No snapshots.

I restarted the node and now the Load in ring is in sync with the disk
usage. Not sure what caused it to go out of sync. However, the Live SStable
count doesn't match exactly with the number of data files on disk.

I am going through the Cassandra code to understand what could be the
reason for the mismatch in the sstable count and also why there is no
reference of some of the data files in system.log.




On Mon, Dec 16, 2013 at 2:45 PM, Arindam Barua <aba...@247-inc.com> wrote:

>
>
> Do you have any snapshots on the nodes where you are seeing this issue?
>
> Snapshots will link to sstables which will cause them not be deleted.
>
>
>
> -Arindam
>
>
>
> *From:* Narendra Sharma [mailto:narendra.sha...@gmail.com]
> *Sent:* Sunday, December 15, 2013 1:15 PM
> *To:* user@cassandra.apache.org
> *Subject:* Cassandra 1.1.6 - Disk usage and Load displayed in ring
> doesn't match
>
>
>
> We have 8 node cluster. Replication factor is 3.
>
>
>
> For some of the nodes the Disk usage (du -ksh .) in the data directory for
> CF doesn't match the Load reported in nodetool ring command. When we
> expanded the cluster from 4 node to 8 nodes (4 weeks back), everything was
> okay. Over period of last 2-3 weeks the disk usage has gone up. We
> increased the RF from 2 to 3 2 weeks ago.
>
>
>
> I am not sure if increasing the RF is causing this issue.
>
>
>
> For one of the nodes that I analyzed:
>
> 1. nodetool ring reported load as 575.38 GB
>
>
>
> 2. nodetool cfstats for the CF reported:
>
> SSTable count: 28
>
> Space used (live): 572671381955
>
> Space used (total): 572671381955
>
>
>
>
>
> 3. 'ls -1 *Data* | wc -l' in the data folder for CF returned
>
> 46
>
>
>
> 4. 'du -ksh .' in the data folder for CF returned
>
> 720G
>
>
>
> The above numbers indicate that there are some sstables that are obsolete
> and are still occupying space on disk. What could be wrong? Will restarting
> the node help? The cassandra process is running for last 45 days with no
> downtime. However, because the disk usage is high, we are not able to run
> full compaction.
>
>
>
> Also, I can't find reference to each of the sstables on disk in the
> system.log file. For eg I have one data file on disk as (ls -lth):
>
> 86G Nov 20 06:14
>
>
>
> I have system.log file with first line:
>
> INFO [main] 2013-11-18 09:41:56,120 AbstractCassandraDaemon.java (line
> 101) Logging initialized
>
>
>
> The 86G file must be a result of some compaction. I see no reference of
> data file in system.log file between 11/18 to 11/25. What could be the
> reason for that? The only reference is dated 11/29 when the file was being
> streamed to another node (new node).
>
>
>
> How can I identify the obsolete files and remove them? I am thinking about
> following. Let me know if it make sense.
>
> 1. Restart the node and check the state.
>
> 2. Move the oldest data files to another location (to another mount point)
>
> 3. Restart the node again
>
> 4. Run repair on the node so that it can get the missing data from its
> peers.
>
>
>
>
>
> I compared the numbers of a healthy node for the same CF:
>
> 1. nodetool ring reported load as 662.95 GB
>
>
>
> 2. nodetool cfstats for the CF reported:
>
> SSTable count: 16
>
> Space used (live): 670524321067
>
> Space used (total): 670524321067
>
>
>
> 3. 'ls -1 *Data* | wc -l' in the data folder for CF returned
>
> 16
>
>
>
> 4. 'du -ksh .' in the data folder for CF returned
>
> 625G
>
>
>
>
>
> -Naren
>
>
>
>
>
>
> --
> Narendra Sharma
>
> Software Engineer
>
> *http://www.aeris.com <http://www.aeris.com>*
>
> *http://narendrasharma.blogspot.com/ <http://narendrasharma.blogspot.com/>*
>
>
>



-- 
Narendra Sharma
Software Engineer
*http://www.aeris.com <http://www.aeris.com>*
*http://narendrasharma.blogspot.com/ <http://narendrasharma.blogspot.com/>*

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