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)