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From Yiming Sun <yiming....@gmail.com>
Subject Re: need some help with row cache
Date Wed, 28 Nov 2012 14:09:50 GMT
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 <btalbot@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 <wz1975@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.sun@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.sun@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 <btalbot@aeriagames.com>
> >> wrote:
> >>>
> >>> On Tue, Nov 27, 2012 at 8:16 PM, Yiming Sun <yiming.sun@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
> >>
> >>
> >
>

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