注册服务

看这个里面有pdf：

umbrella yarn-913

概念：

• 服务 an app server for hbase
• 服务类 注册内部的叫法
• 组件 服务的元素
• 服务实例 app实例
• 组件实例（regionserver ,master)
• endpoints 接入服务的接口比如hbase 的rest thrift等等 ipc port ipcinfoport等等
• 服务record 实例注册描述
• rm
• yarn app
• am
• container

绑定问题

- ip 或host静态方式绑定组件实例行不通

1. yarn实例id变化
2. 不能注册rest/zkpath/endpoints
3. 实例存活

服务

1. A client application looks up a dynamically deployed service instance whose user, service class and instance name is known, e.g.

   "/users/joe/services/hbase/demo1", and retrieves the information needed to connect to the service

2. A client application looks up a statically deployed Hadoop service

   Example: "/services/hdfs".

3. An Application Master enumerates all registered component instances, discovers their listed JMX ports, and, inits own web UI, offers links to these endpoints.

4. A user connects to a private HBase service instance at

   "/users/joe/services/hbase/demo1"

5. A user connects to the cluster’s HBase service at "/services/hbase".
6. A user looks up the binding information to a remote Hadoop cluster's filesystem at "/net/cluster4/services/hdfs". The registration information includes the webhdfs:// URL for the remote filesystem

7. A user lists their HBase service instances:

   ls /users/joe/services/hbase

8. User finds all Hbase services in the cluster:

   find -endpointField.api=org.apache.hbase

9. Possibly in future: looking up a service via DNS.

注册意义发现

1. 没有yarn
2. 注册信息要比实例存活长，解耦实例。
3. 组件发布info
4. 绑定实例
5. 组件实例使用注册
6. 不自动注册

注册关键点

1. 动态注册 （绑定并发现、绑定不随服务移动而移动或是因为HAfailover)
2. endpoint多样
3. 注册服务属性：ha,scale,Ubiquity
4. 分层命名
5. 跨语言
6. 读写控制

7. 远程读写

8. Service Record: application. info

9. persistence attribute policies 0-5
10. Endpoint
11. Address Type(path url )

eg:

/users/devteam/tomcat/components/container-1408631738011-0001-01-000001 (ephemeral) 

{
"registrationTime" : 1408638082445,
"id" : "container_1408631738011_0001_01_000001",
"persistence" : "1",
"description" : null,
"external" : [ {
"api" : "www",
"addressType" : "uri",
"protocolType" : "REST",
"addresses" : [ [ "http://rack4server3:43572" ] ]
} ],
"internal" : [ {
"api" : "jmx",
"addressType" : "host/port",
"protocolType" : "JMX",
"addresses" : [ [ "rack4server3", "43573" ] ]
} ]
}

存取设计：

RegistryOperations