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https://issues.apache.org/jira/browse/CASSANDRA-14670?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16877071#comment-16877071
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Aleksey Yeschenko commented on CASSANDRA-14670:
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I'm not sure I agree. This same effect can be achieved with changes to `ORDER
BY`, without hacking in the partition key. It's more work to get right, but we
can do it later if pressed for time now. APIs, on the other hand, are 'forever'
and and shouldn't be sacrificed for expediency.
> Table Metrics Virtual Table
> ---------------------------
>
> Key: CASSANDRA-14670
> URL: https://issues.apache.org/jira/browse/CASSANDRA-14670
> Project: Cassandra
> Issue Type: Improvement
> Components: Legacy/CQL, Legacy/Observability
> Reporter: Chris Lohfink
> Assignee: Chris Lohfink
> Priority: Low
> Labels: pull-request-available, virtual-tables
> Fix For: 4.0.x
>
> Time Spent: 10m
> Remaining Estimate: 0h
>
> Different than CASSANDRA-14572 whose goal is to expose all metrics. This is
> to expose a few hand tailored tables that are particularly useful in
> debugging slow Cassandra instances (in my experience). These are useful in
> finding out which table it is that is having issues if you see a node
> performing poorly in general. This can kinda be figured out with cfstats
> sorting and some clever bash-foo but its been a bit of a operational UX pain
> for me personally for awhile.
> examples:
> {code}
> cqlsh> select * from system_views.max_partition_size limit 5;
> max_partition_size | keyspace_name | table_name
> --------------------+---------------+----------------
> 126934 | system | size_estimates
> 9887 | system_schema | columns
> 9887 | system_schema | tables
> 6866 | system | local
> 258 | keyspace1 | standard1
> (5 rows)
> cqlsh> select * from system_views.local_reads limit 5 ;
> count | keyspace_name | table_name | 99th | max | median |
> per_second
> -------+---------------+-----------------+-----------+-----------+---------+------------
> 23 | system | local | 186563160 | 186563160 | 1629722 |
> 3.56101
> 22 | system_schema | tables | 4055269 | 4055269 | 454826 |
> 3.72452
> 14 | system_schema | columns | 1131752 | 1131752 | 545791 |
> 2.37015
> 14 | system_schema | dropped_columns | 126934 | 126934 | 88148 |
> 2.37015
> 14 | system_schema | indexes | 219342 | 219342 | 152321 |
> 2.37015
> (5 rows)
> cqlsh> select * from system_views.coordinator_reads limit 5;
> count | keyspace_name | table_name | 99th | max | median | per_second
> -------+---------------+------------+------+-----+--------+------------
> 2 | system | local | 0 | 0 | 0 | 0.005324
> 1 | system_auth | roles | 0 | 0 | 0 | 0.002662
> 0 | basic | wide | 0 | 0 | 0 | 0
> 0 | basic | wide3 | 0 | 0 | 0 | 0
> 0 | keyspace1 | counter1 | 0 | 0 | 0 | 0
> (5 rows)
> {code}
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