Allow configuring the default number of stored rule's update states in memory
via global `-rule.updateEntriesLimit` command-line flag or per-rule via rule's
`update_entries_limit` configuration param.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
This simplifies manual usage of the APIs. For example, the following query
would return the results over the 2022 year.
/api/v1/query_range?start=2022&end=2023&step=1d&query=...
This is equivalent to:
/api/v1/query_range?start=2022-01-01T00:00:00Z&end=2023-01-01T00:00:00Z&step=1d&query=...
- Rename `Custom panel` tab to more clear `Query` tab
- Rename `Cardinality` tab to `Explore cardinality`, so it becomes consistent with `Explore metrics` tab
- Move `Dashboards` tab to the end, since it isn't used too much
- Document the feature at docs/CHANGELOG.md.
- Document the metrics explorer at https://docs.victoriametrics.com/#metrics-explorer .
- Properly set `start` and `end` args for the selected time range
when performing the request, which returns metric names.
- Improve queries, so they return lower number of lines and labels.
This should improve metrics' exploration.
- Properly encode label filters and query args before passing them to VictoriaMetrics.
- Various cosmetic fixes.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3386
* vmagent: respect `-usePromCompatibleNaming` if no relabeling is set
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3493
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* vmagent: upd test
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
* app/vmbackupmanager: add metrics for better observability, include more information to `/api/v1/backups` API call response
* app/vmbackupmanager: drop old metrics before creating new ones
* app/vmbackupmanager: use `_total` postfix for counter metrics
* app/vmbackupmanager: remove `_total` postfix for gauge-like metrics
* app/vmbackupmanager: add `_last_run_failed` metrics for backups and retention
* app/vmbackupmanager: address review feedback
* app/vmbackupmanager: fix metric name
* app/vmbackupmanager: address review feedback, remove background updates of metrics, add restoring state of `_last_run_failed` metric from remote storage
* app/vmbackupmanager: improve performance for backup size calculation
* app/vmbackupmanager: refactor backup and retention runs to deduplicate each run logic
* {app/vmbackupmanager,lib/formatutil}: move HumanizeBytes into lib package
* app/vmbackupmanager: fix creating new metrics instead of reusing existing ones
* lit/formatutil: add comment to make linter happy
* app/vmbackupmanager: address review feedback
Previously too short lookbehind window d for rate(m[d]) could be automatically extended
if it didn't cover at least two raw samples. This was needed in order to guarantee
non-empty results from rate(m[d]) on short time ranges.
Now the lookbehind window isn't extended if it is set explicitly,
since it is expected that the user knows what he is doing.
The lookbehind window continues to be extended when needed if it isn't set explicitly.
For example, in the case of rate(m).
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3483
support overriding of `-search.latencyOffset` value via
URL param `latency_offset`.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3481
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
This fixes handling of values bigger than 2GiB for the following command-line flags:
- -storage.minFreeDiskSpaceBytes
- -remoteWrite.maxDiskUsagePerURL
Blocked small merges may result into big number of small parts, which, in turn,
may result in increased CPU and memory usage during queries, since queries need to inspect
all the existing small parts.
The issue has been introduced in 8189770c50
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3337
The system links are absolute, e.g. they start from `/`, so there are high chances
they won't work as expected when requested via proxy such as vmselect with -vmalert.proxyURL
command-line flag.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/3424
http.Request was used as a part of state struct
for generating the curl command when viewing the rule's
state changes.
It appears, that holding a referencing is far more expensive
than generating the curl command immediately.
On the test with 40k rules, this change reduces memory
and CPU usage by 50%.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
- Document the change at docs/CHANGELOG.md
- Run `make docs-sync` for copying app/vmgateway/README.md to docs/vmgateway.md
in order to propagate docs' changes to https://docs.victoriametrics.com/vmgateway.html
* vmalert: correctly return error for RW failures
By mistake, in 0989649ad0 the error
for remote write failures weren't return to user.
This change fixes it.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Fixes security vulnerability in nth-check version <=1.0.2
My previous version pin was insufficient, as it was imported again through a different (svgo -> css-select).
The main purpose of this command-line flag is to increase the lifetime of low-end flash storage
with the limited number of write operations it can perform. Such flash storage is usually
installed on Raspberry PI or similar appliances.
For example, `-inmemoryDataFlushInterval=1h` reduces the frequency of disk write operations
to up to once per hour if the ingested one-hour worth of data fits the limit for in-memory data.
The in-memory data is searchable in the same way as the data stored on disk.
VictoriaMetrics automatically flushes the in-memory data to disk on graceful shutdown via SIGINT signal.
The in-memory data is lost on unclean shutdown (hardware power loss, OOM crash, SIGKILL).
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3337
Method `metrics()` now pre-allocates slices for labels
and results from query responses. This reduces the number
of allocations on the hot path for instant requests.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
The recent change in modifying default value
of `datasource.queryStep` flag resulted in situation
where replay mode was always running queries with
step=`datasource.queryStep`. When it should always
use rule's evaluation interval.
The fix is related not to replay mode only, but
for all Range requests. Now step param is set
individually for each mode.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* app/vmalert: add `remoteWrite.sendTimeout` command-line flag to configure timeout for sending data to `remoteWrite.url`
* vmalert: remove WriteTimeout from clients Cfg
No need to have it as a part of configuration struct:
* the client isn't used by other packages;
* there are no internal tests to check the WriteTimeout.
* vmalert: remove DisablePathAppend from clients Cfg
No need to have it as a part of configuration struct:
* the client isn't used by other packages;
* there are no internal tests to check the DisablePathAppend.
Co-authored-by: hagen1778 <roman@victoriametrics.com>
- Return meta-labels for the discovered targets via promutils.Labels
instead of map[string]string. This improves the speed of generating
meta-labels for discovered targets by up to 5x.
- Remove memory allocations in hot paths during ScrapeWork generation.
The ScrapeWork contains scrape settings for a single discovered target.
This improves the service discovery speed by up to 2x.
* flag reference update
there is no flag `-datasource.disablePathAppend` and datasource actually checking for `-remoteRead.disablePathAppend`
* update source for doc as well
* {app/vmstorage,app/vmselect}: add API to get list of existing tenants
* {app/vmstorage,app/vmselect}: add API to get list of existing tenants
* app/vmselect: fix error message
* {app/vmstorage,app/vmselect}: fix error messages
* app/vmselect: change log level for error handling
* wip
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
* fix: reset the value of the switches trace and cache
* fix: add cursor text for inputs
* fix: solve the Infinite loop of useFetchQuery.ts
* fix: change condition for show/hide autocomplete
* fix: add limit error length for input
The default list of alerting rules contains the basic
rules for checking vmalert's health state and is recommended
to use for monitoring vmalert deployments.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
The change disables initing the `-version` flag in new
`urfave/cli/v2` update. The `-version` flag conflicts
with the identical flag from `lib/buildinfo` and causes panic.
See https://github.com/VictoriaMetrics/VictoriaMetrics/pull/3299
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* feat: apply serverURL on down Enter
* fix: change method of set time range
* fix: remove prevent run fetch without changes
* fix: prevent reset timerange when autorefresh
Previously the `quotesEscape` function was escaping only double quotes.
This wasn't enough, since the input string could contain other special chars,
which must be escaped when put inside JSON string. For example, carriage return and line feed chars (\n\r),
backslash char, etc. This led to the following issues, which were improperly fixed:
- https://github.com/VictoriaMetrics/VictoriaMetrics/issues/890 - this issue
was "fixed" by introducing the `crlfEscape` function, which led to unnecessary
complications in user templates, while not fixing various corner cases
such as backslash chars in the input string.
See 1de15ad490
- https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3139 - this issue
was "fixed" by urlencoding the whole string passed to -external.alert.source
command-line flag. This led to invalid urls, which couldn't be parsed by Grafana.
See 00c838353d
and 4bd0244599
This commit properly encodes the input string passed to `quotesEscape`, so it can be safely embedded inside JSON strings.
This commit deprecates crlfEscape template function and adds the following new template functions:
- strvalue and stripDomain - these functions are supported by Prometheus, so they were added
for compatibility purposes.
- jsonEscape and htmlEscape for converting the input string to valid quoted JSON string
and for html-escaping the input string, so it could be safely embedded as a plaintext
into html.
This commit also documents all supported template functions at https://docs.victoriametrics.com/vmalert.html#template-functions
The deprecated crlfEscape function isn't documented on purpose, since its usefulness is negative in general case.
This reverts commit 00c838353d.
Reason for revert: it incorrectly fixes the issue https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3139 .
Now `-external.alert.source=explore?orgId=1&left=...` is converted to the following invalid url, which cannot be handled by Grafana:
https://grafana.example.com/explore%3ForgId%3D1%26left%3D...
The next commit will contain the correct fix of the issue - the `quotesEscape` function must
properly escape the string, so it could be embedded into JSON string. This function must
properly escape \n\r chars too. In this case the `crlfEscape` function becomes unnecessary.
Actually, the next commit makes the `crlfEscape` function deprecated.
Previously netstorage.MustStop() call didn't free up all the resources,
so the subsequent call to nestorage.Init() would panic.
This allows writing tests, which call nestorage.Init() + nestorage.MustStop() in a loop.
The searchTSIDs function was searching for metricIDs matching the the given tag filters
and then was locating the corresponding TSID entries for the found metricIDs.
The TSID entries aren't needed when searching for time series names (aka MetricName),
so this commit removes the uneeded TSID search from the implementation of /api/v1/series API.
This improves perfromance of /api/v1/series calls.
This commit also improves performance a bit for /api/v1/query and /api/v1/query_range calls,
since now these calls cache small metricIDs instead of big TSID entries
in the indexdb/tagFilters cache (now this cache is named indexdb/tagFiltersToMetricIDs)
without the need to compress the saved entries in order to save cache space.
This commit also removes concurrency limiter during searching for matching time series,
which was introduced in 8f16388428, since the concurrency
for all the read queries is already limited with -search.maxConcurrentRequests command-line flag.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/648
The message about dropped data still remains at `error` level.
The change supposed to make log message more clear about how
serious it is.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* feat: add maximum display series by tabs
* feat: add warning on PredefinedPanels.tsx
* docs/CHANGELOG.md: vmui limit number of plotted series
* docs/CHANGELOG.md: vmui limit number of plotted series
* wip
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
The default value of `-datasource.queryStep` has changed, so we update
the troubleshooting docs accordingly.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Due to auto-refactoring, the filed `state` was automatically
renamed to `ruleState` when the entity with the same name
was renamed in other file. Reverting the change.
https://github.com/VictoriaMetrics/helm-charts/issues/391
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
vmalert: prevent duplicating label `alertname` for notifications
The issue has no impact on alerting procedure. But still needs to be fixed
for clarity.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3053
Signed-off-by: lihaowei <haoweili35@gmail.com>
Sort labels explicitly after calling the ParsedConfigs.Apply() when needed.
This reduces CPU usage when performing metric-level relabeling, where labels' sorting isn't needed.
* Optimize fast path for /api/v1/import when importing numeric values
* Move the docs about the change from features to bugfixes at docs/CHANGELOG.md
* Update tests at lib/protoparser/vmimport
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3161
* app/vmselect: properly work when export import json from `api/v1/{export, import}` API
* app/vmselect: update convert function
* app/vmselect: export null if `math.IsNaN(v)`
* app/vmselect: get float from json
* lib/protoparser: add test
* docs: add change log
* lib/protoparser: make export import api compatible
* Document the addition of Azure blob storage support in vmbackup / vmrestore
* List the supported storage system types at docs/vmrestore.md
* Mention about azblob storage system support at -src and -dst command-line flags
for vmbackup / vmrestore tools.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1029
* Use vm_account_id and vm_project_id labels to be consistent with https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#multitenancy-via-labels
* Document the feature that vmalert now exposes vm_account_id and vm_project_id
labels if -clusterMode is set.
* Use literal strings instead of string constants for vm_account_id and vm_project_id.
This improves code readability.
The change is supposed to provide additional flexibility for generating alert's
source link based on label values.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Incorrect 301 redirects can be cached by user agents such as web browsers.
This can complicate recovery procedure after the incorrect redirect is fixed,
e.g. web browser cache must be reset.
The related issue - https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1752
Allow configuring authorization params per list of targets
in vmalert's notifier config for `static_configs`.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2690
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* app/vminsert: allows parsing tenant id from labels
it should help mitigate issues with vmagent's multiTenant mode, which works incorrectly at heavy load
and it cannot handle more then 100 different tenants.
This functional hidden with flag and do not change vminsert default behaviour
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2970
* Update docs/Cluster-VictoriaMetrics.md
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
* wip
* app/vminsert/netstorage: clean remaining labels in order to free up GC
* docs/Cluster-VictoriaMetrics.md: typo fix
* wip
* wip
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
Previously empty series (e.g. series with all NaN samples) were passed to aggregate functions.
Such series must be ingored by all the aggregate functions.
So it is better from consistency PoV filtering out empty series before applying aggregate functions.
* app/vmselect: ignore empty series for `limit_offset`
VictoriaMetrics doesn't return empty series (with all NaN values) to
the user. But such series are filtered after transform functions.
It means `limit_offset` will account for empty series as well.
For example, let's consider following data set:
```
time series:
foo{label="1"} NaN, NaN, NaN, NaN // empty series
foo{label="2"} 1, 2, 3, 4
foo{label="3"} 4, 3, 2, 1
```
When user requests all series for metric `foo` the empty series
will be filtered out:
```
/query=foo:
foo{label="v2"} 1, 2, 3, 4
foo{label="v3"} 4, 3, 2, 1
```
But `limit_offset(1, 1, foo)` is applied to original series, not filtered yet.
So it will return `foo{label="v2"}` (skips the first in list)
```
/query=limit_offset(1, 1, foo):
foo{label="v2"} 1, 2, 3, 4
```
Expected result would be to apply `limit_offset` to already filtered list,
so in result we receive `foo{label="v3"}`:
```
/query=limit_offset(1, 1, foo):
foo{label="v3"} 4, 3, 2, 1
```
The change does exactly that - filters empty series before applying `limit_offset`.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* app/vmselect: ignore empty series for `limit_offset`
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
According to Ruler specification, only labels returned within time series
should be available for use in annotations.
For long time, vmalert didn't respect this rule. And in PR
https://github.com/VictoriaMetrics/VictoriaMetrics/pull/2403
this was fixed for the sake of compatibility. However, this resulted
into users confusion, as they expected all configured and extra labels
to be available - https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3013
This fix allows to use extra labels in Annotations. But in the case of conflicts
the original labels (extracted from time series) are preferred.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* lib/{httpserver,netutil}: allow to define min and max TLS version of the http server
* lib/httpserver: added descriptions about tls supported versions
* lib/netutil: check minimal tls version, added supported tls versions to error
* wip
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
The workaround was introduced to fix https://github.com/VictoriaMetrics/VictoriaMetrics/issues/962.
However, it didn't prove itself useful. Instead, it is recommended using `increase_pure` function.
Removing the workaround makes VM to produce accurate results when calculating
`delta` or `increase` functions over slow-changing counters with vary intervals
between data points.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
- Clarify the description for -datasource.queryStep command-line flag
- Consistently use a single dash in front of -datasource.queryStep command-line flag
- Update -help output at docs/vmalert.md
- Consistently use single dash in front of command-line flags instead of double dashes.
- Add a warning that too small -search.latencyOffset may lead to incomplete query results.
Change default value for command-line flag `datasource.queryStep` from `0s` to `5m`.
Param `step` is added by vmalert to every rule evaluation request sent to datasource.
Before this change, `step` was equal to group's evaluation interval by default.
Param `step` for instant queries defines how far VM can look back for the last written data point.
The change supposed to improve reliability of the rules evaluation when evaluation interval
is lower than scraping interval.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Now vmalert will print the following messages on dupliсates:
```
"recording rule \"record\"; expr: \"up == 1\"; labels: summary={{ value|query }}" is a duplicate within the group "test"
"alerting rule \"alert\"; expr: \"up == 1\"; labels: description={{ value|query }}" is a duplicate within the group "test"
```
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3127
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* vmalert: always re-evaluate Annotations
Previously, Annotations were evaluated only:
1. On alert creating.
2. On alert's value change.
This is premature optimization. It was assumed that since annotations
could contain only text with alert's labels or value - there is no need
in spending resources to re-compile Annotations.
Later, template function `query` was added, which can execute
arbitrary queries and return different results on every evaluation.
So if it was used in annotations, it would be executed only on init
or value change.
Another case when optimization caused an issue - annotations hot reload.
In this case, annotations of the active alert won't change even if Rule's
annotations were changed.
This fix enables Annotations re-evaluation on each iteration to resolve
issues above. It would have some impact on performance, but it is unlikely
it will be noticeable.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* vmalert: add tp Changelog
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
The change adds an example of `curl` command to the Rule's page.
The command is generated for each recorded state. It is supposed
user can just copy&execute the command to see what was returned
to vmalert.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
The standard Snappy encoder from github.com/golang/snappy shows quite good performance number
for compressing the Prometheus remote_write proto messages according to the added benchmarks,
so there is no need in switching to github.com/klauspost/compress/s2 yet.
* vmselect/promql: add alphanumeric sort by label (sort_by_label_numeric)
* vmselect/promql: fix tests, add documentation
* vmselect/promql: update test
* vmselect/promql: update for alphanumeric sorting, fix tests
* vmselect/promql: remove comments
* vmselect/promql: cleanup
* vmselect/promql: avoid memory allocations, update functions descriptions
* vmselect/promql: make linter happy (remove ineffectual assigment)
* vmselect/promql: add test case, fix behavior when strings are equal
* vendor: update github.com/VictoriaMetrics/metricsql from v0.44.1 to v0.45.0
this adds support for sort_by_label_numeric and sort_by_label_numeric_desc functions
* wip
* lib/promscrape: read response body into memory in stream parsing mode before parsing it
This reduces scrape duration for targets returning big responses.
The response body was already read into memory in stream parsing mode before this change,
so this commit shouldn't increase memory usage.
* wip
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
vmalert: add experimental feature of storing Rule's evaluation state
The new feature keeps last 20 state changes of each Rule
in memory. The state are available for view on the Rule's
view page. The page can be opened by clicking on `Details`
link next to Rule's name on the `/groups` page.
States change suppose to help in investigating cases when Rule
doesn't generate alerts or records.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
The reason is to cover vulnerability GO-2022-0969
Found in: net/http@go1.18.5
Fixed in: net/http@go1.19.1
More info: https://pkg.go.dev/vuln/GO-2022-0969
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
- Rename logDebug() to logDebugf() and pass format string together
with format args directly to logDebugf(). This eliminates fmt.Sprintf()
overhead at logDebug() call site when debugging is disabled.
- Format labels in debug message in Prometheus format, e.g. {label1="value1",...labelN="valueN"}
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3025
* vmalert: add `debug` mode for alerting rules
Debug information includes alerts state changes and requests
sent to the datasource. Debug can be enabled only on rule's
level. It might be useful for debugging unexpected
behaviour of alerting rule.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3025
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* vmalert: review fixes
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* Update app/vmalert/alerting.go
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
* vmalert: go fmt
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
- Add getCommonParamsWithDefaultDuration function and use it at /api/v1/series, /api/v1/labels and /api/v1/label/.../values
- Document the default behaviour for setting 5 minutes time range if start arg isn't passed to /api/v1/series, /api/v1/labels and /api/v1/label/.../values
- Document the change at docs/CHANGELOG.md
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/3052
The panic may trigger during data blocks' processing received
from vmstorage nodes when some of vmstorage nodes return an error
or when `-replicationFactor` is set to values higher than 2 at `vmselect`.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3058
Note that the parallel execution of `union()` args may take more memory and CPU time
than the sequential execution if args contain heavy queries, which may load all the available CPU,
disk and memory resources and vmselect and vmstorage levels.
- Use getScalar() function for obtaining the expected scalar from phi arg
- Reduce the error message returned to the user when incorrect phi is passed to histogram_quantiles
- Improve the description of this bugfix in the docs/CHANGELOG.md
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3026