###一、下载解压 ###二、配置 配置config/server.properties 配置broker.id从0开始，后面的节点配置1，2，3，4等 ###事先启动zookeeper集群，这里配置zookeeper集群的地址
###分发到其他机器上
scp -r kafka root@slave1:/opt/
scp -r kafka root@slave2:/opt/
##注意修改broker.id
###修改完配置以后在每个节点启动kafka
bin/kafka-server-start.sh config/server.properties
##二、测试 ###2.1、新建一个topic
./bin/kafka-topics.sh -zookeeper master:3384,slave1:3384,slave2:3384 -topic test -replication-factor 2 -partitions 5 -create
###2.2、查看当前的topic
./bin/kafka-topics.sh -zookeeper master:3384,slave1:3384,slave2:3384 -list
###2.3、在一个节点创建一个provider
./bin/kafka-console-producer.sh --broker-list master:9092,slave1:9092,slave2:9092 --topic test1
###2.4、在另外一个节点创建一个consumer
./bin/kafka-console-consumer.sh --zookeeper master:3384,slave1:3384,slave2:3384 --from-beginning -topic test1
##出现错误
[2017-03-16 04:03:57,360] WARN Error while fetching metadata with correlation id 363 : {test=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2017-03-16 04:03:57,462] WARN Error while fetching metadata with correlation id 364 : {test=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2017-03-16 04:03:57,564] WARN Error while fetching metadata with correlation id 365 : {test=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
[2017-03-16 04:03:57,668] WARN Error while fetching metadata with correlation id 366 : {test=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
##解决思路：
###1、将hosts文件中127.0.0.1后面的主机名删除
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 master
改为:
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
###2、修改kafka文件中的listener
listeners=PLAINTEXT://:9092
改为:
listeners=PLAINTEXT://master:9092
3、重启kafka,成功了
##kafka的负载均衡
##segment ###一个topic由多个partition组成， 一个partition由多个segment组成。
##三、Kafka的配置文件config/server.properties
[root@slave1 kafka]# cd config/
[root@slave1 config]# more server.properties
############################# Server Basics #############################
#在kafka集群中，每个结点都有一个唯一的borker.id, 序号从零开始
# The id of the broker. This must be set to a unique integer for each broker.
broker.id=1
############################# Socket Server Settings #############################
listeners=PLAINTEXT://:9092
# The port the socket server listens on
port=9092
# Hostname the broker will bind to. If not set, the server will bind to all interfaces
#本机的hostname
host.name=slave1
# Hostname the broker will advertise to producers and consumers. If not set, it uses the
# value for "host.name" if configured. Otherwise, it will use the value returned from
# java.net.InetAddress.getCanonicalHostName().
#advertised.host.name=
# The port to publish to ZooKeeper for clients to use. If this is not set,
# it will publish the same port that the broker binds to.
#advertised.port=
# The number of threads handling network requests
num.network.threads=3
# The number of threads doing disk I/O
num.io.threads=8
# The send buffer (SO_SNDBUF) used by the socket server
socket.send.buffer.bytes=102400
# The receive buffer (SO_RCVBUF) used by the socket server
socket.receive.buffer.bytes=102400
# The maximum size of a request that the socket server will accept (protection against OOM)
socket.request.max.bytes=104857600
############################# Log Basics #############################
#此处实际是kafka的数据存储位置， 可以设置多个目录， 使用逗号隔开
# A comma seperated list of directories under which to store log files
log.dirs=/tmp/kafka-logs
# The default number of log partitions per topic. More partitions allow greater
# parallelism for consumption, but this will also result in more files across
# the brokers.
#默认每个topic只有一个partition
num.partitions=1
# The number of threads per data directory to be used for log recovery at startup and flushing at shutdown.
# This value is recommended to be increased for installations with data dirs located in RAID array.
num.recovery.threads.per.data.dir=1
############################# Log Flush Policy #############################
# Messages are immediately written to the filesystem but by default we only fsync() to sync
# the OS cache lazily. The following configurations control the flush of data to disk.
# There are a few important trade-offs here:
# 1. Durability: Unflushed data may be lost if you are not using replication.
# 2. Latency: Very large flush intervals may lead to latency spikes when the flush does occur as there will be a lot of data to flush.
# 3. Throughput: The flush is generally the most expensive operation, and a small flush interval may lead to exceessive seeks.
# The settings below allow one to configure the flush policy to flush data after a period of time or
# every N messages (or both). This can be done globally and overridden on a per-topic basis.
# The number of messages to accept before forcing a flush of data to disk
#log.flush.interval.messages=10000
# The maximum amount of time a message can sit in a log before we force a flush
#log.flush.interval.ms=1000
############################# Log Retention Policy #############################
# The following configurations control the disposal of log segments. The policy can
# be set to delete segments after a period of time, or after a given size has accumulated.
# A segment will be deleted whenever *either* of these criteria are met. Deletion always happens
# from the end of the log.
# The minimum age of a log file to be eligible for deletion
#数据保存的时间
log.retention.hours=168
# A size-based retention policy for logs. Segments are pruned from the log as long as the remaining
# segments don't drop below log.retention.bytes.
#log.retention.bytes=1073741824
# The maximum size of a log segment file. When this size is reached a new log segment will be created.
log.segment.bytes=1073741824
# The interval at which log segments are checked to see if they can be deleted according
# to the retention policies
log.retention.check.interval.ms=300000
############################# Zookeeper #############################
# Zookeeper connection string (see zookeeper docs for details).
# This is a comma separated host:port pairs, each corresponding to a zk
# server. e.g. "127.0.0.1:3000,127.0.0.1:3001,127.0.0.1:3002".
# You can also append an optional chroot string to the urls to specify the
# root directory for all kafka znodes.
#zookeeper的配置列表
zookeeper.connect=master:3384,slave1:3384,slave2:3384
# Timeout in ms for connecting to zookeeper
zookeeper.connection.timeout.ms=6000
