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Posted to user@cassandra.apache.org by Erik Forsberg <fo...@opera.com> on 2012/03/21 16:36:45 UTC
sstable size increase at compaction
Hi!
We're using the bulkloader to load data to Cassandra. During and after
bulkloading, the minor compaction process seems to result in larger
sstables being created. An example:
INFO [CompactionExecutor:105] 2012-03-21 15:18:46,608
CompactionTask.java (line 115) Compacting [SSTableReader(pat
h='/cassandra/OSP5/Data/OSP5-Data-hc-1755-Data.db'), (REMOVED A BUNCH OF
OTHER SSTABLE PATHS),
SSTableReader(path='/cassandra/OSP5/Data/OSP5-Data-hc-1749-Data.db'),
SSTableReader(path='/cassandra/O
SP5/Data/OSP5-Data-hc-1753-Data.db')]
INFO [CompactionExecutor:105] 2012-03-21 15:30:04,188
CompactionTask.java (line 226) Compacted to
[/cassandra/OSP5/Data/OSP5-Data-hc-3270-Data.db,]. 84,214,484 to
105,498,673 (~125% of original) bytes for 2,132,056 keys at
0.148486MB/s. Time: 677,580ms.
The sstables are compressed (DeflateCompressor with chunk size 128) on
the Hadoop cluster before being transferred to Cassandra, and the CF has
the same compression settings:
[default@Keyspace1] describe Data;
ColumnFamily: Data (Super)
Key Validation Class: org.apache.cassandra.db.marshal.UTF8Type
Default column value validator:
org.apache.cassandra.db.marshal.LongType
Columns sorted by:
org.apache.cassandra.db.marshal.LongType/org.apache.cassandra.db.marshal.UTF8Type
GC grace seconds: 864000
Compaction min/max thresholds: 4/32
Read repair chance: 1.0
DC Local Read repair chance: 0.0
Replicate on write: true
Caching: KEYS_ONLY
Bloom Filter FP chance: 0.01
Built indexes: []
Compaction Strategy:
org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy
Compression Options:
chunk_length_kb: 128
sstable_compression:
org.apache.cassandra.io.compress.DeflateCompressor
Any clues on this?
Regards,
\EF
Re: sstable size increase at compaction
Posted by Erik Forsberg <fo...@opera.com>.
On 2012-03-21 16:36, Erik Forsberg wrote:
> Hi!
>
> We're using the bulkloader to load data to Cassandra. During and after
> bulkloading, the minor compaction process seems to result in larger
> sstables being created. An example:
This is on Cassandra 1.1, btw.
\EF