Thanks guys. However, after I ran the client code several times (same set of 5000 entries), still 2 of the 6 nodes show 0 hits on row cache, despite each node has 1GB capacity for row cache and the caches are full. Since I always request the same entries over and over again, shouldn't there be some hits?
[user@node]$ ./checkinfo.sh Token : 85070591730234615865843651857942052863 Gossip active : true Thrift active : true Load : 587.15 GB Generation No : 1354074048 Uptime (seconds) : 36957 Heap Memory (MB) : 2027.29 / 3948.00 Data Center : DC1 Rack : r2 Exceptions : 0 Key Cache : size 0 (bytes), capacity 0 (bytes), 0 hits, 0 requests, NaN recent hit rate, 14400 save period in seconds Row Cache : size 1072651974 (bytes), capacity 1073741824 (bytes), 0 hits, 2576 requests, NaN recent hit rate, 0 save period in seconds Token : 141784319550391026443072753096570088105 Gossip active : true Thrift active : true Load : 583.21 GB Generation No : 1354074461 Uptime (seconds) : 36535 Heap Memory (MB) : 828.71 / 3948.00 Data Center : DC1 Rack : r2 Exceptions : 0 Key Cache : size 0 (bytes), capacity 0 (bytes), 0 hits, 0 requests, NaN recent hit rate, 14400 save period in seconds Row Cache : size 1072602906 (bytes), capacity 1073741824 (bytes), 0 hits, 3194 requests, NaN recent hit rate, 0 save period in seconds On Wed, Nov 28, 2012 at 4:26 AM, Bryan Talbot <btal...@aeriagames.com>wrote: > The row cache itself is global and the size is set with > row_cache_size_in_mb. It must be enabled per CF using the proper > settings. CQL3 isn't complete yet in C* 1.1 so if the cache settings > aren't shown there, then you'll probably need to use cassandra-cli. > > -Bryan > > > On Tue, Nov 27, 2012 at 10:41 PM, Wz1975 <wz1...@yahoo.com> wrote: > > Use cassandracli. > > > > > > Thanks. > > -Wei > > > > Sent from my Samsung smartphone on AT&T > > > > > > -------- Original message -------- > > Subject: Re: need some help with row cache > > From: Yiming Sun <yiming....@gmail.com> > > To: user@cassandra.apache.org > > CC: > > > > > > Also, what command can I used to see the "caching" setting? "DESC TABLE > > <cf>" doesn't list caching at all. Thanks. > > > > -- Y. > > > > > > On Wed, Nov 28, 2012 at 12:15 AM, Yiming Sun <yiming....@gmail.com> > wrote: > >> > >> Hi Bryan, > >> > >> Thank you very much for this information. So in other words, the > settings > >> such as row_cache_size_in_mb in YAML alone are not enough, and I must > also > >> specify the caching attribute on a per column family basis? > >> > >> -- Y. > >> > >> > >> On Tue, Nov 27, 2012 at 11:57 PM, Bryan Talbot <btal...@aeriagames.com> > >> wrote: > >>> > >>> On Tue, Nov 27, 2012 at 8:16 PM, Yiming Sun <yiming....@gmail.com> > wrote: > >>> > Hello, > >>> > > >>> > but it is not clear to me where this setting belongs to, because even > >>> > in the > >>> > v1.1.6 conf/cassandra.yaml, there is no such property, and > apparently > >>> > adding this property to the yaml causes a fatal configuration error > >>> > upon > >>> > server startup, > >>> > > >>> > >>> It's a per column family setting that can be applied using the CLI or > >>> CQL. > >>> > >>> With CQL3 it would be > >>> > >>> ALTER TABLE <cf> WITH caching = 'rows_only'; > >>> > >>> to enable the row cache but no key cache for that CF. > >>> > >>> -Bryan > >> > >> > > >
