In the head and in v1 postings on disk, it makes no difference whether
postings are sorted. Only for v2 does the code step through in order.
So, move the sorting to where it is required, and thus skip it entirely
in the head.
Label values in on-disk blocks are already sorted, but `slices.Sort` is
very fast on already-sorted data so we don't bother checking.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
This allocates memory for all the returned values, which skews the
result. We aren't trying to benchmark `ExpandPostings`, so just step
through all the values without storing them to consume them.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Previously all the postings constructed were consumed on the first
iteration, so subsequent iterations did no work.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Instead of passing in a `ScratchBuilder` and `Labels`, just pass the
builder and the caller can extract labels from it. In many cases the
caller didn't use the Labels value anyway.
Now in `Labels.ScratchBuilder` we need a slightly different API: one
to assign what will be the result, instead of overwriting some other
`Labels`. This is safer and easier to reason about.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
This necessitates a change to the `tsdb.IndexReader` interface:
`index.Reader` is used from multiple goroutines concurrently, so we
can't have state in it.
We do retain a `ScratchBuilder` in `blockBaseSeriesSet` which is
iterator-like.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Add BenchmarkOpenBlock
* Use specific types when reading offset table
Instead of reading a generic-ish []string, we can read a generic type
which would be specifically labels.Label.
This avoid allocating a slice that escapes to the heap, making it both
faster and more efficient in terms of memory management.
* Update error message for unexpected number of keys
* s/posting offset table/postings offset table/
* Remove useless lastKey assignment
* Use two []bytes vars, simplify
Applied PR feedback: removed generics, moved the label indices reading
to that specific test as we're not using it in production anyway, we're
just testing what we've just built.
Also using two []bytes variables for name and value that use the backing
buffer instead of using strings, this reduces allocations a lot as we
only copy them when we store them (this is optimized by the compiler).
* Fix the dumb bug
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
Co-authored-by: Marco Pracucci <marco@pracucci.com>
Use new experimental package `golang.org/x/exp/slices`.
slices.Sort works on values that are directly comparable, like ints,
so avoids the overhad of an interface call to `.Less()`.
Left tests unchanged, because they don't need the speed and it may be
a cross-check that slices.Sort gives the same answer.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Use new experimental package `golang.org/x/exp/slices`.
Some of the speedup comes from comparing SeriesRef (which is an int64)
directly rather than through an interface `.Less()` call; some comes
from exp/slices using "pattern-defeating quicksort(pdqsort)".
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
This commit fixes a typo when reporting an error that the the symbols
table size has been exceeded.
Signed-off-by: Filip Petkovski <filip.petkovsky@gmail.com>
* refactor: move from io/ioutil to io and os packages
* use fs.DirEntry instead of os.FileInfo after os.ReadDir
Signed-off-by: MOREL Matthieu <matthieu.morel@cnp.fr>
* tsdb: avoid slice-to-interface allocation in EnsureOrder
This is pulling the `seriesRefSlice` out of the loop, so the compiler
doesn't allocate a new one on the heap every time.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* tsdb: use pointer type in Pool for EnsureOrder
As noted by staticcheck, Pool prefers the objects in the pool to have
pointer type. This is a little more fiddly to code, but avoids
allocation of a wrapper object every time a slice is put into the pool.
Removed a comment that said fixing this has a performance penalty: not
borne out by benchmarks.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Unexported postingsWithIndexHeap's methods that don't need to be
exported, and added detailed comments.
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
See this comment for detailed explanation:
https://github.com/prometheus/prometheus/pull/9907#issuecomment-1002189932
TL;DR: if we don't call Pop() on the heap implementation, we don't need
to return our param as an `interface{}` so we save an allocation.
This would be popped for every label value, so it can be thousands of
saved allocations here (see benchmarks).
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
Added validation to expected postings length compared to the bytes slice
length. With 32bit postings, we expect to have 4 bytes per each posting.
If the number doesn't add up, we know that the input data is not
compatible with our code (maybe it's cut, or padded with trash, or even
written in a different coded).
This is needed in downstream projects to correctly identify cached
postings written with an unknown codec, but it's also a good idea to
validate it here.
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* Add more size checks when writing individual sections in the index.
Signed-off-by: Peter Štibraný <pstibrany@gmail.com>
* Use uint and add comment about it.
Signed-off-by: Peter Štibraný <pstibrany@gmail.com>
This creates a new `model` directory and moves all data-model related
packages over there:
exemplar labels relabel rulefmt textparse timestamp value
All the others are more or less utilities and have been moved to `util`:
gate logging modetimevfs pool runtime
Signed-off-by: beorn7 <beorn@grafana.com>
* TSDB: demistify seriesRefs and ChunkRefs
The TSDB package contains many types of series and chunk references,
all shrouded in uint types. Often the same uint value may
actually mean one of different types, in non-obvious ways.
This PR aims to clarify the code and help navigating to relevant docs,
usage, etc much quicker.
Concretely:
* Use appropriately named types and document their semantics and
relations.
* Make multiplexing and demuxing of types explicit
(on the boundaries between concrete implementations and generic
interfaces).
* Casting between different types should be free. None of the changes
should have any impact on how the code runs.
TODO: Implement BlockSeriesRef where appropriate (for a future PR)
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
* feedback
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
* agent: demistify seriesRefs and ChunkRefs
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
We should reuse that method, not only because it saves code, but also
because that method is a good candidate to use a pool of slices some
day.
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* Fix tests not closing head/block properly
Close Head properly in TestWalRepair_DecodingError
Close Block properly in TestReadIndexFormatV1
Co-authored-by: Christian Simon <simon@swine.de>
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* Implement PostingsCloner
PostingsCloner allows obtaining independend clones of a Postings, that
can be used for subsequent calls.
Co-authored-by: Christian Simon <simon@swine.de>
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* IndexReader.PostingsForMatchers() and implement Cache
IndexReader now offers the PostingsForMatchers functionality, which is
provided by PostingsForMatchersCache.
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
Co-authored-by: Marco Pracucci <marco@pracucci.com>
Co-authored-by: Peter Štibraný <peter.stibrany@grafana.com>
Co-authored-by: Oleg Zaytsev <mail@olegzaytsev.com>
Co-authored-by: Marco Pracucci <marco@pracucci.com>
Co-authored-by: Peter Štibraný <peter.stibrany@grafana.com>
This saves memory, effort and locking.
Since every symbol is also added to postings, `Symbols()` can be
implemented there instead. This now has to build a map for
deduplication, but `Symbols()` is only called for compaction, and `gc()`
used to rebuild the symbols map after every compaction so not an
additional cost.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
