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https://issues.apache.org/jira/browse/CASSANDRA-18283?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17693207#comment-17693207
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Stefan Miklosovic commented on CASSANDRA-18283:
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When it comes to sstable size, these metrics are fetched from
ColumnFamilyStoreMBean. While there is a method called "isLeveledCompaction",
returning boolean, based on which we decide in tablestats printer if it is a
table on LCS or not, we do not have similar method for other compaction
strategies. I would rather print this information to whatever table, not only
for tables on LCS.
For TWCS, I am lost what kind of output you would actually like to see? Can you
provide some concrete example?
For ratio, I have added that there too.
For separators, I am not too big fan of doing that.
> Enhance nodetool tablestats
> ---------------------------
>
> Key: CASSANDRA-18283
> URL: https://issues.apache.org/jira/browse/CASSANDRA-18283
> Project: Cassandra
> Issue Type: Improvement
> Components: Tool/nodetool
> Reporter: Brad Schoening
> Priority: Normal
> Time Spent: 10m
> Remaining Estimate: 0h
>
> The nodetool tablestats command lacks some available details which would be
> very useful to report upon. This is especially helpful in
> database-as-a-service environments where servers and their disk files are not
> directly observable by users.
> 1. Currently, for LCS tablestats reports useful details about the number of
> sstables in each level:
> SSTable count: 6635
> SSTables in each level: [1, 9, 98, 805, 5722, 0, 0, 0, 0]
> This type of additional detail about the sstables is absent from STCS and
> TWCS as it only reports the table count.
> 1a) For STCS, tablestats should report the max sstable file size on disk.
> This is useful to know if compaction has failed due to disk space or if a
> forced compaction created a jumbo table.
> 1b) For TWCS, tablestats should report the min and max timestamps of the
> sstables representing windows. This is useful to know if out-of-window
> writes or rows w/out a TTL have lead many more sstables on disk than expected
> by the time window configuration.
> 2. While tablestats reports both memtable and disk file sstable statistics.
> It is useful these are in the same command, but it would clarify the output
> to separate mem vs disk into two sections
> i.e.,
> -- File statistics
> SSTable count: 6635
> SSTables in each level: [1, 9, 98, 805, 5722, 0, 0, 0, 0]
> -- Memtable statistics
> Bloom filter false positives: 12184123
> Bloom filter false ratio: 0.07203
> Bloom filter space used: 16874424
> Bloom filter off heap memory used: 16821344
> Index summary off heap memory used: 7525546
> Space used (live): 1324067896238
> 3. Read / Write count should also be reported as a ratio, such as:
> Local read count: 202961459
> Local write count: 40554481
> Local read/write ratio: 5:1 <new>
> Local read latency: 1.957 ms
> Local write count: 40554481
> Local write latency: 0.040 ms
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