Commit graph

566 commits

Author SHA1 Message Date
William Dumont ce6ad15422 remote-write: TestClientRetryAfter status code 500
and compare the retryAfter values.

Signed-off-by: William Dumont <william.dumont@grafana.com>
2023-09-20 10:25:43 +00:00
William Dumont febd62a23e remote-write: refactor TestClientRetryAfter
The new version features a set of test cases that simplify the addition
of new HTTP status codes.

Signed-off-by: William Dumont <william.dumont@grafana.com>
2023-09-20 10:24:52 +00:00
Bryan Boreham 9b85354acd remote-write: respect Retry-After header on 5xx errors
If the server sent it to us, we should assume it knows better than we
do and respect it.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2023-09-20 10:14:38 +00:00
Paschalis Tsilias c173cd57c9
Add a header to count retried remote write requests (#12729)
Header name is `Retry-Attempt`, only set when >0.

Signed-off-by: Marc Tuduri <marctc@protonmail.com>
Signed-off-by: Paschalis Tsilias <paschalis.tsilias@grafana.com>
2023-09-20 11:11:03 +01:00
zenador 69edd8709b
Add warnings (and annotations) to PromQL query results (#12152)
Return annotations (warnings and infos) from PromQL queries

This generalizes the warnings we have already used before (but only for problems with remote read) as "annotations".

Annotations can be warnings or infos (the latter could be false positives). We do not treat them different in the API for now and return them all as "warnings". It would be easy to distinguish them and return infos separately, should that appear useful in the future.

The new annotations are then used to create a lot of warnings or infos during PromQL evaluations. Partially these are things we have wanted for a long time (e.g. inform the user that they have applied `rate` to a metric that doesn't look like a counter), but the new native histograms have created even more needs for those annotations (e.g. if a query tries to aggregate float numbers with histograms).

The annotations added here are not yet complete. A prominent example would be a warning about a range too short for a rate calculation. But such a warnings is more tricky to create with good fidelity and we will tackle it later.

Another TODO is to take annotations into account when evaluating recording rules.

---------

Signed-off-by: Jeanette Tan <jeanette.tan@grafana.com>
2023-09-14 18:57:31 +02:00
Arve Knudsen 156222cc50
Add context argument to LabelQuerier.LabelValues (#12665)
Add context argument to LabelQuerier.LabelValues and
LabelQuerier.SortedLabelValues.

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>
2023-09-14 16:02:04 +02:00
Arve Knudsen a964349e97
Add context argument to LabelQuerier.LabelNames (#12666)
Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>
2023-09-14 10:39:51 +02:00
Arve Knudsen 6daee89e5f
Add context argument to Querier.Select (#12660)
Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>
2023-09-12 12:37:38 +02:00
Gregor Zeitlinger f01718262a
Unit tests for native histograms (#12668)
promql: Extend testing framework to support native histograms

This includes both the internal testing framework as well as the rules unit test feature of promtool.

This also adds a bunch of basic tests. Many of the code level tests can now be converted to tests within the framework, and more tests can be added easily.

---------

Signed-off-by: Harold Dost <h.dost@criteo.com>
Signed-off-by: Gregor Zeitlinger <gregor.zeitlinger@grafana.com>
Signed-off-by: Stephen Lang <stephen.lang@grafana.com>
Co-authored-by: Harold Dost <h.dost@criteo.com>
Co-authored-by: Stephen Lang <stephen.lang@grafana.com>
Co-authored-by: Gregor Zeitlinger <gregor.zeitlinger@grafana.com>
2023-08-25 23:35:42 +02:00
Justin Lei 8ef7dfdeeb
Add a chunk size limit in bytes (#12054)
Add a chunk size limit in bytes

This creates a hard cap for XOR chunks of 1024 bytes.

The limit for histogram chunk is also 1024 bytes, but it is a soft limit as a histogram has a dynamic size, and even a single one could be larger than 1024 bytes.

This also avoids cutting new histogram chunks if the existing chunk has fewer than 10 histograms yet. In that way, we are accepting "jumbo chunks" in order to have at least 10 histograms in a chunk, allowing compression to kick in.

Signed-off-by: Justin Lei <justin.lei@grafana.com>
2023-08-24 15:21:17 +02:00
beorn7 aa82fe198f tsdb: Fix histogram validation
So far, `ValidateHistogram` would not detect if the count did not
include the count in the zero bucket. This commit fixes the problem
and updates all the tests that have been undetected offenders so far.

Note that this problem would only ever create false negatives, so we
never falsely rejected to store a histogram because of it.

On the other hand, `ValidateFloatHistogram` has been to strict with
the count being at least as large as the sum of the counts in all the
buckets. Float precision issues could create false positives here, see
products of PromQL evaluations, it's actually quite hard to put an
upper limit no the floating point imprecision. Users could produce the
weirdest expressions, maxing out float precision problems. Therefore,
this commit simply removes that particular check from
`ValidateFloatHistogram`.

Signed-off-by: beorn7 <beorn@grafana.com>
2023-08-22 23:04:01 +02:00
Michael Hoffmann 4d8e380269
promql: allow tests to be imported (#12050)
Signed-off-by: Michael Hoffmann <mhoffm@posteo.de>
2023-08-18 20:48:59 +02:00
Bryan Boreham d2ae8dc3cb remote-write: add http.resend_count tracing attribute
As recommended by the OpenTelemetry semantic conventions.

https://opentelemetry.io/docs/specs/otel/trace/semantic_conventions/http/#http-client
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2023-08-11 16:20:12 +00:00
Goutham Veeramachaneni ad4f514e66
Add OTLP Ingestion endpoint (#12571)
* Add OTLP Ingestion endpoint

We copy files from the otel-collector-contrib. See the README in
`storage/remote/otlptranslator/README.md`.

This supersedes: https://github.com/prometheus/prometheus/pull/11965

Signed-off-by: gouthamve <gouthamve@gmail.com>

* Return a 200 OK

It is what the OTEL Golang SDK expect :(

https://github.com/open-telemetry/opentelemetry-go/issues/4363

Signed-off-by: Goutham <gouthamve@gmail.com>

---------

Signed-off-by: gouthamve <gouthamve@gmail.com>
Signed-off-by: Goutham <gouthamve@gmail.com>
2023-07-28 12:35:28 +02:00
LHHDZ 7d8f9b0978
remote-write receiver: reuse 'ref' to optimize multiple samples for same series (#12580)
reuse 'ref' to optimize multi samples processing efficiency

Signed-off-by: changlin.shi <changlin.shi@ly.com>
2023-07-22 14:24:46 +01:00
Julien Pivotto 0f85e4f41d
Merge pull request #12539 from bboreham/slices-sorts
Replace sort.Slice with faster slices.SortFunc
2023-07-11 13:09:02 +02:00
Bryan Boreham ce153e3fff Replace sort.Sort with faster slices.SortFunc
The generic version is more efficient.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2023-07-10 09:43:45 +00:00
Julien Pivotto 986fde06b2
Merge pull request #11688 from damnever/fix/datamodelvalidation-remotewriteapi
Validate the metric names and labels in the remote write handler
2023-07-04 13:52:02 +02:00
Bryan Boreham 5255bf06ad Replace sort.Slice with faster slices.SortFunc
The generic version is more efficient.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2023-07-02 22:17:08 +00:00
rakshith210 b1675e23af
Add Azure AD package for remote write (#11944)
* Add Azure AD package for remote write
* Made AzurePublic default and updated configuration.md
* Updated config structure and removed getToken at initialization
* Changed passing context from request

Signed-off-by: Rakshith Padmanabha <rapadman@microsoft.com>
Signed-off-by: rakshith210 <rakshith.me@gmail.com>
2023-06-01 15:20:10 -06:00
Callum Styan 0d2108ad79
[tsdb] re-implement WAL watcher to read via a "notification" channel (#11949)
* WIP implement WAL watcher reading via notifications over a channel from
the TSDB code

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Notify via head appenders Commit (finished all WAL logging) rather than
on each WAL Log call

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Fix misspelled Notify plus add a metric for dropped Write notifications

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Update tests to handle new notification pattern

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* this test maybe needs more time on windows?

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* does this test need more time on windows as well?

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* read timeout is already a time.Duration

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* remove mistakenly commited benchmark data files

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* address some review feedback

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* fix missed changes from previous commit

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Fix issues from wrapper function

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* try fixing race condition in test by allowing tests to overwrite the
read ticker timeout instead of calling the Notify function

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* fix linting

Signed-off-by: Callum Styan <callumstyan@gmail.com>

---------

Signed-off-by: Callum Styan <callumstyan@gmail.com>
2023-05-15 12:31:49 -07:00
Jeanette Tan 1102ffd188 Fix according to code review
Signed-off-by: Jeanette Tan <jeanette.tan@grafana.com>
2023-04-22 02:27:15 +08:00
Jeanette Tan e9a1e26ab7 Perform integer/float histogram type checking on conversions, and use a consistent method for determining integer vs float histogram
Signed-off-by: Jeanette Tan <jeanette.tan@grafana.com>
2023-04-22 02:27:15 +08:00
Matthieu MOREL bae9a21200
Merge branch 'main' into linter/nilerr
Signed-off-by: Matthieu MOREL <matthieu.morel35@gmail.com>
2023-04-19 19:56:39 +02:00
beorn7 5b53aa1108 style: Replace else if cascades with switch
Wiser coders than myself have come to the conclusion that a `switch`
statement is almost always superior to a statement that includes any
`else if`.

The exceptions that I have found in our codebase are just these two:

* The `if else` is followed by an additional statement before the next
  condition (separated by a `;`).
* The whole thing is within a `for` loop and `break` statements are
  used. In this case, using `switch` would require tagging the `for`
  loop, which probably tips the balance.

Why are `switch` statements more readable?

For one, fewer curly braces. But more importantly, the conditions all
have the same alignment, so the whole thing follows the natural flow
of going down a list of conditions. With `else if`, in contrast, all
conditions but the first are "hidden" behind `} else if `, harder to
spot and (for no good reason) presented differently from the first
condition.

I'm sure the aforemention wise coders can list even more reasons.

In any case, I like it so much that I have found myself recommending
it in code reviews. I would like to make it a habit in our code base,
without making it a hard requirement that we would test on the CI. But
for that, there has to be a role model, so this commit eliminates all
`if else` occurrences, unless it is autogenerated code or fits one of
the exceptions above.

Signed-off-by: beorn7 <beorn@grafana.com>
2023-04-19 17:22:31 +02:00
beorn7 c3c7d44d84 lint: Adjust to the lint warnings raised by current versions of golint-ci
We haven't updated golint-ci in our CI yet, but this commit prepares
for that.

There are a lot of new warnings, and it is mostly because the "revive"
linter got updated. I agree with most of the new warnings, mostly
around not naming unused function parameters (although it is justified
in some cases for documentation purposes – while things like mocks are
a good example where not naming the parameter is clearer).

I'm pretty upset about the "empty block" warning to include `for`
loops. It's such a common pattern to do something in the head of the
`for` loop and then have an empty block. There is still an open issue
about this: https://github.com/mgechev/revive/issues/810 I have
disabled "revive" altogether in files where empty blocks are used
excessively, and I have made the effort to add individual
`// nolint:revive` where empty blocks are used just once or twice.
It's borderline noisy, though, but let's go with it for now.

I should mention that none of the "empty block" warnings for `for`
loop bodies were legitimate.

Signed-off-by: beorn7 <beorn@grafana.com>
2023-04-19 17:10:10 +02:00
Matthieu MOREL fb3eb21230 enable gocritic, unconvert and unused linters
Signed-off-by: Matthieu MOREL <matthieu.morel35@gmail.com>
2023-04-13 19:20:22 +00:00
Björn Rabenstein 6e0a46900b
Merge pull request #12192 from leizor/leizor/prometheus/issues/11204
Add support for native histograms to concreteSeriesIterator
2023-04-11 12:30:35 +02:00
Justin Lei f90013a5a0 Update storage/remote/codec.go
Co-authored-by: Björn Rabenstein <github@rabenste.in>
Signed-off-by: Justin Lei <97976793+leizor@users.noreply.github.com>
2023-04-06 09:54:15 -07:00
Justin Lei 83f43982c9 Add support for native histograms to concreteSeriesIterator
Signed-off-by: Justin Lei <justin.lei@grafana.com>
2023-04-06 09:54:15 -07:00
Xiaochao Dong (@damnever) 2b7202c4cc Validate the metric names and labels in the remote write handler
Signed-off-by: Xiaochao Dong (@damnever) <the.xcdong@gmail.com>
2023-04-05 19:09:05 +08:00
Bryan Boreham b987afa7ef labels: simplify call to get Labels from Builder
It took a `Labels` where the memory could be re-used, but in practice
this hardly ever benefitted. Especially after converting `relabel.Process`
to `relabel.ProcessBuilder`.

Comparing the parameter to `nil` was a bug; `EmptyLabels` is not `nil`
so the slice was reallocated multiple times by `append`.

Lastly `Builder.Labels()` now estimates that the final size will depend
on labels added and deleted.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2023-03-22 17:05:20 +00:00
Björn Rabenstein 559adab471
Merge pull request #12085 from leizor/leizor/prometheus/issues/11204
Handle native histograms in remote read
2023-03-21 17:25:34 +01:00
Oleg Zaytsev beb7d3b80f
remote.Client: store urlString
During remote write, we call url.String() twice:
- to add the Endpoint() to the span
- to actually know where whe should send the request

This value does not change over time, and it's not really that
lightweight to calculate. I wrote this simple benchmark:

    func BenchmarkURLString(b *testing.B) {
        u, err := url.Parse("https://remote.write.com/api/v1")
        require.NoError(b, err)

        b.Run("string", func(b *testing.B) {
            count := 0
            for i := 0; i < b.N; i++ {
                count += len(u.String())
            }
        })
    }

And the results are ~200ns/op, 80B/op, 3 allocs/op.

Yes, we're going to go to the network here, which is a huge amount of
resources compared to this, but still, on agents that send 500 requests
per second, that is 1500 wasteful allocations per second.

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
2023-03-16 09:53:10 +01:00
Justin Lei 60ad864667 Remove hacky promql.Test native histogram thing
Signed-off-by: Justin Lei <justin.lei@grafana.com>
2023-03-09 11:05:53 -08:00
Justin Lei c16b6a0185 Handle native histograms in remote read
Signed-off-by: Justin Lei <justin.lei@grafana.com>
2023-03-09 09:13:53 -08:00
Arve Knudsen bc9a82f5a1
remote: Improve some comments (#12102)
Improve some comments in storage/remote/queue_manager.go, wrt. general
language and a typo.

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>
2023-03-09 11:05:24 +00:00
Arve Knudsen 435b500de7
remote: Convert to RecoverableError using errors.As (#12103)
In storage/remote, try converting to RecoverableError using errors.As,
instead of through direct casting.

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>
2023-03-08 13:58:09 -07:00
Julien Pivotto 475f9984d0
Merge pull request #11787 from damnever/perf/avoid-alloc-if-no-externallabels
Avoid allocation during remote write if external labels is empty
2023-02-22 23:38:21 +01:00
Julien Pivotto dfd2b5340e
Merge pull request #11951 from Fish-pro/chore/httpvar
Use http constants instead of string
2023-02-10 22:44:50 +01:00
Fish-pro 43d77f7c41 Use http constants instead of string
Signed-off-by: Fish-pro <zechun.chen@daocloud.io>
2023-02-10 10:21:05 +08:00
Charles Korn 0a1de58f7e
Mark Histogram.(Positive|Negative)Spans as non-nullable.
As far as I understand it, we'd never expect to receive a nil span,
and remote.spansProtoToSpans would panic if we received a nil span.

Marking the fields as non-nullable also means the generated Golang
code doesn't use pointers for these fields, reducing allocations.

Signed-off-by: Charles Korn <charles.korn@grafana.com>
2023-02-03 13:49:22 +11:00
György Krajcsovits 2d9a9cbc08 Fix storage/remote/codec ignoreing histogram reset hint
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
2023-01-24 12:56:30 +01:00
Jesus Vazquez 136956cca4
Attempt to append ooo sample at the end first (#11615)
This is an optimization on the existing append in OOOChunk.

What we've been doing so far is find the place inside the out-of-order
slice where the new sample should go in and then place it there and move
any samples to the right if necessary. This is OK but requires a binary
search every time the slice is bigger than 0.

The optimization is opinionated and suggests that although out-of-order
samples can be out-of-order amongst themselves they'll probably be in
order thus we can probably optimistically append at the end and if not
do the binary search.

OOOChunks are capped to 30 samples by default so this is a small
optimization but everything adds up, specially if you handle many active
timeseries with out-of-order samples.

Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
Signed-off-by: Jesus Vazquez <jesusvazquez@users.noreply.github.com>
Co-authored-by: Ganesh Vernekar <ganeshvern@gmail.com>
2023-01-13 19:00:50 +05:30
Marc Tudurí 721f33dbb0
histograms: Add remote-write support for Float Histograms (#11817)
* adapt code.go and write_handler.go to support float histograms
* adapt watcher.go to support float histograms
* wip adapt queue_manager.go to support float histograms
* address comments for metrics in queue_manager.go
* set test cases for queue manager
* use same counts for histograms and float histograms
* refactor createHistograms tests
* fix float histograms ref in watcher_test.go
* address PR comments

Signed-off-by: Marc Tuduri <marctc@protonmail.com>
2023-01-13 16:39:20 +05:30
Xiaochao Dong (@damnever) 2d61d012ff Avoid copy during remote write if external labels is empty
Signed-off-by: Xiaochao Dong (@damnever) <the.xcdong@gmail.com>
2022-12-30 19:18:30 +08:00
Fish-pro 6ed71a229e Use errors.Is to check for a specific error
Signed-off-by: Fish-pro <zechun.chen@daocloud.io>
2022-12-29 23:23:07 +08:00
Marc Tudurí 9474610baf
Support FloatHistogram in TSDB (#11522)
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>
2022-12-28 14:25:07 +05:30
Bryan Boreham ccea61c7bf
Merge pull request #11717 from bboreham/labels-abstraction
Add and use abstractions over labels.Labels
2022-12-20 17:23:39 +00:00
Sniper91 46fb802791
reset frameBytesLeft after writing (#11689)
Signed-off-by: sniper91 <kevinzhao91@outlook.com>

Signed-off-by: sniper91 <kevinzhao91@outlook.com>
2022-12-19 16:54:49 +01:00
Bryan Boreham 047585360b Update package storage/remote tests for new labels.Labels type
Use ScratchBuilder to create labels.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2022-12-19 15:22:09 +00:00
Bryan Boreham abd9909595 Update package storage/remote for new labels.Labels type
`QueueManager.externalLabels` becomes a slice rather than a `Labels` so
we can index into it when doing the merge operation.

Note we avoid calling `Labels.Len()` in `labelProtosToLabels()`.
It isn't necessary - `append()` will enlarge the buffer and we're
expecting to re-use it many times.

Also, we now validate protobuf input before converting to Labels.
This way we can detect errors first, and we don't place unnecessary
requirements on the Labels structure.

Re-do seriesFilter using labels.Builder (albeit N^2).

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2022-12-19 15:22:09 +00:00
Bryan Boreham 463f5cafdd storage: re-use iterators to save garbage
Re-use previous memory if it is already of the correct type.

In `NewListSeries` we hoist the conversion to an interface value out
so it only allocates once.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2022-12-15 18:32:45 +00:00
Bryan Boreham 3c7de69059 storage: allow re-use of iterators
Patterned after `Chunk.Iterator()`: pass the old iterator in so it
can be re-used to avoid allocating a new object.

(This commit does not do any re-use; it is just changing all the method
signatures so re-use is possible in later commits.)

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2022-12-15 18:32:45 +00:00
Julius Volz 1a2c645dfa Correctly handle error unwrapping in rules and remote write receiver
errors.Unwrap() actually dangerously returns nil if the error does not have an
Unwrap() method, which is the case in at least one of these places where I
noticed that no error was being logged at all when it should have.

Signed-off-by: Julius Volz <julius.volz@gmail.com>
2022-12-15 12:50:55 +01:00
Giedrius Statkevičius d1d2566055
remote/read_handler: pool input to Marshal() (#11357)
* remote/read_handler: pool input to Marshal()

Use a sync.Pool to reuse byte slices between calls to Marshal() in the
remote read handler.

Signed-off-by: Giedrius Statkevičius <giedrius.statkevicius@vinted.com>

* remote: add microbenchmark for remote read handler

Signed-off-by: Giedrius Statkevičius <giedrius.statkevicius@vinted.com>

Signed-off-by: Giedrius Statkevičius <giedrius.statkevicius@vinted.com>
2022-11-15 16:29:16 +01:00
Ganesh Vernekar 648be89822
Merge remote-tracking branch 'upstream/main' into fix-conflict
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2022-10-12 14:20:02 +05:30
Jesus Vazquez 775d90d5f8
TSDB: Rename wal package to wlog (#11352)
The wlog.WL type can now be used to create a Write Ahead Log or a Write
Behind Log.

Before the prefix for wbl metrics was
'prometheus_tsdb_out_of_order_wal_' and has been replaced with
'prometheus_tsdb_out_of_order_wbl_'.

Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
Signed-off-by: Jesus Vazquez <jesusvazquez@users.noreply.github.com>
Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>
2022-10-10 20:38:46 +05:30
Jesus Vazquez e934d0f011 Merge 'main' into sparsehistogram
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
2022-10-05 22:14:49 +02:00
Bryan Boreham 3029320ce6 storage/remote: in tests use labels.FromStrings
And a few cases of `EmptyLabels()`.
Replacing code which assumes the internal structure of `Labels`.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2022-09-09 13:34:49 +02:00
Ganesh Vernekar f540c1dbd3
Add support for histograms in WAL checkpointing (#11210)
* Add support for histograms in WAL checkpointing

Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>

* Fix review comments

Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>

* Fix tests

Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>

Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2022-08-29 17:38:36 +05:30
beorn7 c9fd3c235d Merge branch 'main' into sparsehistogram 2022-08-10 17:54:37 +02:00
Levi Harrison 0db6b072bc
Export histogramToHistogramProto() (#11046)
Signed-off-by: Levi Harrison <git@leviharrison.dev>
2022-07-21 10:12:50 -04:00
Paschalis Tsilias d1122e0743
Introduce TSDB changes for appending metadata to the WAL (#10972)
* Append metadata to the WAL

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Remove extra whitespace; Reword some docstrings and comments

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Use RLock() for hasNewMetadata check

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Use single byte for metric type in RefMetadata

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Update proposed WAL format for single-byte type metadata

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Implementa MetadataAppender interface for the Agent

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Address first round of review comments

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Amend description of metadata in wal.md

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Correct key used to retrieve metadata from cache

When we're setting metadata entries in the scrapeCace, we're using the
p.Help(), p.Unit(), p.Type() helpers, which retrieve the series name and
use it as the cache key. When checking for cache entries though, we used
p.Series() as the key, which included the metric name _with_ its labels.
That meant that we were never actually hitting the cache. We're fixing
this by utiling the __name__ internal label for correctly getting the
cache entries after they've been set by setHelp(), setType() or
setUnit().

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Put feature behind a feature flag

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Fix AppendMetadata docstring

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Reorder WAL format document

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Change error message of AppendMetadata; Fix access of s.meta in AppendMetadata

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Reuse temporary buffer in Metadata encoder

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Only keep latest metadata for each refID during checkpointing

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Fix test that's referencing decoding metadata

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Avoid creating metadata block if no new metadata are present

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Add tests for corrupt metadata block and relevant record type

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Fix CR comments

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Extract logic about changing metadata in an anonymous function

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Implement new proposed WAL format and amend relevant tests

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Use 'const' for metadata field names

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Apply metadata to head memSeries in Commit, not in AppendMetadata

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Add docstring and rename extracted helper in scrape.go

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Add tests for tsdb-related cases

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Fix linter issues vol1

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Fix linter issues vol2

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Fix Windows test by closing WAL reader files

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Use switch instead of two if statements in metadata decoding

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Fix review comments around TestMetadata* tests

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Add code for replaying WAL; test correctness of in-memory data after a replay

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Remove scrape-loop related code from PR

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Address first round of comments

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Simplify tests by sorting slices before comparison

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Fix test to use separate transactions

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Empty out buffer and record slices after encoding latest metadata

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Fix linting issue

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Update calculation for DroppedMetadata metric

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Rename MetadataAppender interface and AppendMetadata method to MetadataUpdater/UpdateMetadata

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Reuse buffer when encoding latest metadata for each series

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Fix review comments; Check all returned error values using two helpers

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Simplify use of helpers

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>

* Satisfy linter

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>
2022-07-19 10:58:52 +02:00
beorn7 87351f2318 prompb: Modify layout of histograms
Note: This is deliberately an incompatible change. Since we have never
used histograms in remote read/write yet, there is no point in keeping
compatibility. This _is_, however, compatible to the state in the main
branch.

This commit flattens the bucket message into top-level fields. This
has the disadvantage of now having two triples of fields prefixed with
`negative_...` or `positive_...`. However, with this structure, we
save one tag on the wire. And, perhaps more importantly, we mirror the
structure of the `histogram.Histogram` Go type.

This commit also adjusts `repeated` fields to use names in the plural
form, as it is also the case for the fields that already existed.

This also adds a doc comment to `HistogramProtoToHistogram` and
changes its return type to a pointer (which is more convenient and
probably more efficient).

Signed-off-by: beorn7 <beorn@grafana.com>
2022-07-14 17:47:17 +02:00
Levi Harrison 08f3ddb864
Sparse histogram remote-write support (#11001) 2022-07-14 09:13:12 -04:00
beorn7 28f028e938 Merge branch 'main' into sparsehistogram 2022-07-12 19:07:13 +02:00
Matthieu MOREL d56d0a9d52
(storage): move from github.com/pkg/errors to 'errors' and 'fmt' (#10946)
Signed-off-by: Matthieu MOREL <mmorel-35@users.noreply.github.com>

Co-authored-by: Matthieu MOREL <mmorel-35@users.noreply.github.com>
2022-07-01 18:59:50 +02:00
Leonardo Zamariola 3326df42bb
Removing global state modification on unit tests (fix #10033 #10034) (#10935)
* Removing global state modification on unit tests (fix #10033 #10034)

The config.DefaultRemoteReadConfig and config.DefaultRemoteWriteConfig
instances hold global state. Unit tests were changing their url.URL reference
globally causing false positives when tests were ran through package.
Two helper functions were created to copy those global values instead of changing
them in place to fix null point when running unit tests by method instead of
by package.

Signed-off-by: Leonardo Zamariola <leonardo.zamariola@gmail.com>

* Fixing pull request suggestions

Copying by value from default config

Signed-off-by: Leonardo Zamariola <leonardo.zamariola@gmail.com>
2022-06-30 10:20:16 -06:00
beorn7 40ad5e284a Merge branch 'main' into beorn7/sparsehistogram 2022-06-09 20:50:30 +02:00
Matej Gera 1dd247f68b
Remote Write: Rename confusing walDir parameter to dir (#10464)
* Rename walDir parameter to dir

Signed-off-by: Matej Gera <matejgera@gmail.com>

* Improve NewQueueManager comment

Signed-off-by: Matej Gera <matejgera@gmail.com>
2022-05-30 21:45:30 -07:00
Bryan Boreham 4b9f248e85
unit tests: make all Labels sorted alphabetically (#10532)
"Labels is a sorted set of labels. Order has to be guaranteed upon
instantiation." says the comment, so fix all the tests that break this
rule.

For `BenchmarkLabelValuesWithMatchers()` and
`BenchmarkHeadLabelValuesWithMatchers()` the amount of work done changes
significantly if you put the labels in order, because all series refs
get neatly partitioned by the `tens` label, so I renamed the labels
to maintain the previous behaviour.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2022-05-04 23:41:36 +02:00
beorn7 3bc711e333 Merge branch 'main' into sparsehistogram 2022-05-04 13:37:13 +02:00
Matthieu MOREL e2ede285a2
refactor: move from io/ioutil to io and os packages (#10528)
* 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>
2022-04-27 11:24:36 +02:00
Chris Marchbanks a11e73edda
Fix a deadlock between Batch and FlushAndShutdown (#10608)
If FlushAndShutdown is called with a full batchQueue, and then Batch is
called rather than the normal path of reading from a queue a deadlock
might be encountered. Rather than having FlushAndShutdown having
blocking code while holding a lock retry sending the batch every second.

Signed-off-by: Chris Marchbanks <csmarchbanks@gmail.com>
2022-04-20 20:50:41 +02:00
beorn7 4210aac74a Merge branch 'main' into sparsehistogram 2022-03-22 14:47:42 +01:00
beorn7 79376c1e94 Merge branch 'release-2.33' into beorn7/release 2022-03-08 17:42:49 +01:00
Chris Marchbanks e970acb085
Fix deadlock between adding to queue and getting batch
Do not block when trying to write a batch to the queue. This can cause
appends to lock forever if the only thing reading from the queue needs
the mutex to write. Instead, if batchQueue is full pop the sample that
was just added from the partial batch and return false. The code doing
the appending already handles retries with backoff.

Signed-off-by: Chris Marchbanks <csmarchbanks@gmail.com>
2022-03-07 17:15:57 -07:00
Chris Marchbanks afdc1decac
Write a test that reproduces the deadlock
Signed-off-by: Chris Marchbanks <csmarchbanks@gmail.com>
2022-03-07 17:15:51 -07:00
DrAuYueng 5a6e26556b
Add an option to use the external labels as selectors for the remote read endpoint (#10254)
* An option to ignore external_labels

Signed-off-by: DrAuYueng <ouyang1204@gmail.com>
2022-02-16 22:12:47 +01:00
Julien Pivotto b0d70557b7
Merge pull request #10285 from prometheus/release-2.33 2022-02-12 00:02:24 +01:00
Chris Marchbanks bfb1500a38
Fix deadlock when stopping a shard (#10279)
If a queue is stopped and one of its shards happens to hit the
batch_send_deadline at the same time a deadlock can occur where stop
holds the mutex and will not release it until the send is finished, but
the send needs the mutex to retrieve the most recent batch. This is
fixed by using a second mutex just for writing.

In addition, the test I wrote exposed a case where during shutdown a
batch could be sent twice due to concurrent calls to queue.Batch() and
queue.FlushAndShutdown(). Protect these with a mutex as well.

Signed-off-by: Chris Marchbanks <csmarchbanks@gmail.com>
2022-02-11 07:07:41 -07:00
Matej Gera 2c61d29b2a
Tracing: Migrate to OpenTelemetry library (#9724)
Signed-off-by: Matej Gera <matejgera@gmail.com>
2022-01-25 11:08:04 +01:00
Eng Zer Jun 3e67654d37
refactor: use T.TempDir() and B.TempDir to create temporary directory
The directory created by `T.TempDir()` and `B.TempDir()` is
automatically removed when the test and all its subtests complete.

Reference: https://pkg.go.dev/testing#T.TempDir
Reference: https://pkg.go.dev/testing#B.TempDir
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
2022-01-22 18:57:30 +08:00
Bryan Boreham 954c0e8020 remote_write: round desired shards up before check
Previously we would reject an increase from 2 to 2.5 as being
within 30%; by rounding up first we see this as an increase from 2 to 3.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2022-01-10 09:57:37 +00:00
Bryan Boreham 6d01ce8c4d remote_write: shard up more when backlogged
Change the coefficient from 1% to 5%, so instead of targetting to clear
the backlog in 100s we target 20s.

Update unit test to reflect the new behaviour.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2022-01-10 09:57:37 +00:00
Bryan Boreham d588b14d9c remote_write: detailed test for shard calculation
Drive the input parameters to `calculateDesiredShards()` very precisely,
to illustrate some questionable behaviour marked with `?!`.

See https://github.com/prometheus/prometheus/issues/9178,
https://github.com/prometheus/prometheus/issues/9207,

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2022-01-10 09:57:37 +00:00
Chris Marchbanks ba03f7fc23
Merge pull request #10102 from prometheus/update-metrics-on-rw-fails
Update sent timestamp when write irrecoverably fails
2022-01-05 10:46:09 -07:00
Goutham Veeramachaneni 6696b7a5f0
Don't update metrics on context cancellation
Signed-off-by: Goutham Veeramachaneni <gouthamve@gmail.com>
2022-01-04 10:46:52 +01:00
Chris Marchbanks dfa5cb7462
Merge pull request #10038 from charlesxsh/fix-TestReshardRaceWithStop
add proper exit for loop
2022-01-03 09:02:45 -07:00
Goutham Veeramachaneni 1af81dc5c9
Update sent timestamp when write irrecoverably fails.
We have an alert that fires when prometheus_remote_storage_highest_timestamp_in_seconds - prometheus_remote_storage_queue_highest_sent_timestamp_seconds
becomes too high. But we have an agent that fires this when the remote "rate-limits" the user.

This is because prometheus_remote_storage_queue_highest_sent_timestamp_seconds doesn't get updated
when the remote sends a 429.

I think we should update the metrics, and the change I made makes sense. Because if the requests fails
because of connectivity issues, etc. we will never exit the `sendWriteRequestWithBackoff` function. It only
exits the function when there is a non-recoverable error, like a bad status code, and in that case, I think
the metric needs to be updated.

Signed-off-by: Goutham Veeramachaneni <gouthamve@gmail.com>
2022-01-03 11:13:48 +01:00
Shihao Xia c3e7bfb813 add proper exit for loop
Signed-off-by: Shihao Xia <charlesxsh@hotmail.com>
2021-12-29 23:48:11 -05:00
beorn7 86cc83b13c storage: iterator fixes after merge
Signed-off-by: beorn7 <beorn@grafana.com>
2021-12-18 14:12:01 +01:00
beorn7 64c7bd2b08 Merge branch 'main' into sparsehistogram 2021-12-18 14:04:25 +01:00
Julien Pivotto 27343277fa
Merge release-2.32 forward into main (#10032)
* storage: expose bug in iterators #10027

Signed-off-by: beorn7 <beorn@grafana.com>

* storage: fix bug #10027 in iterators' Seek method

Signed-off-by: beorn7 <beorn@grafana.com>

* Append reporting metrics without limit

If reporting metrics fails due to reaching the limit, this makes the
target appear as UP in the UI, but the metrics are missing.

This commit bypasses that limit for report metrics.

Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>

* Remove check against cfg so interval/ timeout are always set (#10023) (#10031)

Signed-off-by: Nicholas Blott <blottn@tcd.ie>

Co-authored-by: Nicholas Blott <blottn@tcd.ie>

* Cut v2.32.1

Signed-off-by: Julius Volz <julius.volz@gmail.com>

* Apply suggestions from code review

Signed-off-by: Julius Volz <julius.volz@gmail.com>

Co-authored-by: Levi Harrison <git@leviharrison.dev>

Co-authored-by: Julien Pivotto <roidelapluie@inuits.eu>
Co-authored-by: Nicholas Blott <blottn@tcd.ie>
Co-authored-by: Julius Volz <julius.volz@gmail.com>
Co-authored-by: Levi Harrison <git@leviharrison.dev>
2021-12-17 23:18:38 +01:00
beorn7 0ede6ae321 storage: fix bug #10027 in iterators' Seek method
Signed-off-by: beorn7 <beorn@grafana.com>
2021-12-16 12:07:35 +01:00
beorn7 b042e29569 storage: expose bug in iterators #10027
Signed-off-by: beorn7 <beorn@grafana.com>
2021-12-16 12:02:15 +01:00
beorn7 6f33ab2b35 Merge branch 'main' into sparsehistogram 2021-12-15 13:49:33 +01:00
Chris Marchbanks 0a8d28ea93
Merge pull request #9934 from bboreham/remote-write-struct
remote-write: buffer struct instead of interface to reduce garbage-collection
2021-12-09 09:17:45 -07:00
Bryan Boreham bd6436605d Review feedback
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2021-12-09 14:40:44 +00:00
Sebastian Rabenhorst d8b8678bd1
Log time series details for out-of-order samples in remote write receiver (#9894)
* Improved out-of-order sample logs in write handler

Signed-off-by: Sebastian Rabenhorst <sebastian.rabenhorst@shopify.com>

sign commit

Signed-off-by: Sebastian Rabenhorst <sebastian.rabenhorst@shopify.com>

Inlined logAppendError

Signed-off-by: Sebastian Rabenhorst <sebastian.rabenhorst@shopify.com>

Update storage/remote/write_handler.go

Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>

Fixed fmt

Signed-off-by: Sebastian Rabenhorst <sebastian.rabenhorst@shopify.com>

* Improved out-of-order sample logs in write handler

Signed-off-by: Sebastian Rabenhorst <sebastian.rabenhorst@shopify.com>

sign commit

Signed-off-by: Sebastian Rabenhorst <sebastian.rabenhorst@shopify.com>

Inlined logAppendError

Signed-off-by: Sebastian Rabenhorst <sebastian.rabenhorst@shopify.com>
2021-12-08 15:07:51 +00:00
Bryan Boreham 50878ebe5e remote-write: buffer struct instead of interface
This reduces the amount of individual objects allocated, allowing sends
to run a bit faster.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2021-12-03 14:30:42 +00:00
Bryan Boreham c478d6477a remote-write: benchmark just sending, on 20 shards
Previously BenchmarkSampleDelivery spent a lot of effort checking each
sample had arrived, so was largely showing the performance of test-only
code.

Increase the number of shards to be more realistic for a large
workload.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2021-12-03 14:02:10 +00:00
Chris Marchbanks e95d4ec3f1
Merge pull request #9830 from prometheus/batch-queues
Batch samples before sending them to channels
2021-12-02 08:37:41 -07:00
Chris Marchbanks c655684142
Subtract from enqueued samples/exemplars upon send
Right now the values for enqueuedSamples and enqueuedExemplars is never
subtracted leading to inflated values for failedSamples/failedExemplars
when a hard shutdown of a shard occurs.

Signed-off-by: Chris Marchbanks <csmarchbanks@gmail.com>
2021-11-30 12:54:50 -07:00
Chris Marchbanks 319249f9db
Batch samples before sending them to channels
Channels can cause bottlenecks and tons of context switches when reading
hundreds of thousands of samples per second from a single queue.
Instead, pre-batch the samples to amortize the cost of the concurrency
overhead.

Signed-off-by: Chris Marchbanks <csmarchbanks@gmail.com>
2021-11-30 12:54:45 -07:00
beorn7 68e02be963 Post-merge fixes
Signed-off-by: beorn7 <beorn@grafana.com>
2021-11-30 17:20:28 +01:00
beorn7 e4e24453fa Merge branch 'main' into beorn7/merge2 2021-11-30 17:19:06 +01:00
Björn Rabenstein b866db009b
storage: Fix and improve the Seek method of various iterators (#9878)
There was a subtle and nasty bug in listSeriesIterator.Seek.

In addition, the Seek call is defined to be a no-op if the current
position of the iterator is already pointing to a suitable
sample. This commit adds fast paths for this case to several
potentially expensive Seek calls.

Another bug was in concreteSeriesIterator.Seek. It always searched the
whole series and not from the current position of the iterator.

Signed-off-by: beorn7 <beorn@grafana.com>
2021-11-29 15:17:56 +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
Matheus Alcantara e673805d67
storage/remote: use t.TempDir instead of ioutil.TempDir on tests (#9811)
Signed-off-by: Matheus Alcantara <matheusssilv97@gmail.com>
2021-11-19 15:21:45 -05:00
Hu Shuai eb43437d83
Fix golint issue (#9800)
Signed-off-by: Hu Shuai <hus.fnst@fujitsu.com>
2021-11-18 09:26:07 +01:00
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
Mateusz Gozdek d8561dbfd8 storage/remote: make tests use separate remote write configs
So tests can be run in parallel without races.

Signed-off-by: Mateusz Gozdek <mgozdekof@gmail.com>
2021-11-10 09:40:43 +01:00
Mateusz Gozdek 116552cc58 storage/remote: check errors from ApplyConfig in tests
So tests do not produce obscure errors when applying configuration
fails.

Signed-off-by: Mateusz Gozdek <mgozdekof@gmail.com>
2021-11-10 09:40:43 +01:00
beorn7 c954cd9d1d Move packages out of deprecated pkg directory
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>
2021-11-09 08:03:10 +01:00
Dieter Plaetinck cda025b5b5
TSDB: demistify SeriesRefs and ChunkRefs (#9536)
* 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>
2021-11-06 15:40:04 +05:30
sniper f82e56fbba
fix request bytes size and continue is useless (#9635)
Signed-off-by: kalmanzhao <kalmanzhao@tencent.com>

Co-authored-by: kalmanzhao <kalmanzhao@tencent.com>
2021-11-03 14:40:31 +05:30
Mateusz Gozdek b7bdf6fab2 Fix imports formatting
According to
2829908806 (r58457095).

Signed-off-by: Mateusz Gozdek <mgozdekof@gmail.com>
2021-11-02 19:52:34 +01:00
Mateusz Gozdek 1a6c2283a3 Format Go source files using 'gofumpt -w -s -extra'
Part of #9557

Signed-off-by: Mateusz Gozdek <mgozdekof@gmail.com>
2021-11-02 19:52:34 +01:00
lzhfromustc 9da5382103
storage/remote: Prevent two goroutines from endless loop (#8967)
Signed-off-by: lzhfromustc <lzhfromustc@gmail.com>
2021-10-29 16:39:02 -07:00
lzhfromustc d42be7be76
test:Fix two potential goroutine leaks (#8964)
Signed-off-by: lzhfromustc <lzhfromustc@gmail.com>
2021-10-29 15:44:32 -07:00
Bryan Boreham 5afa606ecb
Remote-write: reuse memory for marshalling (#9412)
By holding a `proto.Buffer` per shard and passing it down to where
marshalling is done, we avoid creating a lot of garbage.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2021-10-29 14:44:40 -07:00
Robert Fratto bc72a718c4
Initial draft of prometheus-agent (#8785)
* Initial draft of prometheus-agent

This commit introduces a new binary, prometheus-agent, based on the
Grafana Agent code. It runs a WAL-only version of prometheus without the
TSDB, alerting, or rule evaluations. It is intended to be used to
remote_write to Prometheus or another remote_write receiver.

By default, prometheus-agent will listen on port 9095 to not collide
with the prometheus default of 9090.

Truncation of the WAL cooperates on a best-effort case with Remote
Write. Every time the WAL is truncated, the minimum timestamp of data to
truncate is determined by the lowest sent timestamp of all samples
across all remote_write endpoints. This gives loose guarantees that data
from the WAL will not try to be removed until the maximum sample
lifetime passes or remote_write starts functionining.

Signed-off-by: Robert Fratto <robertfratto@gmail.com>

* add tests for Prometheus agent (#22)

* add tests for Prometheus agent

* add tests for Prometheus agent

* rearranged tests as per the review comments

* update tests for Agent

* changes as per code review comments

Signed-off-by: SriKrishna Paparaju <paparaju@gmail.com>

* incremental changes to prometheus agent

Signed-off-by: SriKrishna Paparaju <paparaju@gmail.com>

* changes as per code review comments

Signed-off-by: SriKrishna Paparaju <paparaju@gmail.com>

* Commit feedback from code review

Co-authored-by: Bartlomiej Plotka <bwplotka@gmail.com>
Co-authored-by: Ganesh Vernekar <ganeshvern@gmail.com>

Signed-off-by: Robert Fratto <robertfratto@gmail.com>

* Port over some comments from grafana/agent

Signed-off-by: Robert Fratto <robertfratto@gmail.com>

* Rename agent.Storage to agent.DB for tsdb consistency

Signed-off-by: Robert Fratto <robertfratto@gmail.com>

* Consolidate agentMode ifs in cmd/prometheus/main.go

Signed-off-by: Robert Fratto <robertfratto@gmail.com>

* Document PreAction usage requirements better for agent mode flags

Signed-off-by: Robert Fratto <robertfratto@gmail.com>

* remove unnecessary defaultListenAddr

Signed-off-by: Robert Fratto <robertfratto@gmail.com>

* `go fmt ./tsdb/agent` and fix lint errors

Signed-off-by: Robert Fratto <robertfratto@gmail.com>

Co-authored-by: SriKrishna Paparaju <paparaju@gmail.com>
2021-10-29 16:25:05 +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
beorn7 fd5ea4e0b5 Merge branch 'main' into sparsehistogram 2021-10-07 23:16:42 +02:00
Julien Pivotto 63b3e4e5ec
Enable HTTP2 again (#9398)
We are re-enabling HTTP 2 again. There has been a few bugfixes upstream
in go, and we have also enabled ReadIdleTimeout.

Fix #7588
Fix #9068

Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>
2021-09-26 23:16:12 +02:00
Nick Pillitteri acee8c8a88
Redact remote write URL when used for metric label (#9383)
Redact any basic auth passwords in the remote write URL (which are
technically allowed although not recommended) when used as metric
labels.

Signed-off-by: Nick Pillitteri <nick.pillitteri@grafana.com>
2021-09-23 12:34:09 -06:00
Serge Catudal d77c985f8c
Add initial support for exemplar to the remote write receiver endpoint (#9319)
* Add initial support for exemplar to the remote write receiver endpoint

Signed-off-by: Serge Catudal <serge.catudal@gmail.com>

* Update storage remote write handler tests with exemplars

Signed-off-by: Serge Catudal <serge.catudal@gmail.com>

* Update remote write handler in order to have a distinct checkAppendExemplarError function from scrape

Signed-off-by: Serge Catudal <serge.catudal@gmail.com>
2021-09-21 14:53:27 -06:00
Paweł Szulik f5563bfe95
tests: Move from t.Errorf and others. (Part 2) (#9309)
* Refactor util tests.

Signed-off-by: Paweł Szulik <paul.szulik@gmail.com>
2021-09-13 21:19:20 +02:00
Levi Harrison bd57cd395e
Switch to common/sigv4
Signed-off-by: Levi Harrison <git@leviharrison.dev>
2021-08-26 09:37:19 -04:00
Ganesh Vernekar 095f572d4a
Sync sparsehistogram branch with main (#9189)
* Fix `kuma_sd` targetgroup reporting (#9157)

* Bundle all xDS targets into a single group

Signed-off-by: austin ce <austin.cawley@gmail.com>

* Snapshot in-memory chunks on shutdown for faster restarts (#7229)

Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>

* Rename links

Signed-off-by: Levi Harrison <git@leviharrison.dev>

* Remove Individual Data Type Caps in Per-shard Buffering for Remote Write (#8921)

* Moved everything to nPending buffer

Signed-off-by: Levi Harrison <git@leviharrison.dev>

* Simplify exemplar capacity addition

Signed-off-by: Levi Harrison <git@leviharrison.dev>

* Added pre-allocation

Signed-off-by: Levi Harrison <git@leviharrison.dev>

* Don't allocate if not sending exemplars

Signed-off-by: Levi Harrison <git@leviharrison.dev>

* Avoid deadlock when processing duplicate series record (#9170)

* Avoid deadlock when processing duplicate series record

`processWALSamples()` needs to be able to send on its output channel
before it can read the input channel, so reads to allow this in case the
output channel is full.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* processWALSamples: update comment

Previous text seems to relate to an earlier implementation.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Optimise WAL loading by removing extra map and caching min-time (#9160)

* BenchmarkLoadWAL: close WAL after use

So that goroutines are stopped and resources released

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* BenchmarkLoadWAL: make series IDs co-prime with #workers

Series are distributed across workers by taking the modulus of the
ID with the number of workers, so multiples of 100 are a poor choice.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* BenchmarkLoadWAL: simulate mmapped chunks

Real Prometheus cuts chunks every 120 samples, then skips those samples
when re-reading the WAL. Simulate this by creating a single mapped chunk
for each series, since the max time is all the reader looks at.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Fix comment

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Remove series map from processWALSamples()

The locks that is commented to reduce contention in are now sharded
32,000 ways, so won't be contended. Removing the map saves memory and
goes just as fast.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* loadWAL: Cache the last mmapped chunk time

So we can skip calling append() for samples it will reject.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Improvements from code review

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Full stops and capitals on comments

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Cache max time in both places mmappedChunks is updated

Including refactor to extract function `setMMappedChunks`, to reduce
code duplication.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Update head min/max time when mmapped chunks added

This ensures we have the correct values if no WAL samples are added for
that series.

Note that `mSeries.maxTime()` was always `math.MinInt64` before, since
that function doesn't consider mmapped chunks.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Split Go and React Tests (#8897)

* Added go-ci and react-ci

Co-authored-by: Julien Pivotto <roidelapluie@inuits.eu>
Signed-off-by: Levi Harrison <git@leviharrison.dev>

* Remove search keymap from new expression editor (#9184)

Signed-off-by: Julius Volz <julius.volz@gmail.com>

Co-authored-by: Austin Cawley-Edwards <austin.cawley@gmail.com>
Co-authored-by: Levi Harrison <git@leviharrison.dev>
Co-authored-by: Julien Pivotto <roidelapluie@inuits.eu>
Co-authored-by: Bryan Boreham <bjboreham@gmail.com>
Co-authored-by: Julius Volz <julius.volz@gmail.com>
2021-08-11 15:43:17 +05:30
Levi Harrison fac1b57334
Remove Individual Data Type Caps in Per-shard Buffering for Remote Write (#8921)
* Moved everything to nPending buffer

Signed-off-by: Levi Harrison <git@leviharrison.dev>

* Simplify exemplar capacity addition

Signed-off-by: Levi Harrison <git@leviharrison.dev>

* Added pre-allocation

Signed-off-by: Levi Harrison <git@leviharrison.dev>

* Don't allocate if not sending exemplars

Signed-off-by: Levi Harrison <git@leviharrison.dev>
2021-08-09 15:20:53 -06:00
Ganesh Vernekar 8b70e87ab9
Merge remote-tracking branch 'upstream/main' into sparse-refactor
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2021-08-05 12:16:08 +05:30
jinglina ed24e51e7c
remove redundant type conversion (#9126)
Signed-off-by: jinglina <jinglinax@163.com>
2021-07-28 13:33:46 +05:30
Bryan Boreham 60804c5a09
remote_write: reduce blocking from garbage-collect of series (#9109)
* Refactor: pass segment-reading function as param

To allow a different implementation to be used when garbage-collecting.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* remote_write: reduce blocking from GC of series

Add a method `UpdateSeriesSegment()` which is used together with
`SeriesReset()` to garbage-collect old series. This allows us to
split the lock around queueManager series data and avoid blocking
`Append()` while reading series from the last checkpoint.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Cosmetic: review feedback on comments

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* remote-write benchmark: include GC of series

Reduce the total number of samples per iteration from 5000*5000
(25 million) which is too big for my laptop, to 1*10000.

Extend `createTimeseries()` to add additional labels, so that the
queue manager is doing more realistic work.

Move the Append() call to a background goroutine - this works because
TestWriteClient uses a WaitGroup to signal completion.

Call `StoreSeries()` and `SeriesReset()` while adding samples, to
simulate the garbage-collection that wal.Watcher does.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Change BenchmarkSampleDelivery to call UpdateSeriesSegment

This matches what Watcher.garbageCollectSeries() is doing now

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2021-07-27 13:21:48 -07:00
Oleg Zaytsev b1ed4a0a66
LabelNames API with matchers (#9083)
* Push the matchers for LabelNames all the way into the index.

NB This doesn't actually implement it in the index, just plumbs it through for now...

Signed-off-by: Tom Wilkie <tom@grafana.com>

* Hack it up.  Does not work.

Signed-off-by: Tom Wilkie <tom@grafana.com>

* Revert changes I don't understand

Can't see why do we need to hold a mutex on symbols, and the purpose of
the LabelNamesFor method.

Maybe I'll need to re-add this later.

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

* Implement LabelNamesFor

This method provides the label names that appear in the postings
provided. We do that deeper than the label values because we know
beforehand that most of the label names we'll be the same across
different postings, and we don't want to go down an up looking up the
same symbols for all different series.

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

* Mutex on symbols should be unlocked

However, I still don't understand why do we need a mutex here.

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

* Fix head.LabelNamesFor

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

* Implement mockIndex LabelNames with matchers

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

* Nitpick on slice initialisation

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

* Add tests for LabelNamesWithMatchers

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

* Fix the mutex mess on head.LabelValues/LabelNames

I still don't see why we need to grab that unrelated mutex, but at least
now we're grabbing it consistently

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

* Check error after iterating postings

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

* Use the error from posting when there was en error in postings

Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

* Update storage/interface.go comment

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>

* Update tsdb/index/index.go comment

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>

* Update tsdb/index/index.go wrapped error msg

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>

* Update tsdb/index/index.go wrapped error msg

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>

* Update tsdb/index/index.go warpped error msg

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>

* Remove unneeded comment

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

* Add testcases for LabelNames w/matchers in api.go

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

* Use t.Cleanup() instead of defer in tests

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>

Co-authored-by: Tom Wilkie <tom@grafana.com>
Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>
2021-07-20 18:08:08 +05:30
Ganesh Vernekar a1087ed37a
Fix scraping of sparse histograms (#9031)
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2021-07-01 18:19:04 +05:30
Ganesh Vernekar f4d3af73f0
Query histograms from TSDB and unit test for append+query (#9022)
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2021-06-30 20:18:13 +05:30
Ganesh Vernekar 04ad56d9b8
Append sparse histograms into the Head block (#9013)
* Append sparse histograms into the Head block

Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>

* Add AtHistogram() to Iterator interface. Make HistoChunk conform to Chunk interface.

Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2021-06-29 20:08:46 +05:30
Ganesh Vernekar 64bea6999e
HistogramAppender interface for sparse histograms (#9007)
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2021-06-28 20:30:55 +05:30
Levi Harrison d5c3c567d3
Remote Write: Add max samples per metadata send (#8959)
* Added MaxSamplesPerSend

Signed-off-by: Levi Harrison <git@leviharrison.dev>

* Added tests

Signed-off-by: Levi Harrison <git@leviharrison.dev>

* Fixed order of require

Signed-off-by: Levi Harrison <git@leviharrison.dev>

* Added docs

Signed-off-by: Levi Harrison <git@leviharrison.dev>

* writes -> writesReceived

Signed-off-by: Levi Harrison <git@leviharrison.dev>

* Improved send loop

Signed-off-by: Levi Harrison <git@leviharrison.dev>
2021-06-24 15:39:50 -07:00
Levi Harrison b5f6f8fb36 Switched to go-kit/log
Signed-off-by: Levi Harrison <git@leviharrison.dev>
2021-06-11 12:28:36 -04:00
songjiayang 9a01472780 Refactor processExternalLabels method with slice copy for left labels
Signed-off-by: songjiayang <songjiayang1@gmail.com>
2021-05-12 21:31:41 +08:00
Callum Styan 8fd73b1d28
Add Exemplar Remote Write support (#8296)
* Write exemplars to the WAL and send them over remote write.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Update example for exemplars, print data in a more obvious format.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Add metrics for remote write of exemplars.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Fix incorrect slices passed to send in remote write.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* We need to unregister the new metrics.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Address review comments

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Order of exemplar append vs write exemplar to WAL needs to change.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Several fixes to prevent sending uninitialized or incorrect samples with an exemplar. Fix dropping exemplar for missing series. Add tests for queue_manager sending exemplars

Signed-off-by: Martin Disibio <mdisibio@gmail.com>

* Store both samples and exemplars in the same timeseries buffer to remove the alloc when building final request, keep sub-slices in separate buffers for re-use

Signed-off-by: Martin Disibio <mdisibio@gmail.com>

* Condense sample/exemplar delivery tests to parameterized sub-tests

Signed-off-by: Martin Disibio <mdisibio@gmail.com>

* Rename test methods for clarity now that they also handle exemplars

Signed-off-by: Martin Disibio <mdisibio@gmail.com>

* Rename counter variable. Fix instances where metrics were not updated correctly

Signed-off-by: Martin Disibio <mdisibio@gmail.com>

* Add exemplars to LoadWAL benchmark

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* last exemplars timestamp metric needs to convert value to seconds with
ms precision

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Process exemplar records in a separate go routine when loading the WAL.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Address review comments related to clarifying comments and variable
names. Also refactor sample/exemplar to enqueue prompb types.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Regenerate types proto with comments, update protoc version again.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Put remote write of exemplars behind a feature flag.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Address some of Ganesh's review comments.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Move exemplar remote write feature flag to a config file field.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Address Bartek's review comments.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Don't allocate exemplar buffers in queue_manager if we're not going to
send exemplars over remote write.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Add ValidateExemplar function, validate exemplars when appending to head
and log them all to WAL before adding them to exemplar storage.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Address more reivew comments from Ganesh.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Add exemplar total label length check.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Address a few last review comments

Signed-off-by: Callum Styan <callumstyan@gmail.com>

Co-authored-by: Martin Disibio <mdisibio@gmail.com>
2021-05-06 13:53:52 -07:00
ZouYu c7262f0d70
Fix some gofmt warnings (#8743)
Signed-off-by: Zou Yu <zouy.fnst@cn.fujitsu.com>
2021-04-22 08:43:30 -06:00
Marco Pracucci 4da5c25ea4
Upgrade prometheus/common to v0.21.0
Signed-off-by: Marco Pracucci <marco@pracucci.com>
2021-04-21 12:19:16 +02:00
Marco Pracucci e246670193
Further increase max log line in remote write client (#8616)
Signed-off-by: Marco Pracucci <marco@pracucci.com>
2021-03-18 16:53:18 +00:00
Callum Styan 289ba11b79
Add circular in-memory exemplars storage (#6635)
* Add circular in-memory exemplars storage

Signed-off-by: Callum Styan <callumstyan@gmail.com>
Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>
Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
Signed-off-by: Martin Disibio <mdisibio@gmail.com>

Co-authored-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
Co-authored-by: Tom Wilkie <tom.wilkie@gmail.com>
Co-authored-by: Martin Disibio <mdisibio@gmail.com>

* Fix some comments, clean up exemplar metrics struct and exemplar tests.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Fix exemplar query api null vs empty array issue.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

Co-authored-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
Co-authored-by: Tom Wilkie <tom.wilkie@gmail.com>
Co-authored-by: Martin Disibio <mdisibio@gmail.com>
2021-03-16 15:17:45 +05:30