Thanks Jonathan Ellis,

  I want to make sure that after A return failure message to client at CL.ONE, does A write a hint to C? If so, although the write operation is failed, but the data is still stored in C? if B comes back up, then C forwards to B?

Shen

On Thu, Jul 8, 2010 at 10:08 PM, Jonathan Ellis <jbellis@gmail.com> wrote:
On Thu, Jul 8, 2010 at 12:45 AM, ChingShen <chingshenchen@gmail.com> wrote:
> hmm... I'm really confused.
> The http://wiki.apache.org/cassandra/API document mentioned that if write
> ConsistencyLevel=ANY that "Ensure the write has been written to at least 1
> node, including hinted recipients.", I couldn't imagine this case. :(
>
> If I have A,B,C and D nodes(RF=1), and write ConsistencyLevel=ANY, so A
> coordinator node sends a write request to another node(e.g. B node), but B
> node is down during write operation, what happend? return failure message to
> client immediately? or write a hint to another node(e.g. C node)

It will write a hint and report success.

But if you were writing at CL.ONE it would fail the write because a
hinted write isn't readable until it can be forwarded to the "right"
node (here, B).

--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com