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Posted to user@cassandra.apache.org by Rene Kochen <Re...@emea.schange.com> on 2011/06/21 12:12:40 UTC
Flushing behavior in Cassandra 0.8
I try to understand the flushing behavior in Cassandra 0.8
When I create rows, after a few seconds, I see the following line in the log:
INFO 11:18:46,470 flushing high-traffic column family ColumnFamilyStore(table='Traxis', columnFamily='Customers')
INFO 11:18:46,471 Enqueuing flush of Memtable-Customers@14306556(697958/50059836 serialized/live bytes, 30346 ops)
INFO 11:18:46,472 Writing Memtable-Customers@14306556(697958/50059836 serialized/live bytes, 30346 ops)
INFO 11:18:47,415 Completed flushing C:\Cassandra\Storage\data\Traxis\Customers-g-1-Data.db (4157370 bytes)
The super-column-family is configured as follows:
Memtable thresholds: 0.2953125/63/1440 (millions of ops/MB/minutes):
I don't think any of the three tresholds should trigger the flush?
Thanks,
Rene
Re: Flushing behavior in Cassandra 0.8
Posted by aaron morton <aa...@thelastpickle.com>.
The new memtable_total_space_in_mb option is kicking in
https://github.com/apache/cassandra/blob/cassandra-0.8.0/NEWS.txt#L34
http://thelastpickle.com/2011/05/04/How-are-Memtables-measured/
Cheers
-----------------
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://www.thelastpickle.com
On 21 Jun 2011, at 22:12, Rene Kochen wrote:
> I try to understand the flushing behavior in Cassandra 0.8
>
> When I create rows, after a few seconds, I see the following line in the log:
>
> INFO 11:18:46,470 flushing high-traffic column family ColumnFamilyStore(table='Traxis', columnFamily='Customers')
> INFO 11:18:46,471 Enqueuing flush of Memtable-Customers@14306556(697958/50059836 serialized/live bytes, 30346 ops)
> INFO 11:18:46,472 Writing Memtable-Customers@14306556(697958/50059836 serialized/live bytes, 30346 ops)
> INFO 11:18:47,415 Completed flushing C:\Cassandra\Storage\data\Traxis\Customers-g-1-Data.db (4157370 bytes)
>
> The super-column-family is configured as follows:
>
> Memtable thresholds: 0.2953125/63/1440 (millions of ops/MB/minutes):
>
> I don’t think any of the three tresholds should trigger the flush?
>
> Thanks,
>
> Rene