While at it, stop sending requests to unavailable backend for 3 seconds
before the next attempt. This should reduce the amounts of useless work
and the number of useless network packets when the backend is temporarily unavailable.
* app/vmauth: add concurent requests limit per auth record
* app/vmauth: added clarification comment
* app/vmauth: remove unused code
* app/vmauth: move read from limiter
* app/vmauth: fix text
* app/vmauth: fix comments
* - Clarify the docs for the max_concurrent_requests option at docs/vmauth.md
- Clarify the description of the change at docs/CHANGELOG.md
- Make sure that the -maxConcurrentRequests takes precedence over per-user max_concurrent_requests
- Update tests for verifying that the max_concurrent_requests option is parsed properly
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3346
---------
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
- Document the change at docs/CHANGELOG.md
- Add `Reading rules from object storage` section to docs/vmalert.md
- Add `s3` prefix to command-line flags related to the configuration of s3 and gcs clients
- Explicitly mention that reading rules from object storage is supported only in enterprise version
* vmalert: support object storage for rules
Support loading of alerting and recording rules from object
storages `gcs://`, `gs://`, `s3://`.
* review fixes
* vmalert: use group's ID in UI to avoid collisions
Identical group names are allowed. So we should used IDs
for various groupings and aggregations in UI.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* vmalert: prevent disabling state updates tracking
The minimum number of update states to track is now set to 1.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* vmalert: properly update `debug` and `update_entries_limit` params on hot-reload
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* vmalert: display `debug` field for rule in UI
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* vmalert: exclude `updates` field from json marhsaling
This field isn't correctly marshaled right now.
And implementing the correct marshaling for it doesn't
seem right, since json representation is mostly used
by systems like Grafana. And Grafana doesn't expect this
field to be present.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* fix test for disabled state
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* fix test for disabled state
Signed-off-by: hagen1778 <roman@victoriametrics.com>
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* vmalert: speed up state restore procedure on start
Alerts state restore procedure has been changed to become asynchronous.
It doesn't block groups start anymore which significantly improves vmalert's startup time.
Instead, state restore is called by each group in their goroutines after the first rules
evaluation.
While previously state restore attempt was made for all loaded alerting rules,
now it is called only for alerts which became active after the first evaluation.
This reduces the amount of API calls to the configured remote read URL.
This also means that `remoteRead.ignoreRestoreErrors` command-line flag becomes deprecated now
and will have no effect if configured.
See relevant issue https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2608
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* make lint happy
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* Apply suggestions from code review
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
This allows better controlling requests to backends and providing better error logging.
For example, if the backend was unavailable, then the ReverseProxy was logging the error
message without client ip and the initial request uri. This could harden debugging.
This is based on https://github.com/VictoriaMetrics/VictoriaMetrics/pull/3486
* feat: include fonts in the build
* fix: reduce size fonts
* wip
- Document the change at docs/CHANGELOG.md
- Run `make vmui-update`
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
- Call httpserver.GetQuotedRemoteAddr() and httpserver.GetRequestURI() only when the error occurs.
This saves CPU time on fast path when there are no parsing errors.
- Create a helper function - httpserver.LogError() - for logging the error with the request uri and remote addr context.
This prevents vmbackup from leaking passwords into logs like shown below.
2023-01-11T15:00:01.050Z info VictoriaMetrics/lib/logger/flag.go:12 build version: vmbackup-20221214-211706-tags-v1.85.1-0-g09a70d3e9
2023-01-11T15:00:01.050Z info VictoriaMetrics/lib/logger/flag.go:13 command-line flags
2023-01-11T15:00:01.050Z info VictoriaMetrics/lib/logger/flag.go:20 -dst="fs:///vm-backups/latest"
2023-01-11T15:00:01.050Z info VictoriaMetrics/lib/logger/flag.go:20 -snapshot.createURL="http://user:super_sercret123@victoriametricspshot/create"
2023-01-11T15:00:01.050Z info VictoriaMetrics/lib/logger/flag.go:20 -storageDataPath="/storage"
2023-01-11T15:00:01.050Z info VictoriaMetrics/app/vmbackup/main.go:53 Snapshot create url http://user:super_sercret123@victoriametrics:8428/snapshot/create
2023-01-11T15:00:01.050Z info VictoriaMetrics/app/vmbackup/main.go:60 Snapshot delete url http://user:super_sercret123@victoriametrics:8428/snapshot/delete
* feat: make the step input field global
* fix: correct get step from url
* fix: set minimumSignificantDigits to 1
* app/vmselect/vmui: `make vmui-update`
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
The per-series timestamps are usually shared among series, so it is unsafe modifying them.
The issue has been appeared after the optimization at 2f3ddd4884
* {lib/server, app/}: use `httpAuth.*` flag as fallback for `*AuthKey` if it is not set
* lib/ingestserver/opentsdbhttp: fix opentdb HTTP handler not respecting `httpAuth.*` flags
* Apply suggestions from code review
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
* vmagent: add minimal scrape file exampe for vmagent quick start
Signed-off-by: Artem Navoiev <tenmozes@gmail.com>
* replace example with link to your prometheus.yml in docker
Signed-off-by: Artem Navoiev <tenmozes@gmail.com>
Signed-off-by: Artem Navoiev <tenmozes@gmail.com>
Previously the selected time series were split evenly among available CPU cores
for further processing - e.g unpacking the data and applying the given rollup
function to the unpacked data.
Some time series could be processed slower than others.
This could result in uneven work distribution among available CPU cores,
e.g. some CPU cores could complete their work sooner than others.
This could slow down query execution.
The new algorithm allows stealing time series to process from other CPU cores
when all the local work is done. This should reduce the maximum time
needed for query execution (aka tail latency).
The new algorithm should also scale better on systems with many CPU cores,
since every CPU processes locally assigned time series without inter-CPU communications.
The inter-CPU communications are used only when all the local work is finished
and the pending work from other CPUs needs to be stealed.
Unpack time series with less than 400K samples in the currently running goroutine.
Previously a new goroutine was being started for unpacking the samples.
This was requiring additional memory allocations.
Usually the number of blocks returned per each time series during queries is around 4.
So it is a good idea to pre-allocate 4 block references per time series
in order to reduce the number of memory allocations.
Previously the -maxConcurrentInserts was limiting the number of established client connections,
which write data to VictoriaMetrics. Some of these connections could be idle.
Such connections do not consume big amounts of CPU and RAM, so there is a little sense in limiting
the number of such connections. So now the -maxConcurrentInserts command-line option
limits the number of concurrently executed insert requests, not including idle connections.
It is recommended removing -maxConcurrentInserts command-line option, since the default value
for this option should work good for most cases.
Stress the importance of specifying of all Alertmanager
URLs in vmalert's `-notifier.url` or `notifier.config`
if it runs in cluster mode.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3547
Signed-off-by: hagen1778 <roman@victoriametrics.com>
- Show in the line tooltip the number of the query which generates the given line.
This simplifies comparison of lines generated by multiple queries.
- Show metric name as __name__ label in the line tooltip in the same way as other labels are shown there.
This makes the label information in the tooltip more consistent.
- Properly quote label values with JSON.stringify(). This prevents from improper formatting
when label values contain doublequote chars.
- Remove double curly braces artifact at graph legend for lines without names and labels.
- Properly use modifier for regular expressions across the code.
There is no need to manually call `queryDuration.UpdateDuration(startTime)`, because `defer queryDuration.UpdateDuration(startTime)` is executed at the beginning of the function(L660).
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>
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
* 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.
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
* 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>
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>
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>
