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From "P. Taylor Goetz" <>
Subject Re: trident simplest aggregator into cassandra
Date Mon, 03 Feb 2014 22:21:17 GMT
Which project did the CassandraState implementation come from?

On Feb 3, 2014, at 5:09 PM, Adrian Mocanu <> wrote:

> Hi
> I'm using Trident to perform some aggregations and store the results into cassandra.
> I've looked at IBackingMap and specifically at some tutorials on trident site and I've
tried using CassandraState which I found online in some repository. After creating what I
thought were column family and keys corresponding to the code I still cannot figure out how
to run the sample topology and not crash due to some Cassandra schema error (InvalidRequestException(why:Invalid
cell for CQL3 table state. The CQL3 column component (over) does not correspond to a defined
CQL3 column).
> Here is the sample code I use:
>   val cassandraStateFactory:StateFactory = chat.CassandraState.transactional("")
>     val spout = new FixedBatchSpout(new Fields("sentence"), 3,
>       new Values("the cow jumped over the moon"),
>       new Values("the man went to the store and bought some candy"),
>       new Values("four score and seven years ago"),
>       new Values("how many apples can you eat"))
>     spout.setCycle(true)
>     val wordCounts :TridentState= tridentBuilder.newStream("spout1", spout)
>       .each(new Fields("sentence"), new Split(), new Fields("word"))
>       .groupBy(new Fields("word"))
>       .persistentAggregate(cassandraStateFactory, new Count(), new Fields("count"))
>       .parallelismHint(6)
>     val cluster = new LocalCluster();
>     val config = new Config();
>     config.setMaxSpoutPending(100);
>     config.setMaxSpoutPending(25);
>     cluster.submitTopology("test", config,;
> What is the schema needed to run this example (it also uses CassandraState)?
> thanks
> A

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