Hi Bowen,
Thanks for your answer.
I was thinking of extreme use cases, but as far as I am concerned I can
deal with creation and deletion of 2 tables every 6 hours for a keyspace.
So it lets around 8 folders of deleted tables per day - sometimes more
cause I can see sometimes 2 folders created for a same table name, with 2
different ids, caused by temporary schema disagreements I guess.
Basically it means 20 years before the KS folder has 65K subfolders, so I
would say I have time to think of redesigning the data model ^^
Nevertheless, does it sound too much in terms of thombstones in the systems
tables (with the default GC grace period of 10 days)?
Sébastien.
Le mar. 5 déc. 2023, 12:19, Bowen Song via user <user@cassandra.apache.org>
a écrit :
> Please rethink your use case. Create and delete tables concurrently often
> lead to schema disagreement. Even doing so on a single node sequentially
> will lead to a large number of tombstones in the system tables.
> On 04/12/2023 19:55, Sébastien Rebecchi wrote:
>
> Thank you Dipan.
>
> Do you know if there is a good reason for Cassandra to let tables folder
> even when there is no snapshot?
>
> I'm thinking of use cases where there is the need to create and delete
> small tables at a high rate. You could quickly end with more than 65K
> (limit of ext4) subdirectories in the KS directory, while 99.9.. % of them
> are residual of deleted tables.
>
> That looks quite dirty from Cassandra to not clean its own "garbage" by
> itself, and quite dangerous for the end user to have to do it alone, don't
> you think so?
>
> Thanks,
>
> Sébastien.
>
> Le lun. 4 déc. 2023, 11:28, Dipan Shah <dipan....@hotmail.com> a écrit :
>
>> Hello Sebastien,
>>
>> There are no inbuilt tools that will automatically remove folders of
>> deleted tables.
>>
>> Thanks,
>>
>> Dipan Shah
>> ------------------------------
>> *From:* Sébastien Rebecchi <srebec...@kameleoon.com>
>> *Sent:* 04 December 2023 13:54
>> *To:* user@cassandra.apache.org <user@cassandra.apache.org>
>> *Subject:* Remove folders of deleted tables
>>
>> Hello,
>>
>> When we delete a table with Cassandra, it lets the folder of that table
>> on file system, even if there is no snapshot (auto snapshots disabled).
>> So we end with the empty folder {data folder}/{keyspace name}/{table
>> name-table id} containing only 1 subfolder, backups, which is itself empty.
>> Is there a way to automatically remove folders of deleted tables?
>>
>> Sébastien.
>>
>
