使用 ansible 部署 kafka 集群

置顶环境搭建环境搭建 Kafka

创建时间:2017-12-03 07:01

字数:4.6k

初始化 role
设置要用到的变量
准备 kafka 配置文件的模板
编写 tasks
编写 hosts 文件
编写启动文件
执行
项目地址
kafka 常用配置介绍
测试
命令行操作
常用配置介绍
1. Broker 配置
2. Consumer 配置

【必须】kafka 依赖 zookeeper ,所以安装 kafka 前要前搭建一个zookeeper集群,一般这两个集群是在同一集群内,搭建zookeeper集群可以参考zookeeper 环境

初始化 role

在任意目录(这里以test文件夹为例)下执行 ansible-galaxy init kafka ,初始化一个 roles

设置要用到的变量

---
# defaults file for kafka
# kafka 版本
kafka_version: "1.0.1"
scala_version: "2.12"
scala_kafka_version: "{{ 'kafka_' + scala_version + '-' + kafka_version }}"
# 下载地址
kafka_download_url: "http://mirrors.hust.edu.cn/apache/kafka/{{ kafka_version }}/{{ scala_kafka_version }}.tgz"
# 下载到本地的 ~/Downloads
kafka_download_dest: ~/Downloads/{{ scala_kafka_version }}.tgz

# 安装目录
kafka_install_dir: /usr/local/
# kafka 目录
kafka_dir: "/usr/local/kafka_{{ scala_version }}-{{ kafka_version }}"
# kafka 目录软链接
soft_dir: /usr/local/kafka
# kafka 配置文件目录
kafka_conf_dir: "{{ soft_dir }}/config/"
# kafka 持久化目录
kafka_log_dir: /var/kafka
# 设置环境变量
env_file: ~/.bashrc

准备 kafka 配置文件的模板

提前在控制节点解压出一份 kafka 默认的配置文件server.properties, 复制到 test/kafka/templates/ 下更名为 server.properties.j2, 在这里主要配置以下几项:

{# kafka节点在集群中的标识, 这里的id, 是在 hosts 文件中配置好的 #}
broker.id={{ id }}

{#
  因为 ansible 是用 ssh 的,所以 ansible_env.SSH_CONNECTION 变量一定存在,
  ansible_env.SSH_CONNECTION: "172.17.0.1 20742 172.17.0.4 22"可以通过这个字符串获取到 ip
#}
{% set ip = ansible_env.SSH_CONNECTION.split(" ")[2] %}
listeners=PLAINTEXT://{{ ip }}:9092

{# 
  一般来说,kafka 集群和依赖的 zookeeper 集群都在同一个集群上,
  所以这里获取到hosts列表,遍历输出就是 kafka 对应的 zookeeper 集群配置 
#}
zookeeper.connect={% for host in ansible_play_batch %}{{ host }}:2181,{% endfor %}

编写 tasks

如果一个 tasks 有很多步骤,可以把它们分置在不同的文件中,最后在 test/kafka/tasks/main.yml 文件中引用他们,这样做方便调试,方便阅读

编写下载过程

在 test/kafka/tasks/ 下新建文件 download.yml

---
# 下载 kafka
- name: 判断 kafka 源文件是否已经下载好了
  command: ls {{ kafka_download_dest }}
  ignore_errors: true
  register: file_exist
  connection: local

- name: 下载文件
  get_url:
    url: "{{ kafka_download_url}}"
    dest: "{{ kafka_download_dest }}"
    force: yes
  when: file_exist|failed
  connection: local

- name: 解压
  unarchive:
    src: "{{ kafka_download_dest }}"
    dest: "{{ kafka_install_dir }}"

编写配置和启动过程

在 test/kafka/tasks/ 下新建文件 init.yml

---
- name: 创建 kafka 的软链接
  file:
    src: "{{ kafka_dir }}"
    dest: "{{ soft_dir }}"
    state: link

- name: 设置 kafka 环境变量
  lineinfile:
    dest: "{{env_file}}"
    insertafter: "{{item.position}}"
    line: "{{item.value}}"
    state: present
  with_items:
    - {position: EOF, value: "\n"}
    - {position: EOF, value: "{{ 'export KAFKA_HOME=' + soft_dir }}"}
    - {position: EOF, value: "export PATH=$KAFKA_HOME/bin:$PATH"}

- name: 设置配置文件
  template:
    src: server.properties.j2
    dest: "{{ kafka_conf_dir + 'server.properties' }}"
    force: yes

- name: 启动 kafka 服务器
  shell: "{{ 'kafka-server-start.sh' + ' -daemon ' + kafka_conf_dir + 'server.properties' }}"
  environment:
    PATH: /usr/local/kafka/bin:/usr/local/zookeeper/bin:/usr/local/java/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
    KAFKA_HOME: usr/local/kafka

合并所有tasks

---
# tasks file for kafka
- import_tasks: download.yml
- import_tasks: init.yml

编写 hosts 文件

在 test/ 目录下新建文件 hosts

# 这里的id很重要,用于配置kafka在集群中的标识
[test]
172.17.0.2 id=1
172.17.0.3 id=2
172.17.0.4 id=3

编写启动文件

---
- hosts: test
  remote_user: root
  roles:
    - kafka

执行

在 test/ 目录下执行

1
2
3

# ansible 是通过 ssh 执行命令的,所以最佳实践中推荐的是设置 ssh 免密码登录
# 如果没有设置,而已在执行命令后加 -k 参数,手动输入密码, 这里 root 用户的密码是 root
ansible-playbook -i hosts run.yml -k

至此,就可以在集群中部署完成 kafka

项目地址

kafka 常用配置介绍

broker.id=0  # 当前 kafka 节点在集群中的标识 
port=9092  # 对外提供服务的端口,建议不要设置为默认端口
num.network.thread=4  # 网络连接的线程数,建议默认
num.io.thread=8  # 处理文件io的线程数,这个参数与 log.dirs 参数相关,lo.dir可以配置多个,这个参数至少应该大于 log.dirs 中的目录数量,确保每个目录都有一个线程处理

socket.send.buffer.bytes=1048576  # 发送消息缓冲区,不是一点一点的发送,而是超过buffer再一起发送,可以提高性能
socket.receive.buffer.bytes=1048576  # 接收消息缓冲区
socket.request.max.bytes=104857600  # 向kafka请求的最大数, 不能超过java的堆栈大小

log.dirs=/tmp/kafka, /tmp/kafka2  # kafka 持久化目录
log.retention.hours=168  # 持久化保存的最大时间,默认是 7 天
num.partitions=2  # topic 的默认分区数
zookeeper.connect=ip:port,ip:port  # zookeeper 集群的服务器,用逗号分隔

message.max.byte=5048576  # kafka 每条消息能够容纳的最大大小
default.replication.factor=2  # 默认的副本数
replica.fetch.max.bytes=5048576  # 取消息的最大长度

log.segment.bytes=536870912  # 消息持久化文件的最大大小

测试

安装完成后,可以ssh登录集群上的服务器,进行测试，过程如图，注意观察所用的 ip，只要是在集群中的 ip ，都可以使用

命令行操作

# 查看当前服务器中的所有topic
kafka-topics.sh --zookeeper 127.0.0.1:2181 --list

# 创建 topic
# --topic 定义topic名
# --replication-factor  定义副本数
# --partitions  定义分区数
kafka-topics.sh --zookeeper 127.0.0.1:2181 --create --replication-factor 3 --partitions 1 --topic first

# 删除 topic 
# 需要server.properties中设置delete.topic.enable=true否则只是标记删除或者直接重启。
kafka-topics.sh --zookeeper 127.0.0.1:2181 --delete --topic first

# 发送消息
kafka-console-producer.sh --broker-list 127.0.0.1:9092 --topic first

# 消费消息
# --from-beginning：会把first主题中以往所有的数据都读取出来。根据业务场景选择是否增加该配置。
kafka-console-consumer.sh --zookeeper 127.0.0.1:2181 --from-beginning --topic first

# 查看 topic 详情
kafka-topics.sh --zookeeper 127.0.0.1:2181 --describe --topic first

常用配置介绍

Broker 配置

配置项	默认值	说明
broker.id=0		必填参数, 当前 kafka 节点在集群中的标一标识
port	9092	对外提供服务的端口,建议不要设置为默认端口
num.network.thread	4	网络连接的线程数,建议默认
num.io.thread	4	处理文件io的线程数,这个参数与 log.dirs参数相关,lo.dir可以配置多个,这个参数至少应该大于 log.dirs 中的目录数量,确保每个目录都有一个线程处理
socket.send.buffer.bytes	1048576	发送消息缓冲区,不是一点一点的发送,而是超过buffer再一起发送,可以提高性能
socket.receive.buffer.bytes	1048576	接收消息缓冲区
socket.request.max.bytes	104857600	向kafka请求的最大数, 不能超过java的堆栈大小
log.dirs	/tmp/kafka, /tmp/kafka2	kafka 持久化目录可以指定多个目录，中间用逗号分隔，当新partition被创建的时会被存放到当前存放partition最少的目录。
log.retention.hours	168	持久化保存的最大时间,默认是 7 天
num.partitions	2	topic 的默认分区数
zookeeper.connect	ip:port,ip:port	zookeeper 集群的服务器,用逗号分隔
message.max.byte	5048576	kafka 每条消息能够容纳的最大大小
default.replication.factor	2	默认的副本数
replica.fetch.max.bytes	5048576	取消息的最大长度
log.segment.bytes	536870912	消息持久化文件的最大大小
message.max.bytes	1000000	服务器可以接收到的最大的消息大小。注意此参数要和consumer的maximum.message.size大小一致，否则会因为生产者生产的消息太大导致消费者无法消费。
num.io.threads	8	服务器用来执行读写请求的IO线程数，此参数的数量至少要等于服务器上磁盘的数量。
queued.max.requests	500	I/O线程可以处理请求的队列大小，若实际请求数超过此大小，网络线程将停止接收新的请求。
socket.send.buffer.bytes	100 * 1024	The SO_SNDBUFF buffer the server prefers for socket connections.
socket.receive.buffer.bytes	100 * 1024	The SO_RCVBUFF buffer the server prefers for socket connections.
socket.request.max.bytes	100 * 1024 * 1024	服务器允许请求的最大值，用来防止内存溢出，其值应该小于 Java heap size.
num.partitions	1 默认partition数量	如果topic在创建时没有指定partition数量，默认使用此值，建议改为5
log.segment.bytes	1024 * 1024 * 1024	Segment文件的大小，超过此值将会自动新建一个segment，此值可以被topic级别的参数覆盖。
log.roll.{ms,hours}	24 * 7 hours	新建segment文件的时间，此值可以被topic级别的参数覆盖。
log.retention.{ms,minutes,hours}	7 days	Kafka segment log的保存周期，保存周期超过此时间日志就会被删除。此参数可以被topic级别参数覆盖。数据量大时，建议减小此值。
log.retention.bytes	-1	每个partition的最大容量，若数据量超过此值，partition数据将会被删除。注意这个参数控制的是每个partition而不是topic。此参数可以被log级别参数覆盖。
log.retention.check.interval.ms	5 minutes	删除策略的检查周期
auto.create.topics.enable	true	自动创建topic参数，建议此值设置为false，严格控制topic管理，防止生产者错写topic。
default.replication.factor	1	默认副本数量，建议改为2。
replica.lag.time.max.ms	10000	在此窗口时间内没有收到follower的fetch请求，leader会将其从ISR(in-sync replicas)中移除。
replica.lag.max.messages	4000	如果replica节点落后leader节点此值大小的消息数量，leader节点就会将其从ISR中移除。
replica.socket.timeout.ms	30 * 1000	replica向leader发送请求的超时时间。
replica.socket.receive.buffer.bytes	64 * 1024	The socket receive buffer for network requests to the leader for replicating data.
replica.fetch.max.bytes	1024 * 1024	The number of byes of messages to attempt to fetch for each partition in the fetch requests the replicas send to the leader.
replica.fetch.wait.max.ms	500	The maximum amount of time to wait time for data to arrive on the leader in the fetch requests sent by the replicas to the leader.
num.replica.fetchers	1	Number of threads used to replicate messages from leaders. Increasing this value can increase the degree of I/O parallelism in the follower broker.
fetch.purgatory.purge.interval.requests	1000	The purge interval (in number of requests) of the fetch request purgatory.
zookeeper.session.timeout.ms	6000	ZooKeeper session 超时时间。如果在此时间内server没有向zookeeper发送心跳，zookeeper就会认为此节点已挂掉。此值太低导致节点容易被标记死亡；若太高，.会导致太迟发现节点死亡。
zookeeper.connection.timeout.ms	6000	客户端连接zookeeper的超时时间。
zookeeper.sync.time.ms	2000	H ZK follower落后 ZK leader的时间。
controlled.shutdown.enable	true	允许broker shutdown。如果启用，broker在关闭自己之前会把它上面的所有leaders转移到其它brokers上，建议启用，增加集群稳定性。
auto.leader.rebalance.enable	true	If this is enabled the controller will automatically try to balance leadership for partitions among the brokers by periodically returning leadership to the “preferred” replica for each partition if it is available.
leader.imbalance.per.broker.percentage	10	The percentage of leader imbalance allowed per broker. The controller will rebalance leadership if this ratio goes above the configured value per broker.
leader.imbalance.check.interval.seconds	300	The frequency with which to check for leader imbalance.
offset.metadata.max.bytes	4096	The maximum amount of metadata to allow clients to save with their offsets.
connections.max.idle.ms	600000	Idle connections timeout: the server socket processor threads close the connections that idle more than this.
num.recovery.threads.per.data.dir	1	The number of threads per data directory to be used for log recovery at startup and flushing at shutdown.
unclean.leader.election.enable	true	Indicates whether to enable replicas not in the ISR set to be elected as leader as a last resort, even though doing so may result in data loss.
delete.topic.enable	false	启用deletetopic参数，建议设置为true。
offsets.topic.num.partitions	50	The number of partitions for the offset commit topic. Since changing this after deployment is currently unsupported, we recommend using a higher setting for production (e.g., 100-200).
offsets.topic.retention.minutes	1440	Offsets that are older than this age will be marked for deletion. The actual purge will occur when the log cleaner compacts the offsets topic.
offsets.retention.check.interval.ms	600000	The frequency at which the offset manager checks for stale offsets.
offsets.topic.replication.factor	3	The replication factor for the offset commit topic. A higher setting (e.g., three or four) is recommended in order to ensure higher availability. If the offsets topic is created when fewer brokers than the replication factor then the offsets topic will be created with fewer replicas.
offsets.topic.segment.bytes	104857600	Segment size for the offsets topic. Since it uses a compacted topic, this should be kept relatively low in order to facilitate faster log compaction and loads.
offsets.load.buffer.size	5242880	An offset load occurs when a broker becomes the offset manager for a set of consumer groups (i.e., when it becomes a leader for an offsets topic partition). This setting corresponds to the batch size (in bytes) to use when reading from the offsets segments when loading offsets into the offset manager’s cache.
offsets.commit.required.acks	-1	The number of acknowledgements that are required before the offset commit can be accepted. This is similar to the producer’s acknowledgement setting. In general, the default should not be overridden.
offsets.commit.timeout.ms	5000	The offset commit will be delayed until this timeout or the required number of replicas have received the offset commit. This is similar to the producer request timeout.
##### Producer 配置

配置项	默认值	说明
metadata.broker.list		启动时producer查询brokers的列表，可以是集群中所有brokers的一个子集。注意，这个参数只是用来获取topic的元信息用，producer会从元信息中挑选合适的broker并与之建立socket连接。格式是：host1:port1,host2:port2。
request.required.acks	0
request.timeout.ms	10000	Broker等待ack的超时时间，若等待时间超过此值，会返回客户端错误信息。
producer.type	sync	同步异步模式。async表示异步，sync表示同步。如果设置成异步模式，可以允许生产者以batch的形式push数据，这样会极大的提高broker性能，推荐设置为异步。
serializer.class	kafka.serializer.DefaultEncoder	序列号类，.默认序列化成 byte[] 。
key.serializer.class		Key的序列化类，默认同上。
partitioner.class	kafka.producer.DefaultPartitioner	Partition类，默认对key进行hash。
compression.codec	none	指定producer消息的压缩格式，可选参数为： “none”, “gzip” and “snappy”。关于压缩参见4.1节
compressed.topics	null	启用压缩的topic名称。若上面参数选择了一个压缩格式，那么压缩仅对本参数指定的topic有效，若本参数为空，则对所有topic有效。
message.send.max.retries	3	Producer发送失败时重试次数。若网络出现问题，可能会导致不断重试。
retry.backoff.ms	100	Before each retry, the producer refreshes the metadata of relevant topics to see if a new leader has been elected. Since leader election takes a bit of time, this property specifies the amount of time that the producer waits before refreshing the metadata.
topic.metadata.refresh.interval.ms	600 * 1000	The producer generally refreshes the topic metadata from brokers when there is a failure (partition missing, leader not available…). It will also poll regularly (default: every 10min so 600000ms). If you set this to a negative value, metadata will only get refreshed on failure. If you set this to zero, the metadata will get refreshed after each message sent (not recommended). Important note: the refresh happen only AFTER the message is sent, so if the producer never sends a message the metadata is never refreshed
queue.buffering.max.ms	5000	启用异步模式时，producer缓存消息的时间。比如我们设置成1000时，它会缓存1秒的数据再一次发送出去，这样可以极大的增加broker吞吐量，但也会造成时效性的降低。
queue.buffering.max.messages	10000	采用异步模式时producer buffer 队列里最大缓存的消息数量，如果超过这个数值，producer就会阻塞或者丢掉消息。
queue.enqueue.timeout.ms	-1	当达到上面参数值时producer阻塞等待的时间。如果值设置为0，buffer队列满时producer不会阻塞，消息直接被丢掉。若值设置为-1，producer会被阻塞，不会丢消息。
batch.num.messages	200	采用异步模式时，一个batch缓存的消息数量。达到这个数量值时producer才会发送消息。
send.buffer.bytes	100 * 1024	Socket write buffer size
client.id	“”	The client id is a user-specified string sent in each request to help trace calls. It should logically identify the application making the request.

Consumer 配置

配置项	默认值	说明
group.id		Consumer的组ID，相同goup.id的consumer属于同一个组。
zookeeper.connect		Consumer的zookeeper连接串，要和broker的配置一致。
consumer.id	null	如果不设置会自动生成。
socket.timeout.ms	30 * 1000	网络请求的socket超时时间。实际超时时间由max.fetch.wait + socket.timeout.ms 确定。
socket.receive.buffer.bytes	64 * 1024	The socket receive buffer for network requests.
fetch.message.max.bytes	1024 * 1024	查询topic-partition时允许的最大消息大小。consumer会为每个partition缓存此大小的消息到内存，因此，这个参数可以控制consumer的内存使用量。这个值应该至少比server允许的最大消息大小大，以免producer发送的消息大于consumer允许的消息。
num.consumer.fetchers	1	The number fetcher threads used to fetch data.
auto.commit.enable	true	如果此值设置为true，consumer会周期性的把当前消费的offset值保存到zookeeper。当consumer失败重启之后将会使用此值作为新开始消费的值。
auto.commit.interval.ms	60 * 1000	Consumer提交offset值到zookeeper的周期。
queued.max.message.chunks	2	用来被consumer消费的message chunks 数量，每个chunk可以缓存fetch.message.max.bytes大小的数据量。
auto.commit.interval.ms	60 * 1000	Consumer提交offset值到zookeeper的周期。
queued.max.message.chunks	2	用来被consumer消费的message chunks 数量，每个chunk可以缓存fetch.message.max.bytes大小的数据量。
fetch.min.bytes	1	The minimum amount of data the server should return for a fetch request. If insufficient data is available the request will wait for that much data to accumulate before answering the request.
fetch.wait.max.ms	100	The maximum amount of time the server will block before answering the fetch request if there isn’t sufficient data to immediately satisfy fetch.min.bytes.
rebalance.backoff.ms	2000	Backoff time between retries during rebalance.
refresh.leader.backoff.ms	200	Backoff time to wait before trying to determine the leader of a partition that has just lost its leader.
auto.offset.reset	largest	What to do when there is no initial offset in ZooKeeper or if an offset is out of range ;smallest : automatically reset the offset to the smallest offset; largest : automatically reset the offset to the largest offset;anything else: throw exception to the consumer
consumer.timeout.ms	-1	若在指定时间内没有消息消费，consumer将会抛出异常。
exclude.internal.topics	true	Whether messages from internal topics (such as offsets) should be exposed to the consumer.
zookeeper.session.timeout.ms	6000	ZooKeeper session timeout. If the consumer fails to heartbeat to ZooKeeper for this period of time it is considered dead and a rebalance will occur.
zookeeper.connection.timeout.ms	6000	The max time that the client waits while establishing a connection to zookeeper.
zookeeper.sync.time.ms	2000	How far a ZK follower can be behind a ZK leader