Re: Nodetool tablehistograms

[Chris Lohfink]

Its the number of sstables that may of been read from. This includes
sstables who had their bloom filters checked (which may hit disk). This
changes a bit in https://issues.apache.org/jira/browse/CASSANDRA-13120 to
be only the sstables that its actually reading from.


On Wed, Jul 19, 2017 at 11:04 AM, Abhinav Solan 
wrote:

> Hi Everyone,
>
> Here is the result of my tablehistograms command on one of our tables.
>
> Percentile  SSTables Write Latency  Read LatencyPartition Size
>Cell Count
>   (micros)  (micros)   (bytes)
> 50% 4.00 73.46545.79152321
>  8239
> 75%10.00 88.15   2346.80379022
> 20501
> 95%10.00152.32   4055.27   1358102
> 73457
> 98%10.00219.34   4866.32   1955666
> 88148
> 99%10.00315.85   5839.59   1955666
>105778
> Min 0.00 17.09 35.4373
> 3
> Max10.00  36157.19  52066.35   2816159
>152321
>
> What does SSTables column represent here?
> Does it mean how many SSTables the read is spanning to?
>
> Thanks,
> Abhinav
>

Nodetool tablehistograms

[Abhinav Solan]

Hi Everyone,

Here is the result of my tablehistograms command on one of our tables.

Percentile  SSTables Write Latency  Read LatencyPartition Size
   Cell Count
  (micros)  (micros)   (bytes)
50% 4.00 73.46545.79152321
 8239
75%10.00 88.15   2346.80379022
20501
95%10.00152.32   4055.27   1358102
73457
98%10.00219.34   4866.32   1955666
88148
99%10.00315.85   5839.59   1955666
   105778
Min 0.00 17.09 35.4373
3
Max10.00  36157.19  52066.35   2816159
   152321

What does SSTables column represent here?
Does it mean how many SSTables the read is spanning to?

Thanks,
Abhinav

Re: partition sizes reported by nodetool tablehistograms

[Chris Lohfink]

Its the decompressed size of the partitions. Each sstable has stats
component that contains histograms for the size and number of columns in
the partitions (among other things, can see with sstablemetadata tool),
tablehistograms merges it for each sstable and gives the results.

Chris

On Fri, Feb 24, 2017 at 4:53 PM, John Sanda <john.sa...@gmail.com> wrote:

> I am working on some issues involving really big partitions. I have been
> making extensive use of nodetool tablehistograms. What exactly is the
> partition size being reported? I have a table for which the max value
> reported is about 3.5 GB, but running du -h against the table data
> directory reports 548 MB. Are the partition sizes reported by
> tablehistograms the decompressed size on disk?
>
> - John
>

partition sizes reported by nodetool tablehistograms

[John Sanda]

I am working on some issues involving really big partitions. I have been
making extensive use of nodetool tablehistograms. What exactly is the
partition size being reported? I have a table for which the max value
reported is about 3.5 GB, but running du -h against the table data
directory reports 548 MB. Are the partition sizes reported by
tablehistograms the decompressed size on disk?

- John