ioexception，同时连接到Twitter流API与Apache Flink

Question

我写了一个小的Scala程序，它使用Apache Flink Streaming API来读取Twitter tweets。

object TwitterWordCount {
  private val properties = "/home/twitter-login.properties"
  def main(args: Array[String]) {
    val env = StreamExecutionEnvironment.getExecutionEnvironment
    val twitterStream = env.addSource(new TwitterSource(properties))
    val tweets = twitterStream
      .flatMap(new JSONParseFlatMap[String, String] {
        override def flatMap(in: String, out: Collector[String]): Unit = {
          if (getString(in, "user.lang") == "en") {
            out.collect(getString(in, "text"))
          }
        }
      })
    tweets.print
    env.execute("tweets")
  }
}

执行时遇到以下问题:

14:35:48,353 INFO  com.twitter.hbc.httpclient.ClientBase - twitterSourceClient Establishing a connection
14:35:48,354 DEBUG org.apache.http.impl.conn.PoolingClientConnectionManager - Connection request: [route: {}->http://stream.twitter.com][total kept alive: 0; route allocated: 0 of 2; total allocated: 0 of 20]
14:35:48,354 DEBUG org.apache.http.impl.conn.PoolingClientConnectionManager - Connection leased: [id: 4][route: {}->http://stream.twitter.com][total kept alive: 0; route allocated: 1 of 2; total allocated: 1 of 20]
14:35:48,354 DEBUG org.apache.http.impl.conn.DefaultClientConnectionOperator - Connecting to stream.twitter.com:80
14:35:49,486 DEBUG org.apache.flink.runtime.taskmanager.TaskManager - Received message SendHeartbeat at akka://flink/user/taskmanager_1 from Actor[akka://flink/deadLetters].
14:35:49,486 DEBUG org.apache.flink.runtime.taskmanager.TaskManager - Sending heartbeat to JobManager
14:35:49,487 DEBUG org.apache.flink.runtime.taskmanager.TaskManager - Handled message SendHeartbeat in 1 ms from Actor[akka://flink/deadLetters].
14:35:49,487 DEBUG org.apache.flink.runtime.jobmanager.JobManager - Received message Heartbeat(cb51cdb1bd08879df10bd2198b8e043a,[B@4daaaf5f) at akka://flink/user/jobmanager from Actor[akka://flink/user/taskmanager_1#-64418449].
14:35:49,488 DEBUG org.apache.flink.runtime.jobmanager.JobManager - Received hearbeat message from cb51cdb1bd08879df10bd2198b8e043a.
14:35:49,488 DEBUG org.apache.flink.runtime.instance.InstanceManager - Received heartbeat from TaskManager cb51cdb1bd08879df10bd2198b8e043a @ localhost - 8 slots - URL: akka://flink/user/taskmanager_1
14:35:49,488 DEBUG org.apache.flink.runtime.jobmanager.JobManager - Handled message Heartbeat(cb51cdb1bd08879df10bd2198b8e043a,[B@4daaaf5f) in 0 ms from Actor[akka://flink/user/taskmanager_1#-64418449].
14:35:52,358 DEBUG org.apache.http.impl.conn.DefaultClientConnection - Connection org.apache.http.impl.conn.DefaultClientConnection@64c88f2d closed
14:35:52,358 DEBUG org.apache.http.impl.conn.DefaultClientConnection - Connection org.apache.http.impl.conn.DefaultClientConnection@64c88f2d shut down
14:35:52,358 DEBUG org.apache.http.impl.conn.PoolingClientConnectionManager - Connection [id: 4][route: {}->http://stream.twitter.com] can be kept alive for 9223372036854775807 MILLISECONDS
14:35:52,358 DEBUG org.apache.http.impl.conn.DefaultClientConnection - Connection org.apache.http.impl.conn.DefaultClientConnection@64c88f2d closed
14:35:52,358 DEBUG org.apache.http.impl.conn.PoolingClientConnectionManager - Connection released: [id: 4][route: {}->http://stream.twitter.com][total kept alive: 0; route allocated: 0 of 2; total allocated: 0 of 20]
14:35:52,359 WARN  com.twitter.hbc.httpclient.ClientBase - twitterSourceClient IOException caught when establishing connection to https://stream.twitter.com/1.1/statuses/filter.json?delimited=length
14:35:53,613 WARN  com.twitter.hbc.httpclient.ClientBase - twitterSourceClient failed to establish connection properly
14:35:53,613 INFO  com.twitter.hbc.httpclient.ClientBase - twitterSourceClient Done processing, preparing to close connection
14:35:53,613 DEBUG org.apache.http.impl.conn.PoolingClientConnectionManager - Connection manager is shutting down
14:35:53,613 DEBUG org.apache.http.impl.conn.PoolingClientConnectionManager - Connection manager shut down

程序尝试重建连接。因此，这4行日志消息继续发出。

奇怪的是，当我运行Apache Flink项目中提供的示例时，一切都工作得很好(我从GitHub中提取了最新版本的master)。我甚至使用相同的属性文件。如果我把这个例子类复制到我自己的项目中，上面的问题状态也会发生。

我使用Flink原型来创建我自己的项目。我尝试了0.9.1和0.10-SNAPSHOT版本。flink-scala、flink-streaming-scala、flink-clients、flink-connector-twitter依赖项在对应版本中使用。

有没有人遇到过类似的问题，可以让我走上正确的轨道?

Answer 1

调试com.twitter.hbc.httpclient.ClientBase给我带来了以下异常:org.apache.http.conn.ConnectTimeoutException: Connect to stream.twitter.com:80 timed out

根据Twitter开发者论坛上的一个帖子，这种情况的发生是因为Apaches HttpClient 4.2中的一个bug。事实上，在我的项目上解析依赖树显示，flink-runtime依赖于com.amazonaws:aws-java-sdk:1.81，而后者又依赖于org.apache.httpcomponents:httpclient:4.2。

添加HttpClient 4.2.6到我的项目的依赖项暂时解决了这个问题

Answer 2

谢谢@peedeeX21你的解决方案帮了我!在pom.xml中添加显式依赖可以解决从eclipse运行时的问题，但是当使用flink集群并使用flink run提交程序时，flink发行版中打包的版本仍然胜出。

我已经通过下载httpclient-4.2.6.jar jar到flink/lib并将其重命名为"a"(ahttpclient-4.2.6.jar)来解决它，因此它将首先添加到flink运行时的类路径(由bin/config.sh完成)希望对大家有所帮助。