* lib/storage: creates parts.json on start-up if it not exists.
It fixes migrations from versions below v1.90.0.
Previously parts.json was created only after successful merge.
But if merge was interruped for some reason (OOM or shutdown), parts.json wasn't created and partitions left after interruped merge weren't properly deleted.
Since VM cannot check if it must be removed or not.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4336
* Apply suggestions from code review
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
* Update lib/storage/partition.go
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
---------
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
This error may be wrapped in another error, and should normally be tested using
`errors.Is(err, net.ErrClosed)`.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
This reverts the following commits:
- e0e16a2d36
- 2ce02a7fe6
The reason for revert: the updated logic breaks assumptions made
when fixing https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2698 .
For example, if a time series stop receiving new samples during the first
day after the indexdb rotation, there are chances that the time series
won't be registered in the new indexdb. This is OK until the next indexdb
rotation, since the time series is registered in the previous indexdb,
so it can be found during queries. But the time series will become invisible
for search after the next indexdb rotation, while its data is still there.
There is also incompletely solved issue with the increased CPU and disk IO resource
usage just after the indexdb rotation. There was an attempt to fix it, but it didn't fix
it in full, while introducing the issue mentioned above. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1401
TODO: to find out the solution, which simultaneously solves the following issues:
- increased memory usage for setups high churn rate and long retention (e.g. what the reverted commit does)
- increased CPU and disk IO usage during indexdb rotation ( https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1401 )
- https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2698
Possible solution - to create the new indexdb in one hour before the indexdb rotation
and to gradually pre-populate it with the needed index data during the last hour before indexdb rotation.
Then the new indexdb will contain all the needed data just after the rotation,
so it won't trigger increased CPU and disk IO.
- Document the change at docs/CHANGELOG.md
- Clarify comments for non-trivial code touched by the commit
- Improve the logic behind maybeCreateIndexes():
- Correctly create per-day indexes if the indexdb rotation is performed during
the first hour or the last hour of the day by UTC.
Previously there was a possibility of missing index entries on that day.
- Increase the duration for creating new indexes in the current indexdb for up to 22 hours
after indexdb rotation. This should reduce the increased resource usage
after indexdb rotation.
It is safe to postpone index creation for the current day until the last hour
of the current day after indexdb rotation by UTC, since the corresponding (date, ...)
entries exist in the previous indexdb.
- Search for TSID by (date, MetricName) in both the current and the previous indexdb.
Previously the search was performed only in the current indexdb. This could lead
to excess creation of per-day indexes for the current day just after indexdb rotation.
- Search for (date, metricID) entries in both the current and the previous indexdb.
Previously the search was performed only in the current indexdb. This could lead
to excess creation of per-day indexes for the current day just after indexdb rotation.
The new index substitutes global MetricName=>TSID index
used for locating TSIDs on ingestion path.
For installations with high ingestion and churn rate, global
MetricName=>TSID index can grow enormously making
index lookups too expensive. This also results into bigger
than expected cache growth for indexdb blocks.
New per-day index supposed to be much smaller and more efficient.
This should improve ingestion speed and reliability during
re-routings in cluster.
The negative outcome could be occupied disk size, since
per-day index is more expensive comparing to global index.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* lib/storage: follow-up after a50d63c376
- ensure retentionMsecs is rounded to day
- remove localTimeOffset in test as localOffset is ignored when using `UnixMilli`
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* lib/storage: restore retention timezone offset effect on retention deadline
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
---------
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
This reverts commit 9e99f2f5b3.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4068
Reason for revert: this breaks valid use cases:
- If timestamps aren't specified in the incoming samples on purpose. For example, if stream aggregation is used
as StatsD replacement. StatsD protocol has no timestamp concept for incoming samples.
See https://github.com/b/statsd_spec
- If all the samples must be aggregated, even if they contain stale timestamps.
for example, if the stream aggregation produces some counter of some events,
it may be better to count all the events even if they were delayed before
being ingested into VictoriaMetrics.
Is is also unclear how to determine whether the sample becomes stale.
For example, if the aggregation interval equals to 1h, and the previous
aggregation cycle just finished 10 minutes ago, what to do with the newly
incoming sample with the timestamp 30 minutes older than the current time?
The answer highly depends on the context, so it is unsafe to uncoditionally
use a single logic for dropping the old samples here.
previously during sync for mutable and immutable cache parts, link for hotEntry with current date may be not properly updated
it corrupts cache for backfilling metrics and increased cpu load
When using `retentionTimezoneOffset` and having local timezone being more than 4 hours different from UTC indexdb retention calculation could return negative value. This caused indexdb rotation to get in loop.
Fix calculation of offset to use `retentionTimezoneOffset` value properly and add test to cover all legit timezone configs.
See:
- https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4207
- https://github.com/VictoriaMetrics/VictoriaMetrics/pull/4206
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
Co-authored-by: Nikolay <nik@victoriametrics.com>
Windows doesn't allow to remove dir with opened files. Usually it's a case for snapshots, hard cannot be removed if file is openned.
With this change, dir will be renamed and properly deleted at the next process start.
It's recommended to restart vmstorage/vmsingle for snapshots deletion completion periodically.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/70
* lib/promscrape/discovery/kubernetes: add common labels to all ports discovered from endpoints
Sets
`__meta_kubernetes_endpoints_name` and `__meta_kubernetes_namespace` labels to all ports of pod.
Prometheus sets those labels to all ports in pod (0ab9553611/discovery/kubernetes/endpoints.go (L267C15-L269)) even if port is not matching any service.
See: #4154
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* lib/promscrape/discovery/kubernetes: fix test for updated discovery logic
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
---------
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* lib/streamaggr: discard samples with timestamps not matching aggregation interval
Samples with timestamps lower than `now - aggregation_interval` are likely to be written via backfilling and should not be used for calculation of aggregation.
See #4068
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* lib/streamaggr: make log message more descriptive, fix imports
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
---------
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* lib/promscrape: adds filter for consul_sd_configs:
it allows advanced filtering for consul service discovery requests
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4183
* typo fix
* removes deprecation mentions since it's not relevant
* Update docs/CHANGELOG.md
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
---------
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
* app/vmagent,lib/persistentqueue: show warning message if `--remoteWrite.maxDiskUsagePerURL` flag lower than 500MB
* app/vmagent,lib/persistentqueue: linter fix
* app/vmagent,lib/persistentqueue: fix comment
* lib/httpserver: introduce `-http.maxConcurrentRequests` command-line flag
Introduce `-http.maxConcurrentRequests` command-line flag to protect
VM components from resource exhaustion during unexpected spikes of HTTP requests.
By default, the new flag's value is set to 0 which means no limits are applied.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* lib/httpserver: mention http.maxConcurrentRequests in docs
Signed-off-by: hagen1778 <roman@victoriametrics.com>
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
This handler will instruct search engines that indexing is not allowed for the content exposed to the internet. This should help to address issues like #4128 when instances are exposed to the internet without authentication.
Callers of OpenStorage() log the returned error and exit.
The error logging and exit can be performed inside MustOpenStorage()
alongside with printing the stack trace for better debuggability.
This simplifies the code at caller side.
Use fs.MustReadDir() instead of os.ReadDir() across the code in order to reduce the code verbosity.
The fs.MustReadDir() logs the error with the directory name and the call stack on error
before exit. This information should be enough for debugging the cause of the error.
Callers of CreateFlockFile log the returned err and exit.
It is better to log the error inside the MustCreateFlockFile together with the path
to the specified directory and the call stack. This simplifies
the code at the callers' side while leaving the debuggability at the same level.
Callers of InitFromFilePart log the error and exit.
It is better to log the error with the path to the part and the call stack
directly inside the MustInitFromFilePart() function.
This simplifies the code at callers' side while leaving the same level of debuggability.
Callers of this function log the returned error and exit.
It is better logging the error together with the path to the filename
and call stack directly inside the function. This simplifies
the code at callers' side without reducing the level of debuggability
Callers of this function log the returned error and exit.
Let's log the error with the path to the filename and call stack
inside the function. This simplifies the code at callers' side
without reducing the level of debuggability.
- Add 'BUG:' prefix to error messages related to programming errors aka bugs.
- Consistently log the path to the file in all the messages in order to improve debuggability.
Callers of ReadFullData() log the error and then exit.
So let's log the error with the path to the filename and the call stack
inside MustReadData(). This simplifies the code at callers' side,
while leaving the debuggability at the same level.
Callers of these functions log the returned error and then exit.
Let's log the error with the call stack inside the function itself.
This simplifies the code at callers' side, while leaving the same
level of debuggability in case of errors.
Callers of this function log the returned error and then exit.
Let's log the error with the call stack inside the function itself.
This simplifies the code at callers' side, while leaving the same
level of debuggability in case of errors.
Callers of this function log the returned error and then exit.
Let's log the error with the call stack inside the function itself.
This simplifies the code at callers' side, while leaving the same
level of debuggability in case of errors.
Callers of this function log the returned error and exit.
So let's just log the error with the given filepath and the call stack
inside the function itself and then exit. This simplifies the code
at callers' place while leaves the same level of debuggability in case of errors.
Callers of these functions log the returned error and then exit. The returned error already contains the path
to directory, which was failed to be created. So let's just log the error together with the call stack
inside these functions. This leaves the debuggability of the returned error at the same level
while allows simplifying the code at callers' side.
While at it, properly use MustMkdirFailIfExist instead of MustMkdirIfNotExist inside inmemoryPart.MustStoreToDisk().
It is expected that the inmemoryPart.MustStoreToDick() must fail if there is already a directory under the given path.
When WriteFileAndSync fails, then the caller eventually logs the error message
and exits. The error message returned by WriteFileAndSync already contains the path
to the file, which couldn't be created. This information alongside the call stack
is enough for debugging the issue. So just use log.Panicf("FATAL: ...") inside MustWriteAndSync().
This simplifies error handling at caller side a bit.
This is a follow-up after 42bba64aa7
Previously the part directory listing was fsync'ed implicitly inside partHeader.WriteMetadata()
by calling fs.WriteFileAtomically(). Now it must be fsync'ed explicitly.
There is no need in fsync'ing the parent directory, since it is fsync'ed by the caller
when updating parts.json file.
Previously the created part directory listing was fsynced implicitly
when storing metadata.json file in it.
Also remove superflouous fsync for part directory listing,
which was called at blockStreamWriter.MustClose().
After that the metadata.json file is created, so an additional fsync
for the directory contents is needed.
Improperly configured -bigMergeConcurrency command-line flag usually leads to uncontrolled
growth of unmerged parts, which, in turn, increases CPU usage and query durations.
So it is better deprecating this flag. In rare cases -smallMergeConcurrency command-line flag
can be used instead for controlling the concurrency of background merges.
This makes it easier to understand exact point in time which is included in this backup.
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
The logic employed for re-using the previously loaded scrape target was broken initially.
The commit cc0427897c tried to fix it, but the new logic
became too complex and fragile. So it is better to just remove this logic,
since the targets from temporarily broken file should be eventually loaded on next
attempts every -promscrape.fileSDCheckInterval
This also allows removing fragile hacks around __vm_filepath label.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3989
* lib/promscrape: fix the problem with scrape work duplicates when file_sd_config can't be read
* lib/promscrape: clarified comment
* lib/promscrape: made better approach to handle a problem with growing []*ScrapeWork on each error when loading config
* lib/promscrape: added CHANGELOG.md
* Update docs/CHANGELOG.md
---------
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
* lib/storage: check for free disk space before opening tables
We check for free disk space before call to `openTable`,
so `Storage` can be set to ReadOnly before mergeWorkers start.
Before the change, there was a chance that merges will start
even if Storage has to start in ReadOnly mode because of
`-storage.minFreeDiskSpaceBytes` limit.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4023
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* lib/storage: chore
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* Update lib/storage/storage.go
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
- Make sure that the last successfully loaded config is used on hot-reload failure
- Properly cleanup resources occupied by already initialized aggregators
when the current aggregator fails to be initialized
- Expose distinct vmagent_streamaggr_config_reload* metrics per each -remoteWrite.streamAggr.config
This should simplify monitoring and debugging failed reloads
- Remove race condition at app/vminsert/common.MustStopStreamAggr when calling sa.MustStop() while sa
could be in use at realoadSaConfig()
- Remove lib/streamaggr.aggregator.hasState global variable, since it may negatively impact scalability
on system with big number of CPU cores at hasState.Store(true) call inside aggregator.Push().
- Remove fine-grained aggregator reload - reload all the aggregators on config change instead.
This simplifies the code a bit. The fine-grained aggregator reload may be returned back
if there will be demand from real users for it.
- Check -relabelConfig and -streamAggr.config files when single-node VictoriaMetrics runs with -dryRun flag
- Return back accidentally removed changelog for v1.87.4 at docs/CHANGELOG.md
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3639
Verifying status code helps to avoid misleading errors caused by attempt to parse unsuccessful response.
Related issue: #4034
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
- Compare directory names instead of paths to directory when determining which persistent queues must be deleted
This is less error-prone solution, since paths to the same directory can differ, which could lead
to accidental directory removal for the existing -remoteWrite.url
- Log the `removed %d dangling queues` message when at least a single queue has been removed
- Consistently use filepath.Join() for creating paths to persistent queues.
This is needed for Windows support (see https://github.com/VictoriaMetrics/VictoriaMetrics/issues/70 )
- Clarify the description of the change at docs/CHANGELOG.md
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4014
- Use windows.FlushFileBuffers() instead of windows.Fsync() at streamTracker.adviseDontNeed()
for consistency with implementations for other architectures.
- Use filepath.Base() instead of filepath.Split(), since the dir part isn't used.
This simplifies the code a bit.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/70
This is a follow-up for 43b24164ef
* lib/fs: adds memory map for windows
it should improve performance for file reading
* lib/storage: replace '/' with os specific separator
it must fix an errors for windows
* lib/fs: mention windows fsync support
* lib/filestream: adds fdatasync for windows writes
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/70
* allowed using dashes and dots in environment variables names for templating config files with envtemplate (#3999)
Signed-off-by: Alexander Marshalov <_@marshalov.org>
* Apply suggestions from code review
---------
Signed-off-by: Alexander Marshalov <_@marshalov.org>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
* lib/netutil: log only parsing errors for proxy-protocol
Previosly every error was logged. With configured TCP health checks at load-balancer or kubernetes, vmauth spams a lot of false positive error message into logs
* Update docs/CHANGELOG.md
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
* Update lib/netutil/tcplistener.go
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
---------
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
This commit changes background merge algorithm, so it becomes compatible with Windows file semantics.
The previous algorithm for background merge:
1. Merge source parts into a destination part inside tmp directory.
2. Create a file in txn directory with instructions on how to atomically
swap source parts with the destination part.
3. Perform instructions from the file.
4. Delete the file with instructions.
This algorithm guarantees that either source parts or destination part
is visible in the partition after unclean shutdown at any step above,
since the remaining files with instructions is replayed on the next restart,
after that the remaining contents of the tmp directory is deleted.
Unfortunately this algorithm doesn't work under Windows because
it disallows removing and moving files, which are in use.
So the new algorithm for background merge has been implemented:
1. Merge source parts into a destination part inside the partition directory itself.
E.g. now the partition directory may contain both complete and incomplete parts.
2. Atomically update the parts.json file with the new list of parts after the merge,
e.g. remove the source parts from the list and add the destination part to the list
before storing it to parts.json file.
3. Remove the source parts from disk when they are no longer used.
This algorithm guarantees that either source parts or destination part
is visible in the partition after unclean shutdown at any step above,
since incomplete partitions from step 1 or old source parts from step 3 are removed
on the next startup by inspecting parts.json file.
This algorithm should work under Windows, since it doesn't remove or move files in use.
This algorithm has also the following benefits:
- It should work better for NFS.
- It fits object storage semantics.
The new algorithm changes data storage format, so it is impossible to downgrade
to the previous versions of VictoriaMetrics after upgrading to this algorithm.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3236
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3821
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/70
lib{mergset,storage}: prevent possible race condition with logging stats for merges
Previously partwrapper could be release by background process and reference for part may be invalid
during logging stats. It will lead to panic at vmstorage
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3897
- Use flag.Duration instead of flagutil.Duration for -snapshotCreateTimeout,
since the flagutil.Duration is intended mostly for big durations, e.g. days, months and years,
while the -snapshotCreateTimeout is usually smaller than one hour.
- Add links to https://docs.victoriametrics.com/#how-to-work-with-snapshots in docs/CHANGELOG.md,
so readers could easily find the corresponding docs when reading the changelog.
- Properly remove all the created directories on unsuccessful attempt to create
snapshot in Storage.CreateSnapshot().
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3551
* lib/{fs,mergeset,storage}: skip `.must-remove.` dirs when creating snapshot (#3858)
* lib/{mergeset,storage}: add timeout configuration for snapshots creation, remove incomplete snapshots from storage
* docs: fix formatting
* app/vmstorage: add metrics to track status of snapshots
* app/vmstorage: use `vm_http_requests_total` metric for snapshot endpoints metrics, rename new flag to make name more clear
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* app/vmstorage: update flag name in docs
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* app/vmstorage: reflect new metrics names change in docs
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
---------
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
* lib/promscrape: set `vm_promscrape_config_last_reload_successful` to 1 if there was no promscrape config provided
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* lib/promscrape: register `vm_promscrape_config_*` metrics only in case promscrape config is used
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
---------
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
- Return immediately on context cancel during the backoff sleep.
This should help with https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3747
- Add a comment describing why the second attempt to obtain the response from remote side
is perfromed immediately after the first attempt.
- Remove fasthttp dependency from lib/promscrape/discoveryutils
- Set context deadline before calling doRequestWithPossibleRetry().
This simplifies the doRequestWithPossibleRetry() a bit.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3293
* fix: do not use exponential backoff for first retry of scrape request (#3293)
* lib/promscrape: refactor `doRequestWithPossibleRetry` backoff to simplify logic
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* Update lib/promscrape/client.go
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
* lib/promscrape: refactor `doRequestWithPossibleRetry` to make it more straightforward
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
---------
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
* Modify API version when running in Container App
* Handle expires on from token response
Response from IMDS does not always contain expires in value which is
currently used to get the token expiry time. An example resources that
doesn't provide it are Container Apps and App Service.
Signed-off-by: Mattias Ängehov <mattias.angehov@castoredc.com>
* Fix client id parameter for user assigned identity
* Apply suggestions from code review
---------
Signed-off-by: Mattias Ängehov <mattias.angehov@castoredc.com>
Co-authored-by: Aliaksandr Valialkin <valyala@gmail.com>
- Do not generate __meta_server label, since it is unavailable in Prometheus.
- Add a link to https://docs.victoriametrics.com/sd_configs.html#kuma_sd_configs to docs/CHANGELOG.md,
so users could click it and read the docs without the need to search the corresponding docs.
- Remove kumaTarget struct, since it is easier generating labels for discovered targets
directly from the response returned by Kuma. This simplifies the code.
- Store the generated labels for discovered targets inside atomic.Value. This allows reading them
from concurrent goroutines without the need to use mutex.
- Use synchronouse requests to Kuma instead of long polling, since there is a little sense
in the long polling when the Kuma server may return 304 Not Modified response every -promscrape.kumaSDCheckInterval.
- Remove -promscrape.kuma.waitTime command-line flag, since it is no longer needed when long polling isn't used.
- Set default value for -promscrape.kumaSDCheckInterval to 30s in order to be consistent with Prometheus.
- Remove unnecessary indirections for string literals, which are used only once, in order to improve code readability.
- Remove unused fields from discoveryRequest and discoveryResponse.
- Update tests.
- Document why fetch_timeout and refresh_interval options are missing in kuma_sd_config.
- Add docs to discoveryutils.RequestCallback and discoveryutils.ResponseCallback,
since these are public types.
Side notes: it is weird that Prometheus implementation for kuma_sd_configs sets `instance` label,
since usually this label is set by the Prometheus itself to __address__ after the relabeling phase.
See https://www.robustperception.io/life-of-a-label/
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3389
See https://github.com/prometheus/prometheus/issues/7919
and https://github.com/prometheus/prometheus/pull/8844
as a reference implementation in Prometheus
