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From envio user <enviou...@gmail.com>
Subject read performance very bad with 1M keys, 600 columns per key.
Date Wed, 03 Feb 2010 13:31:30 GMT
Hello Developers,

I originally posted this message to
cassandra-user@incubator.apache.org and want to find my tests are ok
or not.
I did this tests after seeing Jonathan's
blog(http://spyced.blogspot.com/)  and I used same stress.py to do
tests.

H/W: Single node, Quad Core(8 cores), 8GB RAM:
Two separate physical disks, one for the commit log and another for the data.
cassandra version : 0.5

storage-conf.xml
================
<KeysCachedFraction>0.4</KeysCachedFraction>
<CommitLogRotationThresholdInMB>256</CommitLogRotationThresholdInMB>
<MemtableSizeInMB>128</MemtableSizeInMB>
<MemtableObjectCountInMillions>0.2</MemtableObjectCountInMillions>
<MemtableFlushAfterMinutes>1440</MemtableFlushAfterMinutes>
<ConcurrentReads>16</ConcurrentReads>


Data Model:
<ColumnFamily CompareWith="BytesType" Name="Standard1"/>

/home/sun>python stress.py -n 100000 -t 100 -c 600 -r -o insert -i 10

........
83779,297,0.334478345002,290
86736,295,0.335617337551,300
89621,288,0.337104303915,310
92578,295,0.343658989251,320
95567,298,0.331744175047,330
98515,294,0.291284884979,340
100000,148,0.166682253301,350

This test can be ignored, since nobody will insert 600 keys at a time.

/home/sun>python stress.py -n 100000 -t 100 -c 25 -r -o read -i 10
WARNING: multiprocessing not present, threading will be used.
        Benchmark may not be accurate!
total,interval_op_rate,avg_latency,elapsed_time
19828,1982,0.0514599678015,10
40797,2096,0.0473390288764,20
59350,1855,0.0532040532783,30
76317,1696,0.0598703045355,40
100000,2368,0.0332285839526,50

After this I tried with 1 million keys:

Data size on disk : ~ 30G

/home/sun>python stress.py -n 1000000 -t 100 -c 25 -r -o read -i 10
WARNING: multiprocessing not present, threading will be used.
        Benchmark may not be accurate!
total,interval_op_rate,avg_latency,elapsed_time
.......................
.......................
87916,76,1.30730833113,1240
88665,74,1.33158908508,1250
89405,74,1.35333179654,1260
90086,68,1.45503252228,1270
90745,65,1.51978417774,1280
91476,73,1.38719448671,1290
92226,75,1.3288515962,1300
92976,75,1.33220300897,1310
93770,79,1.26187492288,1320
94557,78,1.26394684554,1330

thanks,
-Aita

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