question Ambari namenode HA connect in Archives of Support Questions (Read Only)

Ambari namenode HA connect

stefan1 — Thu, 14 Sep 2017 13:23:47 GMT

Hi,

After successfully enabling HA on a Ambari cluster, what address should we connect to in order to always use the active namenode?

For example origionaly we connected to 'namenode01:8020' to drop files, but now there is namenode01 and namenode02.

So we need to create a keepalived vip which checks '-getServiceState' every few seconds or something?

We currently use the following for connection: https://github.com/colinmarc/hdfs

Re: Ambari namenode HA connect

jsensharma — Thu, 14 Sep 2017 13:30:41 GMT

@Stefan Warmerdam

Usually whatever value you see in the "hdfs-site.xml" for the property "dfs.nameservices" and "fs.defaultFS" is used when HA is enabled.

You can also use the Ambari FileView to upload files. https://docs.hortonworks.com/HDPDocuments/Ambari-2.5.2.0/bk_ambari-views/content/ch_using_files_view.html

Re: Ambari namenode HA connect

jsensharma — Thu, 14 Sep 2017 13:37:00 GMT

@Stefan Warmerdam

Not sure about the client that you mentioned as part fo the github link. But In case of a Java Client it determines it using nameservice name something like following:

    Configuration conf = new Configuration(false);
    conf.set("fs.defaultFS", "hdfs://nameservice1");
    conf.set("fs.default.name", conf.get("fs.defaultFS"));
    conf.set("dfs.nameservices","nameservice1");
    conf.set("dfs.ha.namenodes.nameservice1", "namenode1,namenode2");
    conf.set("dfs.namenode.rpc-address.nameservice1.namenode1","hadoopnamenode01:8020");
    conf.set("dfs.namenode.rpc-address.nameservice1.namenode2", "hadoopnamenode02:8020");
    conf.set("dfs.client.failover.proxy.provider.nameservice1","org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider");

Re: Ambari namenode HA connect

stefan1 — Thu, 14 Sep 2017 14:19:31 GMT

thank you for your detailed answer!