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From Edward Capriolo <edlinuxg...@gmail.com>
Subject Re: max_compaction_threshold removed - bad move
Date Wed, 09 Jan 2013 16:04:35 GMT
Was the change well accounted for in the changes.TXT or the readme.txt?

It hasn't been removed, it has been renamed max_threshold and moved into
the compaction options map for CQL3 (nothing has changed for thrift or
CQL2). The CQL3 reference doc hasn't been updated correctly however, which
I'll fix.

^ statements like above are scary. I worry at this point cassandra is
becoming two separate databases in one, we rename something and move it
around, or give it a double meaning, or something. Things are becoming very
unclear and have different meaning in different contexts.

https://github.com/apache/cassandra/blob/cassandra-1.2/src/java/org/apache/cassandra/cql3/CFDefinition.java#L90


"// Note that isCompact means here that no componet of the comparator
correspond to the column names
// defined in the CREATE TABLE QUERY. This is not exactly equivalent to the
'WITH COMPACT STORAGE'
// option when creating a table in that "static CF" without a composite
type will have isCompact == false
  // even though one must use 'WITH COMPACT STORAGE' to declare them."


Confused

On Wed, Jan 9, 2013 at 10:56 AM, Sylvain Lebresne <sylvain@datastax.com>wrote:

> On Wed, Jan 9, 2013 at 4:21 PM, Radim Kolar <hsn@filez.com> wrote:
>
> > removing max_compaction_threshold in 1.2 was bad move, keeping it low
> > helps compaction throughput because it lowers number of disk seeks.
> >
>
> It hasn't been removed, it has been renamed max_threshold and moved into
> the compaction options map for CQL3 (nothing has changed for thrift or
> CQL2). The CQL3 reference doc hasn't been updated correctly however, which
> I'll fix.
>
>
> >
> > if you have redhat linux, check during install category "performance
> > tools" or something like that, you will get tools for disk monitoring.
> > Learn to use them.
> >
>
> Obviously no Cassandra dev has ever heard of a "disk monitoring tool".
> That's so helpful and not at all condescending for no good reason, thanks
> Radim.
>
> --
> Sylvain
>

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