These benchmarks were testing things related to what Prometheus does, but not testing actual Prometheus code.
Moved the label-copying benchmark into the labels package.
This commit adds an alternate implementation for `labels.Labels`, behind
a build tag `stringlabels`.
Instead of storing label names and values as individual strings, they
are all concatenated into one string in this format:
[len][name0][len][value0][len][name1][len][value1]...
The lengths are varint encoded so usually a single byte.
The previous `[]string` had 24 bytes of overhead for the slice and 16
for each label name and value; this one has 16 bytes overhead plus 1
for each name and value.
In `ScratchBuilder.Overwrite` and `Labels.Hash` we use an unsafe
conversion from string to byte slice. `Overwrite` is explicitly unsafe,
but for `Hash` this is a pure performance hack.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Parsing errors in the Prometheus HTTP format parser are very hard to
investigate since they only approximately indicate what is going wrong
in the parser and don't provide any information about the incorrect
input. As such it is very hard to tell what is wrong in the format
exposed by the application.
Signed-off-by: Damien Grisonnet <dgrisonn@redhat.com>
This commit adds a new 'keep_firing_for' field to Prometheus alerting
rules. The 'resolve_delay' field specifies the minimum amount of time
that an alert should remain firing, even if the expression does not
return any results.
This feature was discussed at a previous dev summit, and it was
determined that a feature like this would be useful in order to allow
the expression time to stabilize and prevent confusing resolved messages
from being propagated through Alertmanager.
This approach is simpler than having two PromQL queries, as was
sometimes discussed, and it should be easy to implement.
This commit does not include tests for the 'resolve_delay' field. This
is intentional, as the purpose of this commit is to gather comments on
the proposed design of the 'resolve_delay' field before implementing
tests. Once the design of the 'resolve_delay' field has been finalized,
a follow-up commit will be submitted with tests."
See https://github.com/prometheus/prometheus/issues/11570
Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
If a (float or integer) histogram is a gauge histogram, set the
CounterResetHint accordingly. (The default value is fine for the
normal counter histograms.)
Signed-off-by: beorn7 <beorn@grafana.com>
With this commit, the parser stops to see a gauge histogram (whether
native or conventional) as an unexpected metric type. It ingests it
normally, it even sets the `GaugeHistogram` type in the metadata (as
it has already done for a conventional gauge histogram scraped using
OpenMetrics), but it otherwise treats it as a normal counter-like
histogram.
Once #11783 is merged, though, it should be very easy to utilize the
type information.
Signed-off-by: beorn7 <beorn@grafana.com>
So far, the parser hasn't validated that the type is valid in the
`Next()` call. Later, in the `Series()` call, however, it assumes that
we will only see valid types and therefore panics with `encountered
unexpected metric type, this is a bug`.
This commit fixes said bug by adding validation to the `Next()` call.
Signed-off-by: beorn7 <beorn@grafana.com>
In some cases, the Prometheus HTTP format parser was not returning the
right token in the error output which made debugging impossible.
Signed-off-by: Damien Grisonnet <dgrisonn@redhat.com>
Extends Appender.AppendHistogram function to accept the FloatHistogram. TSDB supports appending, querying, WAL replay, for this new type of histogram.
Signed-off-by: Marc Tudurí <marctc@protonmail.com>
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
Co-authored-by: Ganesh Vernekar <ganeshvern@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>
Without changing the definition of `labels.Labels`, add methods which
enable code using it to work without knowledge of the internals.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
For performance reasons we may use a different implementation of Hash()
in future, so note this so callers can be warned.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
The bucket receiving math.MaxFloat64 observations now has
math.MaxFloat64 as upper bound, while the bucket after it (the last
possible bucket) has +Inf.
This also adds a test for getBound and moves the getBound code to
generic.go (where it should have been in the first place).
Signed-off-by: beorn7 <beorn@grafana.com>
* histogram: Simplify iterators
We don't really need currLower and currUpper and can calculate it when
needed (as already done for the floatBucketIterator). The calculation
is cheap, while keeping those extra variables around costs RAM
(potentially a lot with many iterators).
* histogram: Convert Bucket/FloatBucket to one generic type
* histogram: Move some bucket iterator code into generic base iterator
* histogram: Remove cumulative iterator for FloatHistogram
We added it in the past for completeness (Histogram has one), but it
has never been used. Plus, even the cumulative iterator for Histogram
is only there for test reasons.
We can always add it back, and then maybe even using generics.
Signed-off-by: beorn7 <beorn@grafana.com>
Where the code was multiplying bytes by number of operations, this
resulted in absurdly high throughput numbers.
Also, in `BenchmarkParse()`, don't run the `expfmt` case twice.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
And use the new method to call to compact Histograms during
parsing. This happens for both `Histogram` and `FloatHistogram`. In
this way, if targets decide to optimize the exposition size by merging
spans with empty buckets in between, we still get a normalized
results. It will also normalize away any valid but weird
representations like empty spans, spans with offset zero, and empty
buckets at the start or end of a span.
The implementation seemed easy at first as it just turns the
`compactBuckets` helper into a generic function (which now got its own
file). However, the integer Histograms have delta buckets instead of
absolute buckets, which had to be treated specially in the generic
`compactBuckets` function. To make sure it works, I have added plenty
of explicit tests for `Histogram` in addition to the `FloatHistogram`
tests.
I have also updated the doc comment for the `Compact` method.
Based on the insights now expressed in the doc comment, compacting
with a maxEmptyBuckets > 0 is rarely useful. Therefore, this commit
also sets the value to 0 in the two cases we were using 3 so far. We
might still want to reconsider, so I don't want to remove the
maxEmptyBuckets parameter right now.
Signed-off-by: beorn7 <beorn@grafana.com>
Replacing code which assumes the internal structure of `Labels`.
Add a convenience function `EmptyLabels()` which is more efficient than
calling `New()`.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Update go to 1.19, set min version to 1.18
Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
* Update golangci-lint
Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
* model/relabel: Add benchmark
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* model/relabel: re-use Builder across relabels
Saves memory allocations.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* labels.Builder: allow re-use of result slice
This reduces memory allocations where the caller has a suitable slice available.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* model/relabel: re-use source values slice
To reduce memory allocations.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Unwind one change causing test failures
Restore original behaviour in PopulateLabels, where we must not overwrite the input set.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* relabel: simplify values optimisation
Use a stack-based array for up to 16 source labels, which will be the
vast majority of cases.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* lint
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
