java - Apache Beam 从 Pub/Sub 流式传输到 ElasticSearch

Question

我正在使用 Apache Beam 编写一个 Java 流管道，它从 Google Cloud PubSub 读取消息并将它们写入 ElasticSearch 实例。目前，我使用的是直接运行程序，但计划将该解决方案部署在 Google Cloud Dataflow 上。

首先，我编写了一个从 PubSub 读取并写入文本文件的管道，它可以工作。然后，我启动了 ElasticSearch 实例，这也起作用了。我用curl写了一些文档，很简单。

然后，当我尝试使用 Beam 的 ElasticSearch 连接器执行写入时，我开始出现一些错误。实际上，我得到了 ava.lang.NoSuchMethodError: org.elasticsearch.client.RestClient.performRequest，尽管我添加了对 pom.xml 文件的依赖项。

我所做的基本上是这样的:

messages.apply(
                        "TwoMinWindow",
                        Window.into(FixedWindows.of(new Duration(120*1000)))
                ).apply(
                        "ElasticWrite",
            ElasticsearchIO.write()
            .withConnectionConfiguration(
                             ElasticsearchIO.ConnectionConfiguration
                             .create(new String[]{"http://xxx.xxx.xxx.xxx:9200"}, "streaming_data", "string")
                             .withUsername("xxxx")
                             .withPassword("xxxxxxxx")
                             )
                );

使用 DirectRunner，我可以连接到 PubSub，但当管道尝试连接 ElasticSearch 实例时出现异常:

java.lang.NoSuchMethodError: org.elasticsearch.client.RestClient.performRequest(Ljava/lang/String;Ljava/lang/String;[Lorg/apache/http/Header;)Lorg/elasticsearch/client/Response;
    at org.apache.beam.sdk.util.UserCodeException.wrap (UserCodeException.java:34)
    at org.apache.beam.sdk.io.elasticsearch.ElasticsearchIO$Write$WriteFn$DoFnInvoker.invokeSetup (Unknown Source)
    at org.apache.beam.sdk.transforms.reflect.DoFnInvokers.tryInvokeSetupFor (DoFnInvokers.java:50)
    at org.apache.beam.runners.direct.DoFnLifecycleManager$DeserializingCacheLoader.load (DoFnLifecycleManager.java:104)
    at org.apache.beam.runners.direct.DoFnLifecycleManager$DeserializingCacheLoader.load (DoFnLifecycleManager.java:91)
    at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache$LoadingValueReference.loadFuture (LocalCache.java:3528)
    at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache$Segment.loadSync (LocalCache.java:2277)
    at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache$Segment.lockedGetOrLoad (LocalCache.java:2154)
    at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache$Segment.get (LocalCache.java:2044)
    at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache.get (LocalCache.java:3952)
    at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache.getOrLoad (LocalCache.java:3974)
    at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache$LocalLoadingCache.get (LocalCache.java:4958)
    at org.apache.beam.runners.direct.DoFnLifecycleManager.get (DoFnLifecycleManager.java:61)
    at org.apache.beam.runners.direct.ParDoEvaluatorFactory.createEvaluator (ParDoEvaluatorFactory.java:129)
    at org.apache.beam.runners.direct.ParDoEvaluatorFactory.forApplication (ParDoEvaluatorFactory.java:79)
    at org.apache.beam.runners.direct.TransformEvaluatorRegistry.forApplication (TransformEvaluatorRegistry.java:169)
    at org.apache.beam.runners.direct.DirectTransformExecutor.run (DirectTransformExecutor.java:117)
    at java.util.concurrent.Executors$RunnableAdapter.call (Executors.java:511)
    at java.util.concurrent.FutureTask.run (FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:624)
    at java.lang.Thread.run (Thread.java:748)
Caused by: java.lang.NoSuchMethodError: org.elasticsearch.client.RestClient.performRequest(Ljava/lang/String;Ljava/lang/String;[Lorg/apache/http/Header;)Lorg/elasticsearch/client/Response;
    at org.apache.beam.sdk.io.elasticsearch.ElasticsearchIO.getBackendVersion (ElasticsearchIO.java:1348)
    at org.apache.beam.sdk.io.elasticsearch.ElasticsearchIO$Write$WriteFn.setup (ElasticsearchIO.java:1200)

我在 pom.xml 中添加的是:

    <dependency>
    <groupId>org.apache.beam</groupId>
    <artifactId>beam-sdks-java-io-google-cloud-platform</artifactId>
    <version>${beam.version}</version>
  </dependency>

    <!-- https://mvnrepository.com/artifact/org.elasticsearch.client/elasticsearch-rest-client -->
  <dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-client</artifactId>
    <version>${elastic.version}</version>
  </dependency>

我被这个问题困扰了，不知道如何解决。如果我使用 JestClient，我可以毫无问题地连接到 ElasticSearch。

你有什么建议吗？

Answer 1

您使用的是较新版本的 RestClient，该版本没有 performRequest(String, Header) 方法。如果你看the latest source code ，您可以看到该方法现在需要一个 Request ，而在旧版本中 there were methods that took Strings and Headers 。这些方法已被弃用，然后 removed from the code on September 1, 2018 .

更改您的代码以使用较新的 Elastic Search 库，或指定与您的兼容的较旧版本的库(它需要在 7.0.x 之前，例如 6.8.4 )代码。