java.lang.RuntimeException: Buffer pool is destroyed.

对于这个异常，要具体问题具体分析，我这个异常是因为在使用侧输出流的时候， outputTag, 向kafka发送数据的时候序列化用的是JSONOBJECT， String cant be cast ....jsonobject 导致的。

18:37:53,728 WARN  org.apache.flink.streaming.api.operators.AbstractStreamOperator  - Error while emitting latency marker.
java.lang.RuntimeException: Buffer pool is destroyed.
	at org.apache.flink.streaming.runtime.io.RecordWriterOutput.emitLatencyMarker(RecordWriterOutput.java:147)
	at org.apache.flink.streaming.api.operators.AbstractStreamOperator$CountingOutput.emitLatencyMarker(AbstractStreamOperator.java:683)
	at org.apache.flink.streaming.api.operators.StreamSource$LatencyMarksEmitter$1.onProcessingTime(StreamSource.java:151)
	at org.apache.flink.streaming.runtime.tasks.SystemProcessingTimeService$RepeatedTriggerTask.run(SystemProcessingTimeService.java:330)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.IllegalStateException: Buffer pool is destroyed.
	at org.apache.flink.runtime.io.network.buffer.LocalBufferPool.requestMemorySegment(LocalBufferPool.java:230)
	at org.apache.flink.runtime.io.network.buffer.LocalBufferPool.requestBufferBuilderBlocking(LocalBufferPool.java:204)
	at org.apache.flink.runtime.io.network.api.writer.RecordWriter.requestNewBufferBuilder(RecordWriter.java:213)
	at org.apache.flink.runtime.io.network.api.writer.RecordWriter.sendToTarget(RecordWriter.java:144)
	at org.apache.flink.runtime.io.network.api.writer.RecordWriter.randomEmit(RecordWriter.java:125)
	at org.apache.flink.streaming.runtime.io.StreamRecordWriter.randomEmit(StreamRecordWriter.java:93)
	at org.apache.flink.streaming.runtime.io.RecordWriterOutput.emitLatencyMarker(RecordWriterOutput.java:144)
	... 10 more