Hi Guys, I have two cassandra 2.0.5 nodes, RF=2. When I do a:
select * from table1 where clustercolumn=‘something' The trace indicates that it only needs to talk to one node, which I would have expected. However when I do a: select * from table2 Which is a small table with only has 20 rows in it, should be fully replicated, and should be a much quicker query, trace indicates that cassandra is talking to both nodes. This adds a 200ms to the query results, and is not necessary for my application (this table might have an amendment once per year if that), theres no real need to check both nodes for consistency. At this point I’ve not altered anything to do with consistency level. Does this mean that cassandra attempts to guess/infer what consistency level you need depending on if your query includes a filter on a particular key or clustering key? Thanks, Jacob CREATE KEYSPACE mykeyspace WITH replication = { 'class': 'SimpleStrategy', 'replication_factor': ‘2' }; CREATE TABLE organisation (uuid uuid, name text, url text, PRIMARY KEY (uuid)) CREATE TABLE lookup_code (type text, code text, name text, PRIMARY KEY ((type), code)) select * from lookup_code where type=‘mylist': activity | timestamp | source | source_elapsed ---------------------------------------------------------------------------+--------------+--------------+---------------- execute_cql3_query | 04:20:15,319 | 74.50.54.123 | 0 Parsing select * from lookup_code where type='research_area' LIMIT 10000; | 04:20:15,319 | 74.50.54.123 | 64 Preparing statement | 04:20:15,320 | 74.50.54.123 | 204 Executing single-partition query on lookup_code | 04:20:15,320 | 74.50.54.123 | 849 Acquiring sstable references | 04:20:15,320 | 74.50.54.123 | 870 Merging memtable tombstones | 04:20:15,320 | 74.50.54.123 | 894 Skipped 0/0 non-slice-intersecting sstables, included 0 due to tombstones | 04:20:15,320 | 74.50.54.123 | 958 Merging data from memtables and 0 sstables | 04:20:15,320 | 74.50.54.123 | 976 Read 168 live and 0 tombstoned cells | 04:20:15,321 | 74.50.54.123 | 1412 Request complete | 04:20:15,321 | 74.50.54.123 | 2043 select * from organisation: activity | timestamp | source | source_elapsed -------------------------------------------------------------------------------------------------+--------------+--------------+---------------- execute_cql3_query | 04:21:03,641 | 74.50.54.123 | 0 Parsing select * from organisation LIMIT 10000; | 04:21:03,641 | 74.50.54.123 | 68 Preparing statement | 04:21:03,641 | 74.50.54.123 | 174 Determining replicas to query | 04:21:03,642 | 74.50.54.123 | 307 Enqueuing request to /72.249.82.85 | 04:21:03,642 | 74.50.54.123 | 1034 Sending message to /72.249.82.85 | 04:21:03,643 | 74.50.54.123 | 1402 Message received from /74.50.54.123 | 04:21:03,644 | 72.249.82.85 | 47 Executing seq scan across 0 sstables for [min(-9223372036854775808), min(-9223372036854775808)] | 04:21:03,644 | 72.249.82.85 | 461 Read 1 live and 0 tombstoned cells | 04:21:03,644 | 72.249.82.85 | 560 Read 1 live and 0 tombstoned cells | 04:21:03,644 | 72.249.82.85 | 611 ………..etc….....
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