[ 
https://issues.apache.org/jira/browse/CASSANDRA-14587?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16981730#comment-16981730
 ] 

Ekaterina Dimitrova commented on CASSANDRA-14587:
-------------------------------------------------

[~Defenestrator] Can you give me a bit more clarification about this bug, 
please?
The idea behind  nodetool listsnapshots is to go through all possible key 
spaces and collect how much space is occupied by all possible snapshots.

But you mention you are checking the snapshots of a specific keyspace and 
column-family ? Maybe I don't get it properly. Please advise. 

> TrueDiskSpaceUsed overcounts snapshots
> --------------------------------------
>
>                 Key: CASSANDRA-14587
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-14587
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Tool/nodetool
>         Environment: Debian 8
> Cassandra 3.11.2
>            Reporter: Elliott Sims
>            Assignee: Ekaterina Dimitrova
>            Priority: Low
>
> Running 'nodetool listsnapshots' seems to overcount "TrueDiskSpaceUsed" under 
> some circumstances.  Specifically when there's a large number of snapshots.  
> I suspect that it's not deduplicating space used when multiple snapshots 
> share sstables that are not part of the current table.
> Results of "nodetool listsnapshots":
> Total TrueDiskSpaceUsed: 396.11 MiB
> Results of "du -hcs" on the table's directory:
> 18M    total
> This is 50+ snapshots (every minute) run with "-t <datestamp> -sf 
> --column-family <tablename> <keyspace>"
> The results of a "du -hcs -L <directory" come out pretty close to the 
> "TrueDiskSpaceUsed"
> I have only tested against 3.11.2, but have no reason to believe it's unique 
> to that version or even 3.x.



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org
For additional commands, e-mail: commits-h...@cassandra.apache.org

Reply via email to