Hi Sam,
Bryan meant the last config bit:
<property>
<name>dfs.client.failover.proxy.provider.gilbert-prod</name>
<value>org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider</value>
</property>
This is the class the client will use to perform the failover (i.e.
active NN discovery).
On Tue, Apr 29, 2014 at 7:37 PM, sam liu <samliuhad...@gmail.com> wrote:
> Hi Bryan,
>
> Thanks for your detailed response!
>
> - 'you use a logical name for your "group of namenodes"': In your case, it
> should be 'MYCLUSTER'
>
> - 'provide a means for the client to handle connecting to the currently
> active one': Could you pls give an example?
>
>
>
>
> 2014-04-29 21:57 GMT+08:00 Bryan Beaudreault <bbeaudrea...@hubspot.com>:
>
>> If you are using the QJM HA solution, the IP addresses of the namenodes
>> should not change. Instead your clients should be connecting using the
>> proper HA configurations. That is, you use a logical name for your "group
>> of namenodes", and provide a means for the client to handle connecting to
>> the currently active one.
>>
>> Example:
>>
>> <property>
>> <name>dfs.nameservices</name>
>> <value>MYCLUSTER</value>
>> </property>
>>
>> <property>
>> <name>dfs.ha.namenodes.MYCLUSTER</name>
>> <value>nn1,nn2</value>
>> </property>
>>
>> <property>
>> <name>dfs.namenode.rpc-address.MYCLUSTER.nn1</name>
>> <value>dnsOfNameNode1:8020</value>
>> </property>
>> <property>
>> <name>dfs.namenode.http-address.MYCLUSTER.nn1</name>
>> <value> dnsOfNameNode1:50070</value>
>> </property>
>>
>> <property>
>> <name>dfs.namenode.rpc-address.MYCLUSTER.nn2</name>
>> <value> dnsOfNameNode2:8020</value>
>> </property>
>> <property>
>> <name>dfs.namenode.http-address.MYCLUSTER.nn2</name>
>> <value> dnsOfNameNode2:50070</value>
>> </property>
>>
>> <property>
>> <name>dfs.client.failover.proxy.provider.gilbert-prod</name>
>>
>> <value>org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider</value>
>> </property>
>>
>>
>> On Tue, Apr 29, 2014 at 9:07 AM, sam liu <samliuhad...@gmail.com> wrote:
>>>
>>> Hi Experts,
>>>
>>> For example, at the beginning, the application will access NameNode using
>>> IP of active NameNode(IP: 9.123.22.1). However, after failover, the IP of
>>> active NameNode is changed to 9.123.22.2 which is the IP of previous standby
>>> NameNode. In this case, application must update NameNode IP?
>>>
>>> Thanks!
>>
>>
>
--
Harsh J
