zookeeper-查询zk服务器成员列表
查询zookeeper服务器成员列表
1. 通过Jmx公开的信息，查询服务器成员列表。
2. 您可以阅读zoo.cfg文件以获取zk服务器成员列表（死亡和活动的）
3. 自从3.4.0开始，新增内容：输出可用于监视群集运行状况的变量列表。
$ echo mntr | nc 192.168.10.133 2181
zk_version 3.4.0
zk_avg_latency 0
zk_max_latency 0
zk_min_latency 0
zk_packets_received 70
zk_packets_sent 69
zk_outstanding_requests 0
zk_server_state leader
zk_znode_count 4
zk_watch_count 0
zk_ephemerals_count 0
zk_approximate_data_size 27
zk_followers 4 - only exposed by the Leader
zk_synced_followers 4 - only exposed by the Leader
zk_pending_syncs 0 - only exposed by the Leader
zk_open_file_descriptor_count 23 - only available on Unix platforms
zk_max_file_descriptor_count 1024 - only available on Unix platforms注释：
- zk_server_state leader #本节点是leader
- zk_followers 4 #有4个followers
4. 显示zkServer配置文件中的成员列表：
echo stat |nc kafka-03.server 2181
Zookeeper version: 3.4.10-39d3a4f269333c922ed3db283be479f9deacaa0f, built on 03/23/2017 10:13 GMT
Clients:
/192.168.10.133:59882[1](queued=0,recved=567716,sent=567716)
/192.168.10.134:39442[1](queued=0,recved=523923,sent=523924)
/192.168.15.115:62226[0](queued=0,recved=1,sent=0)
/192.168.10.133:59332[1](queued=0,recved=82636,sent=82638)
Latency min/avg/max: 0/0/5754
Received: 8304257
Sent: 8302764
Connections: 4
Outstanding: 0
Zxid: 0x40001b172
Mode: leader
Node count: 14058
5. 使用zkCli.sh 查询zk服务器中配置文件的服务列表：
$ ./bin/zkCli.sh -server localhost:2181
[zk: localhost:3181(CONNECTED) 3] get /zookeeper/config
server.1=192.168.5.20:2881:3881:participant
server.2=192.168.5.21:3881:4881:participant
version=0AdminServer : https://zookeeper.apache.org/doc/r3.5.1-alpha/zookeeperAdmin.html
3.5.0中的新增功能： AdminServer是嵌入式Jetty服务器，为四个字母单词命令提供HTTP接口。默认情况下，服务器在端口8080上启动，并且通过访问URL"/commands/[command name]"发出命令，例如http://localhost:8080/commands/stat。命令响应作为JSON返回。与原始协议不同，命令不限于四个字母的名称，命令可以具有多个名称。例如，“ stmk”也可以称为"set_trace_mask"。要查看所有可用命令的列表，请将浏览器指向URL/commands（例如，http://localhost:8080/commands）。
AdminServer默认情况下处于启用状态，但可以通过以下任一方式禁用：
-
将zookeeper.admin.enableServer系统属性设置为false。
-
从类路径中删除Jetty。（如果您想覆盖ZooKeeper's jetty依赖，则此选项很有用。）
请注意，如果AdminServer被禁用，则TCP四字母词接口仍然可用。
$ curl http://localhost:8081/commands/mntr
{
"version" : "3.5.5-390fe37ea45dee01bf87dc1c042b5e3dcce88653, built on 05/03/2019 12:07 GMT",
"avg_latency" : 0,
"max_latency" : 0,
"min_latency" : 0,
"packets_received" : 0,
"packets_sent" : 0,
"num_alive_connections" : 0,
"outstanding_requests" : 0,
"server_state" : "leader",
"znode_count" : 5,
"watch_count" : 0,
"ephemerals_count" : 0,
"approximate_data_size" : 135,
"open_file_descriptor_count" : 73,
"max_file_descriptor_count" : 10240,
"last_client_response_size" : -1,
"max_client_response_size" : -1,
"min_client_response_size" : -1,
"followers" : 2,
"synced_followers" : 2,
"pending_syncs" : 0,
"last_proposal_size" : 36,
"max_proposal_size" : 36,
"min_proposal_size" : 36,
"command" : "monitor",
"error" : null
}- "server_state" : "leader" #本节点是leader
- "followers" : 2 # 有两个fowllower
$ curl http://localhost:8081/commands/stat
{
"version" : "3.5.5-390fe37ea45dee01bf87dc1c042b5e3dcce88653, built on 05/03/2019 12:07 GMT",
"read_only" : false,
"server_stats" : {
"packets_sent" : 0,
"packets_received" : 0,
"max_latency" : 0,
"min_latency" : 0,
"fsync_threshold_exceed_count" : 0,
"client_response_stats" : {
"last_buffer_size" : -1,
"min_buffer_size" : -1,
"max_buffer_size" : -1
},
"data_dir_size" : 201328199,
"log_dir_size" : 201328199,
"last_processed_zxid" : 12884901889,
"provider_null" : false,
"num_alive_client_connections" : 0,
"server_state" : "leader",
"outstanding_requests" : 0,
"avg_latency" : 0
},
"client_response" : {
"last_buffer_size" : -1,
"min_buffer_size" : -1,
"max_buffer_size" : -1
},
"proposal_stats" : {
"last_buffer_size" : 36,
"min_buffer_size" : 36,
"max_buffer_size" : 36
},
"node_count" : 5,
"connections" : [ ],
"command" : "stats",
"error" : null
}
如果使用nc 访问，提示：“stat is not executed because it is not in the whitelist.” 参考：https://www.cnblogs.com/jonrain0625/p/11377508.html 解决。
参考：
zk命令行使用：http://zookeeper.apache.org/doc/r3.4.10/zookeeperAdmin.html#sc_zkCommands
zk监控：http://zookeeper.apache.org/doc/r3.4.10/zookeeperJMX.html
https://stackoverflow.com/questions/16669104/how-to-get-current-zookeeper-clusters-member-server-list