This reverts commit 5a3abfa041.
Reason for revert: exemplars aren't in wide use because they have numerous issues which prevent their adoption (see below).
Adding support for examplars into VictoriaMetrics introduces non-trivial code changes. These code changes need to be supported forever
once the release of VictoriaMetrics with exemplar support is published. That's why I don't think this is a good feature despite
that the source code of the reverted commit has an excellent quality. See https://docs.victoriametrics.com/goals/ .
Issues with Prometheus exemplars:
- Prometheus still has only experimental support for exemplars after more than three years since they were introduced.
It stores exemplars in memory, so they are lost after Prometheus restart. This doesn't look like production-ready feature.
See 0a2f3b3794/content/docs/instrumenting/exposition_formats.md (L153-L159)
and https://prometheus.io/docs/prometheus/latest/feature_flags/#exemplars-storage
- It is very non-trivial to expose exemplars alongside metrics in your application, since the official Prometheus SDKs
for metrics' exposition ( https://prometheus.io/docs/instrumenting/clientlibs/ ) either have very hard-to-use API
for exposing histograms or do not have this API at all. For example, try figuring out how to expose exemplars
via https://pkg.go.dev/github.com/prometheus/client_golang@v1.19.1/prometheus .
- It looks like exemplars are supported for Histogram metric types only -
see https://pkg.go.dev/github.com/prometheus/client_golang@v1.19.1/prometheus#Timer.ObserveDurationWithExemplar .
Exemplars aren't supported for Counter, Gauge and Summary metric types.
- Grafana has very poor support for Prometheus exemplars. It looks like it supports exemplars only when the query
contains histogram_quantile() function. It queries exemplars via special Prometheus API -
https://prometheus.io/docs/prometheus/latest/querying/api/#querying-exemplars - (which is still marked as experimental, btw.)
and then displays all the returned exemplars on the graph as special dots. The issue is that this doesn't work
in production in most cases when the histogram_quantile() is calculated over thousands of histogram buckets
exposed by big number of application instances. Every histogram bucket may expose an exemplar on every timestamp shown on the graph.
This makes the graph unusable, since it is litterally filled with thousands of exemplar dots.
Neither Prometheus API nor Grafana doesn't provide the ability to filter out unneeded exemplars.
- Exemplars are usually connected to traces. While traces are good for some
I doubt exemplars will become production-ready in the near future because of the issues outlined above.
Alternative to exemplars:
Exemplars are marketed as a silver bullet for the correlation between metrics, traces and logs -
just click the exemplar dot on some graph in Grafana and instantly see the corresponding trace or log entry!
This doesn't work as expected in production as shown above. Are there better solutions, which work in production?
Yes - just use time-based and label-based correlation between metrics, traces and logs. Assign the same `job`
and `instance` labels to metrics, logs and traces, so you can quickly find the needed trace or log entry
by these labes on the time range with the anomaly on metrics' graph.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5982
- Export streamaggr.LoadFromData() function, so it could be used in tests outside the lib/streamaggr package.
This allows removing a hack with creation of temporary files at TestRemoteWriteContext_TryPush_ImmutableTimeseries.
- Move common code for mustParsePromMetrics() function into lib/prompbmarshal package,
so it could be used in tests for building []prompbmarshal.TimeSeries from string.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6205
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6206
Move the code responsible for relabelCtx clearing into deferred function.
This allows making more clear the remoteWriteCtx.TryPush code.
This is a follow-up for 879771808b
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6205
While at it, clarify the description of the bugfix at docs/CHANGELOG.md
### Describe Your Changes
- added stale metrics counters for input and output samples
- added labels for aggregator metrics =>
`name="{rwctx}:{aggrId}:{aggrSuffix}"`
- rwctx - global or number starting from 1
- aggrid - aggregator id starting from 1
- aggrSuffix - <interval>_(by|without)_label1_label2_labeln
e.g: `name="global:1:1m_without_instance_pod"`
### Checklist
The following checks are **mandatory**:
- [ ] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
(cherry picked from commit 861852f262)
Signed-off-by: hagen1778 <roman@victoriametrics.com>
use GetOptionalArg instead of index to fallback to a first argument if
index is absent for remotewrite.streamaggr.config
(cherry picked from commit 7e5a206057)
Prevent excessive resource usage when stream aggregation config file
contains no matchers by prevent pushing data into Aggregators object.
Before this change a lot of extra work was invoked without reason.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
(cherry picked from commit 7ce052b32d)
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Occasionally, vmagent sends empty blocks to downstream servers. If a
downstream server returns an unexpected response, vmagent gets stuck in
a retry loop. While vmagent handles 400 and 409 errors, there are
various prometheus remote write implementations that return different
error codes. For example, vector returns a 422 error. To mitigate the
risk of vmagent getting stuck in a retry loop, it is advisable to skip
sending empty blocks to downstream servers.
Co-authored-by: hao.peng <hao.peng@smartx.com>
Co-authored-by: Zhu Jiekun <jiekun.dev@gmail.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
(cherry picked from commit 3661373cc2)
* adds datadog extensions for statsd:
- multiple packed values (v1.1)
- additional types distribution, histogram
* adds type check and append metric type to the labels with special tag
name `__statsd_metric_type__`. It simplifies streaming aggregation
config.
* remove statsd support from cluster, since cluster doesn't support
stream aggregation.
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
(cherry picked from commit b2765c45d0)
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html):
allow configuring `-remoteWrite.disableOnDiskQueue` and
`-remoteWrite.dropSamplesOnOverload` cmd-line flags per each
`-remoteWrite.url`. See this [pull
request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6065).
Thanks to @rbizos for implementaion!
* FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): add
labels `path` and `url` to metrics
`vmagent_remotewrite_push_failures_total` and
`vmagent_remotewrite_samples_dropped_total`. Now number of failed pushes
and dropped samples can be tracked per `-remoteWrite.url`.
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Raphael Bizos <r.bizos@criteo.com>
(cherry picked from commit 87fd400dfc)
This code adds Exemplars to VMagent and the promscrape parser adhering
to OpenMetrics Specifications. This will allow forwarding of exemplars
to Prometheus and other third party apps that support OpenMetrics specs.
---------
Signed-off-by: Ted Possible <ted_possible@cable.comcast.com>
(cherry picked from commit 5a3abfa041)
When at least one remote write has deduplication configured it cleans up
timeseries while they can be in use by another remote write without
deduplication
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6205
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
(cherry picked from commit 879771808b)
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6140
We don't cover this corner case as it has low chance for reproduction.
Precisely, the requirements are following:
1. vmagent need to be configured with multiple identical `remoteWrite.url` flags;
2. At least one of the persistent queues need to be non-empty, which already
signalizes about issues with setup;
3. vmagent need to be restarted with removing of one of `remoteWrite.url` flags.
We do not document this case in vmagent.md as it seems to be a rare corner case
and its explanation will require too much of explanation and confuse users.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
(cherry picked from commit 4251292708)
Stream aggregation may yield inaccurate results if it processes incomplete data.
This issue can arise when data is sourced from clients that maintain a queue of unsent data, such as Prometheus or vmagent.
If the queue isn't fully cleared within the aggregation interval, only a portion of the time series may be included in that period, leading to distorted calculations.
To mitigate this we add an option to ignore first N aggregation intervals. It is expected, that client queues
will be cleared during the time while aggregation ignores first N intervals and all subsequent aggregations
will be correct.
(cherry picked from commit c0e4ccb7b5)
Signed-off-by: hagen1778 <roman@victoriametrics.com>
- Automatically reload changed TLS root CA pointed by -remoteWrite.tlsCAFile command-line flag
- Automatically reload changed TLS root CA configured via oauth2.tsl_config.ca_file option at -promscrape.config
- Document the change as a feature instead of a bug at docs/CHANGELOG.md
- Simplify the code at lib/promauth, which is responsible for reloading changed TLS root CA files.
- Simplify the usage of lib/promauth.Config.NewRoundTripper() - now it accepts the base http.Transport
instead of a callback, which can change the internal http.Transport.
- Reuse the default tls config if lib/promauth.Config doesn't contain tls-specific configs.
This should reduce memory usage a bit when tls isn't used for scraping big number of targets.
- Do not re-read TLS root CA files on every processed request. Re-read them once per second.
This should reduce CPU usage when scraping big number of targets over https.
- Do not store cert.pem and key.pem files in TestTLSConfigWithCertificatesFilesUpdate, since they can be loaded
from byte slices via crypto/tls.X509KeyPair().
- Remove obsolete comparisons of string representations for authConfig and proxyAuthConfig at areEqualScrapeConfigs().
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5725
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5526
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2171
The remotewrite.Stop() expects that there are no pending calls to TryPush().
This means that the ingestionRateLimiter.Register() must be unblocked inside TryPush() when calling remotewrite.Stop().
Provide remotewrite.StopIngestionRateLimiter() function for unblocking the rate limiter before calling the remotewrite.Stop().
While at it, move the rate limiter into lib/ratelimiter package, since it has two users.
Also move the description of the feature to the correct place at docs/CHANGELOG.md.
Also cross-reference -remoteWrite.rateLimit and -maxIngestionRate command-line flags.
This is a follow-up for 02bccd1eb9
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5900
- Make the configuration more clear by accepting the list of ignored labels during sharding
via a dedicated command-line flag - -remoteWrite.shardByURL.ignoreLabels.
This prevents from overloading the meaning of -remoteWrite.shardByURL.labels command-line flag.
- Removed superfluous memory allocation per each processed sample if sharding by remote storage is enabled.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5938
To horizontally scale streaming aggregation, you might want to deploy a separate hashing tier
of vmagents that route to a separate aggregation tier. The hashing tier should shard by all labels
except the instance-level labels, to ensure the input metrics are routed correctly to the aggregator
instance responsible for those labels.
For this to achieve we introduce `remoteWrite.shardByURL.inverseLabels` flag to inverse logic of `remoteWrite.shardByURL.labels`
---------
Co-authored-by: Eugene Ma <eugene.ma@airbnb.com>
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
(cherry picked from commit 166b97b8d0)
* [vmagent] added ingestion rate limiting with new flag `-maxIngestionRate`. This flag can be used to limit the number of samples ingested by vmagent per second. If the limit is exceeded, the ingestion rate will be throttled.
* fix changelog
* fix review comment
(cherry picked from commit 02bccd1eb9)
For example, if `interval: 1m`, then data flush occurs at the end of every minute,
while `interval: 1h` leads to data flush at the end of every hour.
Add `no_align_flush_to_interval` option, which can be used for disabling the alignment.
There is no sense in running more than GOMAXPROCS concurrent marshalers,
since they are CPU-bound. More concurrent marshalers do not increase the marshaling bandwidth,
but they may result in more RAM usage.
This should smooth CPU and RAM usage spikes related to these periodic tasks,
by reducing the probability that multiple concurrent periodic tasks are performed at the same time.
The user may which to control the endpoint parameters for instance to
set the audience when requesting an access token. Exposing the
parameters as a map allows for additional use cases without requiring
modification.
