* 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>
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>
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>
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>
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>
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>
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>
* 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>
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>
* Use zeropool.Pool to workaround SA6002
I built a tiny library called https://github.com/colega/zeropool to
workaround the SA6002 staticheck issue.
While searching for the references of that SA6002 staticheck issues on
Github first results was Prometheus itself, with quite a lot of ignores
of it.
This changes the usages of `sync.Pool` to `zeropool.Pool[T]` where a
pointer is not available.
Also added a benchmark for HeadAppender Append/Commit when series
already exist, which is one of the most usual cases IMO, as I didn't find
any.
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* Improve BenchmarkHeadAppender with more cases
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* A little copying is better than a little dependency
https://www.youtube.com/watch?v=PAAkCSZUG1c&t=9m28s
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* Fix imports order
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* Add license header
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* Copyright should be on one of the first 3 lines
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* Use require.Equal for testing
I don't depend on testify in my lib, but here we have it available.
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* Avoid flaky test
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* Also use zeropool for pointsPool in engine.go
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
---------
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
This is a bit more conservative than we could be. As long as a chunk
isn't the first in a block, we can be pretty sure that the previous
chunk won't disappear. However, the incremental gain of returning
NotCounterReset in these cases is probably very small and might not be
worth the code complications.
Wwith this, we now also pay attention to an explicitly set counter
reset during ingestion. While the case doesn't show up in practice
yet, there could be scenarios where the metric source knows there was
a counter reset even if it might not be visible from the values in the
histogram. It is also useful for testing.
Signed-off-by: beorn7 <beorn@grafana.com>
- Adjust doc comments to go1.19 style.
- Break down some overly long lines.
- Minor doc comment tweaks and fixes.
- Some renaming.
Some rationales for the last point:
I have renamed “interjections” into “inserts”, mostly because it is
shorter, and the word shows up a lot by now (and the concept is
cryptic enough to not obfuscate it even more with abbreviations).
I have also tried to find more descriptive naming for the “compare
spans” functions.
Signed-off-by: beorn7 <beorn@grafana.com>
Extends Appender.AppendHistogram function to accept the FloatHistogram. TSDB supports appending, querying, WAL replay, for this new type of histogram.
Signed-off-by: Marc Tudurí <marctc@protonmail.com>
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
Co-authored-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Switch from 'sanity' to more inclusive lanuage
"Removing ableist language in code is important; it helps to create and
maintain an environment that welcomes all developers of all backgrounds,
while emphasizing that we as developers select the most articulate,
precise, descriptive language we can rather than relying on metaphors.
The phrase sanity check is ableist, and unnecessarily references mental
health in our code bases. It denotes that people with mental illnesses
are inferior, wrong, or incorrect, and the phrase sanity continues to be
used by employers and other individuals to discriminate against these
people."
From https://gist.github.com/seanmhanson/fe370c2d8bd2b3228680e38899baf5cc
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* TSDB chunks: remove race between writing and reading
Because the data is stored as a bit-stream, the last byte in the stream
could change if the stream is appended to after an Iterator is obtained.
Copy the last byte when the Iterator is created, so we don't have to
read it later.
Clarify in comments that concurrent Iterator and Appender are allowed,
but the chunk must not be modified while an Iterator is created.
(This was already the case, in order to copy the bstream slice header.)
* TSDB: stop saving last 4 samples in memSeries
This extra copy of the last 4 samples was introduced to avoid a race
condition between reading the last byte of the chunk and writing to it.
But now we have fixed that by having `bstreamReader` copy the last byte,
we don't need to copy the last 4 samples.
This change saves 56 bytes per series, which is very worthwhile when
you have millions or tens of millions of series.
* TSDB: tidy up stopIterator re-use
Previous changes have left this code duplicating some lines; pull
them out to a separate function and tidy up.
* TSDB head_test: stop checking when iterators are wrapped
The behaviour has changed so chunk iterators are only wrapped when
transaction isolation requires them to stop short of the end.
This makes tests fail which are checking the type.
Tests should check the observable behaviour, not the type.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
Co-authored-by: Ganesh Vernekar <ganeshvern@gmail.com>
* tsdb: add a basic test for read/write isolation
* tsdb: store the min time with isolationAppender
So that we can see when appending has moved past a certain point in time.
* tsdb: allow RangeHead to have isolation disabled
This will be used when for head compaction.
* tsdb: do head compaction with isolation disabled
This saves a lot of work tracking appends done while compaction is ongoing.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* tsdb: remove chunkRange from memSeries
chunkRange is the (oddly-named) configured duration for the head block.
We don't need a copy of this value per series. Pass it down where
required, and remove the copy.
The value in `Head` is only updated in `resetInMemoryState()`, which
also discards all `memSeries`.
* tsdb: remove oooCapMax from memSeries
oooCapMax is the configured maximum capacity for an out-of-order chunk.
Storing it per-series uses extra memory, and has surprising behaviour
if users change the value in config - series created before the change
will keep their old value.
Instead, pass it down where required, and remove the per-series value.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
Co-authored-by: Ganesh Vernekar <ganeshvern@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>
* Add runtime config to control native histogram ingestion
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Make the config into a CLI flag
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
Metadata was added recently but doesn't seem to be used much, at least as far as I could identify.
Yet it's part of memSeries struct and so even when empty takes 48 bytes,
which is a lot given that without it memSeries requires 224 bytes.
This change turns it into a pointer on the struct, that get set only when metadata is actually set of given series.
Signed-off-by: Łukasz Mierzwa <l.mierzwa@gmail.com>
Signed-off-by: Łukasz Mierzwa <l.mierzwa@gmail.com>
* Add histogram validation
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Correct negative offset validation
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Address review comments
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Validation benchmark
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Add more checks
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Attempt to fix tests
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* Fix stuff
Signed-off-by: Levi Harrison <git@leviharrison.dev>
George Krajcsovits