Re: Delete doesn't remove row key?
Second, a followup question: So the row keys will be deleted after 1) the GC
grace period expires, and 2) I do a compaction?
Automatic compaction will purge the tombstones.
Third: Assuming the answer is yes, is there any way to manually force GC of
the deleted keys without doing the full GC shuffle (setting the GC grace
period artificially low, restarting, compacting, setting grace period back to
normal, restarting)?
No. But you do not need to restart. gc_grace_seconds is set per CF and can be
updated without a restart.
Cheers
-
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com
On 1/02/2012, at 2:32 PM, Todd Fast wrote:
First, thanks! I'd read that before, but didn't associate doing a range scan
with using the CLI, much less doing select count(*) in CQL. Now I know what
to call the phenomenon.
Second, a followup question: So the row keys will be deleted after 1) the GC
grace period expires, and 2) I do a compaction?
Third: Assuming the answer is yes, is there any way to manually force GC of
the deleted keys without doing the full GC shuffle (setting the GC grace
period artificially low, restarting, compacting, setting grace period back to
normal, restarting)?
Todd
On 1/31/2012 5:03 PM, Benjamin Hawkes-Lewis wrote:
On Wed, Feb 1, 2012 at 12:58 AM, Todd Fastt...@conga.com wrote:
I added a row with a single column to my 1.0.8 single-node cluster:
RowKey: ----
= (column=test, value=hi, timestamp=...)
I immediately deleted the row using both the CLI and CQL:
del Foo[lexicaluuid('----')];
delete from Foo using consistency all where
KEY=----
In either case, the column test is gone but the empty row key still
remains, and the row count reflects the presence of this phantom row.
I've tried nodetool compact/repair/flush/cleanup/scrub/etc. and nothing
removes the row key.
http://wiki.apache.org/cassandra/FAQ#range_ghosts
--
Benjamin Hawkes-Lewis
Delete doesn't remove row key?
I added a row with a single column to my 1.0.8 single-node cluster:
RowKey: ----
= (column=test, value=hi, timestamp=...)
I immediately deleted the row using both the CLI and CQL:
del Foo[lexicaluuid('----')];
delete from Foo using consistency all where
KEY=----
In either case, the column test is gone but the empty row key still
remains, and the row count reflects the presence of this phantom row.
I've tried nodetool compact/repair/flush/cleanup/scrub/etc. and nothing
removes the row key.
How do I get rid of it?
BTW, I saw this little tidbit in the describe output:
Row cache size / save period in seconds / keys to save : 0.0/0/all
Does all here mean to keep the keys for empty rows? If so, how do I
change that behavior?
ColumnFamily: Foo
...
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.UTF8Type
Row cache size / save period in seconds / keys to save : 0.0/0/all
Row Cache Provider:
org.apache.cassandra.cache.ConcurrentLinkedHashCacheProvider
Key cache size / save period in seconds: 20.0/14400
GC grace seconds: 86400
Compaction min/max thresholds: 4/32
Read repair chance: 0.1
Replicate on write: true
Bloom Filter FP chance: default
Built indexes: []
Compaction Strategy:
org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy
Todd
Re: Delete doesn't remove row key?
On Wed, Feb 1, 2012 at 12:58 AM, Todd Fast t...@conga.com wrote:
I added a row with a single column to my 1.0.8 single-node cluster:
RowKey: ----
= (column=test, value=hi, timestamp=...)
I immediately deleted the row using both the CLI and CQL:
del Foo[lexicaluuid('----')];
delete from Foo using consistency all where
KEY=----
In either case, the column test is gone but the empty row key still
remains, and the row count reflects the presence of this phantom row.
I've tried nodetool compact/repair/flush/cleanup/scrub/etc. and nothing
removes the row key.
http://wiki.apache.org/cassandra/FAQ#range_ghosts
--
Benjamin Hawkes-Lewis
Re: Delete doesn't remove row key?
First, thanks! I'd read that before, but didn't associate doing a range
scan with using the CLI, much less doing select count(*) in CQL. Now I
know what to call the phenomenon.
Second, a followup question: So the row keys will be deleted after 1)
the GC grace period expires, and 2) I do a compaction?
Third: Assuming the answer is yes, is there any way to manually force GC
of the deleted keys without doing the full GC shuffle (setting the GC
grace period artificially low, restarting, compacting, setting grace
period back to normal, restarting)?
Todd
On 1/31/2012 5:03 PM, Benjamin Hawkes-Lewis wrote:
On Wed, Feb 1, 2012 at 12:58 AM, Todd Fastt...@conga.com wrote:
I added a row with a single column to my 1.0.8 single-node cluster:
RowKey: ----
= (column=test, value=hi, timestamp=...)
I immediately deleted the row using both the CLI and CQL:
del Foo[lexicaluuid('----')];
delete from Foo using consistency all where
KEY=----
In either case, the column test is gone but the empty row key still
remains, and the row count reflects the presence of this phantom row.
I've tried nodetool compact/repair/flush/cleanup/scrub/etc. and nothing
removes the row key.
http://wiki.apache.org/cassandra/FAQ#range_ghosts
--
Benjamin Hawkes-Lewis
