[jira] [Created] (CASSANDRA-8646) For Column family

["Nitin Padalia (JIRA)" <ji...@apache.org>]

Nitin Padalia created CASSANDRA-8646:
----------------------------------------

             Summary: For Column family 
                 Key: CASSANDRA-8646
                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8646
             Project: Cassandra
          Issue Type: Bug
          Components: Core
         Environment: OS: CentOS 6.5, [cqlsh 5.0.1 | Cassandra 2.1.2 | CQL spec 3.2.0 | Native protocol v3]. Using CQL CLI for query analysis.
            Reporter: Nitin Padalia
            Priority: Minor
             Fix For: 2.1.2


Cassandra doesn't hit row cache for first and last row of a partition if we mention cluster keys in where condition. However if we use limit then it hits the row cache for the same rows.

E.G. I've a column family:
CREATE TABLE ucxndirdb2.usertable_cache (
    user_id uuid,
    dept_id uuid,
    location_id text,
    locationmap_id uuid,
    PRIMARY KEY ((user_id, dept_id), location_id)
) WITH CLUSTERING ORDER BY (location_id ASC)
    AND bloom_filter_fp_chance = 0.01
    AND caching = '{"keys":"ALL", "rows_per_partition":"3"}'
    AND comment = ''
    AND compaction = {'min_threshold': '4', 'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy', 'max_threshold': '32'}
    AND compression = {'sstable_compression': 'org.apache.cassandra.io.compress.LZ4Compressor'}
    AND dclocal_read_repair_chance = 0.1
    AND default_time_to_live = 0
    AND gc_grace_seconds = 864000
    AND max_index_interval = 2048
    AND memtable_flush_period_in_ms = 0
    AND min_index_interval = 128
    AND read_repair_chance = 0.0
    AND speculative_retry = '99.0PERCENTILE';

It has 3 rows per partition keys enabled for row cache.

Now for a cached request, if I run:
select * from usertable_cache WHERE user_id = 7bf16edf-b552-40f4-94ac-87b2e878d8c2  and dept_id = de3ac44f-2078-4321-a47c-de96c615d40d limit 3;

Then its a cache hit with follow results:
 user_id                              | dept_id                              | location_id | locationmap_id
--------------------------------------+--------------------------------------+-------------+--------------------------------------
 7bf16edf-b552-40f4-94ac-87b2e878d8c2 | de3ac44f-2078-4321-a47c-de96c615d40d |      ABC4:1 | 32b97639-ea5b-427f-8c27-8a5016e2ad6e
 7bf16edf-b552-40f4-94ac-87b2e878d8c2 | de3ac44f-2078-4321-a47c-de96c615d40d |     ABC4:10 | dfacc9fc-7a6a-4fb4-8a4f-c13c606d552b
 7bf16edf-b552-40f4-94ac-87b2e878d8c2 | de3ac44f-2078-4321-a47c-de96c615d40d |    ABC4:100 | 9ba7236a-6124-41c8-839b-edd299f510f7


However If I run:
 select * from usertable_cache WHERE user_id = 7bf16edf-b552-40f4-94ac-87b2e878d8c2  and dept_id = de3ac44f-2078-4321-a47c-de96c615d40d and location_id = 'ABC4:1';
or 
 select * from usertable_cache WHERE user_id = 7bf16edf-b552-40f4-94ac-87b2e878d8c2  and dept_id = de3ac44f-2078-4321-a47c-de96c615d40d and location_id = 'ABC4:100';

Then its a cache miss. However for following its hit for following
 select * from usertable_cache WHERE user_id = 7bf16edf-b552-40f4-94ac-87b2e878d8c2  and dept_id = de3ac44f-2078-4321-a47c-de96c615d40d and location_id = 'ABC4:10';

and this behavior is consistent by increasing/decreasing rows_per_partiton setting. Cache is miss for only first and last record of the partition.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)