Hi,

If I have four name nodes in my cluster: n1, n2, n3, n4, then
n2 is n1's standby,  n4 is n3's standby.

there is no dependency between n1 and n3, which is HDFS federation.

Anybody can kindly give me an example for HA and federation configuration?
especially HDFS HA, how to configure two JN groups (*
dfs.namenode.shared.edits.dir*) for n1/n2 and n3/n4, Thanks.

Sorry all, I maybe get the answer because I didn't read doc carefully.

clustera is for n1, n2
clusterb is for n3,n4

so the following configuration would be answer my question, does that okay?

<property>
  <name>dfs.nameservices</name>
  <value>clustera, clusterb</value>
</property>

<property>
  <name>dfs.namenode.shared.edits.dir</name>
  <value>qjournal://node1.example.com:8485;node2.example.com:8485;node3.example.com:8485/clustera</value>
</property>

<property>
  <name>dfs.namenode.shared.edits.dir</name>
  <value>qjournal://node1.example.com:8485;node2.example.com:8485;node3.example.com:8485/clusterb</value>
</property>

On Sat, Feb 16, 2013 at 12:56 PM, Azuryy Yu <[EMAIL PROTECTED]> wrote:

> Hi,
>
> If I have four name nodes in my cluster: n1, n2, n3, n4, then
> n2 is n1's standby,  n4 is n3's standby.
>
> there is no dependency between n1 and n3, which is HDFS federation.
>
> Anybody can kindly give me an example for HA and federation configuration?
> especially HDFS HA, how to configure two JN groups (*
> dfs.namenode.shared.edits.dir*) for n1/n2 and n3/n4, Thanks.
>
>
>