Voldemort replication and failover details - replication

Question

I'm evaluating Voldemort and encountered some confusing stuff related to replication and failover. I tried to make a simple 2 nodes cluster configuration where each node is a backup for another one. So data written to node 1 should be replicated to node 2 and vice versa. In case of node 1 failover the second node should serve client requests. After node 1 recovery data should be transfered back to node 1. I think it's very common and clear case. So I made the following configuration.
<cluster>
<name>perf_cluster</name>
<server>
<id>0</id>
<host>10.50.3.156</host>
<http-port>8081</http-port>
<socket-port>6666</socket-port>
<admin-port>6667</admin-port>
<partitions>0, 1, 2, 3</partitions>
<zone-id>0</zone-id>
</server>
<server>
<id>1</id>
<host>10.50.3.157</host>
<http-port>8081</http-port>
<socket-port>6666</socket-port>
<admin-port>6667</admin-port>
<partitions>4, 5, 6, 7</partitions>
<zone-id>0</zone-id>
</server>
</cluster>
<stores>
<store>
<name>perftest</name>
<persistence>memory</persistence>
<description>Performance Test store</description>
<owners>owner</owners>
<routing>client</routing>
<replication-factor>2</replication-factor>
<required-reads>1</required-reads>
<required-writes>1</required-writes>
<key-serializer>
<type>string</type>
</key-serializer>
<value-serializer>
<type>java-serialization</type>
</value-serializer>
</store>
</stores>
I perform the following test:
Start both nodes;
Connect cluster via shell using 'bin/voldemort-shell.sh perftest tcp://10.50.3.156:6666';
Put the key-value "1" "a";
Perform 'preflist "1"' which returns me 'Node 1' 'Node 0' so I assume that 'get' request will be sent to Node 1 first;
Crash Node 1;
Get key "1". I see some errors related to loss of connectivity but finally it returns me correct value;
Start Node 1;
Get key "1". It says that Node 1 is available but returns me 'null' instead of the value. So I assume the Node 1 didn't get the data from Node 0 and since my required-reads = 1 it doesn't ask for Node 0 and returns me null.
Crash Node 0;
Key "1" is lost forever because it wasn't replicated to Node 1.
I'm more than sure that I misunderstand something in configuration or cluster replication details. Could you clarify why the data doesn't replicate back from Node 0 to Node 1 after recovery? And am I right that replication is a client responsibility, not server? If so how should the data be replicated after Node recovery?
Thanks in advance.

Answer 1

I don't known if you've already solved the problem, but take a look to: http://code.google.com/p/project-voldemort/issues/detail?id=246
Remember that the memory store is only for testing (junit) purposes, you should use the readonly or bdb stores.