Clear the GroovyClassLoader cache before compiling

src/main/java/org/elasticsearch/script/NativeScriptEngineService.java

@@ -93,4 +93,9 @@ public Object unwrap(Object value) {
     @Override
     public void close() {
     }
+
+    @Override
+    public void scriptRemoved(CompiledScript script) {
+        // Nothing to do here
+    }
 }

src/main/java/org/elasticsearch/script/ScriptEngineService.java

@@ -46,4 +46,11 @@ public interface ScriptEngineService {
     Object unwrap(Object value);
 
     void close();
+
+    /**
+     * Handler method called when a script is removed from the Guava cache.
+     *
+     * The passed script may be null if it has already been garbage collected.
+     * */
+    void scriptRemoved(@Nullable CompiledScript script);
 }

src/main/java/org/elasticsearch/script/ScriptService.java

@@ -22,9 +22,12 @@
 import com.google.common.base.Charsets;
 import com.google.common.cache.Cache;
 import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.RemovalListener;
+import com.google.common.cache.RemovalNotification;
 import com.google.common.collect.ImmutableMap;
 import org.elasticsearch.ElasticsearchIllegalArgumentException;
 import org.elasticsearch.ElasticsearchIllegalStateException;
+import org.elasticsearch.ExceptionsHelper;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.delete.DeleteRequest;
 import org.elasticsearch.action.delete.DeleteResponse;
@@ -64,12 +67,15 @@
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
+import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.TimeUnit;
 
+import static com.google.common.collect.Lists.newArrayList;
+
 /**
  *
  */
@@ -206,7 +212,7 @@ public ScriptService(Settings settings, Environment env, Set<ScriptEngineService
                          ResourceWatcherService resourceWatcherService) {
         super(settings);
 
-        int cacheMaxSize = settings.getAsInt(SCRIPT_CACHE_SIZE_SETTING, 500);
+        int cacheMaxSize = settings.getAsInt(SCRIPT_CACHE_SIZE_SETTING, 100);
         TimeValue cacheExpire = settings.getAsTime(SCRIPT_CACHE_EXPIRE_SETTING, null);
         logger.debug("using script cache with max_size [{}], expire [{}]", cacheMaxSize, cacheExpire);
 
@@ -220,6 +226,7 @@ public ScriptService(Settings settings, Environment env, Set<ScriptEngineService
         if (cacheExpire != null) {
             cacheBuilder.expireAfterAccess(cacheExpire.nanos(), TimeUnit.NANOSECONDS);
         }
+        cacheBuilder.removalListener(new ScriptCacheRemovalListener());
         this.cache = cacheBuilder.build();
 
         ImmutableMap.Builder<String, ScriptEngineService> builder = ImmutableMap.builder();
@@ -483,6 +490,30 @@ private boolean dynamicScriptEnabled(String lang) {
         }
     }
 
+    /**
+     * A small listener for the script cache that calls each
+     * {@code ScriptEngineService}'s {@code scriptRemoved} method when the
+     * script has been removed from the cache
+     */
+    private class ScriptCacheRemovalListener implements RemovalListener<CacheKey, CompiledScript> {
+
+        @Override
+        public void onRemoval(RemovalNotification<CacheKey, CompiledScript> notification) {
+            if (logger.isDebugEnabled()) {
+                logger.debug("notifying script services of script removal due to: [{}]", notification.getCause());
+            }
+            List<Exception> errors = newArrayList();
+            for (ScriptEngineService service : scriptEngines.values()) {
+                try {
+                    service.scriptRemoved(notification.getValue());
+                } catch (Exception e) {
+                    errors.add(e);
+                }
+            }
+            ExceptionsHelper.maybeThrowRuntimeAndSuppress(errors);
+        }
+    }
+
     private class ScriptChangesListener extends FileChangesListener {
 
         private Tuple<String, String> scriptNameExt(File file) {

src/main/java/org/elasticsearch/script/expression/ExpressionScriptEngineService.java

@@ -33,6 +33,7 @@
 import org.elasticsearch.index.mapper.FieldMapper;
 import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.index.mapper.core.NumberFieldMapper;
+import org.elasticsearch.script.CompiledScript;
 import org.elasticsearch.script.ExecutableScript;
 import org.elasticsearch.script.ScriptEngineService;
 import org.elasticsearch.script.SearchScript;
@@ -154,4 +155,9 @@ public Object unwrap(Object value) {
 
     @Override
     public void close() {}
+
+    @Override
+    public void scriptRemoved(CompiledScript script) {
+        // Nothing to do
+    }
 }

src/main/java/org/elasticsearch/script/groovy/GroovyScriptEngineService.java

@@ -43,7 +43,6 @@
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.script.*;
 import org.elasticsearch.search.lookup.SearchLookup;
-import org.elasticsearch.search.suggest.term.TermSuggestion;
 
 import java.io.IOException;
 import java.math.BigDecimal;
@@ -89,6 +88,16 @@ public void close() {
         }
     }
 
+    @Override
+    public void scriptRemoved(@Nullable CompiledScript script) {
+        // script could be null, meaning the script has already been garbage collected
+        if (script == null || "groovy".equals(script.lang())) {
+            // Clear the cache, this removes old script versions from the
+            // cache to prevent running out of PermGen space
+            loader.clearCache();
+        }
+    }
+
     @Override
     public String[] types() {
         return new String[]{"groovy"};
@@ -313,4 +322,4 @@ public Expression transform(Expression expr) {
         }
     }
 
-}
+}

src/main/java/org/elasticsearch/script/mustache/MustacheScriptEngineService.java

@@ -26,6 +26,7 @@
 import org.elasticsearch.common.io.UTF8StreamWriter;
 import org.elasticsearch.common.io.stream.BytesStreamOutput;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.script.CompiledScript;
 import org.elasticsearch.script.ExecutableScript;
 import org.elasticsearch.script.ScriptEngineService;
 import org.elasticsearch.script.SearchScript;
@@ -148,6 +149,11 @@ public void close() {
         // Nothing to do here
     }
 
+    @Override
+    public void scriptRemoved(CompiledScript script) {
+        // Nothing to do here
+    }
+
     /**
      * Used at query execution time by script service in order to execute a query template.
      * */

src/test/java/org/elasticsearch/script/ScriptServiceTests.java

@@ -132,6 +132,11 @@ public Object unwrap(Object value) {
         public void close() {
 
         }
+
+        @Override
+        public void scriptRemoved(CompiledScript script) {
+            // Nothing to do here
+        }
     }
 
 }