I see now.
Well, you do not need to start or configure any caches in this case, but
you will need to manually route your jobs or closures to the proper nodes
and, therefore, you should somehow get distribution info from Cassandra.
See this example for idea:
final String host = YourCassandraMapper.hostForKey(someKey);
ignite.compute(
ignite.cluster().forPredicate(
new IgnitePredicate<ClusterNode>() {
@Override public boolean apply(ClusterNode node) {
return node.hostNames().contains(host);
}
}))
.call(
new IgniteCallable<Object>() {
@Override public Object call() throws Exception {
// This callable will be executed on the HOST
// that holds the data.
return null;
}
}
);
--Yakov
2015-05-18 15:04 GMT+03:00 tcostasouza <[email protected]>:
> Hello,
>
> The second one, I would like to run map-reduce jobs with Ignite using
> data currently stored in Cassandra and properly route that jobs to the
> hosts holding the data?
>
> Cheers!
>
> On Mon, May 18, 2015 at 9:04 AM Yakov Zhdanov [via Apache Ignite Users]
> <[hidden
> email] <http:///user/SendEmail.jtp?type=node&node=317&i=0>> wrote:
>
>> I am not sure if I understand you.
>>
>> I assume your primary data access point will be Ignite cache backed by
>> Cassandra as persistent store. Is this the point?
>>
>> Or you want to run map-reduce jobs with Ignite using data currently
>> stored in Cassandra and properly route that jobs to the hosts holding the
>> data?
>>
>> --
>> Yakov Zhdanov, Director R&D
>> *GridGain Systems*
>> www.gridgain.com
>>
>> 2015-05-18 14:49 GMT+03:00 tcostasouza <[hidden email]
>> <http:///user/SendEmail.jtp?type=node&node=316&i=0>>:
>> Hello!
>>
>> But isn't this tied to Ignite's cache? Wouldn't I need to cache the
>> external data first for this to work?
>>
>> Thanks
>>
>> On Mon, May 18, 2015 at 5:56 AM dsetrakyan [via Apache Ignite Users] <[hidden
> email] <http:///user/SendEmail.jtp?type=node&node=315&i=0>> wrote:
> tcostasouza wrote
> Does it supports data collocated processing by overlaying ignite cluster
> with another storage cluster (i.e. Cassandra)?
> Yes, Ignite supports pluggable AffinityFunction
> <https://ignite.incubator.apache.org/releases/1.0.0/javadoc/org/apache/ignite/cache/affinity/AffinityFunction.html>
> API
> which can be configured through CacheConfiguration.
>
> You should be able to create an implementation which will simply delegate
> to one of the Cassandra Partitioner implementations.
>
> Is this what you were looking for?
>
>
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