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Posted to user@cassandra.apache.org by Anthony John <ch...@gmail.com> on 2011/02/24 21:36:09 UTC
Does CL on "ALL" have special semantics like "ANY" does
All:
So "ANY" CL seems to mean that Write (and read) on any node, even if it is a
hinted handoff, and return success. Correct ?
Guessing this accommodates node failure - right ?
Does "ALL" succeed even if there is a single surviving replica for the
given piece of data ?
Again, tolerates node failure. Does it really mean - from ALL surviving
nodes ?
-JA
Re: Does CL on "ALL" have special semantics like "ANY" does
Posted by "baskar.duraikannu.db@gmail.com" <ba...@gmail.com>.
Even though the client did not get a success message, it is possible
that write may have succeeded on one of the replicas. Let us say that
client did a retry and the write succeeded.
Let us also assume that I was trying to withdraw $100. Initially $100
was withdrawn as per one of the replicas. Since all replicas did not
respond, client retries, results in another $100 withdrawal.
During the hinted hand off/read repair, will first $100 succeed on other
replicas? if so, is there a way to avoid this inconsistency?
On 2/24/11 3:43 PM, Tyler Hobbs wrote:
> On Thu, Feb 24, 2011 at 2:36 PM, Anthony John <chirayithaj@gmail.com
> <ma...@gmail.com>> wrote:
>
>
> Does "ALL" succeed even if there is a single surviving replica
> for the given piece of data ?
> Again, tolerates node failure. Does it really mean - from ALL
> surviving nodes ?
>
>
> All replicas (RF) for that row must respond before an operation at ALL
> is considered a success. That's all there is to it.
>
> --
> Tyler Hobbs
> Software Engineer, DataStax <http://datastax.com/>
> Maintainer of the pycassa <http://github.com/pycassa/pycassa>
> Cassandra Python client library
>
Re: Does CL on "ALL" have special semantics like "ANY" does
Posted by Tyler Hobbs <ty...@datastax.com>.
On Thu, Feb 24, 2011 at 2:36 PM, Anthony John <ch...@gmail.com> wrote:
>
> Does "ALL" succeed even if there is a single surviving replica for the
> given piece of data ?
> Again, tolerates node failure. Does it really mean - from ALL surviving
> nodes ?
>
All replicas (RF) for that row must respond before an operation at ALL is
considered a success. That's all there is to it.
--
Tyler Hobbs
Software Engineer, DataStax <http://datastax.com/>
Maintainer of the pycassa <http://github.com/pycassa/pycassa> Cassandra
Python client library