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From envio user <enviou...@gmail.com>
Subject issue with get_slice() performance.
Date Wed, 20 Jan 2010 16:00:18 GMT
All,
I downloaded 0.5.0 final and tried following test:

Machine : Quad Core(64bit) , 8GB RAM, signle node.

Data model: A single SCF with CompareWith="BytesType" and
CompareSubcolumnsWith="TimeUUIDType"

Sample data stored:
FF = {
        '1' : {
                    'ALL' => {
                                  'TimeUUID1' => '16bytesstring',
                                  ......
                                  'TimeUUID25' => '16bytesstring',
                                }
                      }
         },
....................
     '100K': {
..............
        }
}


Client: PHP

I loaded with 100K keys with 25 columns per key and value for each of
the sub-column is 16 bytes string.
I populated the data using batch_insert(), and no issues with writes.
For my requirement, I need to fecth all 25 columns.
 For this purpose, am using get_slice() method.
Performance of get_slice() is way below our expections. We were
expecting, at least 1000 get_slices/second. "ROW-READ-STAGE" are
piling up.
vmstat and iostat on the machine looks normal.

 nodeprobe  -host localhost -port 8080 info

69914105239252561041379405595605110341
Load             : 200.9 MB
Generation No    : 1263997349
Uptime (seconds) : 2627
Heap Memory (MB) : 117.18 / 1023.06

I tried to  fecth 500 get_slices() per second:
===============================

tpstats:
--------
ROW-READ-STAGE                   16       250          94305
.............
ROW-READ-STAGE                   16       244         112190

Load test stats:

Name    | highest 10sec  mean  | lowest 10sec mean | Highest Rate
|Mean     |  Count
=======================================================================
 request | 48.23 sec                 | 6.94 msec              | 332.6/
sec     | 2.70 sec | 61825

Please let me know how can I improve the performance of get_slice().

thanks,
-Aita

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