* Allow to tune the scrape tolerance
In most of the classic monitoring use cases, a few milliseconds
difference can be omitted.
In Prometheus, a few millisecond difference can however make a big
difference.
Currently, Prometheus will ignore up to 2 ms difference in the
alignments.
It turns out that for users who can afford a 10ms difference, there is a
lot of resources and disk space to win, as shown in this graph, which
shows the bytes / samples over a production Prometheus server. You can
clearly see the switch from 2ms to 10ms tolerance.
This pull request enables the adjustment of the scrape timestamp
alignment tolerance.
Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>
* Fix golint
Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>
* Decrement active_appenders metric when no samples added
Also add a test that the metric is incremented and decremented as
expected with and without samples.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Fix comment
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
Co-authored-by: Ganesh Vernekar <ganeshvern@gmail.com>
This saves memory, effort and locking.
Since every symbol is also added to postings, `Symbols()` can be
implemented there instead. This now has to build a map for
deduplication, but `Symbols()` is only called for compaction, and `gc()`
used to rebuild the symbols map after every compaction so not an
additional cost.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Refactor: extract function to make scrapeLoop for testing
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Add benchmarks for ScrapeLoopAppend
For Prometheus and OpenMetrics
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Create less garbage when parsing metrics
Exemplar escapes to heap due to being passed through text-parser
interface, but we can reduce the impact by hoisting it out of the loop
and resetting it after every use.
(Note the cost was paid on every line even when exemplars were disabled)
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Create less garbage when parsing OpenMetrics
After calling parseLVals() we always append the return value, so pass in
what we want to append it to and save garbage.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
promtool: Speed up checking for duplicate rules
Running promtool check config on large rule files is rather slow. Improve this by adding a testcase, benchmark and changing the algorithm used to find duplicates.
Trade space for speed. Convert all rules into our temporary struct, sort
and then iterate. This is a significant when having many rules.
Signed-off-by: Holger Hans Peter Freyther <holger@moiji-mobile.com>
This adds a new metric exposing per target scrape sample_limit value. Metrics are only exposed if extra-scrape-metrics feature flag is enabled.
scrape_sample_limit will make it easy to monitor and alert on targets getting close to configured sample_limit, which is important given than exceeding sample_limit results in the entire scrape results being rejected.
Signed-off-by: Łukasz Mierzwa <l.mierzwa@gmail.com>
Add a new built-in metric `scrape_timeout_seconds` to allow monitoring
of the ratio of scrape duration to the scrape timeout. Hide behind a
feature flag to avoid additional cardinality by default.
Signed-off-by: SuperQ <superq@gmail.com>
* Allow VectorSelector.String() without matchers
Previously this method was panicking because it was trying to allocate a
slice with capacity -1. There's nothing saying that VectorSelector
should have matchers, and it's actually prepared to have zero matcher
strings, so it's worth checking instead of panicking.
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
Ganesh Vernekar