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From Sorin Julean <sorin.jul...@gmail.com>
Subject Re: memtable flush thresholds
Date Mon, 12 Sep 2011 14:42:08 GMT
Thanks Jonathan !

 memtable_total_space_in_mb is the threshold that is reached.

Kind regards,
Sorin

On Mon, Sep 12, 2011 at 3:16 PM, Jonathan Ellis <jbellis@gmail.com> wrote:

> see memtable_total_space_in_mb at
> http://thelastpickle.com/2011/05/04/How-are-Memtables-measured/
>
> On Mon, Sep 12, 2011 at 6:55 AM, Sorin Julean <sorin.julean@gmail.com>
> wrote:
> > Hi,
> >
> >  I've checked the memtable flush (cassandra 0.8.4)  and it seams to me it
> > hapens sooner then the threshold is reached.
> >
> > Here's the threshould's (the default ones calculated for a heap size of
> > -Xmx1980M):
> >     ColumnFamily: idx_graphable (Super)
> >       Key Validation Class: org.apache.cassandra.db.marshal.BytesType
> >       Default column value validator:
> > org.apache.cassandra.db.marshal.BytesType
> >       Columns sorted by:
> >
> org.apache.cassandra.db.marshal.UTF8Type/org.apache.cassandra.db.marshal.UTF8Type
> >       Row cache size / save period in seconds: 0.0/0
> >       Key cache size / save period in seconds: 200000.0/14400
> >       Memtable thresholds: 0.5671875/1440/121 (millions of
> ops/minutes/MB)
> >       GC grace seconds: 864000
> >       Compaction min/max thresholds: 4/32
> >       Read repair chance: 1.0
> >       Replicate on write: true
> >
> > In the logs it seams to me none oh the thresold is reached ( definitively
> > minutes threshold is not reached ).
> >
> > 9-08 20:12:30,136 MeteredFlusher.java (line 62) flushing high-traffic
> column
> > family ColumnFamilyStore(table='graph', columnFamily='idx_graphable')
> >  INFO [NonPeriodicTasks:1] 2011-09-08 20:12:30,144 ColumnFamilyStore.java
> > (line 1036) Enqueuing flush of
> > Memtable-idx_graphable@915643571(4671498/96780112 serialized/live bytes,
> > 59891 ops)
> >  INFO [FlushWriter:111] 2011-09-08 20:12:30,145 Memtable.java (line 237)
> > Writing Memtable-idx_graphable@915643571(4671498/96780112
> serialized/live
> > bytes, 59891 ops)
> >  INFO [FlushWriter:111] 2011-09-08 20:12:30,348 Memtable.java (line 254)
> > Completed flushing [...]/cassandra/data/graph/idx_graphable-g-23-Data.db
> > (4673905 bytes)
> >
> >
> > Could someone clarify it for me ?
> > "high-traffic column family" has a special meaning ?
> >
> > Many thanks,
> > Sorin
> >
>
>
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of DataStax, the source for professional Cassandra support
> http://www.datastax.com
>

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