When Prometheus restarts it creates every series read in from the WAL,
but many of those series will be finished, and never receive any more
samples. By defering allocation of the txRing slice to when it is first
needed, we save 32 bytes per stale series.
Signed-off-by: Bryan Boreham <bjboreham@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>
I find it useful to know why a restriction exists, to check whether that
reason still applies, or in which other places it might apply.
This is based on the note here:
https://github.com/prometheus/prometheus/pull/9270#pullrequestreview-743820956
on the PR where the original comment was added.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Signed-off-by: Bryan Boreham <bjboreham@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>
Fetch the low watermark value under the same lock as we need for the
appender, rather than releasing then re-aquiring a lock on the same
Mutex.
Signed-off-by: Bryan Boreham <bjboreham@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>
