Kafka Tools

参考，

https://cwiki.apache.org/confluence/display/KAFKA/System+Tools

https://cwiki.apache.org/confluence/display/KAFKA/Replication+tools

http://kafka.apache.org/documentation.html#quickstart

http://kafka.apache.org/documentation.html#operations

为了便于使用，kafka提供了比较强大的Tools，把经常需要使用的整理一下

开关kafka Server

bin/kafka-server-start.sh config/server.properties
bin/kafka-server-stop.sh
JMX_PORT=9999 nohup bin/kafka-server-start.sh config/server.properties &

topic相关

bin/kafka-topics.sh --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic test
bin/kafka-topics.sh --list --zookeeper localhost:2181

describe topic的详细情况

bin/kafka-topics.sh --describe --zookeeper localhost:2181 --topic test

修改topic的partition，只能增加

bin/kafka-topics.sh --alter --zookeeper localhost:2181 --partitions 3 --topic test

到0.8.2才正式支持删除topic，当前是beta版

/usr/local/rds/kafka/bin/kafka-topics.sh --delete --topic topic_name --zookeeper localhost:2181

注意在配置里面，delete.topic.enable=true

查看有问题的partition

bin/kafka-topics.sh --describe --zookeeper localhost:2181 --unavailable-partitions --topic test

per-topic 修改参数

> bin/kafka-topics.sh --zookeeper localhost:2181 --create --topic my-topic --partitions 1
        --replication-factor 1 --config max.message.bytes=64000 --config flush.messages=1

> bin/kafka-topics.sh --zookeeper localhost:2181 --alter --topic my-topic
    --config max.message.bytes=128000

> bin/kafka-topics.sh --zookeeper localhost:2181 --alter --topic my-topic
    --deleteConfig max.message.bytes

集群扩展
集群扩展，对于broker还是比较简单的，但是现有的topic上的partition是不会做自动迁移的

需要手工做迁移，但kafka提供了比较方便的工具，

--generate，生成参考的迁移计划

given a list of topics and a list of brokers，工具会给出迁徙方案

把topic完全迁移到新的brokers

> cat topics-to-move.json
{"topics": [{"topic": "foo1"},
            {"topic": "foo2"}],
 "version":
}

> bin/kafka-reassign-partitions.sh --zookeeper localhost: --topics-to-move-json-file topics-to-move.json --broker-list "5,6" --generate
Current partition replica assignment

{"version":,
 "partitions":[{"topic":"foo1","partition":,"replicas":[,]},
               {"topic":"foo1","partition":,"replicas":[,]},
               {"topic":"foo2","partition":,"replicas":[,]},
               {"topic":"foo2","partition":,"replicas":[,]},
               {"topic":"foo1","partition":,"replicas":[,]},
               {"topic":"foo2","partition":,"replicas":[,]}]
}

Proposed partition reassignment configuration

{"version":,
 "partitions":[{"topic":"foo1","partition":,"replicas":[,]},
               {"topic":"foo1","partition":,"replicas":[,]},
               {"topic":"foo2","partition":,"replicas":[,]},
               {"topic":"foo2","partition":,"replicas":[,]},
               {"topic":"foo1","partition":,"replicas":[,]},
               {"topic":"foo2","partition":,"replicas":[,]}]
}

给出当前的assignment情况和，迁移方案

我们可以同时保存当前的assignment情况和迁移方案，当前的assignment情况可以用于rollback

--execute，开始执行迁移

> bin/kafka-reassign-partitions.sh --zookeeper localhost: --reassignment-json-file expand-cluster-reassignment.json --execute
Current partition replica assignment

{"version":,
 "partitions":[{"topic":"foo1","partition":,"replicas":[,]},
               {"topic":"foo1","partition":,"replicas":[,]},
               {"topic":"foo2","partition":,"replicas":[,]},
               {"topic":"foo2","partition":,"replicas":[,]},
               {"topic":"foo1","partition":,"replicas":[,]},
               {"topic":"foo2","partition":,"replicas":[,]}]
}

Save this to use as the --reassignment-json-file option during rollback
Successfully started reassignment of partitions
{"version":,
 "partitions":[{"topic":"foo1","partition":,"replicas":[,]},
               {"topic":"foo1","partition":,"replicas":[,]},
               {"topic":"foo2","partition":,"replicas":[,]},
               {"topic":"foo2","partition":,"replicas":[,]},
               {"topic":"foo1","partition":,"replicas":[,]},
               {"topic":"foo2","partition":,"replicas":[,]}]
}

--verify，check当前的迁移状态

> bin/kafka-reassign-partitions.sh --zookeeper localhost: --reassignment-json-file expand-cluster-reassignment.json --verify
Status of partition reassignment:
Reassignment of partition [foo1,] completed successfully
Reassignment of partition [foo1,] is in progress
Reassignment of partition [foo1,] is in progress
Reassignment of partition [foo2,] completed successfully
Reassignment of partition [foo2,] completed successfully
Reassignment of partition [foo2,] completed successfully

选择topic的某个partition的某些replica进行迁徙

moves partition 0 of topic foo1 to brokers 5,6 and partition 1 of topic foo2 to brokers 2,3

> cat custom-reassignment.json
{"version":,"partitions":[{"topic":"foo1","partition":,"replicas":[,]},{"topic":"foo2","partition":,"replicas":[,]}]}

> bin/kafka-reassign-partitions.sh --zookeeper localhost: --reassignment-json-file custom-reassignment.json --execute
Current partition replica assignment

{"version":,
 "partitions":[{"topic":"foo1","partition":,"replicas":[,]},
               {"topic":"foo2","partition":,"replicas":[,]}]
}

Save this to use as the --reassignment-json-file option during rollback
Successfully started reassignment of partitions
{"version":,
 "partitions":[{"topic":"foo1","partition":,"replicas":[,]},
               {"topic":"foo2","partition":,"replicas":[,]}]
}

brokers下线

当前版本不支持下线的规划，需要到0.8.2才支持，这需要把一个broker上的replica清空

增加replication factor

partition 0的replica数从1增长到3，当前replica存在broker5，在broker6，7上增加replica

> cat increase-replication-factor.json
{"version":,
 "partitions":[{"topic":"foo","partition":,"replicas":[,,]}]}

> bin/kafka-reassign-partitions.sh --zookeeper localhost: --reassignment-json-file increase-replication-factor.json --execute
Current partition replica assignment

{"version":,
 "partitions":[{"topic":"foo","partition":,"replicas":[]}]}

Save this to use as the --reassignment-json-file option during rollback
Successfully started reassignment of partitions
{"version":,
 "partitions":[{"topic":"foo","partition":,"replicas":[,,]}]}

Producer console

> bin/kafka-console-producer.sh --broker-list localhost:9092 --topic test
This is a message
This is another message

后面可以任意的输入message，都会发到broker的topic中

Comsumer console

bin/kafka-console-consumer.sh --zookeeper localhost:2181 --topic test --from-beginning

从头读这个topic，可以重复读到所有数据
我在想为啥，每次都能replay，原来每次都是随机产生一个groupid

consumerProps.put("group.id","console-consumer-" + new Random().nextInt(100000))

Consumer Offset Checker

这个会显示出consumer group的offset情况， 必须参数为--group， 不指定--topic，默认为所有topic

Displays the:  Consumer Group, Topic, Partitions, Offset, logSize, Lag, Owner for the specified set of Topics and Consumer Group

bin/kafka-run-class.sh kafka.tools.ConsumerOffsetChecker

required argument: [group]

Option Description

------ -----------

--broker-info Print broker info

--group Consumer group.

--help Print this message.

--topic Comma-separated list of consumer

topics (all topics if absent).

--zkconnect ZooKeeper connect string. (default: localhost:2181)

Example,

bin/kafka-run-class.sh kafka.tools.ConsumerOffsetChecker --group pv

Group           Topic                          Pid Offset          logSize         Lag             Owner

pv              page_visits                    0   21              21              0               none

pv              page_visits                    1   19              19              0               none

pv              page_visits                    2   20              20              0               none

Export Zookeeper Offsets

将Zk中的offset信息以下面的形式打到file里面去

A utility that retrieves the offsets of broker partitions in ZK and prints to an output file in the following format:

/consumers/group1/offsets/topic1/1-0:286894308

/consumers/group1/offsets/topic1/2-0:284803985

bin/kafka-run-class.sh kafka.tools.ExportZkOffsets

required argument: [zkconnect]

Option Description

------ -----------

--group Consumer group.

--help Print this message.

--output-file Output file

--zkconnect ZooKeeper connect string. (default: localhost:2181)

Update Offsets In Zookeeper

这个挺有用，用于replay, kafka的文档有点坑爹，看了不知道咋用，还是看源码才看明白

A utility that updates the offset of every broker partition to the offset of earliest or latest log segment file, in ZK.

bin/kafka-run-class.sh kafka.tools.UpdateOffsetsInZK

USAGE: kafka.tools.UpdateOffsetsInZK$ [earliest | latest] consumer.properties topic

Example，

bin/kafka-run-class.sh kafka.tools.UpdateOffsetsInZK earliest config/consumer.properties  page_visits

Group           Topic                          Pid Offset          logSize         Lag             Owner

pv              page_visits                    0   0               21              21              none

pv              page_visits                    1   0               19              19              none

pv              page_visits                    2   0               20              20              none

可以看到offset已经被清0，Lag=logSize

更加直接的方式是，直接去Zookeeper里面看

通过zkCli.sh连上后，通过ls查看

Broker Node Registry

/brokers/ids/[0...N] --> host:port (ephemeral node)

Broker Topic Registry

/brokers/topics/[topic]/[0...N] --> nPartions (ephemeral node)

Consumer Id Registry

/consumers/[group_id]/ids/[consumer_id] --> {"topic1": #streams, ..., "topicN": #streams} (ephemeral node)

Consumer Offset Tracking

/consumers/[group_id]/offsets/[topic]/[broker_id-partition_id] --> offset_counter_value ((persistent node)

Partition Owner registry

/consumers/[group_id]/owners/[topic]/[broker_id-partition_id] --> consumer_node_id (ephemeral node)