Hi! I tried again, I see the scrub action in cassandra logs INFO [CompactionExecutor:4029] 2012-10-24 10:36:54,108 CompactionManager.java (line 476) Scrubbing SSTableReader(path='/raid0/cassandra/data/tok/tk_usus_user-hc-339-Data.db') INFO [CompactionExecutor:4029] 2012-10-24 10:36:54,184 CompactionManager.java (line 658) Scrub of SSTableReader(path='/raid0/cassandra/data/tok/tk_usus_user-hc-339-Data.db') complete: 54 rows in new sstable and 0 empty (tombstoned) rows dropped INFO [CompactionExecutor:4029] 2012-10-24 10:36:54,185 CompactionManager.java (line 476) Scrubbing SSTableReader(path='/raid0/cassandra/data/tok/tk_usus_user-hc-340-Data.db') INFO [CompactionExecutor:4029] 2012-10-24 10:36:54,914 CompactionManager.java (line 658) Scrub of SSTableReader(path='/raid0/cassandra/data/tok/tk_usus_user-hc-340-Data.db') complete: 7037 rows in new sstable and 0 empty (tombstoned) rows dropped
I don't see any CompressionInfo.db files and compression ratio is still 0.0 on this node only, on other nodes it is almost 0.5... Any idea? Thanks, *Tamar Fraenkel * Senior Software Engineer, TOK Media [image: Inline image 1] ta...@tok-media.com Tel: +972 2 6409736 Mob: +972 54 8356490 Fax: +972 2 5612956 On Wed, Sep 26, 2012 at 3:40 AM, aaron morton <aa...@thelastpickle.com>wrote: > Check the logs on nodes 2 and 3 to see if the scrub started. The logs on > 1 will be a good help with that. > > Cheers > > ----------------- > Aaron Morton > Freelance Developer > @aaronmorton > http://www.thelastpickle.com > > On 24/09/2012, at 10:31 PM, Tamar Fraenkel <ta...@tok-media.com> wrote: > > Hi! > I ran > UPDATE COLUMN FAMILY cf_name WITH > compression_options={sstable_compression:SnappyCompressor, > chunk_length_kb:64}; > > I then ran on all my nodes (3) > sudo nodetool -h localhost scrub tok cf_name > > I have replication factor 3. The size of the data on disk was cut in half > in the first node and in the jmx I can see that indeed the compression > ration is 0.46. But on nodes 2 and 3 nothing happened. In the jmx I can see > that compression ratio is 0 and the size of the files of disk stayed the > same. > > In cli > > ColumnFamily: cf_name > Key Validation Class: org.apache.cassandra.db.marshal.UUIDType > Default column value validator: > org.apache.cassandra.db.marshal.UTF8Type > Columns sorted by: > org.apache.cassandra.db.marshal.CompositeType(org.apache.cassandra.db.marshal.UTF8Type,org.apache.cassandra.db.marshal.UTF8Type) > Row cache size / save period in seconds / keys to save : 0.0/0/all > Row Cache Provider: > org.apache.cassandra.cache.SerializingCacheProvider > Key cache size / save period in seconds: 200000.0/14400 > GC grace seconds: 864000 > Compaction min/max thresholds: 4/32 > Read repair chance: 1.0 > Replicate on write: true > Bloom Filter FP chance: default > Built indexes: [] > Compaction Strategy: > org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy > Compression Options: > chunk_length_kb: 64 > sstable_compression: > org.apache.cassandra.io.compress.SnappyCompressor > > Can anyone help? > Thanks > > *Tamar Fraenkel * > Senior Software Engineer, TOK Media > > <tokLogo.png> > > > ta...@tok-media.com > Tel: +972 2 6409736 > Mob: +972 54 8356490 > Fax: +972 2 5612956 > > > > > > On Mon, Sep 24, 2012 at 8:37 AM, Tamar Fraenkel <ta...@tok-media.com>wrote: > >> Thanks all, that helps. Will start with one - two CFs and let you know >> the effect >> >> >> *Tamar Fraenkel * >> Senior Software Engineer, TOK Media >> >> <tokLogo.png> >> >> >> ta...@tok-media.com >> Tel: +972 2 6409736 >> Mob: +972 54 8356490 >> Fax: +972 2 5612956 >> >> >> >> >> >> On Sun, Sep 23, 2012 at 8:21 PM, Hiller, Dean <dean.hil...@nrel.gov>wrote: >> >>> As well as your unlimited column names may all have the same prefix, >>> right? Like "accounts".rowkey56, "accounts".rowkey78, etc. etc. so the >>> "accounts gets a ton of compression then. >>> >>> Later, >>> Dean >>> >>> From: Tyler Hobbs <ty...@datastax.com<mailto:ty...@datastax.com>> >>> Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" >>> <user@cassandra.apache.org<mailto:user@cassandra.apache.org>> >>> Date: Sunday, September 23, 2012 11:46 AM >>> To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" < >>> user@cassandra.apache.org<mailto:user@cassandra.apache.org>> >>> Subject: Re: compression >>> >>> column metadata, you're still likely to get a reasonable amount of >>> compression. This is especially true if there is some amount of repetition >>> in the column names, values, or TTLs in wide rows. Compression will almost >>> always be beneficial unless you're already somehow CPU bound or are using >>> large column values that are high in entropy, such as pre-compressed or >>> encrypted data. >>> >> >> > >
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