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From "PARASHAR, BHASKARJYA JAY" <bp1...@att.com>
Subject Worse perf after Row Caching version 1.2.5:
Date Tue, 11 Feb 2014 15:26:32 GMT
Hi,

I have two tables and I enabled row caching for both of them using CQL. These two CF's are
very small with one about 300 rows and other < 2000 rows. The rows themselves are small.
Cassandra heap: 8gb.
a.       alter table TABLE_X with caching = 'rows_only';
b.      alter table TABLE_Y with caching = 'rows_only';
I also changed row_cache_size_in_mb: 1024 in the Cassandra.yaml file.
After extensive testing, it seems the performance of Table_X degraded from 600ms to 750ms
and Table_Y gained about 10 ms (from 188ms to 177 ms).
More Info
Table X is always queried with "Select * from Table_X";  Cfstats in Table_X shows Read Latency:
NaN ms. I assumed that since we select all the rows, the entire table would be cached.
Table_Y has a secondary index and is queried on that index.


Would appreciate any input why the performance is worse and how to enable row caching for
these two tables.

Thanks
Jay



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