Re: Reading from a centralized stored
No, most rdds partition input data appropriately. On Tue, Jan 6, 2015 at 1:41 PM, Franc Carter franc.car...@rozettatech.com wrote: One more question, to be clarify. Will every node pull in all the data ? thanks On Tue, Jan 6, 2015 at 12:56 PM, Cody Koeninger c...@koeninger.org wrote: If you are not co-locating spark executor processes on the same machines where the data is stored, and using an rdd that knows about which node to prefer scheduling a task on, yes, the data will be pulled over the network. Of the options you listed, S3 and DynamoDB cannot have spark running on the same machines. Cassandra can be run on the same nodes as spark, and recent versions of the spark cassandra connector implement preferred locations. You can run an rdbms on the same nodes as spark, but JdbcRDD doesn't implement preferred locations. On Mon, Jan 5, 2015 at 6:25 PM, Franc Carter franc.car...@rozettatech.com wrote: Hi, I'm trying to understand how a Spark Cluster behaves when the data it is processing resides on a centralized/remote store (S3, Cassandra, DynamoDB, RDBMS etc). Does every node in the cluster retrieve all the data from the central store ? thanks -- *Franc Carter* | Systems Architect | Rozetta Technology franc.car...@rozettatech.com franc.car...@rozettatech.com| www.rozettatechnology.com Tel: +61 2 8355 2515 Level 4, 55 Harrington St, The Rocks NSW 2000 PO Box H58, Australia Square, Sydney NSW 1215 AUSTRALIA -- *Franc Carter* | Systems Architect | Rozetta Technology franc.car...@rozettatech.com franc.car...@rozettatech.com| www.rozettatechnology.com Tel: +61 2 8355 2515 Level 4, 55 Harrington St, The Rocks NSW 2000 PO Box H58, Australia Square, Sydney NSW 1215 AUSTRALIA
Re: Reading from a centralized stored
Ah, so it's rdd specific - that would make sense. For those systems where it is possible to extract sensible susbets the rdds do so. My use case, which is probably biasing my thinking is DynamoDb which I don't think can efficiently extract records from M-to-N cheers On Wed, Jan 7, 2015 at 6:59 AM, Cody Koeninger c...@koeninger.org wrote: No, most rdds partition input data appropriately. On Tue, Jan 6, 2015 at 1:41 PM, Franc Carter franc.car...@rozettatech.com wrote: One more question, to be clarify. Will every node pull in all the data ? thanks On Tue, Jan 6, 2015 at 12:56 PM, Cody Koeninger c...@koeninger.org wrote: If you are not co-locating spark executor processes on the same machines where the data is stored, and using an rdd that knows about which node to prefer scheduling a task on, yes, the data will be pulled over the network. Of the options you listed, S3 and DynamoDB cannot have spark running on the same machines. Cassandra can be run on the same nodes as spark, and recent versions of the spark cassandra connector implement preferred locations. You can run an rdbms on the same nodes as spark, but JdbcRDD doesn't implement preferred locations. On Mon, Jan 5, 2015 at 6:25 PM, Franc Carter franc.car...@rozettatech.com wrote: Hi, I'm trying to understand how a Spark Cluster behaves when the data it is processing resides on a centralized/remote store (S3, Cassandra, DynamoDB, RDBMS etc). Does every node in the cluster retrieve all the data from the central store ? thanks -- *Franc Carter* | Systems Architect | Rozetta Technology franc.car...@rozettatech.com franc.car...@rozettatech.com| www.rozettatechnology.com Tel: +61 2 8355 2515 Level 4, 55 Harrington St, The Rocks NSW 2000 PO Box H58, Australia Square, Sydney NSW 1215 AUSTRALIA -- *Franc Carter* | Systems Architect | Rozetta Technology franc.car...@rozettatech.com franc.car...@rozettatech.com| www.rozettatechnology.com Tel: +61 2 8355 2515 Level 4, 55 Harrington St, The Rocks NSW 2000 PO Box H58, Australia Square, Sydney NSW 1215 AUSTRALIA -- *Franc Carter* | Systems Architect | Rozetta Technology franc.car...@rozettatech.com franc.car...@rozettatech.com| www.rozettatechnology.com Tel: +61 2 8355 2515 Level 4, 55 Harrington St, The Rocks NSW 2000 PO Box H58, Australia Square, Sydney NSW 1215 AUSTRALIA
Re: Reading from a centralized stored
If you are not co-locating spark executor processes on the same machines where the data is stored, and using an rdd that knows about which node to prefer scheduling a task on, yes, the data will be pulled over the network. Of the options you listed, S3 and DynamoDB cannot have spark running on the same machines. Cassandra can be run on the same nodes as spark, and recent versions of the spark cassandra connector implement preferred locations. You can run an rdbms on the same nodes as spark, but JdbcRDD doesn't implement preferred locations. On Mon, Jan 5, 2015 at 6:25 PM, Franc Carter franc.car...@rozettatech.com wrote: Hi, I'm trying to understand how a Spark Cluster behaves when the data it is processing resides on a centralized/remote store (S3, Cassandra, DynamoDB, RDBMS etc). Does every node in the cluster retrieve all the data from the central store ? thanks -- *Franc Carter* | Systems Architect | Rozetta Technology franc.car...@rozettatech.com franc.car...@rozettatech.com| www.rozettatechnology.com Tel: +61 2 8355 2515 Level 4, 55 Harrington St, The Rocks NSW 2000 PO Box H58, Australia Square, Sydney NSW 1215 AUSTRALIA
Re: Reading from a centralized stored
Thanks, that's what I suspected. cheers On Tue, Jan 6, 2015 at 12:56 PM, Cody Koeninger c...@koeninger.org wrote: If you are not co-locating spark executor processes on the same machines where the data is stored, and using an rdd that knows about which node to prefer scheduling a task on, yes, the data will be pulled over the network. Of the options you listed, S3 and DynamoDB cannot have spark running on the same machines. Cassandra can be run on the same nodes as spark, and recent versions of the spark cassandra connector implement preferred locations. You can run an rdbms on the same nodes as spark, but JdbcRDD doesn't implement preferred locations. On Mon, Jan 5, 2015 at 6:25 PM, Franc Carter franc.car...@rozettatech.com wrote: Hi, I'm trying to understand how a Spark Cluster behaves when the data it is processing resides on a centralized/remote store (S3, Cassandra, DynamoDB, RDBMS etc). Does every node in the cluster retrieve all the data from the central store ? thanks -- *Franc Carter* | Systems Architect | Rozetta Technology franc.car...@rozettatech.com franc.car...@rozettatech.com| www.rozettatechnology.com Tel: +61 2 8355 2515 Level 4, 55 Harrington St, The Rocks NSW 2000 PO Box H58, Australia Square, Sydney NSW 1215 AUSTRALIA -- *Franc Carter* | Systems Architect | Rozetta Technology franc.car...@rozettatech.com franc.car...@rozettatech.com| www.rozettatechnology.com Tel: +61 2 8355 2515 Level 4, 55 Harrington St, The Rocks NSW 2000 PO Box H58, Australia Square, Sydney NSW 1215 AUSTRALIA
Reading from a centralized stored
Hi, I'm trying to understand how a Spark Cluster behaves when the data it is processing resides on a centralized/remote store (S3, Cassandra, DynamoDB, RDBMS etc). Does every node in the cluster retrieve all the data from the central store ? thanks -- *Franc Carter* | Systems Architect | Rozetta Technology franc.car...@rozettatech.com franc.car...@rozettatech.com| www.rozettatechnology.com Tel: +61 2 8355 2515 Level 4, 55 Harrington St, The Rocks NSW 2000 PO Box H58, Australia Square, Sydney NSW 1215 AUSTRALIA
