Flink初始化环境时，设置最大并行度报错：具体错误信息如下：
在Exception in thread "main" java.lang.RuntimeException: java.util.concurrent.ExecutionException: org.apache.flink.runtime.client.JobSubmissionException: Failed to submit job.
at org.apache.flink.util.ExceptionUtils.rethrow(ExceptionUtils.java:199)
at org.apache.flink.streaming.api.environment.StreamExecutionEnvironment.executeAsync(StreamExecutionEnvironment.java:1741)
at org.apache.flink.streaming.api.environment.StreamExecutionEnvironment.execute(StreamExecutionEnvironment.java:1634)
at org.apache.flink.streaming.api.environment.LocalStreamEnvironment.execute(LocalStreamEnvironment.java:74)
at org.apache.flink.streaming.api.environment.StreamExecutionEnvironment.execute(StreamExecutionEnvironment.java:1620)
at org.apache.flink.streaming.api.scala.StreamExecutionEnvironment.execute(StreamExecutionEnvironment.scala:678)
at com.hainiu.flink.HotItemsSql$.main(HotItemsSql.scala:60)
at com.hainiu.flink.HotItemsSql.main(HotItemsSql.scala)
Caused by: java.util.concurrent.ExecutionException: org.apache.flink.runtime.client.JobSubmissionException: Failed to submit job.
at java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:357)
at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1895)
at org.apache.flink.streaming.api.environment.StreamExecutionEnvironment.executeAsync(StreamExecutionEnvironment.java:1736)
... 6 more
Caused by: org.apache.flink.runtime.client.JobSubmissionException: Failed to submit job.
at org.apache.flink.runtime.dispatcher.Dispatcher.lambda$internalSubmitJob$3(Dispatcher.java:336)
at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:822)
at java.util.concurrent.CompletableFuture$UniHandle.tryFire(CompletableFuture.java:797)
at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:442)
at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:40)
at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(ForkJoinExecutorConfigurator.scala:44)
at akka.dispatch.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at akka.dispatch.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at akka.dispatch.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at akka.dispatch.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
Caused by: java.lang.RuntimeException: org.apache.flink.runtime.client.JobExecutionException: Could not set up JobManager
at org.apache.flink.util.function.CheckedSupplier.lambda$unchecked$0(CheckedSupplier.java:36)
at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1590)
... 6 more
Caused by: org.apache.flink.runtime.client.JobExecutionException: Could not set up JobManager
at org.apache.flink.runtime.jobmaster.JobManagerRunnerImpl.<init>(JobManagerRunnerImpl.java:152)
at org.apache.flink.runtime.dispatcher.DefaultJobManagerRunnerFactory.createJobManagerRunner(DefaultJobManagerRunnerFactory.java:84)
at org.apache.flink.runtime.dispatcher.Dispatcher.lambda$createJobManagerRunner$6(Dispatcher.java:379)
at org.apache.flink.util.function.CheckedSupplier.lambda$unchecked$0(CheckedSupplier.java:34)
... 7 more
Caused by: org.apache.flink.runtime.JobException: Vertex Split Reader: Custom File Source -> Map -> Timestamps/Watermarks -> SourceConversion(table=[Unregistered_DataStream_4], fields=[itemId, behavior, ts]) -> Calc(select=[itemId, behavior, ts], where=[(behavior = _UTF-16LE'pv')])'s parallelism (12) is higher than the max parallelism (1). Please lower the parallelism or increase the max parallelism.
at org.apache.flink.runtime.executiongraph.ExecutionJobVertex.<init>(ExecutionJobVertex.java:189)
at org.apache.flink.runtime.executiongraph.ExecutionGraph.attachJobGraph(ExecutionGraph.java:807)
at org.apache.flink.runtime.executiongraph.ExecutionGraphBuilder.buildGraph(ExecutionGraphBuilder.java:228)
at org.apache.flink.runtime.scheduler.SchedulerBase.createExecutionGraph(SchedulerBase.java:255)
at org.apache.flink.runtime.scheduler.SchedulerBase.createAndRestoreExecutionGraph(SchedulerBase.java:227)
at org.apache.flink.runtime.scheduler.SchedulerBase.<init>(SchedulerBase.java:215)
at org.apache.flink.runtime.scheduler.DefaultScheduler.<init>(DefaultScheduler.java:120)
at org.apache.flink.runtime.scheduler.DefaultSchedulerFactory.createInstance(DefaultSchedulerFactory.java:105)
at org.apache.flink.runtime.jobmaster.JobMaster.createScheduler(JobMaster.java:278)
at org.apache.flink.runtime.jobmaster.JobMaster.<init>(JobMaster.java:266)
at org.apache.flink.runtime.jobmaster.factories.DefaultJobMasterServiceFactory.createJobMasterService(DefaultJobMasterServiceFactory.java:98)
at org.apache.flink.runtime.jobmaster.factories.DefaultJobMasterServiceFactory.createJobMasterService(DefaultJobMasterServiceFactory.java:40)
at org.apache.flink.runtime.jobmaster.JobManagerRunnerImpl.<init>(JobManagerRunnerImpl.java:146)
... 10 more
env.setMaxParallelism(1)
修改为：
env.setParallelism(1) 即可把当前并行度设置为1
再次执行正确；