The ChunkReader interface's Chunk() has been changed to ChunkOrIterable().
This is a precursor to OOO native histogram support - with OOO native histograms, the chunks.Meta passed to Chunk() can result in multiple chunks being returned rather than just a single chunk (e.g. if oooMergedChunk has a counter reset in the middle).
To support this, ChunkOrIterable() requires either a single chunk or an iterable to be returned. If an iterable is returned, the caller has the responsibility of converting the samples from the iterable into possibly multiple chunks. The OOOHeadChunkReader now returns an iterable rather than a chunk to prepare for the native histograms case. Also as a beneficial side effect, oooMergedChunk and boundedChunk has been simplified as they only need to implement the Iterable interface now, not the full Chunk interface.
---------
Signed-off-by: Fiona Liao <fiona.y.liao@gmail.com>
Co-authored-by: George Krajcsovits <krajorama@users.noreply.github.com>
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>
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>
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>
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>
Use new experimental package `golang.org/x/exp/slices`.
slices.Sort works on values that are directly comparable, like ints,
so avoids the overhad of an interface call to `.Less()`.
Left tests unchanged, because they don't need the speed and it may be
a cross-check that slices.Sort gives the same answer.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Introduce out-of-order TSDB support
This implementation is based on this design doc:
https://docs.google.com/document/d/1Kppm7qL9C-BJB1j6yb6-9ObG3AbdZnFUBYPNNWwDBYM/edit?usp=sharing
This commit adds support to accept out-of-order ("OOO") sample into the TSDB
up to a configurable time allowance. If OOO is enabled, overlapping querying
are automatically enabled.
Most of the additions have been borrowed from
https://github.com/grafana/mimir-prometheus/
Here is the list ist of the original commits cherry picked
from mimir-prometheus into this branch:
- 4b2198d7ec
- 2836e5513f
- 00b379c3a5
- ff0dc75758
- a632c73352
- c6f3d4ab33
- 5e8406a1d4
- abde1e0ba1
- e70e769889
- df59320886
Co-authored-by: Jesus Vazquez <jesus.vazquez@grafana.com>
Co-authored-by: Ganesh Vernekar <ganeshvern@gmail.com>
Co-authored-by: Dieter Plaetinck <dieter@grafana.com>
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* gofumpt files
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Add license header to missing files
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Fix OOO tests due to existing chunk disk mapper implementation
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Fix truncate int overflow
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Add Sync method to the WAL and update tests
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* remove useless sync
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Update minOOOTime after truncating Head
* Update minOOOTime after truncating Head
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Fix lint
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Add a unit test
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Load OutOfOrderTimeWindow only once per appender
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Fix OOO Head LabelValues and PostingsForMatchers
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Fix replay of OOO mmap chunks
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Remove unnecessary err check
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Prevent panic with ApplyConfig
Signed-off-by: Ganesh Vernekar 15064823+codesome@users.noreply.github.com
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Run OOO compaction after restart if there is OOO data from WBL
Signed-off-by: Ganesh Vernekar 15064823+codesome@users.noreply.github.com
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Apply Bartek's suggestions
Co-authored-by: Bartlomiej Plotka <bwplotka@gmail.com>
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Refactor OOO compaction
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Address comments and TODOs
- Added a comment explaining why we need the allow overlapping
compaction toggle
- Clarified TSDBConfig OutOfOrderTimeWindow doc
- Added an owner to all the TODOs in the code
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Run go format
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Fix remaining review comments
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Fix tests
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Change wbl reference when truncating ooo in TestHeadMinOOOTimeUpdate
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
* Fix TestWBLAndMmapReplay test failure on windows
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Address most of the feedback
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Refactor the block meta for out of order
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Fix windows error
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Fix review comments
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
Signed-off-by: Ganesh Vernekar 15064823+codesome@users.noreply.github.com
Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>
Co-authored-by: Ganesh Vernekar <ganeshvern@gmail.com>
Co-authored-by: Dieter Plaetinck <dieter@grafana.com>
Co-authored-by: Oleg Zaytsev <mail@olegzaytsev.com>
Co-authored-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Update go to 1.19, set min version to 1.18
Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
* Update golangci-lint
Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
* Job queue
This PR reimplements chan chunkWriteJob with custom buffered queue that should use less memory, because it doesn't preallocate entire buffer for maximum queue size at once. Instead it allocates individual "segments" with smaller size.
As elements are added to the queue, they fill individual segments. When elements are removed from the queue (and segments), empty segments can be thrown away. This doesn't change memory usage of the queue when it's full, but should decrease its memory footprint when it's empty (queue will keep max 1 segment in such case).
Signed-off-by: Peter Štibraný <pstibrany@gmail.com>
* Modify test to work with low resolution timer.
Signed-off-by: Peter Štibraný <pstibrany@gmail.com>
* Improve comments.
Signed-off-by: Peter Štibraný <pstibrany@gmail.com>
This implementation is based on this design doc:
https://docs.google.com/document/d/1Kppm7qL9C-BJB1j6yb6-9ObG3AbdZnFUBYPNNWwDBYM/edit?usp=sharing
This commit adds support to accept out-of-order ("OOO") sample into the TSDB
up to a configurable time allowance. If OOO is enabled, overlapping querying
are automatically enabled.
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
Co-authored-by: Jesus Vazquez <jesus.vazquez@grafana.com>
Co-authored-by: Ganesh Vernekar <ganeshvern@gmail.com>
Co-authored-by: Dieter Plaetinck <dieter@grafana.com>
* dont waste space on the chunkRefMap
* add time factor
* add comments
* better readability
* add instrumentation and more comments
* formatting
* uppercase comments
* Address review feedback. Renamed "free" to "shrink" everywhere, updated comments and threshold to 1000.
* double space
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
Co-authored-by: Peter Štibraný <pstibrany@gmail.com>
Co-authored-by: Mauro Stettler <mauro.stettler@gmail.com>
Instead of creating a new hashing object every time, call `crc32.Checksum`
which computes the answer without allocations.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
This PR reimplements chan chunkWriteJob with custom buffered queue that should use less memory, because it doesn't preallocate entire buffer for maximum queue size at once. Instead it allocates individual "segments" with smaller size.
As elements are added to the queue, they fill individual segments. When elements are removed from the queue (and segments), empty segments can be thrown away. This doesn't change memory usage of the queue when it's full, but should decrease its memory footprint when it's empty (queue will keep max 1 segment in such case).
* dont waste space on the chunkRefMap
* add time factor
* add comments
* better readability
* add instrumentation and more comments
* formatting
* uppercase comments
* Address review feedback. Renamed "free" to "shrink" everywhere, updated comments and threshold to 1000.
* double space
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
Co-authored-by: Peter Štibraný <pstibrany@gmail.com>
* refactor: move from io/ioutil to io and os packages
* use fs.DirEntry instead of os.FileInfo after os.ReadDir
Signed-off-by: MOREL Matthieu <matthieu.morel@cnp.fr>
* Chunks replay skips chunks with unknown encodings
We've changed the logic of loadMmappedChunks to skip chunks that have
unknown encodings. To do so we've modified IterateAllChunks to accept an
extra encoding argument in the callback function.
Also added unit tests in the head and chunk disk mapper.
* Also add an unit test for the old chunk diskmapper
* s/createUnsupportedChunk/writeUnsupportedChunk/g
