[jira] [Created] (CASSANDRA-6106) QueryState.getTimestamp() & FBUtilities.timestampMicros() reads current timestamp with System.currentTimeMillis() * 1000 instead of System.nanoTime() / 1000

["Christopher Smith (JIRA)" <ji...@apache.org>]

Christopher Smith created CASSANDRA-6106:
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             Summary: QueryState.getTimestamp() & FBUtilities.timestampMicros() reads current timestamp with System.currentTimeMillis() * 1000 instead of System.nanoTime() / 1000
                 Key: CASSANDRA-6106
                 URL: https://issues.apache.org/jira/browse/CASSANDRA-6106
             Project: Cassandra
          Issue Type: Bug
          Components: Core
         Environment: DSE Cassandra 3.1, but also HEAD
            Reporter: Christopher Smith
            Priority: Minor


I noticed this blog post: http://aphyr.com/posts/294-call-me-maybe-cassandra mentioned issues with millisecond rounding in timestamps and was able to reproduce the issue. If I specify a timestamp in a mutating query, I get microsecond precision, but if I don't, I get timestamps rounded to the nearest millisecond, at least for my first query on a given connection, which substantially increases the possibilities of collision.

I believe I found the offending code, though I am by no means sure this is comprehensive. I think we probably need a fairly comprehensive replacement of all uses of System.currentTimeMillis() with System.nanoTime().

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