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From Kallin Nagelberg <kallin.nagelb...@gmail.com>
Subject Re: time to live rows
Date Tue, 08 Feb 2011 16:34:25 GMT
I'm trying to set the gc_grace_seconds column family parameter but no
luck.. I got the name of it from the comment in cassandra.yaml:

#     - gc_grace_seconds: specifies the time to wait before garbage
#        collecting tombstones (deletion markers). defaults to 864000 (10
#        days). See http://wiki.apache.org/cassandra/DistributedDeletes

create column family Session
    with comparator = UTF8Type
    and keys_cached = 10000
    and memtable_flush_after = 1440
    and memtable_throughput = 32
	and gc_grace_seconds = 60;

error is 'No enum const class
org.apache.cassandra.cli.CliUserHelp$ColumnFamilyArgument.GC_GRACE_SECONDS'.

Thanks,
-Kal

On Tue, Feb 8, 2011 at 11:02 AM, Sylvain Lebresne <sylvain@datastax.com> wrote:
>> I hope you don't consider this a hijack of the thread...
>>
>> What I'd like to know is the following:
>>
>> The GC removes TTL rows some time after they expire, at its convenience.
>> But will they stop being returned as soon as they expire? (This is the
>> expected behavior...)
>
> It is the individual column that have TTL. When a column expires, it becomes
> a delete tombstone. Now, a row with tombstones (even only them) will show
> during range request. But the explanation is
> here: http://wiki.apache.org/cassandra/FAQ#range_ghosts
>
>>
>> On Tue, Feb 8, 2011 at 5:11 PM, Kallin Nagelberg
>> <kallin.nagelberg@gmail.com> wrote:
>>>
>>> So the empty row will be ultimately removed then? Is there a way to
>>> for the GC to verify this?
>>>
>>> Thanks,
>>> -Kal
>>>
>>> On Tue, Feb 8, 2011 at 2:21 AM, Stu Hood <stuhood@gmail.com> wrote:
>>> > The expired columns were converted into tombstones, which will live for
>>> > the
>>> > GC timeout. The "empty" row will be cleaned up when those tombstones
>>> > are
>>> > removed.
>>> > Returning the empty row is unfortunate... we'd love to find a more
>>> > appropriate solution that might not involve endless scanning.
>>> > See
>>> > http://wiki.apache.org/cassandra/FAQ#i_deleted_what_gives
>>> > http://wiki.apache.org/cassandra/FAQ#range_ghosts
>>> >
>>> > On Mon, Feb 7, 2011 at 1:49 PM, Kallin Nagelberg
>>> > <kallin.nagelberg@gmail.com> wrote:
>>> >>
>>> >> I also tried forcing a major compaction on the column family using JMX
>>> >> but the row remains.
>>> >>
>>> >> On Mon, Feb 7, 2011 at 4:43 PM, Kallin Nagelberg
>>> >> <kallin.nagelberg@gmail.com> wrote:
>>> >> > I tried that but I still see the row coming back on a list
>>> >> > <columnfamily> in the CLI. My concern is that there will
be a
>>> >> > pointer
>>> >> > to an empty row for all eternity.
>>> >> >
>>> >> > -Kal
>>> >> >
>>> >> > On Mon, Feb 7, 2011 at 4:38 PM, Aaron Morton
>>> >> > <aaron@thelastpickle.com>
>>> >> > wrote:
>>> >> >> Deleting all the columns in a row via TTL has the same affect
as
>>> >> >> deleting th
>>> >> >> row, the data will physically by removed during compaction.
>>> >> >>
>>> >> >> Aaron
>>> >> >>
>>> >> >>
>>> >> >> On 08 Feb, 2011,at 10:24 AM, Bill Speirs <bill.speirs@gmail.com>
>>> >> >> wrote:
>>> >> >>
>>> >> >> I don't think this is supported (but I could be completely
wrong).
>>> >> >> However, I'd love to see this functionality as well.
>>> >> >>
>>> >> >> How would one go about requesting such a feature?
>>> >> >>
>>> >> >> Bill-
>>> >> >>
>>> >> >> On Mon, Feb 7, 2011 at 4:15 PM, Kallin Nagelberg
>>> >> >> <kallin.nagelberg@gmail.com> wrote:
>>> >> >>> Hey,
>>> >> >>>
>>> >> >>> I have read about the new TTL columns in Cassandra 0.7.
In my case
>>> >> >>> I'd
>>> >> >>> like to expire an entire row automatically after a certain
amount
>>> >> >>> of
>>> >> >>> time. Is this possible as well?
>>> >> >>>
>>> >> >>> Thanks,
>>> >> >>> -Kal
>>> >> >>>
>>> >> >>
>>> >> >
>>> >
>>> >
>>
>
>

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