* 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>
* 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>
* Create experimental circular buffer resize method, benchmarks
Signed-off-by: Martin Disibio <mdisibio@gmail.com>
* Optimize exemplar resize to only replay as many exemplars as needed
Signed-off-by: Martin Disibio <mdisibio@gmail.com>
* More comments, benchmark AddExemplar
Signed-off-by: Martin Disibio <mdisibio@gmail.com>
* optimizations
Signed-off-by: Martin Disibio <mdisibio@gmail.com>
* comment
Signed-off-by: Martin Disibio <mdisibio@gmail.com>
* Slight refactor of resize benchmark + make use of resize via runtime
reloadable storage config.
Signed-off-by: Callum Styan <callumstyan@gmail.com>
* Some more config related changes.
Signed-off-by: Callum Styan <callumstyan@gmail.com>
* Address some review comments.
Signed-off-by: Callum Styan <callumstyan@gmail.com>
* Address more review comments.
Signed-off-by: Callum Styan <callumstyan@gmail.com>
* Refactor to remove usage of noopExemplarStorage and avoid race condition
when resizing from Head code.
Signed-off-by: Callum Styan <callumstyan@gmail.com>
* Fix or add comments to clarify some of the new behaviour.
Signed-off-by: Callum Styan <callumstyan@gmail.com>
* fix potential panics related to negative exemplar buffer lengths
Signed-off-by: Callum Styan <callumstyan@gmail.com>
Co-authored-by: Callum Styan <callumstyan@gmail.com>
* Added walreplay API endpoint
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Added starting page to react-ui
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Documented the new endpoint
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Fixed typos
Signed-off-by: Levi Harrison <git@leviharrison.dev>
Co-authored-by: Julius Volz <julius.volz@gmail.com>
* Removed logo
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Changed isResponding to isUnexpected
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Changed width of progress bar
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Changed width of progress bar
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Added DB stats object
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Updated starting page to work with new fields
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Passing nil
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Passing nil (pt. 2)
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Passing nil (pt. 3)
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Passing nil (and also implementing a method this time) (pt. 4)
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Passing nil (and also implementing a method this time) (pt. 5)
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Changed const to let
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Passing nil (pt. 6)
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Remove SetStats method
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Added comma
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Changed api
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Changed to triple equals
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Fixed data response types
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Don't return pointer
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Changed version
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Fixed interface issue
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Fixed pointer
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Fixed copying lock value error
Signed-off-by: Levi Harrison <git@leviharrison.dev>
Co-authored-by: Julius Volz <julius.volz@gmail.com>
* 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>
* Add range query test cases
This includes a couple of failing ones that double count some points due
to the iterator seek bug.
Co-authored-by: Oleg Zaytsev <mail@olegzaytsev.com>
Signed-off-by: Fiona Liao <fiona.y.liao@gmail.com>
* Add Seek() implementation for memSafeIterator
Previously, calling memSafeIterator.Seek() would call the Seek() method
on its embedded iterator. This was causing the embedded iterator and the
memSafeIterator to get out of sync because when the embedded Seek()
moved to the next element of the embedded iterator, memSafeIterator
didn't "know" about it. memSafeIterator has to "know" when the embedded
iterator has moved to be able to work out when it should be reading from
its buffer rather than the embedded iterator.
Used same logic as for xorIterator.Seek() (which in runtime is used as
the embedded iterator) - return false if the iterator has an error and
try to move to next element if the required time hasn't been reached, or
if no elements have been read yet. The memSafeIterator.Next() method is
being called so memSafeIterator.i is always accurate.
Signed-off-by: Fiona Liao <fiona.y.liao@gmail.com>
* Add tsdb package test
Signed-off-by: Fiona Liao <fiona.y.liao@gmail.com>
Co-authored-by: Oleg Zaytsev <mail@olegzaytsev.com>
This moves the label lookup into TSDB, whilst still keeping the cached-ref optimisation for repeated Appends.
This makes the API easier to consume and implement. In particular this change is motivated by the scrape-time-aggregation work, which I don't think is possible to implement without it as it needs access to label values.
Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>
* Set the min time of Head properly after truncation
Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
* Fix lint
Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
* Enhance compaction plan logic for completely deleted small block
Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
* Fix review comments
Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
* Testify: move to require
Moving testify to require to fail tests early in case of errors.
Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>
* More moves
Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>
* Refactor test assertions
This pull request gets rid of assert.True where possible to use
fine-grained assertions.
Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>
As we're looking to expand what's in the WAL,
having old Prometheus servers ignore the new record types
rather than treating them as corruption allows for better
upgrade/downgrade paths.
Adjust some tests accordingly, so they're still testing what they're
meant to test.
Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>
* tsdb: Added ChunkQueryable implementations to db; unified compactor, querier and fanout block iterating.
Chained to https://github.com/prometheus/prometheus/pull/7059
* NewMerge(Chunk)Querier now takies multiple primaries allowing tsdb DB code to use it.
* Added single SeriesEntry / ChunkEntry for all series implementations.
* Unified all vertical, and non vertical for compact and querying to single
merge series / chunk sets by reusing VerticalSeriesMergeFunc for overlapping algorithm (same logic as before)
* Added block (Base/Chunk/)Querier for block querying. We then use populateAndTomb(Base/Chunk/) to iterate over chunks or samples.
* Refactored endpoint tests and querier tests to include subtests.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Addressed comments from Brian and Beorn.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Fixed snapshot test and added chunk iterator support for DBReadOnly.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Fixed race when iterating over Ats first.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Fixed tests.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Fixed populate block tests.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Fixed endpoints test.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Fixed test.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Added test & fixed case of head open chunk.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Fixed DBReadOnly tests and bug producing 1 sample chunks.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Added cases for partial block overlap for multiple full chunks.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Added extra tests for chunk meta after compaction.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Fixed small vertical merge bug and added more tests for that.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* tsdb/chunks: Replace sync/atomic with uber-go/atomic
Signed-off-by: Javier Palomo <javier.palomo.almena@gmail.com>
* tsdb/heaad: Replace sync/atomic with uber-go/atomic
Signed-off-by: Javier Palomo <javier.palomo.almena@gmail.com>
* vendor: Make go.uber.org/atomic a direct dependency
There is no modifications to go.sum and vendor/ because
it was already vendored.
Signed-off-by: Javier Palomo <javier.palomo.almena@gmail.com>
* tsdb: Remove comments referring to the sync/atomic alignment bug
Related: https://golang.org/pkg/sync/atomic/#pkg-note-BUG
Signed-off-by: Javier Palomo <javier.palomo.almena@gmail.com>
* Fix race during head compaction
Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
* Comment out the test
Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
* Skip test instead of commenting it out
Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
* Add errors and Warnings to SeriesSet
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Change Querier interface and refactor accordingly
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Refactor promql/engine to propagate warnings at eval stage
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Address review issues
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Make sure all the series from all Selects are pre-advanced
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Address review issues
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Separate merge series sets
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Clean
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Refactor merge querier failure handling
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Refactored and simplified fanout with improvements from incoming chunk iterator PRs.
* Secondary logic is hidden, instead of weird failed series set logic we had.
* Fanout is well commented
* Fanout closing record all errors
* MergeQuerier improved API (clearer)
* deferredGenericMergeSeriesSet is not needed as we return no samples anyway for failed series sets (next = false).
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Fix formatting
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Fix CI issues
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Added final tests for error handling.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Addressed Brian's comments.
* Moved hints in populate to be allocated only when needed.
* Used sync.Once in secondary Querier to achieve all-or-nothing partial response logic.
* Select after first Next is done will panic.
NOTE: in lazySeriesSet in theory we could just panic, I think however we can
totally just return error, it will panic in expand anyway.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Utilize errWithWarnings
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Fix recently introduced expansion issue
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Add tests for secondary querier error handling
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Implement lazy merge
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Add name to test cases
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Reorganize
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Address review comments
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Address review comments
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Remove redundant warnings
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Fix rebase mistake
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
Co-authored-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Track open appenders in doubly-linked list to make lowWatermark O(1).
* Use RW locks.
* Added BenchmarkIsolationWithState.
Signed-off-by: Peter Štibraný <peter.stibrany@grafana.com>
* add time range params to labelNames api
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* evaluate min/max time range when reading labels from the head
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* add time range params to labelValues api
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* fix test, add docs
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* add a test for head min max range
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* fix test to match comment
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* address CR comments
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* combine vars only used once
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* add time range params to labelNames api
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* evaluate min/max time range when reading labels from the head
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* add time range params to labelValues api
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* fix test, add docs
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* add a test for head min max range
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* fix test to match comment
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* address CR comments
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* combine vars only used once
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* fix test
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* restart ci
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* use range expectedLabelNames instead of range actualLabelNames in test
Signed-off-by: jessicagreben <Jessica.greben1+github@gmail.com>
* Callbacks for lifecycle of series in TSDB
Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
* Add more comments
Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
When appending to the head and a chunk is full it is flushed to the disk and m-mapped (memory mapped) to free up memory
Prom startup now happens in these stages
- Iterate the m-maped chunks from disk and keep a map of series reference to its slice of mmapped chunks.
- Iterate the WAL as usual. Whenever we create a new series, look for it's mmapped chunks in the map created before and add it to that series.
If a head chunk is corrupted the currpted one and all chunks after that are deleted and the data after the corruption is recovered from the existing WAL which means that a corruption in m-mapped files results in NO data loss.
[Mmaped chunks format](https://github.com/prometheus/prometheus/blob/master/tsdb/docs/format/head_chunks.md) - main difference is that the chunk for mmaping now also includes series reference because there is no index for mapping series to chunks.
[The block chunks](https://github.com/prometheus/prometheus/blob/master/tsdb/docs/format/chunks.md) are accessed from the index which includes the offsets for the chunks in the chunks file - example - chunks of series ID have offsets 200, 500 etc in the chunk files.
In case of mmaped chunks, the offsets are stored in memory and accessed from that. During WAL replay, these offsets are restored by iterating all m-mapped chunks as stated above by matching the series id present in the chunk header and offset of that chunk in that file.
**Prombench results**
_WAL Replay_
1h Wal reply time
30% less wal reply time - 4m31 vs 3m36
2h Wal reply time
20% less wal reply time - 8m16 vs 7m
_Memory During WAL Replay_
High Churn:
10-15% less RAM - 32gb vs 28gb
20% less RAM after compaction 34gb vs 27gb
No Churn:
20-30% less RAM - 23gb vs 18gb
40% less RAM after compaction 32.5gb vs 20gb
Screenshots are in [this comment](https://github.com/prometheus/prometheus/pull/6679#issuecomment-621678932)
Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
Prior to this commit we could have situations where we are creating an
appenderId but never creating an appender to go with it, therefore
blocking the low watermak.
Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>
This is technically BREAKING CHANGE, but it was like this from the beginning: I just notice that we rely in
Prometheus on remote read being sorted. This is because we use selected data from remote reads in MergeSeriesSet
which rely on sorting.
I found during work on https://github.com/prometheus/prometheus/pull/5882 that
we do so many repetitions because of this, for not good reason. I think
I found a good balance between convenience and readability with just one method.
Smaller the interface = better.
Also I don't know what TestSelectSorted was testing, but now it's testing sorting.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
