Remove reuse EntityManagerFactory since we need to have different one…

… for different realm

extension/persistence/eclipselink/src/main/java/io/polaris/extension/persistence/impl/eclipselink/PolarisEclipseLinkMetaStoreSessionImpl.java

@@ -83,7 +83,7 @@ public class PolarisEclipseLinkMetaStoreSessionImpl implements PolarisMetaStoreS
   private static final Logger LOG =
       LoggerFactory.getLogger(PolarisEclipseLinkMetaStoreSessionImpl.class);
 
-  private static volatile EntityManagerFactory emf;
+  private final EntityManagerFactory emf;
   private final ThreadLocal<EntityManager> localSession = new ThreadLocal<>();
   private final PolarisEclipseLinkStore store;
   private final PolarisStorageIntegrationProvider storageIntegrationProvider;
@@ -114,17 +114,13 @@ public PolarisEclipseLinkMetaStoreSessionImpl(
   /**
    * Create EntityManagerFactory.
    *
-   * <p>The creation is expensive, but it should only need to create once and can be reused across
-   * the sessions.
+   * <p>TODO: The EntityManagerFactory creation is expensive. We should consider save and reuse for
+   * each realm.
    */
   private EntityManagerFactory createEntityManagerFactory(
       @NotNull RealmContext realmContext,
       @Nullable String confFile,
       @Nullable String persistenceUnitName) {
-    if (emf != null) {
-      return emf;
-    }
-
     ClassLoader prevClassLoader = Thread.currentThread().getContextClassLoader();
     try {
       persistenceUnitName = persistenceUnitName == null ? "polaris" : persistenceUnitName;
@@ -171,14 +167,6 @@ private EntityManagerFactory createEntityManagerFactory(
     }
   }
 
-  @TestOnly
-  static void clearEntityManagerFactory() {
-    if (emf != null) {
-      emf.close();
-      emf = null;
-    }
-  }
-
   /** Load the persistence unit properties from a given configuration file */
   private Map<String, String> loadProperties(
       @NotNull String confFile, @NotNull String persistenceUnitName) throws IOException {

extension/persistence/eclipselink/src/test/java/io/polaris/extension/persistence/impl/eclipselink/PolarisEclipseLinkMetaStoreTest.java

@@ -61,9 +61,6 @@ protected PolarisTestMetaStoreManager createPolarisTestMetaStoreManager() {
   @ParameterizedTest()
   @ArgumentsSource(CreateStoreSessionArgs.class)
   void testCreateStoreSession(String confFile, boolean success) {
-    // Clear to test out EntityManagerFactory creation rather than reusing
-    PolarisEclipseLinkMetaStoreSessionImpl.clearEntityManagerFactory();
-
     PolarisDiagnostics diagServices = new PolarisDefaultDiagServiceImpl();
     PolarisEclipseLinkStore store = new PolarisEclipseLinkStore(diagServices);
     try {