question Re: How to get backup hmaster in Hbase HA mode in ambari using command in Archives of Support Questions (Read Only)

How to get backup hmaster in Hbase HA mode in ambari using command

xiaqinglinv5 — Wed, 28 Dec 2016 16:43:57 GMT

Hi, guys, I am tryign to write a autotest shell script killing the hmasters in HA mode, do you know how can I get the backup hmaster host address by using the command? I can manully find it in the ambari UI, but can not locate it by using the command

Re: How to get backup hmaster in Hbase HA mode in ambari using command

jsensharma — Wed, 28 Dec 2016 17:40:32 GMT

@Qinglin Xia

You can use the Ambari APIs to find that out using simple "curl" GET you should be able to find the Active HBase Master:

http://erie1.example.com:8080/api/v1/clusters/ErieCluster/components/HBASE_MASTER?ServiceComponentInfo/category=MASTER&fields=ServiceComponentInfo/service_name,host_components/HostRoles/display_name,host_components/metrics/hbase/master/IsActiveMaster

Example Output:

{
  "href" : "http://erie1.example.com:8080/api/v1/clusters/ErieCluster/components/HBASE_MASTER?ServiceComponentInfo/category=MASTER&fields=ServiceComponentInfo/service_name,host_components/HostRoles/display_name,host_components/metrics/hbase/master/IsActiveMaster",
  "ServiceComponentInfo" : {
    "category" : "MASTER",
    "cluster_name" : "ErieCluster",
    "component_name" : "HBASE_MASTER",
    "service_name" : "HBASE"
  },
  "host_components" : [
    {
      "href" : "http://erie1.example.com:8080/api/v1/clusters/ErieCluster/hosts/erie3.example.com/host_components/HBASE_MASTER",
      "HostRoles" : {
        "cluster_name" : "ErieCluster",
        "component_name" : "HBASE_MASTER",
        "display_name" : "HBase Master",
        "host_name" : "erie3.example.com"
      },
      "metrics" : {
        "hbase" : {
          "master" : {
            "IsActiveMaster" : "false"
          }
        }
      }
    },
    {
      "href" : "http://erie1.example.com:8080/api/v1/clusters/ErieCluster/hosts/erie4.example.com/host_components/HBASE_MASTER",
      "HostRoles" : {
        "cluster_name" : "ErieCluster",
        "component_name" : "HBASE_MASTER",
        "display_name" : "HBase Master",
        "host_name" : "erie4.example.com"
      },
      "metrics" : {
        "hbase" : {
          "master" : {
            "IsActiveMaster" : "true"
          }
        }
      }
    }
  ]
}

Notice:

 "IsActiveMaster" : "false"

Re: How to get backup hmaster in Hbase HA mode in ambari using command

jsensharma — Wed, 28 Dec 2016 18:10:23 GMT

@Qinglin Xia

More easy command to access this info using curl by hitting the URL:

http://erie1.example.com:8080/api/v1/clusters/ErieCluster/hosts/erie3.example.com/host_components/HBASE_MASTER?fields=metrics/hbase/master/IsActiveMaster

 curl -u admin:admin -H "X-Requested-By: ambari"  -X GET http://erie1.example.com:8080/api/v1/clusters/ErieCluster/hosts/erie4.example.com/host_components/HBASE_MASTER?fields=metrics/hbase/master/IsActiveMaster


{
  "href" : "http://erie1.example.com:8080/api/v1/clusters/ErieCluster/hosts/erie4.example.com/host_components/HBASE_MASTER?fields=metrics/hbase/master/IsActiveMaster",
  "HostRoles" : {
    "cluster_name" : "ErieCluster",
    "component_name" : "HBASE_MASTER",
    "host_name" : "erie4.example.com"
  },
  "host" : {
    "href" : "http://erie1.example.com:8080/api/v1/clusters/ErieCluster/hosts/erie4.example.com"
  },
  "metrics" : {
    "hbase" : {
      "master" : {
        "IsActiveMaster" : "true"
      }
    }
  }
}

Re: How to get backup hmaster in Hbase HA mode in ambari using command

yusaku — Thu, 29 Dec 2016 02:00:36 GMT

You should also be able to specify the condition IsActiveMaster=false to have the API respond with non-active HBaseMasters only. Instead of saying "fields=metrics/hbase/master/IsActiveMaster" in the query, you can turn that into a predicate by saying "metrics/hbase/master/IsActiveMaster=false".

Re: How to get backup hmaster in Hbase HA mode in ambari using command

jaimin — Thu, 29 Dec 2016 14:31:38 GMT

@Qinglin Xia

This can be achieved with single Ambari REST API as @yusaku suggested. Following is the actual working API

{
  "href" : "http://c6401.ambari.apache.org:8080/api/v1/clusters/c1/components/HBASE_MASTER?host_components/metrics/hbase/master/IsActiveMaster=true&fields=host_components/HostRoles/host_name",
  "ServiceComponentInfo" : {
    "cluster_name" : "c1",
    "component_name" : "HBASE_MASTER",
    "service_name" : "HBASE"
  },
  "host_components" : [
    {
      "href" : "http://c6401.ambari.apache.org:8080/api/v1/clusters/c1/hosts/c6401.ambari.apache.org/host_components/HBASE_MASTER",
      "HostRoles" : {
        "cluster_name" : "c1",
        "component_name" : "HBASE_MASTER",
        "host_name" : "c6401.ambari.apache.org"
      },
      "metrics" : {
        "hbase" : {
          "master" : {
            "IsActiveMaster" : "true"
          }
        }
      }
    }
  ]
}

Re: How to get backup hmaster in Hbase HA mode in ambari using command

jsensharma — Thu, 29 Dec 2016 15:19:11 GMT

@Qinglin Xia

Additionally if you due to some reason if the Ambari is down (not accessible) and still if you want to get the Active HBase Master detail then you can simply use the HBase JMX for the same. Here "16010" is HBase JMX ui port.

Exampe:

$ curl -v --silent 'http://erie4.example.com:16010/jmx?qry=Hadoop:service=HBase,name=Master,sub=Server'  2>&1 | grep isActiveMaster
    "tag.isActiveMaster" : "true",


$ curl -v --silent 'http://erie3.example.com:16010/jmx?qry=Hadoop:service=HBase,name=Master,sub=Server'  2>&1 | grep isActiveMaster
    "tag.isActiveMaster" : "false",

Re: How to get backup hmaster in Hbase HA mode in ambari using command

xiaqinglinv5 — Fri, 30 Dec 2016 11:26:12 GMT

Thanks, I used this url to get the backup masters

http://fsmanager:8080/api/v1/clusters/${cluster_name}/components/HBASE_MASTER?host_components/metrics/hbase/master/IsActiveMaster=false&fields=host_components/HostRoles/host_name