[jira] [Created] (CASSANDRA-7041) Select query returns inconsistent result

["Ngoc Minh Vo (JIRA)" <ji...@apache.org>]

Ngoc Minh Vo created CASSANDRA-7041:
---------------------------------------

             Summary: Select query returns inconsistent result
                 Key: CASSANDRA-7041
                 URL: https://issues.apache.org/jira/browse/CASSANDRA-7041
             Project: Cassandra
          Issue Type: Bug
          Components: Core
         Environment: Cassandra v2.0.6 (upgraded from v2.0.3)
4-node cluster: Windows7, 12GB JVM
            Reporter: Ngoc Minh Vo
            Priority: Critical


Hello,

We are running in an issue with C* v2.0.x: CQL queries randomly return empty result.
Here is the scenario:
1. Schema:
{noformat}
CREATE TABLE string_values (
  date int,
  field text,
  value text,
  PRIMARY KEY ((date, field), value)
) WITH
  bloom_filter_fp_chance=0.100000 AND
  caching='KEYS_ONLY' AND
  comment='' AND
  dclocal_read_repair_chance=0.000000 AND
  gc_grace_seconds=864000 AND
  index_interval=128 AND
  read_repair_chance=0.100000 AND
  replicate_on_write='true' AND
  populate_io_cache_on_flush='false' AND
  default_time_to_live=0 AND
  speculative_retry='99.0PERCENTILE' AND
  memtable_flush_period_in_ms=0 AND
  compaction={'class': 'LeveledCompactionStrategy'} AND
  compression={'sstable_compression': 'LZ4Compressor'};
{noformat}

2. There is no new data imported to the cluster during the test.

3. CQL query:
{noformat}
select * from string_values where date=20140122 and field='SCONYKSP1';
{noformat}

4. In Cqlsh, the same query has been executed several times during a short interval (~1-2 seconds). The first query results are empty and then we got the data. And from that point, we always get the correct result:
{noformat}
cqlsh:titan_test> select * from string_values where date=20140122 and field='SCONYKSP1';
(0 rows)
cqlsh:titan_test> select * from string_values where date=20140122 and field='SCONYKSP1';
(0 rows)
... ...
cqlsh:titan_test> select * from string_values where date=20140122 and field='SCONYKSP1';
(0 rows)
cqlsh:titan_test> select * from string_values where date=20140122 and field='SCONYKSP1';
(0 rows)
cqlsh:titan_test> select * from string_values where date=20140122 and field='SCONYKSP1';
 date     | field     | value
----------+-----------+-------------------------
 20140122 | SCONYKSP1 | 201401220251826297a_0_3
(1 rows)
cqlsh:titan_test> select * from string_values where date=20140122 and field='SCONYKSP1';
 date     | field     | value
----------+-----------+-------------------------
 20140122 | SCONYKSP1 | 201401220251826297a_0_3
(1 rows)
{noformat}

5. It might relate to some kind of "warmup" process. We tried to disable key/data caching but it does not help.

Upgrading cluster from v2.0.3 to v2.0.6 does not fix the issue (hence, not related to CASSANDRA-6555).

Long time ago, we posted a report on Java Driver JIRA: https://datastax-oss.atlassian.net/browse/JAVA-217. But it seems that the issue is in the server side.

Best regards,
Minh



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