Rethrowing Exception from CassandraIO's ReadFn

Author: VardhanThigle

sdks/java/io/cassandra/src/main/java/org/apache/beam/sdk/io/cassandra/ReadFn.java

@@ -42,7 +42,7 @@ class ReadFn<T> extends DoFn<Read<T>, T> {
   private static final Logger LOG = LoggerFactory.getLogger(ReadFn.class);
 
   @ProcessElement
-  public void processElement(@Element Read<T> read, OutputReceiver<T> receiver) {
+  public void processElement(@Element Read<T> read, OutputReceiver<T> receiver) throws Exception {
     try {
       Session session = ConnectionManager.getSession(read);
       Mapper<T> mapper = read.mapperFactoryFn().apply(session);
@@ -89,6 +89,7 @@ public void processElement(@Element Read<T> read, OutputReceiver<T> receiver) {
       }
     } catch (Exception ex) {
       LOG.error("error", ex);
+      throw ex;
     }
   }