* Export single ith test histogram generation functions
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
* Do not set counter reset hint for non-gauge histograms individually
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
* Apply suggestions from code review
Co-authored-by: Ganesh Vernekar <ganeshvern@gmail.com>
Signed-off-by: George Krajcsovits <krajorama@users.noreply.github.com>
---------
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
Signed-off-by: George Krajcsovits <krajorama@users.noreply.github.com>
Co-authored-by: Ganesh Vernekar <ganeshvern@gmail.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>
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>
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>
* 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>
The chunk pool belongs to the head not to the series. Pass it down where
required, and remove the copy of the pointer that `memSeries` was
holding.
`safeChunk` also needs to hold it, because in scenarios where it is used
we don't have a reference to the head. However it was already holding
`chunkDiskMapper` for the same reason, so no big change.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Signed-off-by: Bryan Boreham <bjboreham@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>
* 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>
* Write chunks via queue, predicting the refs
Our load tests have shown that there is a latency spike in the
remote write handler whenever the head chunks need to be written,
because chunkDiskMapper.WriteChunk() blocks until the chunks are written
to disk.
This adds a queue to the chunk disk mapper which makes the WriteChunk()
method non-blocking unless the queue is full. Reads can still be served
from the queue.
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* address PR feeddback
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* initialize metrics without .Add(0)
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* change isRunningMtx to normal lock
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* do not re-initialize chunkrefmap
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* update metric outside of lock scope
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* add benchmark for adding job to chunk write queue
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* remove unnecessary "success" var
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* gofumpt -extra
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* avoid WithLabelValues call in addJob
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* format comments
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* addressing PR feedback
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* rename cutExpectRef to cutAndExpectRef
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* use head.Init() instead of .initTime()
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* address PR feedback
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* PR feedback
Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* update test according to PR feedback
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* replace callbackWg -> awaitCb
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* better test of truncation with empty files
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
* replace callbackWg -> awaitCb
Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>
The atomic Int64 type wasn't able to be represented when logging
via go-kit log and ended up as `"unsupported value type"`.
Signed-off-by: Nick Pillitteri <nick.pillitteri@grafana.com>
- 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>
* Support appending different sample types to the same series
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Fix comments
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Fix build
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Disable isolation in isolation struct
Signed-off-by: darshanime <deathbullet@gmail.com>
* Run tsdb tests with isolation disabled
Signed-off-by: darshanime <deathbullet@gmail.com>
* Check for isolation disabled in isoState.Close()
Signed-off-by: darshanime <deathbullet@gmail.com>
* use t.Skip to skip isolation tests when disabled
Signed-off-by: darshanime <deathbullet@gmail.com>
* address review comments
Signed-off-by: darshanime <deathbullet@gmail.com>
* fix test for defaultIsolationState
Signed-off-by: darshanime <deathbullet@gmail.com>
* Change flag name. Set flag in DB. Do not init txRing. Close isoState.
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Test disabled isolation in CircleCI test_go
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Skip isolation related tests in db_test.go
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
Co-authored-by: Ganesh Vernekar <ganeshvern@gmail.com>
* Add basic initial developer docs for TSDB
There's a decent amount of content already out there (blog posts,
conference talks, etc), but:
* when they get stale, they don't tend to get updated
* they still leave me with questions that I'ld like to answer
for developers (like me) who want to use, or work with, TSDB
What I propose is developer docs inside the prometheus
repository. Easy to find and harness the power of the community
to expand it and keep it up to date.
* perfect is the enemy of good. Let's have a base and incrementally improve
* Markdown docs should be broad but not too deep. Source code comments
can complement them, and are the ideal place for implementation details.
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
* use example code that works out of the box
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
* Apply suggestions from code review
Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
* PR feedback
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
* more docs
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
* PR feedback
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
* Apply suggestions from code review
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
Co-authored-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Apply suggestions from code review
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>
* feedback
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
* Update tsdb/docs/usage.md
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>
* final tweaks
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
* workaround docs versioning issue
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
* Move example code to real executable, testable example.
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
* cleanup example test and make sure it always reproduces
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
* obtain temp dir in a way that works with older Go versions
Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
* Fix Ganesh's comments
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
Co-authored-by: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>
Co-authored-by: Bartlomiej Plotka <bwplotka@gmail.com>
Co-authored-by: Ganesh Vernekar <ganeshvern@gmail.com>
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>
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>
