[jira] [Issue Comment Deleted] (CASSANDRA-8938) Full Row Scan does not count towards Reads

["Phil Yang (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CASSANDRA-8938?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Phil Yang updated CASSANDRA-8938:
---------------------------------
    Comment: was deleted

(was: The "readLatency" is a counter both counting "read count" and "read latency" for the query with WHERE clause. I think the reason that nodetool only show the count of readLatency rather than readLatency+rangeLatency is that usually it is not a good idea to select the whole table(because it will read all sstables in all nodes) so it is not commonly used and usually be zero. 

Anyone other think the read count and read latency should add the counter of range read?

Why do you think all sstables must be available for next compaction after a range read? It has few help for range read and compaction will increase the load of all nodes.)

> Full Row Scan does not count towards Reads
> ------------------------------------------
>
>                 Key: CASSANDRA-8938
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8938
>             Project: Cassandra
>          Issue Type: Bug
>          Components: API, Core, Tools
>         Environment: Unix, Cassandra 2.0.3
>            Reporter: Amit Singh Chowdhery
>            Priority: Minor
>              Labels: none
>
> When a CQL SELECT statement is executed with WHERE clause, Read Count is incremented in cfstats of the column family. But, when a full row scan is done using SELECT statement without WHERE clause, Read Count is not incremented. 
> Similarly, when using Size Tiered Compaction, if we do a full row scan using Hector RangeslicesQuery, Read Count is not incremented in cfstats, Cassandra still considers all sstables as cold and does not trigger compaction for them. If we fire MultigetSliceQuery, Read Count is incremented and sstables becomes hot, triggering compaction of these sstables. 
> Expected Behavior:
> 1. Read Count must be incremented by number of rows read during a full row scan done using CQL SELECT statement or Hector RangeslicesQuery.
> 2. Size Tiered compaction must consider all sstables as Hot after a full row scan.



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