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>
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>
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>
Optimize histogram iterators
Histogram iterators allocate new objects in the AtHistogram and
AtFloatHistogram methods, which makes calculating rates over long
ranges expensive.
In #13215 we allowed an existing object to be reused
when converting an integer histogram to a float histogram. This commit follows
the same idea and allows injecting an existing object in the AtHistogram and
AtFloatHistogram methods. When the injected value is nil, iterators allocate
new histograms, otherwise they populate and return the injected object.
The commit also adds a CopyTo method to Histogram and FloatHistogram which
is used in the BufferedIterator to overwrite items in the ring instead of making
new copies.
Note that a specialized HPoint pool is needed for all of this to work
(`matrixSelectorHPool`).
---------
Signed-off-by: Filip Petkovski <filip.petkovsky@gmail.com>
Co-authored-by: George Krajcsovits <krajorama@users.noreply.github.com>
SD Managers take over responsibility for SD metrics registration
---------
Signed-off-by: Paulin Todev <paulin.todev@gmail.com>
Signed-off-by: Björn Rabenstein <github@rabenste.in>
Co-authored-by: Björn Rabenstein <github@rabenste.in>
Enable automatic detection of memory limits and configure GOMEMLIMIT to
match.
* Also includes a flag to allow controlling the reserved ratio.
Signed-off-by: SuperQ <superq@gmail.com>
Don't calculate postings beforehand: we may not need them. If all
matchers are for the requested label, we can just filter its values.
Also, if there are no values at all, no need to run any kind of
logic.
Also add more labelValuesWithMatchers benchmarks
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
I have not had the time to keep up with remote write and have no plans
to work on it in the near future so I am withdrawing my maintainership
of that part of the codebase. I continue to focus on client_python.
Signed-off-by: Chris Marchbanks <csmarchbanks@gmail.com>
Prometheus is hard-coded to use a fanout storage between TSDB and
a remote storage which by default is empty.
This change detects the empty storage and skips merging between
result sets, which would make `Select()` sort results.
Bottom line: we skip a sort unless there really is some remote storage
configured.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
