Flink常见报错持续更新

Flink-1.10

1、Job因为没有可用的任务slot而失败

2021-06-24 12:50:36,433 INFO org.apache.flink.runtime.executiongraph.ExecutionGraph - Job Windowed Join Example (d2f1e2b84ab8bc67298b32022a77c4fa) switched from state RUNNING to FAILING.org.apache.flink.runtime.jobmanager.scheduler.NoResourceAvailableException: Could not allocate all requires slots within timeout of 300000 ms. Slots required: 5, slots allocated: 3 at org.apache.flink.runtime.executiongraph.ExecutionGraph.lambda$scheduleEager$3(ExecutionGraph.java:991) at java.util.concurrent.CompletableFuture.uniExceptionally(Unknown Source) at java.util.concurrent.CompletableFuture$UniExceptionally.tryFire(Unknown Source) at java.util.concurrent.CompletableFuture.postComplete(Unknown Source) at java.util.concurrent.CompletableFuture.completeExceptionally(Unknown Source) at org.apache.flink.runtime.concurrent.FutureUtils$ResultConjunctFuture.handleCompletedFuture(FutureUtils.java:535) at java.util.concurrent.CompletableFuture.uniWhenComplete(Unknown Source) at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(Unknown Source) at java.util.concurrent.CompletableFuture.postComplete(Unknown Source) at java.util.concurrent.CompletableFuture.completeExceptionally(Unknown Source) at org.apache.flink.runtime.concurrent.FutureUtils$1.onComplete(FutureUtils.java:772)

解决：增加slot数设置

2、批任务处理中print可以不使用execute，否则会因为没有sink而报错

Exception in thread "main" java.lang.RuntimeException: No new data sinks have been defined since the last execution. The last execution refers to the latest call to 'execute()', 'count()', 'collect()', or 'print()'.at org.apache.flink.api.java.ExecutionEnvironment.createProgramPlan(ExecutionEnvironment.java:940)at org.apache.flink.api.java.ExecutionEnvironment.createProgramPlan(ExecutionEnvironment.java:922)at org.apache.flink.api.java.LocalEnvironment.execute(LocalEnvironment.java:85)at cn.test.BatchJob.main(BatchJob.java:77)

解决：可以直接使用print，无需execute触发

如：

 val ws = text.flatMap(_.split(" ")).map((_, 1)).groupBy(0).sum(1)
 ws.print()

3、Table环境执行缺少依赖包

java: 无法访问org.apache.flink.api.scala.ExecutionEnvironment找不到org.apache.flink.api.scala.ExecutionEnvironment的类文件

解决：

    <dependency> 
    <groupId>org.apache.flink</groupId> 
    <artifactId>flink-streaming-scala_2.12</artifactId> 
    <version>${flink.version}</version>
    </dependency>
    <dependency> 
    <groupId>org.apache.flink</groupId> 
    <artifactId>flink-table_2.12</artifactId> 
    <version>${flink.version}</version>
    </dependency>

4、scala类型转化问题

Error:(22, 40) could not find implicit value for evidence parameter of type org.apache.flink.api.common.typeinfo.TypeInformation[String]
    val wordCountDataSet = text.flatMap(_.split(" ")).map((_, 1)).groupBy(0).sum(1)

解决：import org.apache.flink.api.scala._

5、scala版本问题

xception in thread "main" java.lang.NoSuchMethodError: scala.Product.$init$(Lscala/Product;)V
	at akka.util.Timeout.<init>(Timeout.scala:13)
	at akka.actor.ActorSystem$Settings.<init>(ActorSystem.scala:329)
	at akka.actor.ActorSystemImpl.<init>(ActorSystem.scala:686)
	at akka.actor.RobustActorSystem.<init>(RobustActorSystem.scala:47)
	at akka.actor.RobustActorSystem$.internalApply(RobustActorSystem.scala:96)

解决：

1. 注意当前引入scala版本是否和IDEA的scala一致

2. 缺flink-clients_xx包

3. Scala开发核心依赖包

    <!-- flink scala 核心依赖 -->
           <dependency>
               <groupId>org.apache.flink</groupId>
               <artifactId>flink-scala_2.11</artifactId>
               <version>1.10.0</version>
           </dependency>
           <dependency>
               <groupId>org.apache.flink</groupId>
               <artifactId>flink-streaming-scala_2.11</artifactId>
               <version>1.10.0</version>
           </dependency>
           <dependency>
               <groupId>org.apache.flink</groupId>
               <artifactId>flink-clients_2.11</artifactId>
               <version>${flink.version}</version>
           </dependency>