All the Exceptions are documented on the API page
(http://wiki.apache.org/cassandra/API) on the wiki.
* UnavailableException -- "Not all the replicas required could be created
and/or read."
* TimedOutException -- "The node responsible for the write or read did not
respond during the rpc interval specified in your configuration (default 10s).
This can happen if the request is too large, the node is oversaturated with
requests, or the node is down but the failure detector has not yet realized it
(usually this takes < 30s)."
Its hard to give a generic solution proposal. The "proper course of action"
depends on your application domain.
As stated on the wiki the reason for timeout exception could be because of
different reasons.
* "request is too large" -- Proposal: try to narrow your request
* "node is oversaturated with requests" -- Proposal: using order preserving
partitioner? try random partitioner for better load balancing.
need more nodes in your cluster?
* "node is down but the failure detector has not yet realized it": altered
the phi constant in o.a.c.gsm.FailureDetector (phiConvictThreshold_,
default == 8)?
// Roger Schildmeijer
On 13 maj 2010, at 19.53em, Ian Soboroff wrote:
> I searched the Wiki and the mailing list archives a bit but couldn't find the
> answer.
>
> If I catch an exception from a Cassandra.Client method, in my case
> batch_mutate, what's the proper course of action?
>
> Ignoring InvalidRequestException, we have Unavailable, TimedOut, and generic
> Thrift exceptions.
>
> Do I just gin up a new client? Do I need to build the TTransport/Tproto bits
> as well?
>
> Thanks,
> Ian
>
