If given a single querier, just return it instead of constructing a
complicated wrapper. The code in `mergeGenericQuerier` which skipped
merging when there was only one is not needed any more.
This change required a few tests to be tweaked, because they relied on
the specific behaviour of `mergeGenericQuerier.Select()`.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
One was silently doing nothing; one was doing something but the work
didn't go up linearly with iteration count.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
This PR is a reference implementation of the proposal described in #10420.
In addition to what described in #10420, in this PR I've introduced labels.StableHash(). The idea is to offer an hashing function which doesn't change over time, and that's used by query sharding in order to get a stable behaviour over time. The implementation of labels.StableHash() is the hashing function used by Prometheus before stringlabels, and what's used by Grafana Mimir for query sharding (because built before stringlabels was a thing).
Follow up work
As mentioned in #10420, if this PR is accepted I'm also open to upload another foundamental piece used by Grafana Mimir query sharding to accelerate the query execution: an optional, configurable and fast in-memory cache for the series hashes.
Signed-off-by: Marco Pracucci <marco@pracucci.com>
Converted maps into labels.Labels to avoid a lot of copying of data which leads to very high memory consumption while opening the /service-discovery endpoint in the Prometheus UI
Signed-off-by: Leegin <114397475+Leegin-darknight@users.noreply.github.com>
Converted maps into labels.Labels to avoid a lot of copying of data which leads to very high memory consumption while opening the /service-discovery endpoint in the Prometheus UI
Signed-off-by: Leegin <114397475+Leegin-darknight@users.noreply.github.com>
Updated & added tests
Review feedback nits
Return empty map if not indeterminate
Use highWatermark to track inflight requests counter
Appease the linter
Clarify feature flag
Signed-off-by: Danny Kopping <danny.kopping@grafana.com>
The last_over_time retains a histogram sample without making a copy.
This sample is now coming from the buffered iterator used for windowing functions,
and can be reused for reading subsequent samples as the iterator progresses.
I would propose copying the sample in the last_over_time function, similar to
how it is done for rate, sum_over_time and others.
Signed-off-by: Filip Petkovski <filip.petkovsky@gmail.com>
Mutex is 8 bytes; RWMutex is 24 bytes and much more complicated. Since
`RLock` is only used in two places, `UpdateMetadata` and `Delete`,
neither of which are hotspots, we should use the cheaper one.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
I have been the de-facto maintainer for native histograms from the
beginning. So let's put this into MAINTAINERS.md.
In addition, I hereby proposose George Krajcsovits AKA Krajo as a
co-maintainer. He has contributed a lot of native histogram code, but
more importantly, he has contributed substantially to reviewing other
contributors' native histogram code, up to a point where I was merely
rubberstamping the PRs he had already reviewed. I'm confident that he
is ready to to be granted commit rights as outlined in the
"Maintainers" section of the governance:
https://prometheus.io/governance/#maintainers
According to the same section of the governance, I will announce the
proposed change on the developers mailing list and will give some time
for lazy consensus before merging this PR.
Signed-off-by: beorn7 <beorn@grafana.com>
Rollback k8s.io Go modules to v0.28.6 to avoid forcing upgrade of Go to
1.21. This allows us to keep compatibility with the currently supported
upstream Go releases.
Signed-off-by: SuperQ <superq@gmail.com>
Lifting an optimisation from Agent code, `seriesHashmap.del` can use
the unique series reference, doesn't need to check Labels.
Also streamline the logic for deleting from `unique` and `conflicts` maps,
and add some comments to help the next person.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
This function is called very frequently when executing PromQL functions,
and we can do it much more efficiently inside Labels.
In the common case that `__name__` comes first in the labels, we simply
re-point to start at the next label, which is nearly free.
`DropMetricName` is now so cheap I removed the cache - benchmarks show
everything still goes faster.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Add test case to TestHeadLabelValuesWithMatchers, while fixing a couple
of typos in other test cases. Also enclosing some implicit sub-tests in a
`t.Run` call to make them explicitly sub-tests.
Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>
