graphite-project
Data from several slices should be merged, not appended.
If for some reasons you have situation when you have overlapping slices, reading data from the interval that matched one of them, will result in more points, then it should be there.
For example - you have some metric that due to broken merge/rollup got into this shape for the interval 1404000000 - 1412640000:
[email protected] with 100 points in it (up to 1412640000)
[email protected] with 100 points in it (up to 1414454400)
If you'll try to read the data from 1404000000 to 1412640000, you'll get in result 104 points (100 from [email protected] and 4 approximated points from [email protected] appended to the end).
I understand that it shouldn't happen, but right now there is no way to fix this situation (except to remove wrong data by hands/script), but I think that it should be handled by ceres.
Should be mostly solved by this commit (against dkulikovsky's fork): https://github.com/vladimir-smirnov-sociomantic/ceres/commit/5d1b7424b69dd591a4ba12690d5ea24939b21289
(Sorry no tests for that yet, currently I don't have time to create proper test for that, but at least steps to reproduce the issue are in this ticket)