[GitHub] keith-turner commented on a change in pull request #560: Provide new Crypto interface & impl

[GitBox <gi...@apache.org>]

keith-turner commented on a change in pull request #560: Provide new Crypto interface & impl
URL: https://github.com/apache/accumulo/pull/560#discussion_r207218228
 
 

 ##########
 File path: core/src/main/java/org/apache/accumulo/core/security/crypto/CryptoServiceFactory.java
 ##########
 @@ -0,0 +1,54 @@
+/*
+ * 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.accumulo.core.security.crypto;
+
+import org.apache.accumulo.core.conf.AccumuloConfiguration;
+import org.apache.accumulo.core.conf.Property;
+import org.apache.accumulo.core.spi.crypto.CryptoService;
+import org.apache.accumulo.core.spi.crypto.CryptoService.CryptoException;
+import org.apache.accumulo.start.classloader.vfs.AccumuloVFSClassLoader;
+
+public class CryptoServiceFactory {
+  private static CryptoService singleton = null;
+
+  /**
+   * Load the singleton class configured in {@link Property#INSTANCE_CRYPTO_SERVICE}
+   */
+  public static CryptoService getConfigured(AccumuloConfiguration conf) {
 
 Review comment:
   This method has multiple concurrency issues.  There is a race condition where one thread may use singleton while another thread is calling init.  Also, because the variable is not volatile processors with different caches will not see each others updates.  It would be nice to avoid synchronization, the following is one possible way to avoid these issue w/o sync.
   
   ```java
   private static AtomicReference<CryptoService> singleton = new AtomicReference<>(null);
   
     /**
      * Load the singleton class configured in {@link Property#INSTANCE_CRYPTO_SERVICE}
      */
     public static CryptoService getConfigured(AccumuloConfiguration conf) {
       CryptoService cyptoService = singleton.get();
       String configuredClass = conf.get(Property.INSTANCE_CRYPTO_SERVICE.getKey());
       if (cyptoService == null || !cyptoService.getClass().getName().equals(configuredClass)) {
         CryptoService newCryptoService = loadCryptoService(configuredClass);
         newCryptoService.init(conf.getAllPropertiesWithPrefix(Property.INSTANCE_CRYPTO_PREFIX));
         singleton.compareAndSet(cyptoService, newCryptoService);
         return singleton.get();
       }
       return cyptoService;
     }
   ```
   
   It would probably be better to not have the singleton in the first place.  Tservers could create a single cryptoservice.

----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
users@infra.apache.org


With regards,
Apache Git Services