In digital communication, "jitter" usually refers to how much a signal deviates
from true periodicity, see https://en.wikipedia.org/wiki/Jitter. The way we are
using the "jitterSeed" in Prometheus does not affect the true periodicity at
all, but just introduces a constant phase shift (or offset) within the period.
So it would be more correct and less confusing to call the "jitterSeed" an
"offsetSeed" instead.
Signed-off-by: Julius Volz <julius.volz@gmail.com>
Inline one call to `decodeString`, and skip decoding the value string
until we find a match for the name.
Do a quick check on the first character in each string,
and exit early if we've gone past - labels are sorted in order.
Also improve tests and benchmark:
* labels: test Get with varying lengths - it's not typical for Prometheus labels to all be the same length.
* extend benchmark with label not found
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Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Instead of unpacking every individual string, we skip to the point
where there is a difference, going 8 bytes at a time where possible.
Add benchmark for Compare; extend tests too.
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Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Co-authored-by: Oleg Zaytsev <mail@olegzaytsev.com>
Use AppendableGauge to detect corrupt chunk with gauge histograms.
Detect if first sample is a gauge but the chunk is not set up to contain
gauge histograms.
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
Signed-off-by: George Krajcsovits <krajorama@users.noreply.github.com>
Problem:
LabelValueStats - This will provide a list of the label names and memory used in bytes.
It is calculated by adding the length of all values for a given label name.
But internally Prometheus stores the name and the value independently for each series.
Solution:
MemPostings struct maintains the values to seriesRef map which is used
to get the number of series which contains the label values.
Using that LabelValueStats is calculated as: seriesCnt * len(value
name)
Signed-off-by: Baskar Shanmugam <baskar.shanmugam.career@gmail.com>
Handle more arithmetic operators and aggregators for native histograms
This includes operators for multiplication (formerly known as scaling), division, and subtraction. Plus aggregations for average and the avg_over_time function.
Stdvar and stddev will (for now) ignore histograms properly (rather than counting them but adding a 0 for them).
Signed-off-by: Jeanette Tan <jeanette.tan@grafana.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>
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Signed-off-by: Callum Styan <callumstyan@gmail.com>
The code did not handle spans with 0 length properly.
Spans with length zero are now skipped in the comparison.
Span index check not done against length-1, since length is a unit32,
thus subtracting 1 leads to 2^32, not -1.
Fixes and unit tests for both integer and float histograms added.
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
So far, if a target exposes a histogram with both classic and native
buckets, a native-histogram enabled Prometheus would ignore the
classic buckets. With the new scrape config option
`scrape_classic_histograms` set, both buckets will be ingested,
creating all the series of a classic histogram in parallel to the
native histogram series. For example, a histogram `foo` would create a
native histogram series `foo` and classic series called `foo_sum`,
`foo_count`, and `foo_bucket`.
This feature can be used in a migration strategy from classic to
native histograms, where it is desired to have a transition period
during which both native and classic histograms are present.
Note that two bugs in classic histogram parsing were found and fixed
as a byproduct of testing the new feature:
1. Series created from classic _gauge_ histograms didn't get the
_sum/_count/_bucket prefix set.
2. Values of classic _float_ histograms weren't parsed properly.
Signed-off-by: beorn7 <beorn@grafana.com>
wlog: use filepath for getting checkpoint number
'path' is intended for things like URLs that are forward-slash-only.
'filepath' is for file paths, as used here.
