Schema size

[Sasha Yanushkevich <ya...@gmail.com>]

 Hi All,

I have a question about schema cleaning in cassandra.

I use cassandra version 1.0.9. I have 5 keyspaces and about 1500 column
family per keyspace. After dynamically creating and deleting CF my schema's
sstables  size were very high. For example size of Migrations was 45 GB and
Schema sstable size was 45 GB whereas all data size was about 10 GB.

Why schema grow was so fast? And how may I cleanup schema or later schema
cleanup itself?


-- 
Best regards,
Alexander

Re: Schema size

[Edward Capriolo <ed...@gmail.com>]

In Cassandra 1.1 the schema is no longer a full migration history.
Before that each schema change is recorded in the table and they all
have to be replayed when a node bootstraps. Also 1.1 has some bug ATM
that means you should not switch to it.

People tend to say things like "with cassandra X you now can have more
CF and KS's" but back in the day the thinking was "You only need 1"

Hector has a concept of "virtual keyspaces" which is a model that is
likely to give you more success then 1500 CFs. I am not a fan of
dynamically creating and tearing down CFS on the fly or 1 per customer
designs.

When the wrinkles come out of 1.1 and up upgrade the schema size
should shrink down.

On Fri, May 25, 2012 at 6:25 AM, Sasha Yanushkevich <ya...@gmail.com> wrote:
> Hi All,
>
> I have a question about schema cleaning in cassandra.
>
> I use cassandra version 1.0.9. I have 5 keyspaces and about 1500 column
> family per keyspace. After dynamically creating and deleting CF my schema's
> sstables  size were very high. For example size of Migrations was 45 GB and
> Schema sstable size was 45 GB whereas all data size was about 10 GB.
>
> Why schema grow was so fast? And how may I cleanup schema or later schema
> cleanup itself?
>
>
> --
> Best regards,
> Alexander
>