[da-vinci] Do not throw exception when trying to close a closed/not-r…

…eady DVC client (#1289)

clients/da-vinci-client/src/main/java/com/linkedin/davinci/client/AvroGenericDaVinciClient.java

@@ -842,24 +842,38 @@ public synchronized void start() {
 
   @Override
   public synchronized void close() {
-    throwIfNotReady();
+    if (isReady()) {
+      closeInner();
+    } else {
+      getClientLogger()
+          .warn("Client is not ready or already closed, will ignore close request, storeName=" + getStoreName());
+    }
+  }
+
+  @Override
+  public String toString() {
+    return this.getClass().getSimpleName();
+  }
+
+  // Visible for testing
+  void closeInner() {
     try {
       logger.info("Closing client, storeName=" + getStoreName());
       ready.set(false);
       if (cacheBackend != null) {
         cacheBackend.close();
       }
       daVinciBackend.release();
-      logger.info("Client is closed successfully, storeName=" + getStoreName());
+      logger.info("Client is closed successfully, storeName={}", getStoreName());
     } catch (Throwable e) {
       String msg = "Unable to close Da Vinci client, storeName=" + getStoreName();
       logger.error(msg, e);
       throw new VeniceClientException(msg, e);
     }
   }
 
-  @Override
-  public String toString() {
-    return this.getClass().getSimpleName();
+  Logger getClientLogger() {
+    return logger;
   }
+
 }

clients/da-vinci-client/src/test/java/com/linkedin/davinci/client/AvroGenericDaVinciClientTest.java

@@ -4,10 +4,14 @@
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.Mockito.anyString;
+import static org.mockito.Mockito.doCallRealMethod;
 import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 import static org.testng.Assert.assertEquals;
 import static org.testng.Assert.assertThrows;
@@ -42,6 +46,7 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executor;
 import org.apache.avro.Schema;
+import org.apache.logging.log4j.LogManager;
 import org.testng.Assert;
 import org.testng.annotations.Test;
 
@@ -230,5 +235,20 @@ public void constructorTest() {
         readChunkExecutor);
     assertEquals(daVinciClient.getReadChunkExecutorForLargeRequest(), readChunkExecutor);
 
+    // Close a not-ready client won't throw exception.
+    daVinciClient.close();
+  }
+
+  @Test
+  public void closeTest() {
+    AvroGenericDaVinciClient client = mock(AvroGenericDaVinciClient.class);
+    doCallRealMethod().when(client).close();
+    doReturn(LogManager.getLogger(AvroGenericDaVinciClient.class)).when(client).getClientLogger();
+    doReturn(false).when(client).isReady();
+    client.close();
+    verify(client, never()).closeInner();
+    doReturn(true).when(client).isReady();
+    client.close();
+    verify(client, times(1)).closeInner();
   }
 }

internal/venice-test-common/src/integrationTest/java/com/linkedin/venice/endToEnd/DaVinciClientTest.java

@@ -1106,6 +1106,8 @@ public void testHybridStore() throws Exception {
 
         // Verify that closed cached client can be restarted.
         client.close();
+        // Verify that 2nd close call on the same store won't throw exception.
+        client.close();
         DaVinciClient<Integer, Integer> client1 = factory.getAndStartGenericAvroClient(storeName, new DaVinciConfig());
         assertEquals((int) client1.get(1).get(), 1);