Commit graph

214 commits

Author SHA1 Message Date
Zakhar Bessarab
f7834767c1
vmcluster: re-routing enhancement (#5293)
* app/vmstorage: close vminsert connections gradually before stopping storage

Implements graceful shutdown approach suggested here - https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4922#issuecomment-1768146878

Test results for this can be found here - https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4922#issuecomment-1790640274

Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>

* app/vmstorage: update graceful shutdown logic

- close connections from vminsert in determenistic order
- update flag description
- lower default timeout to 25 seconds. 25 seconds value was chosen because the lowest default value used in default configuration deployments is 30s(default value in Kubernetes and ansible-playbooks).

Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>

* docs/cluster: add information about re-routing enhancement during restart

Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>

* docs/changelog: add entry for new command-line flag

Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>

* {app/vmstorage,lib/ingestserver}: address review feedback

Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>

* docs/cluster: add note to update workload scheduler timeout

Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>

* wip

---------

Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
2023-11-14 01:00:42 +01:00
Aliaksandr Valialkin
a421db5977
lib/storage: stop exposing vm_merge_need_free_disk_space metric
This metric confuses users and has no any useful information.

See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/686#issuecomment-1733844128
2023-09-25 17:00:14 +02:00
Aliaksandr Valialkin
d8afd7fe98
Makefile: update golangci-lint from v1.51.2 to v1.54.2
See https://github.com/golangci/golangci-lint/releases/tag/v1.54.2
2023-09-01 10:25:49 +02:00
Dima Lazerka
1d60c236b1
Add flagutil.Duration to avoid conversion bugs (#4835)
* Introduce flagutil.Duration

To avoid conversion bugs

* Fix tests

* Comment why not .Seconds()
2023-09-01 09:30:30 +02:00
Aliaksandr Valialkin
bde876f7c9
all: refer to https://docs.victoriametrics.com/#resource-usage-limits in the error message about -search.max* limit
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4827
2023-08-14 02:02:12 -07:00
Nikolay
30b32583f4
lib/storage: pre-create timeseries before indexDB rotation (#4652)
* lib/storage: pre-create timeseries before indexDB rotation
during an hour before indexDB rotation start creating records at the next indexDB
it must improve performance during switch for the next indexDB and remove ingestion issues.
Since there is no need for creation new index records for timeseries already ingested into current indexDB
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4563

* lib/storage: further work on indexdb rotation optimization

- Document the change at docs/CHAGNELOG.md
- Move back various caches from indexDB to Storage. This makes the change less intrusive.
  The dateMetricIDCache now takes into account indexDB generation, so it stores (date, metricID)
  entries for both the current and the next indexDB.
- Consolidate the code responsible for idbNext pre-filling into prefillNextIndexDB() function.
  This improves code readability and maintainability a bit.
- Rewrite and simplify the code responsible for calculating the next retention timestamp.
  Add various tests for corner cases of this code.
- Remove indexdb pre-filling from RegisterMetricNames() function, since this function is rarely called.
  It is OK to add indexdb entries on demand in this function. This simplifies the code.

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1401

* docs/CHANGELOG.md: refer to https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4563

---------

Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
2023-07-22 15:23:14 -07:00
Aliaksandr Valialkin
e1cf962bad
lib/storage: switch from global to per-day index for MetricName -> TSID mapping
Previously all the newly ingested time series were registered in global `MetricName -> TSID` index.
This index was used during data ingestion for locating the TSID (internal series id)
for the given canonical metric name (the canonical metric name consists of metric name plus all its labels sorted by label names).

The `MetricName -> TSID` index is stored on disk in order to make sure that the data
isn't lost on VictoriaMetrics restart or unclean shutdown.

The lookup in this index is relatively slow, since VictoriaMetrics needs to read the corresponding
data block from disk, unpack it, put the unpacked block into `indexdb/dataBlocks` cache,
and then search for the given `MetricName -> TSID` entry there. So VictoriaMetrics
uses in-memory cache for speeding up the lookup for active time series.
This cache is named `storage/tsid`. If this cache capacity is enough for all the currently ingested
active time series, then VictoriaMetrics works fast, since it doesn't need to read the data from disk.

VictoriaMetrics starts reading data from `MetricName -> TSID` on-disk index in the following cases:

- If `storage/tsid` cache capacity isn't enough for active time series.
  Then just increase available memory for VictoriaMetrics or reduce the number of active time series
  ingested into VictoriaMetrics.

- If new time series is ingested into VictoriaMetrics. In this case it cannot find
  the needed entry in the `storage/tsid` cache, so it needs to consult on-disk `MetricName -> TSID` index,
  since it doesn't know that the index has no the corresponding entry too.
  This is a typical event under high churn rate, when old time series are constantly substituted
  with new time series.

Reading the data from `MetricName -> TSID` index is slow, so inserts, which lead to reading this index,
are counted as slow inserts, and they can be monitored via `vm_slow_row_inserts_total` metric exposed by VictoriaMetrics.

Prior to this commit the `MetricName -> TSID` index was global, e.g. it contained entries sorted by `MetricName`
for all the time series ever ingested into VictoriaMetrics during the configured -retentionPeriod.
This index can become very large under high churn rate and long retention. VictoriaMetrics
caches data from this index in `indexdb/dataBlocks` in-memory cache for speeding up index lookups.
The `indexdb/dataBlocks` cache may occupy significant share of available memory for storing
recently accessed blocks at `MetricName -> TSID` index when searching for newly ingested time series.

This commit switches from global `MetricName -> TSID` index to per-day index. This allows significantly
reducing the amounts of data, which needs to be cached in `indexdb/dataBlocks`, since now VictoriaMetrics
consults only the index for the current day when new time series is ingested into it.

The downside of this change is increased indexdb size on disk for workloads without high churn rate,
e.g. with static time series, which do no change over time, since now VictoriaMetrics needs to store
identical `MetricName -> TSID` entries for static time series for every day.

This change removes an optimization for reducing CPU and disk IO spikes at indexdb rotation,
since it didn't work correctly - see https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1401 .

At the same time the change fixes the issue, which could result in lost access to time series,
which stop receving new samples during the first hour after indexdb rotation - see https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2698

The issue with the increased CPU and disk IO usage during indexdb rotation will be addressed
in a separate commit according to https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1401#issuecomment-1553488685

This is a follow-up for 1f28b46ae9
2023-07-13 17:03:50 -07:00
Dmytro Kozlov
88ac6116bd
docs: clarify -retentionPeriod flag usage (#4417)
app/vmstorage: clarify the min value for `-retentionPeriod` flag

Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>

(cherry picked from commit 24f34347f1)
Signed-off-by: hagen1778 <roman@victoriametrics.com>
2023-06-09 10:44:22 +02:00
Roman Khavronenko
576e59d82c
cluster: standardize default HTTP responses (#4368)
Signed-off-by: hagen1778 <roman@victoriametrics.com>
2023-06-01 10:26:52 +02:00
Aliaksandr Valialkin
0397b3f0f7
lib/handshake: do not pollute logs with cannot read hello messages on TCP health checks
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1762
2023-05-18 10:37:59 -07:00
Aliaksandr Valialkin
d739511f5b
lib/storage: replace OpenStorage() with MustOpenStorage()
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.
2023-04-14 23:04:42 -07:00
Aliaksandr Valialkin
cf53ce83a0
app/vmstorage: deprecate -bigMergeConcurrency command-line flag
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.
2023-04-13 20:42:22 -07:00
Aliaksandr Valialkin
fc3d826d7f
all: add Windows build for VictoriaMetrics
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
2023-03-19 23:28:26 -07:00
Aliaksandr Valialkin
54fe207cc0
all: follow-up for 7a3e16e774
- Sync the description for -httpListenAddr.useProxyProtocol command-line flag at vmagent and vmauth,
  so it is consistent with the description at vmauth and victoria-metrics
- Add a sample of panic text to docs/CHANGELOG.md, so it could be googled
- Mention the -httpListenAddr.useProxyProtocol command-line flag in the description for the bugfix

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3335
2023-03-08 01:42:58 -08:00
Aliaksandr Valialkin
1ad0d22e80
lib/storage: follow-up for 39cdc546dd
- 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
2023-02-27 13:11:10 -08:00
Zakhar Bessarab
26682e369e
lib/storage: enhancements for snapshots process (#3873)
* 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>
2023-02-27 13:11:06 -08:00
Aliaksandr Valialkin
bbd5914eb1
all: add makefile rules for GOARCH=s390x for all the VictoriaMetrics components
This is a follow-up for 007530f882
2023-02-26 12:38:48 -08:00
Aliaksandr Valialkin
0c60e4a30a
all: consistently use http.Method{Get,Post,Put} across the codebase
This is a follow-up after 9dec3c8f80
2023-02-22 19:01:09 -08:00
Aliaksandr Valialkin
086516a02b
lib/protoparser/clusternative: extract stream parsing code into a separate stream package
This is a follow-up for 057698f7fb
2023-02-13 10:38:02 -08:00
Aliaksandr Valialkin
34379d4cf1
all: run apk update && apk upgrade in base Alpine Docker image in order to get all the recent security fixes 2023-02-09 14:03:02 -08:00
Nikolay
ebebaecd94
lib/netutil: init implimentation of proxy protocol (#3687)
* lib/netutil: init implimentation of proxy protocol
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3335

* wip

Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
2023-01-26 23:25:22 -08:00
Aliaksandr Valialkin
103dfd0525
lib/{mergeset,storage}: do not slow down concurrently executed queries during assisted merges
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3647
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3641
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/648
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/291
2023-01-16 14:45:40 -08:00
Aliaksandr Valialkin
aa027529eb
lib/httpserver: directly pass flag value to CheckAuthFlag()
There is no sense in passing a pointer to flag value there.

This is a follow-up for 4225a0bd75
2023-01-10 15:59:55 -08:00
Zakhar Bessarab
10f314cdbd
Use httpAuth.* flags as a fallback for endpoints protected by *AuthKey flags (#3582)
* {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>
2023-01-10 15:57:55 -08:00
Aliaksandr Valialkin
b275983403
lib/writeconcurrencylimiter: improve the logic behind -maxConcurrentInserts limit
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.
2023-01-06 22:07:16 -08:00
Aliaksandr Valialkin
20e9598254
lib/vmselectapi: limit the number of concurrently executed requests
This should prevent from out of memory errors when big number of vmselect
nodes send many concurrent requests to vmstorage

The limit can be controlled at vmstorage via the following command-line flags:
- search.maxConcurrentRequests
- search.maxQueueDuration

See https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#resource-usage-limits
2023-01-06 18:39:46 -08:00
Aliaksandr Valialkin
1a88fe5b1f
lib/flagutil/bytes.go: properly handle values bigger than 2GiB on 32-bit architectures
This fixes handling of values bigger than 2GiB for the following command-line flags:

- -storage.minFreeDiskSpaceBytes
- -remoteWrite.maxDiskUsagePerURL
2022-12-14 19:29:57 -08:00
Aliaksandr Valialkin
2a190f6451
lib/{mergeset,storage}: do not block small merges by pending big merges - assist with small merges instead
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
2022-12-12 17:01:33 -08:00
Aliaksandr Valialkin
7d5c64eb7a
all: add -inmemoryDataFlushInterval command-line flag for controlling the frequency of saving in-memory data to disk
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
2022-12-05 15:28:09 -08:00
Zakhar Bessarab
e407e7243a
{app/vmstorage,app/vmselect}: add API to get list of existing tenants (#3348)
* {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>
2022-11-25 10:32:45 -08:00
Dmytro Kozlov
6f7956503f
app/vmstorage: fix potential file inclusion via variable (#3339)
* app/vmstorage: fix potential file inclusion via variable

* app/vmstorage: cleanup
2022-11-17 01:31:37 +02:00
Aliaksandr Valialkin
a6d4711ac6
lib/storage: add support for retention filters (aka multiple retentions for distinct sets of time series)
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/143
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/289
2022-10-24 16:41:59 +03:00
Aliaksandr Valialkin
2dd93449d8
lib/storage: subsitute searchTSIDs functions with more lightweight searchMetricIDs function
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
2022-10-23 12:43:44 +03:00
Aliaksandr Valialkin
98bd843f3c
app/{vminsert,vmselect,vmstorage}: add package-{vminsert,vmselect,vmstorage}-{goarch} Makefile rules for building arch-specific docker images 2022-10-07 20:17:01 +03:00
Aliaksandr Valialkin
916f1ab86c
app/vmstorage/servers: properly copy MetricName into MetricBlock inside blockIterator.NextBlock
This should fix the issue at cf36bfa189
2022-10-07 02:57:54 +03:00
Aliaksandr Valialkin
7b9ba456ff
app/vmstorage: expose vm_{hourly,daily}_series_limit_{max,current}_series metrics if -storage.max{Hourly,Daily}Series limits are set
These metrics allow alerting when the number of unique series approach the limit.
For example, the following query alerts when the number of series reaches 90% of the configured limit:

    vm_hourly_series_limit_current_series / vm_hourly_series_limit_max_series > 0.9
2022-08-24 13:41:57 +03:00
Aliaksandr Valialkin
c0c9f30870
lib/pushmetrics: properly handle errors when initializing pushmetrics 2022-07-22 13:38:25 +03:00
Aliaksandr Valialkin
fe68bb3ba7
all: follow-up after 46f803fa7a
Add -pushmetrics.* command-line flags to all the VictoriaMetrics apps
2022-07-21 20:18:25 +03:00
Aliaksandr Valialkin
70b9925bf7
app: fix make publish-* after ed93330e66
Add missing `-linux` substring to built binary names for copying into Docker images
2022-07-14 11:01:34 +03:00
Aliaksandr Valialkin
da6c85a2f6
all: follow-up for d99ba3481b 2022-07-13 17:17:08 +03:00
Dmytro Kozlov
4e4def9df8
Rename release packages (#2810)
* makefile: add os to each release file

* makefile: update vmutils arm64

* makefile: update victoria-metrics release process

* makefile: update publish with os

* makefile: update publish with os

* makefile: change tar library

* update release logic

* copy all releases

* sort command by GOOS

* rollback commands

* rollback OSARCH

* fix commands

* cleanup

* fix windows build

* sort build by GOOS, update README.md
2022-07-13 17:11:01 +03:00
guidao
f2d24a660b
add next retention metric (#2863)
Co-authored-by: wangfeng <wangfeng@zhihu.com>
2022-07-13 12:41:22 +03:00
Aliaksandr Valialkin
1ec4dfd678
lib/vmselectapi: pass storage.SearchQuery to API calls instead of []*storage.TagFilters + storage.TimeRange + maxMetrics
This reduces the number of args to vmselectapi calls
2022-07-06 12:46:22 +03:00
Aliaksandr Valialkin
2e721f7d16
lib/vmselectapi: rename Server.MustClose to more clear Server.MustStop 2022-07-06 12:46:22 +03:00
Aliaksandr Valialkin
78eeca6f0d
lib/vmselectapi: rename deleteMetrics to more correct deleteSeries 2022-07-06 12:46:21 +03:00
Aliaksandr Valialkin
5afa54e845
lib/vmselectapi: use string type for tagKey and tagValuePrefix args at TagValueSuffixes()
This improves the API consistency
2022-07-06 12:46:21 +03:00
Aliaksandr Valialkin
7d5d33fd71
lib/storage: return marshaled metric names from SearchMetricNames
Previously SearchMetricNames was returning unmarshaled metric names.
This wasn't great for vmstorage, which should spend additional CPU time
for marshaling the metric names before sending them to vmselect.

While at it, remove possible duplicate metric names, which could occur when
multiple samples for new time series are ingested via concurrent requests.

Also sort the metric names before returning them to the client.
This simplifies debugging of the returned metric names across repeated requests to /api/v1/series
2022-06-28 18:16:32 +03:00
Aliaksandr Valialkin
36edb1912b
app/vmstorage: rename "transport" package to "servers" package for better clarity 2022-06-28 14:04:14 +03:00
Aliaksandr Valialkin
399d4c36ae
app/vmselect: optimize /api/v1/series a bit for time ranges smaller than one day 2022-06-28 12:55:20 +03:00
Aliaksandr Valialkin
64505e924d
app/vmstorage: extract vmselect api server into a separate package - lib/vmselectapi
This opens doors for implementing vmselect api server at vmselect level,
so top-level vmselect could query lower-level vmselect nodes in the same way
as it queries vmstorage nodes.

This will create the ability to create highly available querying architecture
when multiple independent VictoriaMetrics clusters with the same data
are located in distinct availability zones. In this case we can use top-level
vmselect instead of Promxy for simultaneous querying of all the clusters
in all the AZs.
2022-06-27 14:20:41 +03:00