bootstrapClassMatchDefines = pluginFinder.getBootstrapClassAndExtClassMatchDefine();
         for (AbstractClassEnhancePluginDefine define : bootstrapClassMatchDefines) {
             if (Objects.nonNull(define.getInstanceMethodsInterceptPoints())) {
                 for (InstanceMethodsInterceptPoint point : define.getInstanceMethodsInterceptPoints()) {
@@ -197,7 +197,7 @@ private static boolean prepareJREInstrumentation(PluginFinder pluginFinder,
     private static boolean prepareJREInstrumentationV2(PluginFinder pluginFinder,
                                                        Map<String, byte[]> classesTypeMap) throws PluginException {
         TypePool typePool = TypePool.Default.of(BootstrapInstrumentBoost.class.getClassLoader());
-        List<AbstractClassEnhancePluginDefine> bootstrapClassMatchDefines = pluginFinder.getBootstrapClassMatchDefine();
+        List<AbstractClassEnhancePluginDefine> bootstrapClassMatchDefines = pluginFinder.getBootstrapClassAndExtClassMatchDefine();
         for (AbstractClassEnhancePluginDefine define : bootstrapClassMatchDefines) {
             if (Objects.nonNull(define.getInstanceMethodsInterceptV2Points())) {
                 for (InstanceMethodsInterceptV2Point point : define.getInstanceMethodsInterceptV2Points()) {

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassEnhancePluginDefine.java

@@ -151,7 +151,7 @@ protected DynamicType.Builder<?> enhanceInstance(TypeDescription typeDescription
                                                                                     .to(new InstMethodsInterWithOverrideArgs(interceptor, classLoader)));
                     }
                 } else {
-                    if (isBootstrapInstrumentation()) {
+                    if (isBootstrapInstrumentation() || isExtClassLoaderLoaded()) {
                         newClassBuilder = newClassBuilder.method(junction)
                                                          .intercept(MethodDelegation.withDefaultConfiguration()
                                                                                     .to(BootstrapInstrumentBoost.forInternalDelegateClass(interceptor)));
@@ -189,7 +189,7 @@ protected DynamicType.Builder<?> enhanceClass(TypeDescription typeDescription, D
             }
 
             if (staticMethodsInterceptPoint.isOverrideArgs()) {
-                if (isBootstrapInstrumentation()) {
+                if (isBootstrapInstrumentation() || isExtClassLoaderLoaded()) {
                     newClassBuilder = newClassBuilder.method(isStatic().and(staticMethodsInterceptPoint.getMethodsMatcher()))
                                                      .intercept(MethodDelegation.withDefaultConfiguration()
                                                                                 .withBinders(Morph.Binder.install(OverrideCallable.class))
@@ -201,7 +201,7 @@ protected DynamicType.Builder<?> enhanceClass(TypeDescription typeDescription, D
                                                                                 .to(new StaticMethodsInterWithOverrideArgs(interceptor)));
                 }
             } else {
-                if (isBootstrapInstrumentation()) {
+                if (isBootstrapInstrumentation() || isExtClassLoaderLoaded()) {
                     newClassBuilder = newClassBuilder.method(isStatic().and(staticMethodsInterceptPoint.getMethodsMatcher()))
                                                      .intercept(MethodDelegation.withDefaultConfiguration()
                                                                                 .to(BootstrapInstrumentBoost.forInternalDelegateClass(interceptor)));

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/v2/ClassEnhancePluginDefineV2.java

@@ -73,7 +73,7 @@ protected DynamicType.Builder<?> enhanceClass(TypeDescription typeDescription,
             }
 
             if (staticMethodsInterceptV2Point.isOverrideArgs()) {
-                if (isBootstrapInstrumentation()) {
+                if (isBootstrapInstrumentation() || isExtClassLoaderLoaded()) {
                     newClassBuilder = newClassBuilder.method(
                         isStatic().and(staticMethodsInterceptV2Point.getMethodsMatcher()))
                                                      .intercept(MethodDelegation.withDefaultConfiguration()
@@ -87,7 +87,7 @@ protected DynamicType.Builder<?> enhanceClass(TypeDescription typeDescription,
                                                                                 .to(new StaticMethodsInterV2WithOverrideArgs(interceptor)));
                 }
             } else {
-                if (isBootstrapInstrumentation()) {
+                if (isBootstrapInstrumentation() || isExtClassLoaderLoaded()) {
                     newClassBuilder = newClassBuilder.method(
                         isStatic().and(staticMethodsInterceptV2Point.getMethodsMatcher()))
                                                      .intercept(MethodDelegation.withDefaultConfiguration()
@@ -165,7 +165,7 @@ protected DynamicType.Builder<?> enhanceInstance(TypeDescription typeDescription
                     junction = junction.and(ElementMatchers.<MethodDescription>isDeclaredBy(typeDescription));
                 }
                 if (instanceMethodsInterceptV2Point.isOverrideArgs()) {
-                    if (isBootstrapInstrumentation()) {
+                    if (isBootstrapInstrumentation() || isExtClassLoaderLoaded()) {
                         newClassBuilder = newClassBuilder.method(junction)
                                                          .intercept(MethodDelegation.withDefaultConfiguration()
                                                                                     .withBinders(Morph.Binder.install(OverrideCallable.class))
@@ -177,7 +177,7 @@ protected DynamicType.Builder<?> enhanceInstance(TypeDescription typeDescription
                                                                                     .to(new InstMethodsInterV2WithOverrideArgs(interceptor, classLoader)));
                     }
                 } else {
-                    if (isBootstrapInstrumentation()) {
+                    if (isBootstrapInstrumentation() || isExtClassLoaderLoaded()) {
                         newClassBuilder = newClassBuilder.method(junction)
                                                          .intercept(MethodDelegation.withDefaultConfiguration()
                                                                                     .to(BootstrapInstrumentBoost.forInternalDelegateClass(interceptor)));

apm-sniffer/config/agent.config

@@ -171,6 +171,8 @@ plugin.mount=${SW_MOUNT_FOLDERS:plugins,activations}
 plugin.peer_max_length=${SW_PLUGIN_PEER_MAX_LENGTH:200}
 # Exclude some plugins define in plugins dir.Plugin names is defined in [Agent plugin list](Plugin-list.md)
 plugin.exclude_plugins=${SW_EXCLUDE_PLUGINS:}
+# Declare which plugins are for excClassloader.Multiple values should be separated by ",". Support wildcard "*",like "ehcache*".The plugin names are defined in [Agent plugin list](Plugin-list.md)
+plugin.plugins_in_ext_class_loader=${SW_PLUGINS_IN_EXT_CLASS_LOADER:}
 # If true, trace all the parameters in MongoDB access, default is false. Only trace the operation, not include parameters.
 plugin.mongodb.trace_param=${SW_PLUGIN_MONGODB_TRACE_PARAM:false}
 # If set to positive number, the `WriteRequest.params` would be truncated to this length, otherwise it would be completely saved, which may cause performance problem.

docs/en/setup/service-agent/java-agent/Extension-classloader.md

@@ -0,0 +1,7 @@
+## Extension ClassLoader
+**Extension ClassLoader**: The Extension ClassLoader is a child of Bootstrap ClassLoader and loads the extensions of core java classes from the respective JDK Extension library.
+It loads files from jre/lib/ext directory or any other directory pointed by the system property java.ext.dirs.
+User decides which parts of the service should be loaded by the extension classloader, so, we open `plugin.plugins_in_ext_class_loader=${SW_PLUGINS_IN_EXT_CLASS_LOADER:}` in the `agent.config` file.
+
+Through this setting, users declare plugins are for excClassloader. Multiple values should be separated by ",".
+Also support wildcard(`\*`),like `ehcache\*`. All plugin names are defined in [Agent plugin list](Plugin-list.md)

docs/en/setup/service-agent/java-agent/README.md

@@ -77,4 +77,5 @@ active it.
 - All plugins in `/plugins` folder are active. Remove the plugin jar, it disabled.
 - The default logging output folder is `/logs`.
 
-
+If you are using `Extension ClassLoader` for Java services, please refer
+to [Extension ClassLoader Setup](Extension-classloader.md) doc for more details.

docs/en/setup/service-agent/java-agent/configurations.md

@@ -60,6 +60,7 @@ property key | Description | Default |
 `plugin.mount` | Mount the specific folders of the plugins. Plugins in mounted folders would work. | `plugins,activations` |
 `plugin.peer_max_length `|Peer maximum description limit.|`200`|
 `plugin.exclude_plugins `|Exclude some plugins define in plugins dir.Plugin names is defined in [Agent plugin list](Plugin-list.md)|`""`|
+`plugin.plugins_in_ext_class_loader `|Declare which plugins are for excClassloader.Multiple values should be separated by ",". Support wildcard "\*",like "ehcache\*".The plugin names are defined in [Agent plugin list](Plugin-list.md)|`""`|
 `plugin.mongodb.trace_param`|If true, trace all the parameters in MongoDB access, default is false. Only trace the operation, not include parameters.|`false`|
 `plugin.mongodb.filter_length_limit`|If set to positive number, the `WriteRequest.params` would be truncated to this length, otherwise it would be completely saved, which may cause performance problem.|`256`|
 `plugin.elasticsearch.trace_dsl`|If true, trace all the DSL(Domain Specific Language) in ElasticSearch access, default is false.|`false`|