导入：/usr/local/kafka/bin/kafka-console-producer.sh --broker-list 10.16.252.48:9092,10.16.252.49:9092,10.16.252.50:9092 --topic k8s_log_pl_old < /data/k8s_log_pl.txt
导出：/usr/local/kafka/bin/kafka-console-consumer.sh --zookeeper 10.16.252.48:2181,10.16.252.49:2181,10.16.252.50:2181 --topic k8s_log_pl --from-beginning > /data/k8s_log_pl.txt &
kafka增加分区：./kafka-topics.sh --alter --zookeeper 10.16.252.48:2181,10.16.252.49:2181,10.16.252.50:2181 --topic k8scs1_log_online --partitions 24
Kafka专为分布式高吞吐量系统而设计。 作为一个更传统的消息代理的替代品。 与其他消息传递系统相比，Kafka具有更好的吞吐量，内置分区，复制和固有的容错能力，这使得它非常适合大规模消息处理应用程序。
在实际使用中，kafka的不同版本协议也不完全一致，不是向下兼容的，使用时需特别注意，我这里使用的是0.9.0.1的版本。
本次安装的服务器为物理机3台: CPU：双Intel(R) Xeon(R) Silver 4110 CPU @ 2.10GHz 内存：128G配置 10块SAS HDD 1T盘做raid10，挂载到/data1。
| 主机名 | IP | 备注 |
|---|---|---|
| sh-saas-k8s-kafka-online-01 | 10.16.252.33 | zookeeper,kafka |
| sh-saas-k8s-kafka-online-02 | 10.16.252.39 | zookeeper,kafka |
| sh-saas-k8s-kafka-online-03 | 10.16.252.40 | zookeeper,kafka |
kafka需要用到zookeeper，所以我们需要先安装zookeeper。kafka及zookeeper都需要是JAVA语言开发，需要使用JDK，推荐1.8版本。
在使用fluentd采集数据到kafka时，一直不通，碰到了很多报错。 fluentd版本为：1.2.5 fluent-plugin-kafka版本为：0.7.8 kafka版本为：0.9 最开始碰到了这个报错：
2018-09-05 01:42:06 +0000 [warn]: fluent/log.rb:342:warn: Send exception occurred: unknown topic
2018-09-05 01:42:06 +0000 [warn]: fluent/log.rb:342:warn: Exception Backtrace : /var/lib/gems/2.3.0/gems/ruby-kafka-0.6.8/lib/kafka/protocol/metadata_response.rb:141:in `partitions_for'
/var/lib/gems/2.3.0/gems/ruby-kafka-0.6.8/lib/kafka/cluster.rb:155:in `partitions_for'
/var/lib/gems/2.3.0/gems/fluent-plugin-kafka-0.7.6/lib/fluent/plugin/kafka_producer_ext.rb:190:in `assign_partitions!'
/var/lib/gems/2.3.0/gems/fluent-plugin-kafka-0.7.6/lib/fluent/plugin/kafka_producer_ext.rb:153:in `block in deliver_messages_with_retries'
/var/lib/gems/2.3.0/gems/fluent-plugin-kafka-0.7.6/lib/fluent/plugin/kafka_producer_ext.rb:148:in `loop'
/var/lib/gems/2.3.0/gems/fluent-plugin-kafka-0.7.6/lib/fluent/plugin/kafka_producer_ext.rb:148:in `deliver_messages_with_retries'
/var/lib/gems/2.3.0/gems/fluent-plugin-kafka-0.7.6/lib/fluent/plugin/kafka_producer_ext.rb:102:in `deliver_messages'
/var/lib/gems/2.3.0/gems/fluent-plugin-kafka-0.7.6/lib/fluent/plugin/out_kafka2.rb:220:in `write'
/var/lib/gems/2.3.0/gems/fluentd-1.2.4/lib/fluent/plugin/output.rb:1110:in `try_flush'
/var/lib/gems/2.3.0/gems/fluentd-1.2.4/lib/fluent/plugin/output.rb:1389:in `flush_thread_run'
/var/lib/gems/2.3.0/gems/fluentd-1.2.4/lib/fluent/plugin/output.rb:444:in `block (2 levels) in start'
/var/lib/gems/2.3.0/gems/fluentd-1.2.4/lib/fluent/plugin_helper/thread.rb:78:in `block in thread_create'
2018-09-05 01:42:06 +0000 [info]: fluent/log.rb:322:info: initialized kafka producer: fluentd
2018-09-05 01:42:06 +0000 [debug]: fluent/log.rb:302:debug: taking back chunk for errors. chunk="57515e0ef787da843836cc864f9d1581"
2018-09-05 01:42:06 +0000 [warn]: fluent/log.rb:342:warn: failed to flush the buffer. retry_time=2 next_retry_seconds=2018-09-05 01:42:06 +0000 chunk="57515e0ef787da843836cc864f9d1581" error_class=Kafka::UnknownTopicOrPartition error="unknown topic "
2018-09-05 01:42:06 +0000 [warn]: plugin/output.rb:1157:rescue in try_flush: suppressed same stacktrace
2018-09-05 01:42:09 +0000 [debug]: fluent/log.rb:302:debug: 61 messages send.
2018-09-05 01:42:09 +0000 [warn]: fluent/log.rb:342:warn: Send exception occurred: unknown topic
2018-09-05 01:42:09 +0000 [warn]: fluent/log.rb:342:warn: Exception Backtrace : /var/lib/gems/2.3.0/gems/ruby-kafka-0.6.8/lib/kafka/protocol/metadata_response.rb:141:in `partitions_for'
/var/lib/gems/2.3.0/gems/ruby-kafka-0.6.8/lib/kafka/cluster.rb:155:in `partitions_for'
/var/lib/gems/2.3.0/gems/fluent-plugin-kafka-0.7.6/lib/fluent/plugin/kafka_producer_ext.rb:190:in `assign_partitions!'
/var/lib/gems/2.3.0/gems/fluent-plugin-kafka-0.7.6/lib/fluent/plugin/kafka_producer_ext.rb:153:in `block in deliver_messages_with_retries'
/var/lib/gems/2.3.0/gems/fluent-plugin-kafka-0.7.6/lib/fluent/plugin/kafka_producer_ext.rb:148:in `loop'
/var/lib/gems/2.3.0/gems/fluent-plugin-kafka-0.7.6/lib/fluent/plugin/kafka_producer_ext.rb:148:in `deliver_messages_with_retries'
/var/lib/gems/2.3.0/gems/fluent-plugin-kafka-0.7.6/lib/fluent/plugin/kafka_producer_ext.rb:102:in `deliver_messages'
/var/lib/gems/2.3.0/gems/fluent-plugin-kafka-0.7.6/lib/fluent/plugin/out_kafka2.rb:220:in `write'
/var/lib/gems/2.3.0/gems/fluentd-1.2.4/lib/fluent/plugin/output.rb:1110:in `try_flush'
/var/lib/gems/2.3.0/gems/fluentd-1.2.4/lib/fluent/plugin/output.rb:1389:in `flush_thread_run'
/var/lib/gems/2.3.0/gems/fluentd-1.2.4/lib/fluent/plugin/output.rb:444:in `block (2 levels) in start'
/var/lib/gems/2.3.0/gems/fluentd-1.2.4/lib/fluent/plugin_helper/thread.rb:78:in `block in thread_create'
2018-09-05 01:42:09 +0000 [info]: fluent/log.rb:322:info: initialized kafka producer: fluentd
2018-09-05 01:42:09 +0000 [debug]: fluent/log.rb:302:debug: taking back chunk for errors. chunk="57515e0ef787da843836cc864f9d1581"
2018-09-05 01:42:09 +0000 [warn]: fluent/log.rb:342:warn: failed to flush the buffer. retry_time=3 next_retry_seconds=2018-09-05 01:42:09 +0000
这是因为没有配置default_topic,使用下面的配置指定topic就可以了。
