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7 commits

Author SHA1 Message Date
beorn7 5f366e9b62 histograms: Improve tests and fix exposed bugs
This adds negative buckets and access of float histograms to
TestHistogramChunkSameBuckets and TestHistogramChunkBucketChanges.

It also exercises a specific pattern of reusing an iterator (one where
no access has happened).

This exposes two bugs (where entries for positive buckets where used
where the corresponding entries for negative buckets should have been
used). One was fixed in #11627 (not merged), which triggered the work
in this commit.

This commit fixes both issues, so #11627 can be closed.

It also simplifies the code in the histogramIterator.Next method that
aims to recycle existing slice capacity.

Furthermore, this is on top of the release-2.40 branch because we
should probably cut a bugfix release for this.

Signed-off-by: beorn7 <beorn@grafana.com>
2022-12-12 00:08:23 +01:00
Ganesh Vernekar b8b0d45d69
Fix reset of a histogram chunk iterator
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2022-11-30 17:50:05 +05:30
Ganesh Vernekar 507bfa46fd
Fix HistogramChunk's AtFloatHistogram()
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2022-10-12 10:38:13 +05:30
Björn Rabenstein 7e42acd3b1
tsdb: Rework iterators (#9877)
- Pick At... method via return value of Next/Seek.
- Do not clobber returned buckets.
- Add partial FloatHistogram suppert.

Note that the promql package is now _only_ dealing with
FloatHistograms, following the idea that PromQL only knows float
values.

As a byproduct, I have removed the histogramSeries metric. In my
understanding, series can have both float and histogram samples, so
that metric doesn't make sense anymore.

As another byproduct, I have converged the sampleBuf and the
histogramSampleBuf in memSeries into one. The sample type stored in
the sampleBuf has been extended to also contain histograms even before
this commit.

Signed-off-by: beorn7 <beorn@grafana.com>
2021-11-29 13:24:23 +05:30
beorn7 5d4db805ac Merge branch 'main' into sparsehistogram 2021-11-17 19:57:31 +01:00
beorn7 4c28d9fac7 Move to histogram.Histogram pointers
This is to avoid copying the many fields of a histogram.Histogram all
the time.

This also fixes a bunch of formerly broken tests.

Signed-off-by: beorn7 <beorn@grafana.com>
2021-11-12 23:17:35 +01:00
beorn7 7a8bb8222c Style cleanup of all the changes in sparsehistogram so far
A lot of this code was hacked together, literally during a
hackathon. This commit intends not to change the code substantially,
but just make the code obey the usual style practices.

A (possibly incomplete) list of areas:

* Generally address linter warnings.

* The `pgk` directory is deprecated as per dev-summit. No new packages should
  be added to it. I moved the new `pkg/histogram` package to `model`
  anticipating what's proposed in #9478.

* Make the naming of the Sparse Histogram more consistent. Including
  abbreviations, there were just too many names for it: SparseHistogram,
  Histogram, Histo, hist, his, shs, h. The idea is to call it "Histogram" in
  general. Only add "Sparse" if it is needed to avoid confusion with
  conventional Histograms (which is rare because the TSDB really has no notion
  of conventional Histograms). Use abbreviations only in local scope, and then
  really abbreviate (not just removing three out of seven letters like in
  "Histo"). This is in the spirit of
  https://github.com/golang/go/wiki/CodeReviewComments#variable-names

* Several other minor name changes.

* A lot of formatting of doc comments. For one, following
  https://github.com/golang/go/wiki/CodeReviewComments#comment-sentences
  , but also layout question, anticipating how things will look like
  when rendered by `godoc` (even where `godoc` doesn't render them
  right now because they are for unexported types or not a doc comment
  at all but just a normal code comment - consistency is queen!).

* Re-enabled `TestQueryLog` and `TestEndopints` (they pass now,
  leaving them disabled was presumably an oversight).

* Bucket iterator for histogram.Histogram is now created with a
  method.

* HistogramChunk.iterator now allows iterator recycling. (I think
  @dieterbe only commented it out because he was confused by the
  question in the comment.)

* HistogramAppender.Append panics now because we decided to treat
  staleness marker differently.

Signed-off-by: beorn7 <beorn@grafana.com>
2021-10-11 13:02:03 +02:00
Renamed from tsdb/chunkenc/histo_test.go (Browse further)