You can start compaction via JMX if you need it and you know what you're
doing:
Find org.apache.cassandra.db:type=CompactionManager MBean and
forceUserDefinedCompaction operation in it.
First argument is keyspace name, second one is a comma-separated list of
SSTables to compact (filename)
You can also perform a major compaction via nodetool compact (for
SizeTieredCompaction), but - again - you really should not do it unless
you're really sure what you do, as it compacts all the SSTables
together, which is not something you might want to achieve in most of
the cases.
M.
W dniu 19.06.2013 14:31, Rodrigo Felix pisze:
Thanks Eric. Is there a way to start manually compaction operations?
I'm thinking about doing after loading data and before start run phase of
the benchmark.
Thanks.
Att.
*Rodrigo Felix de Almeida*
LSBD - Universidade Federal do Ceará
Project Manager
MBA, CSM, CSPO, SCJP
On Mon, Jun 17, 2013 at 12:41 PM, Eric Stevens <migh...@gmail.com> wrote:
Load is the size of the storage on disk as I understand it. This can
fluctuate during normal usage even if records are not being added or
removed, a node's load may be reduced during compaction for example.
During compaction, especially if you use Size Tiered Compaction strategy
(the default), load may temporarily double for a column family.
On Mon, Jun 17, 2013 at 11:33 AM, Rodrigo Felix <
rodrigofelixdealme...@gmail.com> wrote:
Hi,
I've been running a benchmark on Cassandra and I'm facing a problem
regarding to the size of the database.
I performed a load phase and then, when running nodetool ring, I got
the following output:
*ubuntu@domU-12-31-39-0E-11-F1:~/cassandra$ bin/nodetool ring *
*Address DC Rack Status State Load
Effective-Ownership Token *
*
85070591730234615865843651857942052864 *
*10.192.18.3 datacenter1 rack1 Up Normal 2.07 GB
50.00% 0 *
*10.85.135.169 datacenter1 rack1 Up Normal 2.09 GB
50.00% 85070591730234615865843651857942052864*
After that I executed, for about one hour, a workload with scan and
insert queries. Then, after finishing the workload execution, I run again
nodetool ring and got the following:
*ubuntu@domU-12-31-39-0E-11-F1:~/cassandra$ bin/nodetool ring *
*Address DC Rack Status State Load
Effective-Ownership Token *
*
85070591730234615865843651857942052864 *
*10.192.18.3 datacenter1 rack1 Up Normal 1.07 GB
50.00% 0 *
*10.85.135.169 datacenter1 rack1 Up Normal 2.15 GB
50.00% 85070591730234615865843651857942052864*
Any idea why a node had its size reduced if no record was removed? No
machine or added or removed during this workload.
Is this related to any kind of compression? If yes, is there a command
to confirm that?
I also faced a problem where a node has its size increased from about
2gb to about 4gb. In this last scenario, I both added and removed nodes
during the workload depending on the load (CPU).
Thanks in advance for any help.
Att.
*Rodrigo Felix de Almeida*
LSBD - Universidade Federal do Ceará
Project Manager
MBA, CSM, CSPO, SCJP
