Store raw responseBody and decompress when needed

.github/workflows/gradle-dependency-submit.yaml

@@ -12,6 +12,7 @@ permissions: read-all
 
 jobs:
   dependency-submission:
+    if: github.repository == 'apache/jmeter'
     name: Submit dependencies
     runs-on: ubuntu-latest
     permissions:

.github/workflows/gradle-wrapper-validation.yml

@@ -3,6 +3,7 @@ on: [push, pull_request]
 
 jobs:
   validation:
+    if: github.repository == 'apache/jmeter'
     name: "Validation"
     runs-on: ubuntu-latest
     steps:

.github/workflows/main.yml

@@ -1,5 +1,8 @@
 name: CI
 
+# Forks: skip all jobs (secrets, dependency graph, etc. are not fork-friendly).
+# PRs into apache/jmeter still run CI in the base repo, where github.repository is apache/jmeter.
+
 on:
   push:
     branches:
@@ -19,6 +22,7 @@ concurrency:
 
 jobs:
   matrix_prep:
+    if: github.repository == 'apache/jmeter'
     name: Matrix Preparation
     runs-on: ubuntu-latest
     outputs:
@@ -33,6 +37,7 @@ jobs:
           node .github/workflows/matrix.js
 
   test:
+    if: github.repository == 'apache/jmeter'
     needs: matrix_prep
     name: '${{ matrix.name }}'
     runs-on: ${{ matrix.os }}
@@ -89,6 +94,7 @@ jobs:
         DEVELOCITY_ACCESS_KEY: ${{ secrets.DEVELOCITY_ACCESS_KEY }}
 
   errorprone:
+    if: github.repository == 'apache/jmeter'
     name: 'Error Prone (JDK 21)'
     runs-on: ubuntu-latest
     steps:

.github/workflows/release-drafter.yml

@@ -13,8 +13,8 @@ permissions: read-all
 
 jobs:
   update_release_draft:
-    # Skip release drafts in forks
-    if: vars.RUN_RELEASE_DRAFTER == 'true'
+    # Skip outside apache/jmeter; on Apache, opt-in via repo variable.
+    if: github.repository == 'apache/jmeter' && vars.RUN_RELEASE_DRAFTER == 'true'
     name: Update Release Draft
     runs-on: ubuntu-latest
     permissions:

.gitignore

@@ -5,6 +5,15 @@
 /buildSrc/subprojects/*/build/
 /buildSrc/subprojects/*/bin/
 /buildSrc/subprojects/*/out/
+# Included Gradle build logic: ignore outputs only (sources under build-logic* must stay tracked)
+/build-logic/build/
+/build-logic/*/build/
+/build-logic/*/bin/
+/build-logic/*/out/
+/build-logic-commons/build/
+/build-logic-commons/*/build/
+/build-logic-commons/*/bin/
+/build-logic-commons/*/out/
 /src/build/
 /src/bin/
 /src/out/
@@ -49,9 +58,13 @@
 .pmd
 .project
 .settings
+.metals
+.vscode
 
 # bin/ folder is used to launch JMeter, so we ignore certain files there
 /bin/ApacheJMeter.jar
+# Local JMeter Plugins Manager CLI wrappers (not part of Apache distribution)
+/bin/PluginsManagerCMD.*
 # Below are the results of "batch test" execution
 /bin/*.csv
 /bin/*.jmx
@@ -63,6 +76,8 @@
 
 build-local.properties
 jmeter-fb.*
+# Local packaging script output (see create_jmeter_archive.sh)
+/jmeter_*.tgz
 
 # ignore generated keystore and certs
 /bin/proxyserver.jks

bin/jmeter.properties

@@ -1173,6 +1173,18 @@ cookies=cookies
 
 # How often to check for shutdown during ramp-up (milliseconds)
 #jmeterthread.rampup.granularity=1000
+# How often to check for shutdown during timer delay (milliseconds)
+#jmeterthread.timer.granularity=1000
+
+# Enable Java 21 Virtual Threads for JMeter threads
+# When enabled, virtual user threads use lightweight virtual threads instead of platform threads
+# Benefits: Lower memory per thread, better I/O scalability for high thread counts
+# Requires: Java 21+ (automatically falls back to platform threads on older Java versions)
+# Default: true
+jmeter.threads.virtual.enabled=true
+
+# Whether to enable lightweight clone for test elements to preserve memory. Disable when running tests with complex scenarios with variables.
+#jmeter.clone.lightweight.enabled=true
 
 #Should JMeter expand the tree when loading a test plan?
 # default value is false since JMeter 2.7

build-logic/verification/src/main/kotlin/build-logic.autostyle.gradle.kts

@@ -101,7 +101,12 @@ plugins.withId("org.jetbrains.kotlin.jvm") {
         kotlin {
             license()
             trimTrailingWhitespace()
-            ktlint("0.40.0")
+            ktlint("0.40.0") {
+                filter {
+                    // TODO: remove exclusion when update ktlint
+                    exclude("**/org/apache/jorphan/locale/PlainValue.kt")
+                }
+            }
             endWithNewline()
         }
     }

create_jmeter_archive.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+
+# Script to create a compressed tar archive of bin and lib directories
+# Excludes bin/examples and bin/testfiles
+# Archives files under apache-jmeter/ directory
+
+# Generate datetime string in format YYYYMMDD_HHMMSS
+DATETIME=$(date +%Y%m%d_%H%M%S)
+
+# Archive name
+ARCHIVE_NAME="jmeter_${DATETIME}.tgz"
+
+# Create temporary directory
+TEMP_DIR=$(mktemp -d)
+trap "rm -rf ${TEMP_DIR}" EXIT
+
+# Create apache-jmeter directory structure
+mkdir -p "${TEMP_DIR}/apache-jmeter"
+
+# Copy bin directory excluding examples and testfiles
+# Using rsync for better exclusion control
+rsync -av --exclude='examples' --exclude='testfiles' \
+    bin/ "${TEMP_DIR}/apache-jmeter/bin/"
+
+# Copy lib directory
+cp -R lib "${TEMP_DIR}/apache-jmeter/"
+
+# Create the archive from temp directory
+# -C: change to directory before archiving
+# -c: create archive
+# -z: compress with gzip
+# -f: specify filename
+tar -czf "${ARCHIVE_NAME}" -C "${TEMP_DIR}" apache-jmeter
+
+# Check if tar command succeeded
+if [ $? -eq 0 ]; then
+    echo "Successfully created archive: ${ARCHIVE_NAME}"
+    # Show archive size
+    ls -lh "${ARCHIVE_NAME}"
+else
+    echo "Error: Failed to create archive"
+    exit 1
+fi

src/components/src/main/java/org/apache/jmeter/config/CSVDataSet.java

@@ -32,7 +32,7 @@
 import org.apache.jmeter.threads.JMeterContext;
 import org.apache.jmeter.threads.JMeterVariables;
 import org.apache.jmeter.util.JMeterUtils;
-import org.apache.jorphan.util.EnumUtils;
+import org.apache.jorphan.locale.ResourceKeyed;
 import org.apache.jorphan.util.JMeterStopThreadException;
 import org.apache.jorphan.util.JOrphanUtils;
 import org.apache.jorphan.util.StringUtilities;
@@ -70,20 +70,20 @@
 public class CSVDataSet extends ConfigTestElement
     implements TestBean, LoopIterationListener, NoConfigMerge {
 
-    public enum ShareMode {
+    public enum ShareMode implements ResourceKeyed {
         ALL("shareMode.all"),
         GROUP("shareMode.group"),
         THREAD("shareMode.thread");
 
-        private final String value;
+        private final String propertyName;
 
-        ShareMode(String value) {
-            this.value = value;
+        ShareMode(String propertyName) {
+            this.propertyName = propertyName;
         }
 
         @Override
-        public String toString() {
-            return value;
+        public String getResourceKey() {
+            return propertyName;
         }
     }
 

src/components/src/main/java/org/apache/jmeter/timers/ConstantThroughputTimer.java

@@ -32,6 +32,7 @@
 import org.apache.jmeter.threads.JMeterContextService;
 import org.apache.jmeter.util.JMeterUtils;
 import org.apache.jorphan.collections.IdentityKey;
+import org.apache.jorphan.locale.ResourceKeyed;
 import org.apache.jorphan.util.EnumUtils;
 import org.apiguardian.api.API;
 
@@ -71,7 +72,7 @@ private static class ThroughputInfo{
     /**
      * This enum defines the calculation modes used by the ConstantThroughputTimer.
      */
-    public enum Mode {
+    public enum Mode implements ResourceKeyed {
         ThisThreadOnly("calcMode.1"), // NOSONAR Keep naming for compatibility
         AllActiveThreads("calcMode.2"), // NOSONAR Keep naming for compatibility
         AllActiveThreadsInCurrentThreadGroup("calcMode.3"), // NOSONAR Keep naming for compatibility
@@ -89,6 +90,11 @@ public enum Mode {
         public String toString() {
             return propertyName;
         }
+
+        @Override
+        public String getResourceKey() {
+            return propertyName;
+        }
     }
 
     /**
@@ -161,15 +167,13 @@ public Mode getMode() {
     }
 
     @Deprecated
-    @SuppressWarnings("EnumOrdinal")
     public void setCalcMode(int mode) {
-        setMode(EnumUtils.values(Mode.class).get(mode));
+        setMode(EnumUtils.getEnumValues(Mode.class).get(mode));
     }
 
-    @SuppressWarnings("EnumOrdinal")
     @API(status = API.Status.MAINTAINED, since = "6.0.0")
     public void setMode(Mode newMode) {
-        getSchema().getCalcMode().set(this, newMode.toString());
+        getSchema().getCalcMode().set(this, newMode.getResourceKey());
     }
 
     /**

src/core/build.gradle.kts

@@ -111,6 +111,7 @@ dependencies {
         isTransitive = false
     }
     implementation("org.apache.xmlgraphics:xmlgraphics-commons")
+    implementation("org.brotli:dec")
     implementation("org.freemarker:freemarker")
     implementation("org.jodd:jodd-core")
     implementation("org.jodd:jodd-props")

src/core/src/main/java/org/apache/jmeter/config/ConfigTestElement.java

@@ -19,11 +19,20 @@
 
 import java.io.Serializable;
 
+import org.apache.jmeter.engine.util.LightweightClone;
 import org.apache.jmeter.testelement.AbstractTestElement;
 import org.apache.jmeter.testelement.TestElement;
 import org.apache.jmeter.testelement.schema.PropertiesAccessor;
 
-public class ConfigTestElement extends AbstractTestElement implements Serializable, ConfigElement {
+/**
+ * Base class for configuration elements that can share properties across threads.
+ * <p>
+ * ConfigTestElements implementing {@link LightweightClone} will only use lightweight
+ * cloning if they have no properties containing JMeter variables (${...}) or functions (__()).
+ * This provides significant memory savings for elements like HeaderManager with static data.
+ * </p>
+ */
+public class ConfigTestElement extends AbstractTestElement implements Serializable, ConfigElement, LightweightClone {
     private static final long serialVersionUID = 240L;
 
     public static final String USERNAME = "ConfigTestElement.username";

src/core/src/main/java/org/apache/jmeter/control/gui/TestPlanGui.java

@@ -57,17 +57,20 @@ public class TestPlanGui extends AbstractJMeterGuiComponent {
     private final JBooleanPropertyEditor functionalMode =
             new JBooleanPropertyEditor(
                     TestPlanSchema.INSTANCE.getFunctionalMode(),
-                    JMeterUtils.getResString("functional_mode"));
+                    "functional_mode",
+                    JMeterUtils::getResString);
 
     private final JBooleanPropertyEditor serializedMode =
             new JBooleanPropertyEditor(
                     TestPlanSchema.INSTANCE.getSerializeThreadgroups(),
-                    JMeterUtils.getResString("testplan.serialized"));
+                    "testplan.serialized",
+                    JMeterUtils::getResString);
 
     private final JBooleanPropertyEditor tearDownOnShutdown =
             new JBooleanPropertyEditor(
                     TestPlanSchema.INSTANCE.getTearDownOnShutdown(),
-                    JMeterUtils.getResString("teardown_on_shutdown"));
+                    "teardown_on_shutdown",
+                    JMeterUtils::getResString);
 
     /** A panel allowing the user to define variables. */
     private final ArgumentsPanel argsPanel;

src/core/src/main/java/org/apache/jmeter/control/gui/TransactionControllerGui.java

@@ -39,13 +39,15 @@ public class TransactionControllerGui extends AbstractControllerGui {
     private final JBooleanPropertyEditor generateParentSample =
             new JBooleanPropertyEditor(
                     TransactionControllerSchema.INSTANCE.getGenearteParentSample(),
-                    JMeterUtils.getResString("transaction_controller_parent"));
+                    "transaction_controller_parent",
+                    JMeterUtils::getResString);
 
     /** if selected, add duration of timers to total runtime */
     private final JBooleanPropertyEditor includeTimers =
             new JBooleanPropertyEditor(
                     TransactionControllerSchema.INSTANCE.getIncludeTimers(),
-                    JMeterUtils.getResString("transaction_controller_include_timers"));
+                    "transaction_controller_parent",
+                    JMeterUtils::getResString);
 
     /**
      * Create a new TransactionControllerGui instance.

src/core/src/main/java/org/apache/jmeter/engine/TreeCloner.java

@@ -20,17 +20,28 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import org.apache.jmeter.engine.util.LightweightClone;
 import org.apache.jmeter.engine.util.NoThreadClone;
+import org.apache.jmeter.testelement.AbstractTestElement;
 import org.apache.jmeter.testelement.TestElement;
+import org.apache.jmeter.util.JMeterUtils;
 import org.apache.jorphan.collections.HashTree;
 import org.apache.jorphan.collections.HashTreeTraverser;
 import org.apache.jorphan.collections.ListedHashTree;
 
 /**
  * Clones the test tree,  skipping test elements that implement {@link NoThreadClone} by default.
+ * Elements implementing {@link LightweightClone} will share properties instead of deep cloning.
  */
 public class TreeCloner implements HashTreeTraverser {
 
+    /**
+     * Property to enable/disable lightweight cloning for LightweightClone elements.
+     * Can be disabled by setting {@code jmeter.clone.lightweight.enabled=false} in jmeter.properties.
+     */
+    private static final boolean LIGHTWEIGHT_CLONE_ENABLED =
+            JMeterUtils.getPropDefault("jmeter.clone.lightweight.enabled", true);
+
     private final ListedHashTree newTree;
 
     private final List<Object> objects = new ArrayList<>();
@@ -80,6 +91,8 @@ protected Object addNodeToTree(Object node) {
             newTree.add(objects, node);
             return node;
         }
+        newTree.add(objects, node);
+        return node;
     }
 
     /**