promql, tsdb (histograms): Do not re-use spans between histograms
When multiple points exist with the same native histogram schemas they
share their spans.
This causes a problem when a native histogram (NH) schema is modified (for example, during
a Sum) then the other NH's with the same spans are also modified. As such,
we should create a new Span for each NH. This will ensure NH's interfaces
are safe to use without considering the effect on other histograms.
At the moment this doesn't present itself as a problem because in all
aggregations and functions operating on native histograms they are copied
by the promql query engine first.
Signed-off-by: Joshua Hesketh <josh@nitrotech.org>
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Signed-off-by: Joshua Hesketh <josh@nitrotech.org>
This was part of #14525 which was reverted.
I still think that having this benchmark committed in to the repo is
useful.
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
Starts its index from 0 , but users call Next() before first sample
so it needs to start from -1
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
`getOOOSeriesChunks` was already finding sets of overlapping chunks; we
store those in a `multiMeta` struct so that `ChunkOrIterable` can
reconstruct an `Iterable` easily and predictably.
We no longer need a `MergeOOO` flag to indicate that this Meta should
be merged with other ones; this is explicit in the `multiMeta` structure.
We also no longer need `chunkMetaAndChunkDiskMapperRef`.
Add `wrapOOOHeadChunk` to defeat `chunkenc.Pool` - chunks are reset
during compaction, but if we wrap them (like `safeHeadChunk` was doing
then this is skipped) .
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Case 1: OOO in-memory head chunk overlaps with first mmaped in-order chunk.
Query: |----------------------------------------------------------------|
InO: |------mmap---------------||---------mem----------------------|
OOO: |-----mem-----------|
This triggers ChunkOrIterableWithCopy not including OOO head chunks bug.
Similar to #14693 however testing the end of the interval doesn't
trigger the problem because there the in-order head chunk will be
trimmed with a tombstone, causing the code to switch to ChunkOrIterable
which was fixed.
See a36d1a8a92/tsdb/querier.go (L646)
where len(p.bufIter.Intervals) will be non zero, because it includes the
tombstone to trim the result to the query max time.
Thus a new test is added to check the overlap at the beginning of the
interval that has a separate chunk, which does not need trimming.
Note: same test doesn't fail for sample querier in Test_Querier_OOOQuery
as that doesn't use copy, that is copyHeadChunk is false in the if
condition above.
Case 2:
OOO mmaped head chunk overlaps with first mmaped in-order chunk.
Query: |----------------------------------------------------------------|
InO: |------mmap---------------||---------mem----------------------|
OOO: |-----mmap-----------| |--mem--|
In this case the meta contains the reference of the in-order chunk and
no indication that a merge is needed with the OOO mmaped chunk.
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
Several things done here:
- Set `max-issues-per-linter` to 0 so that we actually see all linter
warnings and not just 50 per linter. (As we also set
`max-same-issues` to 0, I assume this was the intention from the
beginning.)
- Stop using the golangci-lint default excludes (by setting
`exclude-use-default: false`. Those are too generous and don't match
our style conventions. (I have re-added some of the excludes
explicitly in this commit. See below.)
- Re-add the `errcheck` exclusion we have used so far via the
defaults.
- Exclude the signature requirement `govet` has for `Seek` methods
because we use non-standard `Seek` methods a lot. (But we keep other
requirements, while the default excludes completely disabled the
check for common method segnatures.)
- Exclude warnings about missing doc comments on exported symbols. (We
used to be pretty adamant about doc comments, but stopped that at
some point in the past. By now, we have about 500 missing doc
comments. We may consider reintroducing this check, but that's
outside of the scope of this commit. The default excludes of
golangci-lint essentially ignore doc comments completely.)
- By stop using the default excludes, we now get warnings back on
malformed doc comments. That's the most impactful change in this
commit. It does not enforce doc comments (again), but _if_ there is
a doc comment, it has to have the recommended form. (Most of the
changes in this commit are fixing this form.)
- Improve wording/spelling of some comments in .golangci.yml, and
remove an outdated comment.
- Leave `package-comments` inactive, but add a TODO asking if we
should change that.
- Add a new sub-linter `comment-spacings` (and fix corresponding
comments), which avoids missing spaces after the leading `//`.
Signed-off-by: beorn7 <beorn@grafana.com>
* tsdb: Unit test query overlapping in order and ooo head
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
* TSDB: Merge overlapping head chunk
The basic idea is that getOOOSeriesChunks can populate Meta.Chunk, but since
it only returns one Meta per overlapping time-slot, that pointer may end up in a
Meta with a head-chunk ID. So we need HeadAndOOOChunkReader.ChunkOrIterable()
to call mergedChunks in that case.
Previously, mergedChunks was checking that meta.Ref was a valid OOO chunk reference,
but it never actually uses that reference; it just finds all chunks overlapping in time.
So we can delete that code.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Co-authored-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
In `mmapCurrentOOOHeadChunk`, check if the number is at the maximum and
drop the data with an error log. This is not expected to happen as the
maximum is over 8 million; that's 8 years of 1 sample every second.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Re-enable check in `createHeadWithOOOSamples` which wasn't really broken.
* Move code making `Block` into a `Queryable` into test file.
* Make `getSeriesChunks` return a slice (renamed `appendSeriesChunks`).
* Rename `oooMergedChunks` to `mergedChunks`.
* Improve comment on `ChunkOrIterableWithCopy`.
* Name return values from unpackHeadChunkRef.
Co-authored-by: Oleg Zaytsev <mail@olegzaytsev.com>
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Use headIndexReader instead.
OOOCompactionHeadIndexReader needs to be expanded slightly, because it previously delegated to OOOHeadIndexReader.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Just query via `HeadAndOOOQuerier`, which will skip series where no
in-order chunks are in range.
Now we don't need `OOORangeHead`.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Add `HeadAndOOOQuerier` which iterates just once over series, then
where necessary merges chunks from in-order and out-of-order lists.
Add a ChunkQuerier for in-order and ooo together
Add copy-last-chunk behaviour to HeadAndOOOChunkReader
Out-of-order chunk IDs are distinguished from in-order by setting bit 23.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Refactor existing BenchmarkQuerierSelect to provide the set-up.
Note that Head queries now run faster because they use a RangeHead.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Rename a variable.
Add parameters to memSeries.insert function.
No effect on how float samples are handled.
Related to #14546
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
Discovered while working on #14546 OOO native histograms.
Not triggered on main before #14546 as the code path is unused.
There was a bug where the min time of a chunk was adjusted even
if it was only recoded and not completely new.
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
The histogram stats decoder keeps track of the last seen histogram sample
in order to properly detect counter resets. We are seeing an issue where
a histogram with UnknownResetHint gets treated as a counter reset when it follows
a stale histogram sample.
I believe that this is incorrect since stale samples should be completely ignored
in PromQL. As a result, they should not be stored in the histogram stats iterator
and the counter reset detection needs to be done against the last non-stale sample.
Signed-off-by: Filip Petkovski <filip.petkovsky@gmail.com>
avoid simultaneous compactions and reduce stress on shared resources.
This is enabled via `--enable-feature=delayed-compaction`.
Signed-off-by: machine424 <ayoubmrini424@gmail.com>
* Fix appendable: check whether last val was a histogram
When appending a float, we were checking whether lastValue was equal to
current value, but we didn't check whether last value was a float value.
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
Iterator may share spans without copy, so we always have to make a copy
before modification - copy-on-write.
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
* chunkenc: allow missing empty buckets on histogram append
Allow appending to chunks when the histogram to be added is missing
some buckets, but the missing buckets are empty in the chunk.
For example bucket at index 5 is present in the chunk, but its value
is 0 and the new histogram doesn't have a bucket at index 5.
This fixes an issue of merging chunks where one chunk was recoded to
retroactively have some empty buckets in all the histograms and we are
merging in a histogram that doesn't have the empty bucket (because it
was not recoded yet).
The operation alters the histogram that is being added, however this has
already been the case when appending gauge histograms. Thus the test
TestHistogramSeriesToChunks in storage package is changed to explicitly
test what happened to the appended histogram - Compact(0) call is removed.
The new expandIntSpansAndBuckets and expandFloatSpansAndBuckets functions
are a merge of expandSpansForward and counterResetInAnyBucket and
counterResetInAnyFloatBucket.
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
Joshua Hesketh