Commit Graph

120 Commits (405f65a48a7a3d24b3bd1e4dc779d81bd915a9c3)

Author SHA1 Message Date
Bryan Boreham f42b37ff2f
[BUGFIX] TSDB: Fix race on stale values in headAppender (#15322)
* [BUGFIX] TSDB: Fix race on stale values in headAppender

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

* Simplify

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

---------

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2024-11-06 16:51:39 +01:00
Nicolas Takashi b6c538972c
[REFACTORY] simplify appender commit (#15112)
* [REFACTOR] simplify appender commit

Signed-off-by: Nicolas Takashi <nicolas.tcs@hotmail.com>
Signed-off-by: Arthur Silva Sens <arthursens2005@gmail.com>
Co-authored-by: George Krajcsovits <krajorama@users.noreply.github.com>
Co-authored-by: Arthur Silva Sens <arthursens2005@gmail.com>
2024-10-29 12:34:02 +00:00
Pedro Tanaka bab587b9dc
Agent: allow for ingestion of CT samples (#15124)
* Remove unused option from HeadOptions

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* Improve docs for appendable() method in head appender

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* Ingest CT (float) samples in Agent DB

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* allow for ingestion of CT native histogram

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* adding some verification for ct ts

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* Validating CT histogram before append and add newly created series to pending series

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* checking the wal for written samples

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* Checking for samples in test

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* adding case for validations

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* fixing comparison when dedupelabels is enabled

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* unite tests, use table testing

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* Implement CT related methods in timestampTracker for write storage

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* adding error case to test

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* removing unused fields

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* Updating lastTs for series when adding CT to invalidate duplicates

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

* making sure that updating the lastTS wont cause OOO later on in Commit();

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>

---------

Signed-off-by: Pedro Tanaka <pedro.tanaka@shopify.com>
2024-10-27 01:06:34 +01:00
Vanshika cccbe72514
TSDB: Fix some edge cases when OOO is enabled (#14710)
Fix some edge cases when OOO is enabled

Signed-off-by: Vanshikav123 <vanshikav928@gmail.com>
Signed-off-by: Vanshika <102902652+Vanshikav123@users.noreply.github.com>
Signed-off-by: Jesus Vazquez <jesusvzpg@gmail.com>
Co-authored-by: Jesus Vazquez <jesusvzpg@gmail.com>
2024-10-23 17:34:28 +02:00
György Krajcsovits bb70370d72 TSDB head: fix race between AppendHistogram and Commit
Move writing memSeries lastHistogramValue and lastFloatHistogramValue
after series creation under lock.

The resulting code isn't totally correct in the sense that we're setting
these values before Commit() , so they might be overwritten/rolled back
later.

Also Append of stale sample checks the values without lock, so there's
still a potential race.

The correct solution would be to set these only in Commit() which we
actually do, but then Commit() would also need to process samples in
order and not floats first, then histograms, then float histograms - which
leads to not knowing what stale marker to write for histograms.

Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
2024-10-10 16:59:15 +02:00
TJ Hoplock 6ebfbd2d54 chore!: adopt log/slog, remove go-kit/log
For: #14355

This commit updates Prometheus to adopt stdlib's log/slog package in
favor of go-kit/log. As part of converting to use slog, several other
related changes are required to get prometheus working, including:
- removed unused logging util func `RateLimit()`
- forward ported the util/logging/Deduper logging by implementing a small custom slog.Handler that does the deduping before chaining log calls to the underlying real slog.Logger
- move some of the json file logging functionality to use prom/common package functionality
- refactored some of the new json file logging for scraping
- changes to promql.QueryLogger interface to swap out logging methods for relevant slog sugar wrappers
- updated lots of tests that used/replicated custom logging functionality, attempting to keep the logical goal of the tests consistent after the transition
- added a healthy amount of `if logger == nil { $makeLogger }` type conditional checks amongst various functions where none were provided -- old code that used the go-kit/log.Logger interface had several places where there were nil references when trying to use functions like `With()` to add keyvals on the new *slog.Logger type

Signed-off-by: TJ Hoplock <t.hoplock@gmail.com>
2024-10-07 15:58:50 -04:00
Arthur Silva Sens 6bd9b1a7cc
Histogram CT Zero ingestion
Signed-off-by: Arthur Silva Sens <arthursens2005@gmail.com>
2024-09-26 11:29:22 -03:00
Carrie Edwards 14e3c05ce8
tsdb: Add support for ingestion of out-of-order native histogram samples (#14546)
Add support for ingesting OOO native histograms

* Add flag for enabling and disabling OOO native histogram ingestion
* Update OOO querying tests to include native histogram samples
* Add OOO head tests
* Add test for OOO native histogram counter reset headers

Signed-off-by: Carrie Edwards <edwrdscarrie@gmail.com>
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
Co-authored by: Carrie Edwards <edwrdscarrie@gmail.com>
Co-authored by: Jeanette Tan <jeanette.tan@grafana.com>
Co-authored by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
Co-authored by: Fiona Liao <fiona.liao@grafana.com>
2024-09-17 11:19:06 +02:00
George Krajcsovits 5aa3d8260a
TSDB: OOO native histograms: prep for multiple ooo head chunks (#14850)
* tsdb: mmapCurrentOOOHeadChunk prepare for multiple ooo chunks

Currently float samples can only create a single ooo head chunk, but
native histograms can result in multiple due to counter resets, etc.

Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>

* tsdb: getOOOSeriesChunks prepare for multiple ooo chunks

Currently float samples can only create a single ooo head chunk, but
native histograms can result in multiple due to counter resets, etc.

Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>

---------

Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
2024-09-11 23:55:39 +01:00
Arve Knudsen 3a78e76282 Upgrade golangci-lint to v1.60.1
Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>
2024-08-18 12:13:25 +02:00
Bryan Boreham 512c67ec26 TSDB: Never go over maximum number of OOO chunks
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>
2024-08-14 13:41:59 +01:00
György Krajcsovits 41656162fc tsdb: prepare inserting native histograms into OOO head
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>
2024-08-14 11:13:47 +02:00
George Krajcsovits cf62fb5c44
Merge pull request #14629 from krajorama/fix-to-encoded-chunks
Fix ToEncodedChunks minT for recoded chunks
2024-08-08 20:00:31 +02:00
György Krajcsovits 1ea3781699 Fix ToEncodedChunks minT for recoded chunks
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>
2024-08-08 15:22:46 +02:00
Oleg Zaytsev 0833d2a230
Fix appendable: check whether last val was a histogram (#14613)
* 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>
2024-08-07 15:02:59 +02:00
Carrie Edwards a28d1974b4
Merge pull request #14438 from prometheus/cedwards/ooo-chunk-encoding
tsdb: Add support for handling multiple chunks in OOO head
2024-07-16 11:12:23 -07:00
Carrie Edwards 7e020bb4e9 Refactor
Signed-off-by: Carrie Edwards <edwrdscarrie@gmail.com>
2024-07-16 10:53:23 -07:00
Carrie Edwards e0d7cef545 Rename some variables in Commit()
Signed-off-by: Carrie Edwards <edwrdscarrie@gmail.com>
2024-07-16 10:53:23 -07:00
Carrie Edwards 2e0e4e9ce9 Add support for handling multiple chunks in OOO head
Signed-off-by: Carrie Edwards <edwrdscarrie@gmail.com>
Co-authored by: Jeanette Tan <jeanette.tan@grafana.com>:
Co-authored by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>:
Signed-off-by: Carrie Edwards <edwrdscarrie@gmail.com>
Co-authored by: Fiona Liao <fiona.liao@grafana.com>:
2024-07-16 10:53:09 -07:00
Bryan Boreham 709c5d6fc3
TSDB: Lock around access to labels in head under -tags dedupelabels (#14322)
* TSDB: Document what needs locking in memSeries

* TSDB: Lock around access to series labels

So we can modify them to reset the symbol-table.

* TSDB: Make label locking conditional on build tag

---------

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2024-07-05 10:11:32 +01:00
Bryan Boreham 42b546a43d
tsdb: add details to duplicate sample error (#13277)
Now the error will include the timestamp and the existing and new values.
When you are trying to track down the source of this error, it can be
useful to see that the values are close, or alternating, or something
else.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2024-06-04 08:54:09 +01:00
Arve Knudsen d699dc3c77
Fix language in docs and comments (#14041)
Fix language in docs and comments

---------

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>
Co-authored-by: Björn Rabenstein <github@rabenste.in>
2024-05-08 17:57:09 +02:00
Matthieu MOREL 6f595c6762
golangci-lint: enable whitespace linter (#13905)
Signed-off-by: Matthieu MOREL <matthieu.morel35@gmail.com>
2024-04-11 09:27:54 +01:00
komisan19 0249e080b4 refactor: utilize standard functions max/min
Signed-off-by: komisan19 <18901496+komisan19@users.noreply.github.com>
2024-04-04 03:15:38 +09:00
Nick Pillitteri 481f14e1c0
TSDB: Don't rely on integer overflow in head compaction check (#13755)
* TSDB: Don't compact the head block when empty

Don't compact the Head block if there have not yet been any samples
appended.

Previously, the logic for determining if the head should be compacted
relied on the default values for min and max time and integer overflow
when they were checked in `Head.compactable()`. The check in
`Head.compactable()` effectively did `math.MinInt64 - math.MaxInt64`
which overflowed and wrapped to `1`. Since `1` is less than `1.5`
times the chunk range, compaction did not happen. This was the correct
behavior but relying on overflow wrapping is surprising.

This change add a method for checking if the min and max time for the
head is unset and uses it to short-circuit compaction in that case.
It also replaces several explicit checks for the default value to
determine if the head has not yet had any samples added.

Signed-off-by: Nick Pillitteri <nick.pillitteri@grafana.com>
2024-03-26 12:17:38 +01:00
Bryan Boreham bbe39af99f
tsdb: zero out Labels and memSeries pointers in pool (#13712)
* tsdb: zero out Labels and memSeries pointers in pool

So that the garbage-collector doesn't see this memory as still in use.

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

---------

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Signed-off-by: Björn Rabenstein <github@rabenste.in>
Co-authored-by: Björn Rabenstein <github@rabenste.in>
2024-03-06 13:36:34 +01:00
Fiona Liao 841a133514 Move histogramsAppended to be more consistent
Signed-off-by: Fiona Liao <fiona.liao@grafana.com>
2024-02-21 11:15:04 +00:00
Fiona Liao 52389647b2 Add type label to outOfOrderSamplesAppended metric
Signed-off-by: Fiona Liao <fiona.liao@grafana.com>
2024-02-19 15:24:39 +00:00
Bryan Boreham 66237c1996 tsdb: use cheaper Mutex on series
Mutex is 8 bytes; RWMutex is 24 bytes and much more complicated. Since
`RLock` is only used in two places, `UpdateMetadata` and `Delete`,
neither of which are hotspots, we should use the cheaper one.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2024-01-26 11:01:39 +00:00
Bryan Boreham 8065bef172 Move metric type definitions to common/model
They are used in multiple repos, so common is a better place for them.
Several packages now don't depend on `model/textparse`, e.g.
`storage/remote`.

Also remove `metadata` struct from `api.go`, since it was identical to
a struct in the `metadata` package.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2023-12-19 18:56:54 +00:00
Matthieu MOREL 8f6cf3aabb tsdb: use Go standard errors
Signed-off-by: Matthieu MOREL <matthieu.morel35@gmail.com>
2023-12-11 12:18:54 +00:00
Arthur Silva Sens 5082655392
Append Created Timestamps (#12733)
* Append created timestamps.

Signed-off-by: Arthur Silva Sens <arthur.sens@coralogix.com>

* Log when created timestamps are ignored

Signed-off-by: Arthur Silva Sens <arthur.sens@coralogix.com>

* Proposed changes to Append CT PR.

Changes:

* Changed textparse Parser interface for consistency and robustness.
* Changed CT interface to be more explicit and handle validation.
* Simplified test, change scrapeManager to allow testability.
* Added TODOs.

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

* Updates.

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

* Addressed comments.

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

* Refactor head_appender test

Signed-off-by: Arthur Silva Sens <arthur.sens@coralogix.com>

* Fix linter issues

Signed-off-by: Arthur Silva Sens <arthur.sens@coralogix.com>

* Use model.Sample in head appender test

Signed-off-by: Arthur Silva Sens <arthur.sens@coralogix.com>

---------

Signed-off-by: Arthur Silva Sens <arthur.sens@coralogix.com>
Signed-off-by: bwplotka <bwplotka@gmail.com>
Co-authored-by: bwplotka <bwplotka@gmail.com>
2023-12-11 08:43:42 +00:00
George Krajcsovits acc114fe55
Fix panic during tsdb Commit (#13092)
* Fix panic during tsdb Commit

Fixes the following

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x20 pc=0x19deb45]

goroutine 651118930 [running]:
github.com/prometheus/prometheus/tsdb.(*headAppender).Commit(0xc19100f7c0)
	/drone/src/vendor/github.com/prometheus/prometheus/tsdb/head_append.go:855 +0x245
github.com/prometheus/prometheus/tsdb.dbAppender.Commit({{0x35bd6f0?, 0xc19100f7c0?}, 0xc000fa4c00?})
	/drone/src/vendor/github.com/prometheus/prometheus/tsdb/db.go:1159 +0x2f

We theorize that the panic happened due the the series referenced by the
exemplar being removed between AppendExemplar and Commit due to being idle.

Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
2023-11-12 14:51:37 +00:00
George Krajcsovits 39a35d92bc
tsdb/head: wlog exemplars after samples (#13113)
When samples are committed in the head, they are also written to the WAL.
The order of WAL records should be sample then exemplar, but this was
not the case for native histogram samples. This PR fixes that.

The problem with the wrong order is that remote write reads the WAL and
sends the recorded timeseries in the WAL order, which means exemplars
arrived before histogram samples. If the receiving side is Prometheus
TSDB and the series has not existed before then the exemplar does not
currently create the series. Which means the exemplar is rejected and lost.

Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
2023-11-11 17:30:16 +01:00
Linas Medziunas ebed7d0612 Change Validate to be a method on histogram structs
Signed-off-by: Linas Medziunas <linas.medziunas@gmail.com>
2023-11-03 16:47:59 +02:00
Linas Medziunas 1f8aea11d6 Move histogram validation code to model/histogram
Signed-off-by: Linas Medziunas <linas.medziunas@gmail.com>
2023-11-03 16:17:24 +02:00
Linas Medziunas 1cd6c1cde5 ValidateHistogram: strict Count check in absence of NaNs
Signed-off-by: Linas Medziunas <linas.medziunas@gmail.com>
2023-11-03 16:17:24 +02:00
György Krajcsovits 9dbd100a5e Refactor solution to not repeat code
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
2023-09-20 15:54:00 +02:00
György Krajcsovits 96d03b6f46 Fix duplicate sample detection at chunks size limit
Before cutting a new XOR chunk in case the chunk goes over the size
limit, check that the timestamp is in order and not equal or older
than the latest sample in the old chunk.

Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
2023-09-20 14:49:56 +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
Oleg Zaytsev cd7d0b69a2
Check nil err first when committing (#12625)
The most common case is to have a nil error when appending series, so
let's check that first instead of checking the 3 error types first.

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
2023-08-01 14:04:45 +02:00
Łukasz Mierzwa 3c80963e81
Use a linked list for memSeries.headChunk (#11818)
Currently memSeries holds a single head chunk in-memory and a slice of mmapped chunks.
When append() is called on memSeries it might decide that a new headChunk is needed to use for given append() call.
If that happens it will first mmap existing head chunk and only after that happens it will create a new empty headChunk and continue appending
our sample to it.

Since appending samples uses write lock on memSeries no other read or write can happen until any append is completed.
When we have an append() that must create a new head chunk the whole memSeries is blocked until mmapping of existing head chunk finishes.
Mmapping itself uses a lock as it needs to be serialised, which means that the more chunks to mmap we have the longer each chunk might wait
for it to be mmapped.
If there's enough chunks that require mmapping some memSeries will be locked for long enough that it will start affecting
queries and scrapes.
Queries might timeout, since by default they have a 2 minute timeout set.
Scrapes will be blocked inside append() call, which means there will be a gap between samples. This will first affect range queries
or calls using rate() and such, since the time range requested in the query might have too few samples to calculate anything.

To avoid this we need to remove mmapping from append path, since mmapping is blocking.
But this means that when we cut a new head chunk we need to keep the old one around, so we can mmap it later.
This change makes memSeries.headChunk a linked list, memSeries.headChunk still points to the 'open' head chunk that receives new samples,
while older, yet to be mmapped, chunks are linked to it.
Mmapping is done on a schedule by iterating all memSeries one by one. Thanks to this we control when mmapping is done, since we trigger
it manually, which reduces the risk that it will have to compete for mmap locks with other chunks.

Signed-off-by: Łukasz Mierzwa <l.mierzwa@gmail.com>
2023-07-31 11:10:24 +02:00
George Krajcsovits 6cd2d1621f
Hide histogram chunk append and reset header internals (#12352)
tsdb: Hide histogram chunk append and reset header internals

Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
Signed-off-by: George Krajcsovits <krajorama@users.noreply.github.com>
2023-07-26 15:08:16 +02:00
Justin Lei e73d8b2084 Also pass chunkOpts into appendPreprocessor
Signed-off-by: Justin Lei <justin.lei@grafana.com>
2023-05-25 13:37:18 -07:00
Justin Lei 4c4454e4c9 Group args to append to memSeries in chunkOpts
Signed-off-by: Justin Lei <justin.lei@grafana.com>
2023-05-25 13:12:46 -07:00
Justin Lei 89af351730
Remove samplesPerChunk from memSeries (#12390)
Signed-off-by: Justin Lei <justin.lei@grafana.com>
2023-05-25 11:18:41 +02:00
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
Björn Rabenstein 37fe9b89dc
Merge pull request #12055 from leizor/leizor/prometheus/issues/12009
Adjust samplesPerChunk from 120 to 220
2023-05-10 14:45:12 +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