Github user zentol commented on a diff in the pull request:
https://github.com/apache/flink/pull/5823#discussion_r181699493
--- Diff:
flink-end-to-end-tests/test-scripts/test-class/ElasticsearchStreamingJob.java
---
@@ -0,0 +1,97 @@
+/*
+ * 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.flink.quickstart;
+
+import org.apache.flink.api.common.functions.FilterFunction;
+import org.apache.flink.api.common.functions.MapFunction;
+import org.apache.flink.api.common.functions.RuntimeContext;
+import org.apache.flink.streaming.api.datastream.DataStream;
+import
org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
+import
org.apache.flink.streaming.connectors.elasticsearch2.ElasticsearchSink;
+
+import org.elasticsearch.action.index.IndexRequest;
+import org.elasticsearch.client.Requests;
+
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Elasticsearch example for Flink Streaming Job.
+ *
+ * <p>In this streaming job, we generate a bunch of data from numbers,
apply two operators map
+ * and filter to that data. Then we choose elasticsearch as its sink to
storage these data.
+ *
+ * <p>Run test_quickstarts.sh to verify this program. Package this class
to a jar, verify the jar,
+ * then deploy it on a flink cluster.
+ */
+public class ElasticsearchStreamingJob {
+
+ public static void main(String[] args) throws Exception {
+ // set up the streaming execution environment
+ final StreamExecutionEnvironment env =
StreamExecutionEnvironment.getExecutionEnvironment();
+
+ DataStream<String> source = env.generateSequence(0, 20)
+ // map the data from 1,2,3... to the form of message
#1, message #2, message #3...
+ .map(new MapFunction<Long, String>() {
+ @Override
+ public String map(Long value) throws Exception {
+ return "message #" + value;
+ }})
+ // filter out the data that contains message #11 and
message #17
+ .filter(new FilterFunction<String>() {
+ @Override
+ public boolean filter(String value) throws
Exception {
+ return !value.equals("message #11") &&
!value.equals("message #17");
+ }
+ });
+
+ Map<String, String> userConfig = new HashMap<>();
+ userConfig.put("cluster.name", "elasticsearch");
+ // This instructs the sink to emit after every element,
otherwise they would be buffered
--- End diff --
why would buffering be a problem?
---
