kafka
(1)kafka是一个分布式的消息缓存系统(2)kafka集群中的服务器都叫做broker(3)kafka有两类客户端,一个叫做producer(消息生产者),一类叫做consumer(消息消费者),客户端和broker服务器之间采用TCP协议连接(4)kafka中的消息可以通过topic进行区分,而且每一个消息topic都会被分区,以分担消息服务器的负载(5)每一个分区都可以有多个副本,以防止数据的丢失(6)某一个分区中的数据如果需要更新,都必须通知该分区所有副本中的leader来更新(7)消费者可以分组,比如有两个消费者组A和B,共同消费一个topic:order_info,A和B所消费的消息不会重复,如order_info中有100个消息,每个消息都有一个id,编号从1-99,那么如果A组消费从0-49,B组消费就从50-99,当然不一定都是连续的(8)消费者在具体消费某个topic中的消息时,可以制定起始偏移量 
集群安装
官网教程http://kafka.apache.org/22/documentation.html#introduction1.解压2.修改server.propertiesbroker.id=1zookeeper.connect=hadoop01:2182,hadoop02:2182,hadoop03:21823.将zookeeper集群启动4.在每一台节点上启动brokerbin/kafka-server-start.sh config/server.properties#5.自带zookeeper,用于单节点,一般集群不用#bin/zookeeper-server-start.sh config/zookeeper.proterties开始安装1.下载解压
[linyouyi@hadoop01 software]$ wget https://mirrors.aliyun.com/apache/kafka/2.2.0/kafka_2.11-2.2.0.tgz[linyouyi@hadoop01 software]$ tar -zxvf kafka_2.11-2.2.0.tgz -C /hadoop/module/
2.修改配置文件
[linyouyi@hadoop01 software]$ cd /hadoop/module/[linyouyi@hadoop01 module]$ lltotal 24drwxrwxr-x 18 linyouyi linyouyi 4096 Aug 12 21:24 apache-storm-2.0.0drwxr-xr-x 12 linyouyi linyouyi 4096 Aug 9 22:51 hadoop-2.7.7drwxrwxr-x 7 linyouyi linyouyi 4096 Aug 11 12:10 hbase-2.0.5drwxr-xr-x 7 linyouyi linyouyi 4096 Jul 22 2017 jdk1.8.0_144drwxr-xr-x 6 linyouyi linyouyi 4096 Mar 10 03:47 kafka_2.11-2.2.0drwxr-xr-x 15 linyouyi linyouyi 4096 Aug 8 11:03 zookeeper-3.4.14[linyouyi@hadoop01 kafka_2.11-2.2.0]$ vim config/server.propertiesbroker.id=1log.dirs=/hadoop/kafka_2.11-2.2.0/log/kafka-logszookeeper.connect=hadoop01:2182,hadoop02:2182,hadoop03:2182
3.拷贝到其他节点
[linyouyi@hadoop01 kafka_2.11-2.2.0]$ cd ../[linyouyi@hadoop01 module]$ scp -r kafka_2.11-2.2.0/ linyouyi@hadoop02:/hadoop/module/[linyouyi@hadoop01 module]$ scp -r kafka_2.11-2.2.0/ linyouyi@hadoop03:/hadoop/module/
4.修改另外两台的broker.id
[linyouyi@hadoop02 kafka_2.11-2.2.0]$ vim config/server.properties broker.id=2[linyouyi@hadoop03 kafka_2.11-2.2.0]$ vim config/server.propertiesbroker.id=3
5.启动kafka
[linyouyi@hadoop01 kafka_2.11-2.2.0]$ bin/kafka-server-start.sh config/server.properties &[linyouyi@hadoop01 kafka_2.11-2.2.0]$ jps109904 Jps44057 QuorumPeerMain109503 Kafka[linyouyi@hadoop02 kafka_2.11-2.2.0]$ bin/kafka-server-start.sh config/server.properties &[linyouyi@hadoop02 kafka_2.11-2.2.0]$ jps21308 Jps20925 Kafka34879 QuorumPeerMain[linyouyi@hadoop03 kafka_2.11-2.2.0]$ bin/kafka-server-start.sh config/server.properties &[linyouyi@hadoop03 kafka_2.11-2.2.0]$ jps119587 QuorumPeerMain37651 Jps37269 Kafka
使用
1.创建话题//hadoop01:9092,hadoop02:9092,hadoop03:9092都行[linyouyi@hadoop03 kafka_2.11-2.2.0]$ bin/kafka-topics.sh --create --bootstrap-server hadoop01:9092 --replication-factor 3 --partitions 1 --topic linyouyi[2019-08-17 15:30:34,616] INFO [ReplicaFetcherManager on broker 3] Removed fetcher for partitions Set(linyouyi-0) (kafka.server.ReplicaFetcherManager)[2019-08-17 15:30:34,649] INFO [Log partition=linyouyi-0, dir=/tmp/kafka-logs] Loading producer state till offset 0 with message format version 2 (kafka.log.Log)[2019-08-17 15:30:34,653] INFO [Log partition=linyouyi-0, dir=/tmp/kafka-logs] Completed load of log with 1 segments, log start offset 0 and log end offset 0 in 25 ms (kafka.log.Log)[2019-08-17 15:30:34,655] INFO Created log for partition linyouyi-0 in /tmp/kafka-logs with properties {compression.type -> producer, message.format.version -> 2.2-IV1, file.delete.delay.ms -> 60000, max.message.bytes -> 1000012, min.compaction.lag.ms -> 0, message.timestamp.type -> CreateTime, message.downconversion.enable -> true, min.insync.replicas -> 1, segment.jitter.ms -> 0, preallocate -> false, min.cleanable.dirty.ratio -> 0.5, index.interval.bytes -> 4096, unclean.leader.election.enable -> false, retention.bytes -> -1, delete.retention.ms -> 86400000, cleanup.policy -> [delete], flush.ms -> 9223372036854775807, segment.ms -> 604800000, segment.bytes -> 1073741824, retention.ms -> 604800000, message.timestamp.difference.max.ms -> 9223372036854775807, segment.index.bytes -> 10485760, flush.messages -> 9223372036854775807}. (kafka.log.LogManager)[2019-08-17 15:30:34,656] INFO [Partition linyouyi-0 broker=3] No checkpointed highwatermark is found for partition linyouyi-0 (kafka.cluster.Partition)[2019-08-17 15:30:34,658] INFO Replica loaded for partition linyouyi-0 with initial high watermark 0 (kafka.cluster.Replica)[2019-08-17 15:30:34,658] INFO Replica loaded for partition linyouyi-0 with initial high watermark 0 (kafka.cluster.Replica)[2019-08-17 15:30:34,658] INFO Replica loaded for partition linyouyi-0 with initial high watermark 0 (kafka.cluster.Replica)[2019-08-17 15:30:34,660] INFO [Partition linyouyi-0 broker=3] linyouyi-0 starts at Leader Epoch 0 from offset 0. Previous Leader Epoch was: -1 (kafka.cluster.Partition)[linyouyi@hadoop03 kafka_2.11-2.2.0]$ bin/kafka-topics.sh --list --bootstrap-server localhost:9092linyouyi[linyouyi@hadoop03 kafka_2.11-2.2.0]$ bin/kafka-topics.sh --list --bootstrap-server hadoop01:9092linyouyi[linyouyi@hadoop03 kafka_2.11-2.2.0]$ bin/kafka-topics.sh --list --zookeeper hadoop01:2181linyouyi[linyouyi@hadoop03 kafka_2.11-2.2.0]$ bin/kafka-topics.sh --create --bootstrap-server hadoop01:9092 --replication-factor 3 --partitions 1 --topic youyi[linyouyi@hadoop03 kafka_2.11-2.2.0]$ bin/kafka-topics.sh --list --zookeeper hadoop01:2181linyouyiyouyi 2.生产者往话题里面写消息
[linyouyi@hadoop03 kafka_2.11-2.2.0]$ bin/kafka-console-producer.sh --broker-list localhost:9092 --topic linyouyi>This is a message>This is a message>This is another message
3.消费者消费消息
[linyouyi@hadoop02 kafka_2.11-2.2.0]$ bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic linyouyi --from-beginningThis is a messageThis is another message
4.接着在生产者继续写话题,消费者立马就消费了
5.查看topic linyouyi总体情况
[linyouyi@hadoop01 kafka_2.11-2.2.0]$ bin/kafka-topics.sh --describe --bootstrap-server localhost:9092 --topic linyouyiTopic:linyouyi PartitionCount:1 ReplicationFactor:3 Configs:segment.bytes=1073741824 Topic: linyouyi Partition: 0 Leader: 3 Replicas: 3,1,2 Isr: 3,1,2
[linyouyi@hadoop01 kafka_2.11-2.2.0]$ bin/kafka-topics.sh --describe --bootstrap-server localhost:9092 --topic youyiTopic:youyi PartitionCount:1 ReplicationFactor:3 Configs:segment.bytes=1073741824 Topic: youyi Partition: 0 Leader: 3 Replicas: 3,1,2 Isr: 3,1,2