--- /mnt/c/cbrethes/dev/sandbox/PluginManager.java	2018-11-25 21:59:38.000000000 +0100
+++ /mnt/c/cbrethes/dev/sandbox/apache-log4j-2.11.2-src/log4j-core/src/main/java/org/apache/logging/log4j/core/config/plugins/util/PluginManager.java	2019-02-18 16:07:53.932305500 +0100
@@ -21,6 +21,7 @@
 import org.apache.logging.log4j.status.StatusLogger;
 import org.apache.logging.log4j.util.Strings;
 
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -35,11 +36,14 @@
 
     private static final CopyOnWriteArrayList<String> PACKAGES = new CopyOnWriteArrayList<>();
     private static final String LOG4J_PACKAGES = "org.apache.logging.log4j.core";
-
+    private static final String LOG4J_PLUGIN_PACKAGES_PROPERTY="log4j.plugin.packages" ;
+    private static final CopyOnWriteArrayList<String> PROPERTY_PACKAGES = new CopyOnWriteArrayList<>();
     private static final Logger LOGGER = StatusLogger.getLogger();
 
     private Map<String, PluginType<?>> plugins = new HashMap<>();
     private final String category;
+    //just a boolean to know if system property  if log4j.plugin.packages has been processed
+	private static Boolean pluginSystemPropertiesHandled = false ;
 
     /**
      * Constructs a PluginManager for the plugin category name given.
@@ -141,7 +145,28 @@
         for (final Map<String, List<PluginType<?>>> pluginsByCategory : PluginRegistry.getInstance().getPluginsByCategoryByBundleId().values()) {
             mergeByName(newPlugins, pluginsByCategory.get(categoryLowerCase));
         }
-
+        // load packages defined by system property log4j.plugin.packages        
+        if( ! pluginSystemPropertiesHandled ) {
+        	synchronized (pluginSystemPropertiesHandled) {
+        		//clear in case of synchronization issue has we synchronized inside if to avoid too many synchronization
+        		PROPERTY_PACKAGES.clear();
+            	final String pluginPackagesStr = System.getProperty(LOG4J_PLUGIN_PACKAGES_PROPERTY);
+            	if (pluginPackagesStr != null && pluginPackagesStr.trim().length()>1) {
+            		if(pluginPackagesStr.indexOf(',')>0) {
+            			PluginManager.PROPERTY_PACKAGES.addAll(Arrays.asList(pluginPackagesStr.split(",")));
+            		}
+            		else {
+            			PluginManager.PROPERTY_PACKAGES.add(pluginPackagesStr);
+            		}
+            	}
+            	pluginSystemPropertiesHandled = Boolean.TRUE ; 
+			}
+        }
+        // Next, iterate any package defined by system property log4j.plugin.packages
+        for (final String pkg : PROPERTY_PACKAGES) {
+            mergeByName(newPlugins, PluginRegistry.getInstance().loadFromPackage(pkg).get(categoryLowerCase));
+        }
+        
         // Next iterate any packages passed to the static addPackage method.
         for (final String pkg : PACKAGES) {
             mergeByName(newPlugins, PluginRegistry.getInstance().loadFromPackage(pkg).get(categoryLowerCase));