问题：
1. Kafka的哪些信息记录在Zookeeper中
2. Consumer Group消费的每个Partition的Offset信息存放在什么位置3. Topic的每个Partition存放在哪个Broker上的信息存放在哪里
4. Producer跟Zookeeper究竟有没有关系？没有关系！！！
//consumers、config、brokers、controller_epoch都是Kafka相关的znode [zk: localhost:2181(CONNECTED) 0] ls / [abc, admin, zookeeper, consumers, config, controller, storm, brokers, controller_epoch] [zk: localhost:2181(CONNECTED) 1] ls ///consumers目录下是所有的consumer group的定义 [zk: localhost:2181(CONNECTED) 2] ls /consumers [test-consumer-group, topic-p6-r2-consumer-group, learn.topic.consumers.group, learn.topic.p8.r2.consumers.group] [zk: localhost:2181(CONNECTED) 3] ls learn.topic.p8.r2.consumers.group Command failed: java.lang.IllegalArgumentException: Path must start with / character ///consumer group下游offsets、owners和ids的定义 [zk: localhost:2181(CONNECTED) 4] ls /consumers/learn.topic.p8.r2.consumers.group [offsets, owners, ids] ///offsets下面是topic的定义 [zk: localhost:2181(CONNECTED) 5] ls /consumers/learn.topic.p8.r2.consumers.group/offsets [learn.topic.p8.r2] ///topic下面是partition的定义，learn.topic.p8.r2表示8个partition，2个副本 ///partition中的offset的设置在znode的data中，而不是子znode中 [zk: localhost:2181(CONNECTED) 6] ls /consumers/learn.topic.p8.r2.consumers.group/offsets/learn.topic.p8.r2 [3, 2, 1, 0, 7, 6, 5, 4] [zk: localhost:2181(CONNECTED) 7] ls /consumers/learn.topic.p8.r2.consumers.group/offsets/learn.topic.p8.r2/2 [] [zk: localhost:2181(CONNECTED) 8] ls /consumers/learn.topic.p8.r2.consumers.group/offsets/learn.topic.p8.r2/3 [] [zk: localhost:2181(CONNECTED) 9] ls /consumers/learn.topic.p8.r2.consumers.group/offsets/learn.topic.p8.r2/4 [] ///consumer group属于哪个topic所有，代码中不需要显式指定 ///consumer group消费哪个topic，kafka自动将topic设置为这个consumer group的owner [zk: localhost:2181(CONNECTED) 19] ls /consumers/learn.topic.p8.r2.consumers.group/owners [learn.topic.p8.r2] [zk: localhost:2181(CONNECTED) 20] ls /consumers/learn.topic.p8.r2.consumers.group/owners/learn.topic.p8.r2 [3, 2, 1, 0, 7, 6, 5, 4] [zk: localhost:2181(CONNECTED) 21] ls /consumers/learn.topic.p8.r2.consumers.group/owners/learn.topic.p8.r2/3 [] ///后面是broker的ID [zk: localhost:2181(CONNECTED) 23] ls /consumers/learn.topic.p8.r2.consumers.group/ids [learn.topic.p8.r2.consumers.group_TP-A383-D-1427853446455-efa1e47b] [zk: localhost:2181(CONNECTED) 24] ls /consumers/learn.topic.p8.r2.consumers.group/ids/learn.topic.p8.r2.consumers.group_TP-A383-D-1427853446455-efa1e47b [] [zk: localhost:2181(CONNECTED) 10] ls /brokers [topics, ids] [zk: localhost:2181(CONNECTED) 11] ls /brokers/topics [topic_p10_r3, topic-p6-r2, test_many_partitions, test, topic_p10_r1, learn.topic.p8.r2, learn.topic, topic-3-replica-1-part] [zk: localhost:2181(CONNECTED) 12] ls /brokers/topics/learn.topic.p8.r2 [partitions] [zk: localhost:2181(CONNECTED) 13] ls /brokers/topics/learn.topic.p8.r2/partitions [3, 2, 1, 0, 7, 6, 5, 4] [zk: localhost:2181(CONNECTED) 14] ls /brokers/topics/learn.topic.p8.r2/partitions/3 [state] [zk: localhost:2181(CONNECTED) 15] ls /brokers/topics/learn.topic.p8.r2/partitions/3/state [] [zk: localhost:2181(CONNECTED) 16] ls /brokers/ids [2, 1, 0] [zk: localhost:2181(CONNECTED) 17] ls /brokers/ids/2 [] [zk: localhost:2181(CONNECTED) 18]
每个Consumer Group的每个Partition的Offset信息是作为值存放在Partition节点上的，而不是作为子节点，如下所示，4704是3号Partition已经消费的Offset数
[zk: localhost:2181(CONNECTED) 28] get /consumers/learn.topic.p8.r2.consumers.group/offsets/learn.topic.p8.r2/3 4704 cZxid = 0x1bf14 ctime = Tue Mar 31 06:25:39 EDT 2015 mZxid = 0x1c658 mtime = Tue Mar 31 22:03:48 EDT 2015 pZxid = 0x1bf14 cversion = 0 dataVersion = 177 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 4 numChildren = 0
Topic的每个Partition存放在哪个Broker上的信息存放在哪里？
[zk: localhost:2181(CONNECTED) 30] ls /brokers
[topics, ids]
[zk: localhost:2181(CONNECTED) 31] ls /brokers/topics
[topic_p10_r3, topic-p6-r2, test_many_partitions, test, topic_p10_r1, learn.topic.p8.r2, learn.topic, topic-3-replica-1-part]
[zk: localhost:2181(CONNECTED) 32] ls /brokers/topics/learn.topic.p8.r2
[partitions]
[zk: localhost:2181(CONNECTED) 33] ls /brokers/topics/learn.topic.p8.r2/partitions
[3, 2, 1, 0, 7, 6, 5, 4]
[zk: localhost:2181(CONNECTED) 34] ls /brokers/topics/learn.topic.p8.r2/partitions/3
[state]
[zk: localhost:2181(CONNECTED) 35] ls /brokers/topics/learn.topic.p8.r2/partitions/3/state
[]
///
[zk: localhost:2181(CONNECTED) 36] get /brokers/topics/learn.topic.p8.r2/partitions/3/state
{"controller_epoch":42,"leader":0,"version":1,"leader_epoch":2,"isr":[0,1]}
cZxid = 0x1bee8
ctime = Tue Mar 31 05:34:16 EDT 2015
mZxid = 0x1c247
mtime = Tue Mar 31 21:48:01 EDT 2015
pZxid = 0x1bee8
cversion = 0
dataVersion = 5
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 75
numChildren = 0
每个Broker的信息：包括host和port
//三个broker
[zk: localhost:2181(CONNECTED) 38] ls /brokers/ids
[2, 1, 0]
[zk: localhost:2181(CONNECTED) 39] ls /brokers/ids/2
[]
///host和port信息
[zk: localhost:2181(CONNECTED) 40] get /brokers/ids/2
{"jmx_port":-1,"timestamp":"1427852973061","host":"192.168.26.140","version":1,"port":9094}
cZxid = 0x1c257
ctime = Tue Mar 31 21:49:33 EDT 2015
mZxid = 0x1c257
mtime = Tue Mar 31 21:49:33 EDT 2015
pZxid = 0x1c257
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x14c72a6b3610003
dataLength = 91
numChildren = 0
每个Topic的Partion存放在哪个或者哪些Broker上，信息存放在
///每个partition的leaderpartition和follower partition信息
[zk: localhost:2181(CONNECTED) 53] get /brokers/topics/learn.topic.p8.r2
{"version":1,"partitions":{"4":[2,1],"5":[0,2],"6":[1,2],"1":[2,0],"0":[1,2],"2":[0,1],"7":[2,0],"3":[1,0]}}