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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