Kafka docs Producer可能的消息丢失
Kafka docs Producer possible message loss
我目前正在了解有关 Kafka Producer 的更多信息。我对文档中的以下段落感到有些困惑：
Messages written to the partition leader are not immediately readable
by consumers regardless of the producer’s acknowledgement settings.
When all in-sync replicas have acknowledged the write, then the
message is considered committed, which makes it available for reading.
This ensures that messages cannot be lost by a broker failure after
they have already been read. Note that this implies that messages
which were acknowledged by the leader only (that is, acks=1) can be
lost if the partition leader fails before the replicas have copied the
message. Nevertheless, this is often a reasonable compromise in
practice to ensure durability in most cases while not impacting
throughput too significantly.
我对此的解释是，消息可能会在领导者和复制代理之间的同步过程中丢失，即消息不会被提交，除非它们已被成功复制。
我不明白（例如）Java 应用程序如何防止此消息丢失。
它在 'only-leader' 和完整复制之间是否收到不同的确认？
this is often a reasonable compromise in practice
怎么样？他们是否假设您应该记录失败的消息并手动将它们重新排队？或者它是如何工作的？
"Does it receive different acknowledgements between 'only-leader' and the full replication?"
领导者和副本确认之间没有区别。您只能通过其配置 acks 来控制生产者的行为。如果它被设置为 1 它只会等待领导者确认，如果你将它设置为 all 它会在生产者考虑写入之前等待所有副本（基于主题的复制因子）消息成功。
如果你设置了acks=all并且领导者和副本之间的同步失败，你的生产者将收到一个可重试异常（“NotEnoughReplicasException”或“NotEnoughReplicasAfterAppendException”，参见更多详细信息 ）。基于生产者配置 retries 它将尝试重新发送消息。 Kafka 的构建方式是希望崩溃的代理再次可用（在“短”时间内）。
如果您设置了 acks=1 并且领导者和副本之间的同步失败，您的生产者认为消息已成功写入集群，并且不会尝试复制消息。当然领导者会继续将消息复制到它的副本。但并不能真正保证这会发生。在消息被复制之前，leader broker 本身可能会出现问题，导致消息永远丢失。
我目前正在了解有关 Kafka Producer 的更多信息。我对文档中的以下段落感到有些困惑：
Messages written to the partition leader are not immediately readable by consumers regardless of the producer’s acknowledgement settings. When all in-sync replicas have acknowledged the write, then the message is considered committed, which makes it available for reading. This ensures that messages cannot be lost by a broker failure after they have already been read. Note that this implies that messages which were acknowledged by the leader only (that is, acks=1) can be lost if the partition leader fails before the replicas have copied the message. Nevertheless, this is often a reasonable compromise in practice to ensure durability in most cases while not impacting throughput too significantly.
我对此的解释是，消息可能会在领导者和复制代理之间的同步过程中丢失，即消息不会被提交，除非它们已被成功复制。
我不明白（例如）Java 应用程序如何防止此消息丢失。 它在 'only-leader' 和完整复制之间是否收到不同的确认？
this is often a reasonable compromise in practice
怎么样？他们是否假设您应该记录失败的消息并手动将它们重新排队？或者它是如何工作的？
"Does it receive different acknowledgements between 'only-leader' and the full replication?"
领导者和副本确认之间没有区别。您只能通过其配置 acks 来控制生产者的行为。如果它被设置为 1 它只会等待领导者确认，如果你将它设置为 all 它会在生产者考虑写入之前等待所有副本（基于主题的复制因子）消息成功。
如果你设置了acks=all并且领导者和副本之间的同步失败，你的生产者将收到一个可重试异常（“NotEnoughReplicasException”或“NotEnoughReplicasAfterAppendException”，参见更多详细信息 retries 它将尝试重新发送消息。 Kafka 的构建方式是希望崩溃的代理再次可用（在“短”时间内）。
如果您设置了 acks=1 并且领导者和副本之间的同步失败，您的生产者认为消息已成功写入集群，并且不会尝试复制消息。当然领导者会继续将消息复制到它的副本。但并不能真正保证这会发生。在消息被复制之前，leader broker 本身可能会出现问题，导致消息永远丢失。