It should help identifying cases when too much CPU is spent on garbage collection,
and advice users on how this can be addressed.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
The easyproto-based marshaler is 2x slower than the previous custom marshaler,
so let's stick with it. This improves the performance for sending data to remote storage at vmagent
and reduces CPU usage to pre-v1.97.0 levels.
* adding support for username_file in basic_auth of scrape config
Signed-off-by: Syed Nihal <syed.nihal@nokia.com>
* adding support for username_file in basic_auth of scrape config. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5511
Signed-off-by: Syed Nihal <syed.nihal@nokia.com>
* adding support for username_file in basic_auth of scrape config
Signed-off-by: Syed Nihal <syed.nihal@nokia.com>
* adding support for username_file in basic_auth of scrape config
Signed-off-by: Syed Nihal <syed.nihal@nokia.com>
* adding support for username_file in basic_auth of scrape config
Signed-off-by: Syed Nihal <syed.nihal@nokia.com>
---------
Signed-off-by: Syed Nihal <syed.nihal@nokia.com>
This case is possible after a new brsPool is allocated. The fix is to verify whether len(brsPool) >= len(brs.brs)
before trying to append a new item to brsPool and sharing its contents with brs.brs.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5733
* app/vmselect: set proper timestamp for cached instant responses
The change updates `getSumInstantValues` to prefer timestamp
from the most recent results. Before, timestamp from cached series
was used.
The old behavior had negative impact on recording rules as they
were getting responses with shifted timestamps in past.
Subsequent recording or alerting rules fetching results of these
recording rules could get no result due to staleness interval.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5659
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* wip
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
This limit has little sense for these APIs, since:
- Thses APIs frequently result in scanning of all the time series on the given time range.
For example, if extra_filters={datacenter="some_dc"} .
- Users expect these APIs shouldn't hit the -search.maxUniqueTimeseries limit,
which is intended for limiting resource usage at /api/v1/query and /api/v1/query_range requests.
Also limit the concurrency for /api/v1/labels, /api/v1/label/.../values
and /api/v1/series requests in order to limit the maximum memory usage and CPU usage for these API.
This limit shouldn't affect typical use cases for these APIs:
- Grafana dashboard load when dashboard labels should be loaded
- Auto-suggestion list load when editing the query in Grafana or vmui
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5055
Sending unfinished aggregate states tend to produce unexpected anomalies with lower values than expected.
The old behavior can be restored by specifying `flush_on_shutdown: true` setting in streaming aggregation config
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* app/vmalert: fix data race during hot-config reload
During hot-reload, the logic evokes the group update and rules evaluation
interruption simultaneously. Falsely assuming that interruption happens before
the update. However, it could happen that group will be updated first and only
after the rules evaluation will be cancelled. Which will result in permanent
interruption for all rules within the group.
The fix caches the cancel context function into local variable first. And only after
performs the group update. With cached cancel function we can safely call it without
worrying that we cancel the evaluation for already updated group.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* Revert "app/vmalert: fix data race during hot-config reload"
This reverts commit a4bb7e8932.
* app/vmalert: fix data race during hot-config reload
During hot-reload, the logic evokes the group update and rules evaluation
interruption simultaneously. Falsely assuming that interruption happens before
the update. However, it could happen that group will be updated first and only
after the rules evaluation will be cancelled. Which will result in permanent
interruption for all rules within the group.
The fix cancels the evaulation context before applying the update, making sure
that the context will be cancelled for old group always.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* wip
Signed-off-by: hagen1778 <roman@victoriametrics.com>
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
- Maintain a separate worker pool per each part type (in-memory, file, big and small).
Previously a shared pool was used for merging all the part types.
A single merge worker could merge parts with mixed types at once. For example,
it could merge simultaneously an in-memory part plus a big file part.
Such a merge could take hours for big file part. During the duration of this merge
the in-memory part was pinned in memory and couldn't be persisted to disk
under the configured -inmemoryDataFlushInterval .
Another common issue, which could happen when parts with mixed types are merged,
is uncontrolled growth of in-memory parts or small parts when all the merge workers
were busy with merging big files. Such growth could lead to significant performance
degradataion for queries, since every query needs to check ever growing list of parts.
This could also slow down the registration of new time series, since VictoriaMetrics
searches for the internal series_id in the indexdb for every new time series.
The third issue is graceful shutdown duration, which could be very long when a background
merge is running on in-memory parts plus big file parts. This merge couldn't be interrupted,
since it merges in-memory parts.
A separate pool of merge workers per every part type elegantly resolves both issues:
- In-memory parts are merged to file-based parts in a timely manner, since the maximum
size of in-memory parts is limited.
- Long-running merges for big parts do not block merges for in-memory parts and small parts.
- Graceful shutdown duration is now limited by the time needed for flushing in-memory parts to files.
Merging for file parts is instantly canceled on graceful shutdown now.
- Deprecate -smallMergeConcurrency command-line flag, since the new background merge algorithm
should automatically self-tune according to the number of available CPU cores.
- Deprecate -finalMergeDelay command-line flag, since it wasn't working correctly.
It is better to run forced merge when needed - https://docs.victoriametrics.com/#forced-merge
- Tune the number of shards for pending rows and items before the data goes to in-memory parts
and becomes visible for search. This improves the maximum data ingestion rate and the maximum rate
for registration of new time series. This should reduce the duration of data ingestion slowdown
in VictoriaMetrics cluster on e.g. re-routing events, when some of vmstorage nodes become temporarily
unavailable.
- Prevent from possible "sync: WaitGroup misuse" panic on graceful shutdown.
This is a follow-up for fa566c68a6 .
Thanks @misutoth to for the inspiration at https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5212
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5190
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3790
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3551
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3337
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3425
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
* app/vmalert: autogenerate `ALERTS_FOR_STATE` time series for alerting rules with `for: 0`
Previously, `ALERTS_FOR_STATE` was generated only for alerts with `for > 0`.
This behavior differs from Prometheus behavior - it generates ALERTS_FOR_STATE
time series for alerting rules with `for: 0` as well. Such time series can
be useful for tracking the moment when alerting rule became active.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5648https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3056
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* app/vmalert: support ALERTS_FOR_STATE in `replay` mode
Signed-off-by: hagen1778 <roman@victoriametrics.com>
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
This reverts cd4f641d32 , since it has been appeared that the disabled compression
for vmstorage->vmselect data increase network bandwidth usage by more than 10x on typical production workloads,
while it decreases CPU usage at vmstorage by up to 10% and improves query latency by up to 10%.
The 10x increase in network usage is too high price for 10% improvements on query latency and vmstorage CPU usage.
This may result in network bandwidth bottlenecks, which can reduce the overall performance and stability
of VictoriaMetrics cluster. That's why return back the vmstorage->vmselect data compression by default.
The vmstorage->vmselect compression can be disabled by passing -rpc.disableCompression command-line flag to vmstorage.
The vmselect->vmselect compression in multi-level cluster setup can be disabled by passing -clusternative.disableCompression command-line flag.
It has been appeared that the registration of new time series slows down linearly
with the number of indexdb parts, since VictoriaMetrics needs to check every indexdb part
when it searches for TSID by newly ingested metric name.
The number of in-memory parts grows when new time series are registered
at high rate. The number of in-memory parts grows faster on systems with big number
of CPU cores, because the mergeset maintains per-CPU buffers with newly added entries
for the indexdb, and every such entry is transformed eventually into a separate in-memory part.
The solution has been suggested in https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5212
by @misutoth - to limit the number of in-memory parts with buffered channel.
This solution is implemented in this commit. Additionally, this commit merges per-CPU parts
into a single part before adding it to the list of in-memory parts. This reduces CPU load
when searching for TSID by newly ingested metric name.
The https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5212 recommends setting the limit on the number
of in-memory parts to 100, but my internal testing shows that much lower limit 15 works with the same efficiency
on a system with 16 CPU cores while reducing memory usage for `indexdb/dataBlocks` cache by up to 50%.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5190
* lib/promscrape: respect `0` value for `series_limit` param
Respect `0` value for `series_limit` param in `scrape_config`
even if global limit was set via `-promscrape.seriesLimitPerTarget`.
Previously, `0` value will be ignored in favor of `-promscrape.seriesLimitPerTarget`.
This behavior aligns with possibility to override `series_limit` value via
relabeling with `__series_limit__` label.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* Update docs/CHANGELOG.md
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
Previously, it was not possible to determine which tenant sends metrics with excessive amount of labels of label values.
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
* vmui: fix the logic of closing the popper #5470
* vmui: fix the logic of caching autocomplete results #5472
---------
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
* lib/promscrape/discovery/kubernetes: fix watcher start order for roles endpoints and endpointslice
Previously the groupWatcher could be mistakenly stopped when requests for pod or services resources take too long.
* remove mislead comment
* docs/sd_configs.md: mention -promscrape.kubernetes.attachNodeMetadataAll flag in the description for attach_metadata section
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4640
* wip
* lib/promscrape/kubernetes: prevent from stopping groupWatcher when there are in-flight apiWatcher.mustStart() calls
groupWatcher is stopped if it has zero registered apiWatchers during 14 seconds.
But such a groupWatcher can be still in use if apiWatcher for `role: endpoints` or `role: endpointslice`
is being registered and the discovery of the associated `pod` and/or `service` objects takes longer
than 14 seconds - see the beginning of groupWatcher.startWatchersForRole() function for details.
Track the number of in-flight calls to apiWatcher.mustStart() and prevent from stopping the associated groupWatcher
if the number of in-flight calls is non-zero.
P.S. postponing the discovery of `pod` and/or `service` objects associated with `endpoints` or `endpointslice` roles
isn't the best solution, since it slows down initial discovery of `endpoints` and `endpointslice` targets.
* typo fix
---------
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
Examples:
1) -metricsAuthKey=file:///abs/path/to/file - reads flag value from the given absolute filepath
2) -metricsAuthKey=file://./relative/path/to/file - reads flag value from the given relative filepath
3) -metricsAuthKey=http://some-host/some/path?query_arg=abc - reads flag value from the given url
The flag value is automatically updated when the file contents changes.
* app/vmauth: adds metric_labels and backend_errors counter
it must improve observability for user requests with new metric - per user backend errors counter.
it's needed to calculate requests fail rate to the configured backends.
metric_labels configuration allows to perform additional aggregations on top of multiple users from configuration section.
It could be multiple clients or clients with separate read/write tokens
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5565
* wip
---------
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
* app/vmselect/promql: properly handle possible negative results caused by float operations precision error in rollup functions like rate() or increase()
* fix test
- docs/sd_configs.md: moved hetzner_sd_configs docs to the correct place according to alphabetical order of SD names,
document missing __meta_hetzner_role label.
- lib/promscrape/config.go: added missing MustStop() call for Hetzner SD,
and moved the code to the correct place according to alphabetical order of SD names.
- lib/promscrape/discovery/hetzner: properly handle pagination for hloud API responses,
populate missing __meta_hetzner_role label like Prometheus does.
- Properly populate __meta_hetzner_public_ipv6_network label like Prometheus does.
- Remove unused SDConfig.Token.
- Remove "omitempty" annotation from SDConfig.Role field, since this field is mandatory.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5550
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3154
Properly determine time range search for instant queries with too big look-behind window like `foo[100y]`.
Previously, such queries could return empty responses even if `foo` is present in database.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5553
Signed-off-by: hagen1778 <roman@victoriametrics.com>
- Clarify the bugfix description at docs/CHANGELOG.md
- Simplify the code by accessing prefetchedMetricIDs struct under the lock
instead of using lockless access to immutable struct.
This shouldn't worsen code scalability too much on busy systems with many CPU cores,
since the code executed under the lock is quite small and fast.
This allows removing cloning of prefetchedMetricIDs struct every time
new metric names are pre-fetched. This should reduce load on Go GC,
since the cloning of uin64set.Set struct allocates many new objects.
Before, this cache was limited only by size.
Cache invalidation by time happens with jitter to prevent thundering herd problem.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
It was calculating the number of dropped time series instead of the number of dropped samples.
While at it, drop vmalert_remotewrite_dropped_bytes_total metric, since it was inconsistently calculated -
at one place it was calculating raw protobuf-encoded sample sizes, while at another place it was calculating
the size of snappy-compressed prompbmarshal.WriteRequest protobuf message.
Additionally, this metric has zero practical sense, so just drop it in order to reduce the level of confusion.
* add panels for detailed visualization of traffic usage between vmstorage, vminsert, vmselect
components and their clients. New panels are available in the rows dedicated to specific components.
* update "Slow Queries" panel to show percentage of the slow queries to the total number of read queries
served by vmselect. The percentage value should make it more clear for users whether there is a service degradation.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
automatically add `exported_` prefix for original evaluation result label if it's conflicted with external or reserved one,
previously it was overridden.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5161
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
The user may which to control the endpoint parameters for instance to
set the audience when requesting an access token. Exposing the
parameters as a map allows for additional use cases without requiring
modification.
* lib/awsapi: properly assume role with webIdentity token
introduce new irsaRoleArn param for config. It's only needed for authorization with webIdentity token.
First credentials obtained with irsa role and the next sts assume call for an actual roleArn made with those credentials.
Common use case for it - cross AWS accounts authorization
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3822
* wip
---------
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
Some clients may ingest samples via OpenTelemetry protocol without Resource labels.
Previously VictoriaMetrics was silently dropping such samples.
The commit 317834f876 added vm_protoparser_rows_dropped_total{type="opentelemetry",reason="resource_not_set"}
counter for tracking of such dropped samples. See https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5459
It is better from usability PoV to accept such samples instead of dropping them and incrementing the corresponding counter.
Before, retries happened only on writes into a network connection
between source and destination. But errors returned by server after
all the data was transmitted were logged, but not retried.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* vmui: add show quick tip for autocomplete
* vmui: auto-completion usability improvements #5348
* vmui: add const for min symbols in autocomplete
* Use proper queries to VictoriaMetrics
* vmui: fix comments for autocomplete
* app/vmselect: run `make vmui-update`
---------
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
Before, vmalert would send notifications with labels containing characters
not supported by Alertmanager validator, resulting into validation errors
like `msg="Failed to validate alerts" err="invalid label set: invalid name "foo.bar"`
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Previously the lower bound could be too small, which could result in missing values at the beginning of the graph
for default_rollup() function. This function is automatically applied to all the series selectors if they aren't
explicitly wrapped into a rollup function - see https://docs.victoriametrics.com/MetricsQL.html#implicit-query-conversions
While at it, properly take into account `-search.minStalenessInterval` command-line flag when adjusting
the lower bound for the selected time range.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5388
* vmagent: export `vm_promscrape_scrape_pool_targets` metric to track the number of targets that each scrape_job discovers
* add extra panel for new metric
* app/vmalert: expose `/vmalert/api/v1/rule` and `/api/v1/rule` API which returns rule status in JSON format
* app/vmalert: hide updates if query param not set
* app/vmalert: fix panic (recursion call)
* app/vmalert: add needed group name and file name
* app/vmalert: fix comment, update behavior
* app/vmalert: fix description
* app/vmalert: simplify API for /api/v1/rule
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* app/vmalert: simplify API for /api/v1/rule
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* app/vmalert: simplify API for /api/v1/rule
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* app/vmalert: simplify API for /api/v1/rule
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* app/vmalert: simplify API for /api/v1/rule
Signed-off-by: hagen1778 <roman@victoriametrics.com>
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
* lib/backup/s3remote: remove prev object versions for recursive delete
- fix error caused by sending empty objects list to be deleted. This was possible in case old versions of objects where deleted, but root-level entries where still available. This caused paginator to return an empty page which wasn't skipped.
- delete previous versions of objects recursively for S3 remote
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* docs/changelog: add vmbackupmanager fix entry
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* lib/backup/s3remote: unify path construction for S3 objects
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
---------
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
Previously concurrency for static and fast queries was limited with the -search.maxConcurrentRequests
command-line flag. This could complicate identifying heavy queries via `vmui` at `Top queries` and `Active queries` pages,
since `vmui` and these pages couldn't be opened on overloaded vmselect.
Thanks to @f41gh7 for the idea.
Previously the /service-discovery page didn't show targets dropped because of sharding
( https://docs.victoriametrics.com/vmagent.html#scraping-big-number-of-targets ).
Show also the reason why every target is dropped at /service-discovery page.
This should improve debuging why particular targets are dropped.
While at it, do not remove dropped targets from the list at /service-discovery page
until the total number of targets exceeds the limit passed to -promscrape.maxDroppedTargets .
Previously the list was cleaned up every 10 minutes from the entries, which weren't updated
for the last minute. This could complicate debugging of dropped targets.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5389
* lib/streamaggr: properly reference slice with labels
by limiting slice capacity. It must fix issues with slice modification, in case of append new slice will be allocated, instead of modifying refrenced slice
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5402
* Reduce memory allocations when output_relabel_configs adds new labels to output samples
---------
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
* prevent /api/v1 from panic on parsing rows
* add tests for Extract function for v1 and v2 api's
* separate request types in different pools to prevent different objects mixing
* add changelog line
543f218fe9
Signed-off-by: hagen1778 <roman@victoriametrics.com>
- Add Try* prefix to functions, which return bool result in order to improve readability and reduce the probability of missing check
for the result returned from these functions.
- Call the adjustSampleValues() only once on input samples. Previously it was called on every attempt to flush data to peristent queue.
- Properly restore the initial state of WriteRequest passed to tryPushWriteRequest() before returning from this function
after unsuccessful push to persistent queue. Previously a part of WriteRequest samples may be lost in such case.
- Add -remoteWrite.dropSamplesOnOverload command-line flag, which can be used for dropping incoming samples instead
of returning 429 Too Many Requests error to the client when -remoteWrite.disableOnDiskQueue is set and the remote storage
cannot keep up with the data ingestion rate.
- Add vmagent_remotewrite_samples_dropped_total metric, which counts the number of dropped samples.
- Add vmagent_remotewrite_push_failures_total metric, which counts the number of unsuccessful attempts to push
data to persistent queue when -remoteWrite.disableOnDiskQueue is set.
- Remove vmagent_remotewrite_aggregation_metrics_dropped_total and vm_promscrape_push_samples_dropped_total metrics,
because they are replaced with vmagent_remotewrite_samples_dropped_total metric.
- Update 'Disabling on-disk persistence' docs at docs/vmagent.md
- Update stale comments in the code
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5088
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2110
* app/vmagent: allow to disabled on-disk queue
Previously, it wasn't possible to build data processing pipeline with a
chain of vmagents. In case when remoteWrite for the last vmagent in the
chain wasn't accessible, it persisted data only when it has enough disk
capacity. If disk queue is full, it started to silently drop ingested
metrics.
New flags allows to disable on-disk persistent and immediatly return an
error if remoteWrite is not accessible anymore. It blocks any writes and
notify client, that data ingestion isn't possible.
Main use case for this feature - use external queue such as kafka for
data persistence.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2110
* adds test, updates readme
* apply review suggestions
* update docs for vmagent
* makes linter happy
---------
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
Tests showed that importing a single line with 70MB size takes 5.3GiB
RSS memory for VictoriaMetrics single-node.
In the scenario when user exports and imports data from one VM to another,
it could possibly lead to OOM exception for destination VM.
Importing a single line with 16MB size taks 1.3GiB RSS memory.
Hence, the limit for `import.maxLineLen` was decreased from 100MB to 10MB
to improve reliability of VictoriaMetrics during imports.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
This case is possible after the following steps:
1. vmagent successfully performed handshake with the -remoteWrite.url and the remote storage supports zstd-compressed data.
2. remote storage became unavailable or slow to ingest data, vmagent compressed the collected data into blocks with zstd and puts these blocks to persistent queue on disk.
3. vmagent restarts and the remote storage is unavailable during the handshake, then vmagent falls back to Snappy compression.
4. vmagent starts sending zstd-compressed data from persistent queue to the remote storage, while falsely advertizing it sends Snappy-compressed data.
5. The remote storage receives zstd-compressed data and fails unpacking it with Snappy.
The solution is the same as 12cd32fd75, just fall back to zstd decompression if Snappy decompression fails.
The buffered connection could have exceeded the underlying connection
deadline during reading or writing to an internal buffer.
With this change, buffered connection struct additionally checks
for a deadline in Read/Write methods.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
