* 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>
This fixes#6992, which was introduced by #6777. There was an
intermediate component which translated TSDB errors into storage errors,
but that component was deleted and this bug went unnoticed, until we
were watching at the Prombench results. Without this, scrape will fail
instead of dropping samples or using "Add" when the series have been
garbage collected.
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>
This is part of https://github.com/prometheus/prometheus/pull/5882 that can be done to simplify things.
All todos I added will be fixed in follow up PRs.
* querier.Querier, querier.Appender, querier.SeriesSet, and querier.Series interfaces merged
with storage interface.go. All imports that.
* querier.SeriesIterator replaced by chunkenc.Iterator
* Added chunkenc.Iterator.Seek method and tests for xor implementation (?)
* Since we properly handle SelectParams for Select methods I adjusted min max
based on that. This should help in terms of performance for queries with functions like offset.
* added Seek to deletedIterator and test.
* storage/tsdb was removed as it was only a unnecessary glue with incompatible structs.
No logic was changed, only different source of abstractions, so no need for benchmarks.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
* Make WAL replay benchmark more representative
Signed-off-by: Chris Marchbanks <csmarchbanks@gmail.com>
* Move decoding records from the WAL into goroutine
Decoding the WAL records accounts for a significant amount of time on
startup, and can be done in parallel with creating series/samples to
speed up startup. However, records still must be handled in order, so
only a single goroutine can do the decoding.
benchmark
old ns/op new ns/op delta
BenchmarkLoadWAL/batches=10,seriesPerBatch=100,samplesPerSeries=7200-8
481607033 391971490 -18.61%
BenchmarkLoadWAL/batches=10,seriesPerBatch=10000,samplesPerSeries=50-8
836394378 629067006 -24.79%
BenchmarkLoadWAL/batches=10,seriesPerBatch=1000,samplesPerSeries=480-8
348238658 234218667 -32.74%
Signed-off-by: Chris Marchbanks <csmarchbanks@gmail.com>
