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From Russell Cardullo <>
Subject Re: Spark performance on smallerish data sets: EC2 Mediums
Date Wed, 02 Oct 2013 03:46:17 GMT
No, we're reading from S3 rather than HDFS.

On Oct 1, 2013, at 8:42 PM, Gary Malouf <> wrote:

> Hi Russell,
> I think I did not clarify that my set up has HDFS on separate nodes from Spark.  It sounds
like your setup has them together right?
> On Tue, Oct 1, 2013 at 11:23 PM, Russell Cardullo <> wrote:
> We have a similar setup using 3 Large EC2 nodes.  We get 64MB of logs from flume roughly
every 2 minutes pushed to S3, and are able to have Spark read a single 64MB file from S3 and
process it in about 30 seconds (doing multiple maps and a reduce by key).
> When we first started out though we saw very long processing times around the order of
6 minutes for a 64 MB file.  It turned out to be caused by one of our map closures that was
referencing a singleton object that was created outside of the filter closure.
> Don't know if that's the case here but first thing I would check is try to run the job
locally and use something like visualvm to see how many threads it's using.
> --Russell
> On Oct 1, 2013, at 10:54 AM, Gary Malouf <> wrote:
> > Hi everyone,
> >
> > We have an HDFS set up of a namenode and three datanodes all on EC2 mediums.  One
of our data partitions basically has files that are fed from a few Flume instances rolling
hourly.  This equates to around 3 16mb files right now, all though our traffic even now is
projected to double in the next few weeks.
> >
> > Our Mesos cluster consists of a Master and three slave nodes on EC2 mediums as well.
 Spark scheduled jobs are launched from the master across the cluster.
> >
> > My question is, for grabbing on the order of 3 hours of data this size, what would
the expected Spark performance be?  For a simple count query of our thousands od data entries
serialized in these sequence files, we are seeing query times of around 180-200 seconds. 
While this is surely faster than Hadoop, we were under the impression that the response times
would be significantly faster than this.
> >
> > Has anyone tested Spark+HDFS on instances smaller than the XL's?
> >
> >

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