我正在运行一个Samza流作业，该作业正在向Kafka主题写入数据。Kafka正在运行一个3节点集群。Samza作业部署在纱线上。我们在容器日志中看到了很多这样的异常：
INFO [2018-10-16 11:14:19,410] [U:2,151,F:455,T:2,606,M:2,658] samza.container.ContainerHeartbeatMonitor:[ContainerHeartbeatMonitor:stop:61] - [main] - Stopping ContainerHeartbeatMonitor
ERROR [2018-10-16 11:14:19,410] [U:2,151,F:455,T:2,606,M:2,658] samza.runtime.LocalContainerRunner:[LocalContainerRunner:run:107] - [main] - Container stopped with Exception. Exiting process now.
org.apache.samza.SamzaException: org.apache.samza.SamzaException: Unable to send message from TaskName-Partition 15 to system kafka.
at org.apache.samza.task.AsyncRunLoop.run(AsyncRunLoop.java:147)
at org.apache.samza.container.SamzaContainer.run(SamzaContainer.scala:694)
at org.apache.samza.runtime.LocalContainerRunner.run(LocalContainerRunner.java:104)
at org.apache.samza.runtime.LocalContainerRunner.main(LocalContainerRunner.java:149)
Caused by: org.apache.samza.SamzaException: Unable to send message from TaskName-Partition 15 to system kafka.
at org.apache.samza.system.kafka.KafkaSystemProducer$$anon$1.onCompletion(KafkaSystemProducer.scala:181)
at org.apache.kafka.clients.producer.internals.RecordBatch.done(RecordBatch.java:109)
at org.apache.kafka.clients.producer.internals.RecordBatch.maybeExpire(RecordBatch.java:160)
at org.apache.kafka.clients.producer.internals.RecordAccumulator.abortExpiredBatches(RecordAccumulator.java:245)
at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:212)
at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:135)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.kafka.common.errors.TimeoutException: Expiring 5 record(s) for Topic3-16 due to 30332 ms has passed since last attempt plus backoff time
这三种类型的异常情况层出不穷。
59088 org.apache.kafka.common.errors.TimeoutException: Expiring 115 record(s) for Topic3-1 due to 30028 ms has passed since last attempt plus backoff time
61015 org.apache.kafka.common.errors.TimeoutException: Expiring 60 record(s) for Topic3-1 due to 74949 ms has passed since batch creation plus linger time
62275 org.apache.kafka.common.errors.TimeoutException: Expiring 176 record(s) for Topic3-4 due to 74917 ms has passed since last append
请帮我理解这里的问题。无论何时，Samza容器都会重新启动。
此错误表示某些记录放入队列的速度比从客户端发送的速度快。
当您的Producer发送消息时，它们会存储在缓冲区中(在将发送到目标broker之前(，并且记录会被分组为批，以提高吞吐量。将新记录添加到批中时，必须在由request.timeout.ms控制的可配置时间窗口内发送(默认设置为30秒(。如果批处理在队列中的时间较长，则抛出TimeoutException，然后批处理记录将从队列中删除，并且不会传递到代理。
增加request.timeout.ms的值应该对您有用。
如果这不起作用，您也可以尝试减少batch.size，以便更频繁地发送批处理(但这次将包括更少的消息(，并确保linger.ms设置为0(这是默认值(。
请注意，在更改任何配置参数后，您需要重新启动kafka代理。
如果你仍然收到错误，我认为你的网络出了问题。您是否启用了SSL？