….url` using `-remoteWrite.streamAggr.dropInputLabels`
Before, labels were set to all the `remoteWrite.url`.
address https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6780
---------
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
Recent versions of `docker build` started generating the InvalidDefaultArgInFrom warning if Dockerfile contains
an ARG without default value. While this warning doesn't affect building Docker packages via `make package-*` commands,
it is better suppressing the warning, so it doesn't clutter `make package-*` output with the noise,
which can hide real issues in the future.
…specifying `-streamAggr.dedupInterval` or
`-remoteWrite.streamAggr.dedupInterval` command-line flag
[The
documentation](https://docs.victoriametrics.com/stream-aggregation/)
contains conflicting descriptions regarding deduplication for
non-matched series when `-remoteWrite.streamAggr.config` and / or
`-streamAggr.config` are set:
1. Statement below says **all the received data** is deduplicated:
>[vmagent](https://docs.victoriametrics.com/vmagent/) supports
relabeling, deduplication and stream aggregation for all the received
data, scraped or pushed. Then, the collected data will be forwarded to
specified -remoteWrite.url destinations. The data processing order is
the following:
>1. all the received data is relabeled according to the specified
[-remoteWrite.relabelConfig](https://docs.victoriametrics.com/vmagent/#relabeling)
(if it is set)
>2. all the received data is deduplicated according to specified
[-streamAggr.dedupInterval](https://docs.victoriametrics.com/stream-aggregation/#deduplication)
(if it is set to duration bigger than 0)
2. Another statement says the deduplication is performed individually
for the **matching samples**
>The de-deduplication is performed after applying
[relabeling](https://docs.victoriametrics.com/vmagent/#relabeling) and
before performing the aggregation. If the -remoteWrite.streamAggr.config
and / or -streamAggr.config is set, then the de-duplication is performed
individually per each [stream aggregation
config](https://docs.victoriametrics.com/stream-aggregation/#stream-aggregation-config)
for the matching samples after applying
[input_relabel_configs](https://docs.victoriametrics.com/stream-aggregation/#relabeling).
Considering the following deduplication use cases:
1. To apply deduplication(globally or for specific remoteWrite
destination) for all the received data, scraped or pushed
--- using `-streamAggr.dedupInterval` or
`-remoteWrite.streamAggr.dedupInterval`.
2. To deduplicate and aggregate metrics that match the rule `match`
filters
--- using `-remoteWrite.streamAggr.config` and specifiying
`dedup_interval` option in [stream aggregation
config](https://docs.victoriametrics.com/stream-aggregation/#stream-aggregation-config).
3. To deduplicate all the received data while having `streamAggr.config`
for some metrics
--- no way for a single vmagent now, need to set up two level vmagents
This PR implements case3.
---------
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
## Describe Your Changes
Add RemoteWrite Retry Controls
This PR introduces two new flags to the remote write functionality:
- remoteWrite.retryMinInterval
- remoteWrite.retryMaxTime
These flags provide finer control over the retry behavior for
remoteWrite operations, allowing users to customize the minimum interval
between retries and the maximum duration for retry attempts.
Fixes#5486.
## Checklist
- [x] The following checks are mandatory:
My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
---------
Signed-off-by: Yury Akudovich <ya@matterlabs.dev>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
Describe Your Changes
When I use usePromCompatibleNaming with vmagent to process data that
needs to be formatted from different sources such as InfluxDB, I find
that it doesn’t work
However, it works in vminsert. I found that vminsert uses the
HasRelabeling method to determine whether to relabel.
```go
func HasRelabeling() bool {
pcs := pcsGlobal.Load()
return pcs.Len() > 0 || *usePromCompatibleNaming
}
```
in vmagent, the decision to relabel is determined only by
pcsGlobal.Len() > 0. However, in the applyRelabeling method, the
usePromCompatibleNaming logic is also used to determine whether to
relabel in the error handling.
```go
func (rctx *relabelCtx) applyRelabeling(tss []prompbmarshal.TimeSeries, pcs *promrelabel.ParsedConfigs) []prompbmarshal.TimeSeries {
if pcs.Len() == 0 && !*usePromCompatibleNaming {
// Nothing to change.
return tss
}
```
So I think that the logic for determining whether to relabel in vmagent
is not as expected.
Checklist
The following checks are mandatory:
[✅]My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
---------
Co-authored-by: Roman Khavronenko <hagen1778@gmail.com>
…eep_metric_names` options in stream aggregation config together
With aggregated data and raw data under the same metric, results would
be confusing.
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
Make `-remoteWrite.streamAggr.ignoreFirstIntervals` of array type so it could
accept multiple values which can be applied to the corresponding`-remoteWrite.url`.
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
Fix `-streamAggr.dropInputLabels` behavior when global deduplication is enabled without `-streamAggr.config`.
Previously, `-remoteWrite.streamAggr.dropInputLabels` is misapplied.
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
### Describe Your Changes
This is useful for clients which validate InfluxDB is available before
data ingestion can be started.
See: https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6653
### Checklist
The following checks are **mandatory**:
- [x] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
---------
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
The %q formatter may result in incorrectly formatted JSON string if the original string
contains special chars such as \x1b . They must be encoded as \u001b , otherwise the resulting JSON string
cannot be parsed by JSON parsers.
This is a follow-up for c0caa69939
See https://github.com/VictoriaMetrics/victorialogs-datasource/issues/24
- Rename GetStatDialFunc to NewStatDialFunc, since it returns new function with every call
- NewStatDialFunc isn't related to http in any way, so it must be moved from lib/httputils to lib/netutil
- Simplify the implementation of NewStatDialFunc by removing sync.Map from there.
- Use netutil.NewStatDialFunc at app/vmauth and lib/promscrape/discoveryutils
- Use gauge instead of counter type for *_conns metric
This is a follow-up for d7b5062917
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6299
- Move the remaining code responsible for stream aggregation initialization from remotewrite.go to streamaggr.go .
This improves code maintainability a bit.
- Properly shut down streamaggr.Aggregators initialized inside remotewrite.CheckStreamAggrConfigs().
This prevents from potential resource leaks.
- Use separate functions for initializing and reloading of global stream aggregation and per-remoteWrite.url stream aggregation.
This makes the code easier to read and maintain. This also fixes INFO and ERROR logs emitted by these functions.
- Add an ability to specify `name` option in every stream aggregation config. This option is used as `name` label
in metrics exposed by stream aggregation at /metrics page. This simplifies investigation of the exposed metrics.
- Add `path` label additionally to `name`, `url` and `position` labels at metrics exposed by streaming aggregation.
This label should simplify investigation of the exposed metrics.
- Remove `match` and `group` labels from metrics exposed by streaming aggregation, since they have little practical applicability:
it is hard to use these labels in query filters and aggregation functions.
- Rename the metric `vm_streamaggr_flushed_samples_total` to less misleading `vm_streamaggr_output_samples_total` .
This metric shows the number of samples generated by the corresponding streaming aggregation rule.
This metric has been added in the commit 861852f262 .
See https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6462
- Remove the metric `vm_streamaggr_stale_samples_total`, since it is unclear how it can be used in practice.
This metric has been added in the commit 861852f262 .
See https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6462
- Remove Alias and aggrID fields from streamaggr.Options struct, since these fields aren't related to optional params,
which could modify the behaviour of the constructed streaming aggregator.
Convert the Alias field to regular argument passed to LoadFromFile() function, since this argument is mandatory.
- Pass Options arg to LoadFromFile() function by reference, since this structure is quite big.
This also allows passing nil instead of Options when default options are enough.
- Add `name`, `path`, `url` and `position` labels to `vm_streamaggr_dedup_state_size_bytes` and `vm_streamaggr_dedup_state_items_count` metrics,
so they have consistent set of labels comparing to the rest of streaming aggregation metrics.
- Convert aggregator.aggrStates field type from `map[string]aggrState` to `[]aggrOutput`, where `aggrOutput` contains the corresponding
`aggrState` plus all the related metrics (currently only `vm_streamaggr_output_samples_total` metric is exposed with the corresponding
`output` label per each configured output function). This simplifies and speeds up the code responsible for updating per-output
metrics. This is a follow-up for the commit 2eb1bc4f81 .
See https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6604
- Added missing urls to docs ( https://docs.victoriametrics.com/stream-aggregation/ ) in error messages. These urls help users
figuring out why VictoriaMetrics or vmagent generates the corresponding error messages. The urls were removed for unknown reason
in the commit 2eb1bc4f81 .
- Fix incorrect update for `vm_streamaggr_output_samples_total` metric in flushCtx.appendSeriesWithExtraLabel() function.
While at it, reduce memory usage by limiting the maximum number of samples per flush to 10K.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5467
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6268
The old link was changed globally to the new link in the commit f4b1cbfef0 .
Unfortunately, old links are still posted in new commits :(
This is a follow-up for 680b8c25c8 .
While at it, remove duplicate 'len(*remoteWriteURLs) > 0' check in the remotewrite.Init() functions,
since this check is already made at the beginning of the function.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6253
- Drop samples and return true from remotewrite.TryPush() at fast path when all the remote storage
systems are configured with the disabled on-disk queue, every in-memory queue is full
and -remoteWrite.dropSamplesOnOverload is set to true. This case is quite common,
so it should be optimized. Previously additional CPU time was spent on per-remoteWriteCtx
relabeling and other processing in this case.
- Properly count the number of dropped samples inside remoteWriteCtx.pushInternalTrackDropped().
Previously dropped samples were counted only if -remoteWrite.dropSamplesOnOverload flag is set.
In reality, the samples are dropped when they couldn't be sent to the queue because in-memory queue is full
and on-disk queue is disabled.
The remoteWriteCtx.pushInternalTrackDropped() function is called by streaming aggregation for pushing
the aggregated data to the remote storage. Streaming aggregation cannot wait until the remote storage
processes pending data, so it drops aggregated samples in this case.
- Clarify the description for -remoteWrite.disableOnDiskQueue command-line flag at -help output,
so it is clear that this flag can be set individually per each -remoteWrite.url.
- Make the -remoteWrite.dropSamplesOnOverload flag global. If some of the remote storage systems
are configured with the disabled on-disk queue, then there is no sense in keeping samples
on some of these systems, while dropping samples on the remaining systems, since this
will result in global stall on the remote storage system with the disabled on-disk queue
and with the -remoteWrite.dropSamplesOnOverload=false flag. vmagent will always return false
from remotewrite.TryPush() in this case. This will result in infinite duplicate samples
written to the remaining remote storage systems. That's why the -remoteWrite.dropSamplesOnOverload
is forcibly set to true if more than one -remoteWrite.disableOnDiskQueue flag is set.
This allows proceeding with newly scraped / pushed samples by sending them to the remaining
remote storage systems, while dropping them on overloaded systems with the -remoteWrite.disableOnDiskQueue flag set.
- Verify that the remoteWriteCtx.TryPush() returns true in the TestRemoteWriteContext_TryPush_ImmutableTimeseries test.
- Mention in vmagent docs that the -remoteWrite.disableOnDiskQueue command-line flag can be set individually per each -remoteWrite.url.
See https://docs.victoriametrics.com/vmagent/#disabling-on-disk-persistence
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6248
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6065
Consistently using t.Fatal* simplifies the test code and makes it less fragile, since it is common error
to forget to make proper cleanup after t.Error* call. Also t.Error* calls do not provide any practical
benefits when some tests fail. They just clutter test output with additional noise information,
which do not help in fixing failing tests most of the time.
While at it, improve errors generated at app/victoria-metrics tests, so they contain more useful information
when debugging failed tests.
This is a follow-up for a9525da8a4
'any' type is supported starting from Go1.18. Let's consistently use it
instead of 'interface{}' type across the code base, since `any` is easier to read than 'interface{}'.
Reason for revert:
There are many statsd servers exist:
- https://github.com/statsd/statsd - classical statsd server
- https://docs.datadoghq.com/developers/dogstatsd/ - statsd server from DataDog built into DatDog Agent ( https://docs.datadoghq.com/agent/ )
- https://github.com/avito-tech/bioyino - high-performance statsd server
- https://github.com/atlassian/gostatsd - statsd server in Go
- https://github.com/prometheus/statsd_exporter - statsd server, which exposes the aggregated data as Prometheus metrics
These servers can be used for efficient aggregating of statsd data and sending it to VictoriaMetrics
according to https://docs.victoriametrics.com/#how-to-send-data-from-graphite-compatible-agents-such-as-statsd (
the https://github.com/prometheus/statsd_exporter can be scraped as usual Prometheus target
according to https://docs.victoriametrics.com/#how-to-scrape-prometheus-exporters-such-as-node-exporter ).
Adding support for statsd data ingestion protocol into VictoriaMetrics makes sense only if it provides
significant advantages over the existing statsd servers, while has no significant drawbacks comparing
to existing statsd servers.
The main advantage of statsd server built into VictoriaMetrics and vmagent - getting rid of additional statsd server.
The main drawback is non-trivial and inconvenient streaming aggregation configs, which must be used for the ingested statsd metrics (
see https://docs.victoriametrics.com/stream-aggregation/ ). These configs are incompatible with the configs for standalone statsd servers.
So you need to manually translate configs of the used statsd server to stream aggregation configs when migrating
from standalone statsd server to statsd server built into VictoriaMetrics (or vmagent).
Another important drawback is that it is very easy to shoot yourself in the foot when using built-in statsd server
with the -statsd.disableAggregationEnforcement command-line flag or with improperly configured streaming aggregation.
In this case the ingested statsd metrics will be stored to VictoriaMetrics as is without any aggregation.
This may result in high CPU usage during data ingestion, high disk space usage for storing all the unaggregated
statsd metrics and high CPU usage during querying, since all the unaggregated metrics must be read, unpacked and processed
during querying.
P.S. Built-in statsd server can be added to VictoriaMetrics and vmagent after figuring out more ergonomic
specialized configuration for aggregating of statsd metrics. The main requirements for this configuration:
- easy to write, read and update (ideally it should work out of the box for most cases without additional configuration)
- hard to misconfigure (e.g. hard to shoot yourself in the foot)
It would be great if this configuration will be compatible with the configuration of the most widely used statsd server.
In the mean time it is recommended continue using external statsd server.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6265
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5053
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5052
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/206
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4600
This reverts commit 5a3abfa041.
Reason for revert: exemplars aren't in wide use because they have numerous issues which prevent their adoption (see below).
Adding support for examplars into VictoriaMetrics introduces non-trivial code changes. These code changes need to be supported forever
once the release of VictoriaMetrics with exemplar support is published. That's why I don't think this is a good feature despite
that the source code of the reverted commit has an excellent quality. See https://docs.victoriametrics.com/goals/ .
Issues with Prometheus exemplars:
- Prometheus still has only experimental support for exemplars after more than three years since they were introduced.
It stores exemplars in memory, so they are lost after Prometheus restart. This doesn't look like production-ready feature.
See 0a2f3b3794/content/docs/instrumenting/exposition_formats.md (L153-L159)
and https://prometheus.io/docs/prometheus/latest/feature_flags/#exemplars-storage
- It is very non-trivial to expose exemplars alongside metrics in your application, since the official Prometheus SDKs
for metrics' exposition ( https://prometheus.io/docs/instrumenting/clientlibs/ ) either have very hard-to-use API
for exposing histograms or do not have this API at all. For example, try figuring out how to expose exemplars
via https://pkg.go.dev/github.com/prometheus/client_golang@v1.19.1/prometheus .
- It looks like exemplars are supported for Histogram metric types only -
see https://pkg.go.dev/github.com/prometheus/client_golang@v1.19.1/prometheus#Timer.ObserveDurationWithExemplar .
Exemplars aren't supported for Counter, Gauge and Summary metric types.
- Grafana has very poor support for Prometheus exemplars. It looks like it supports exemplars only when the query
contains histogram_quantile() function. It queries exemplars via special Prometheus API -
https://prometheus.io/docs/prometheus/latest/querying/api/#querying-exemplars - (which is still marked as experimental, btw.)
and then displays all the returned exemplars on the graph as special dots. The issue is that this doesn't work
in production in most cases when the histogram_quantile() is calculated over thousands of histogram buckets
exposed by big number of application instances. Every histogram bucket may expose an exemplar on every timestamp shown on the graph.
This makes the graph unusable, since it is litterally filled with thousands of exemplar dots.
Neither Prometheus API nor Grafana doesn't provide the ability to filter out unneeded exemplars.
- Exemplars are usually connected to traces. While traces are good for some
I doubt exemplars will become production-ready in the near future because of the issues outlined above.
Alternative to exemplars:
Exemplars are marketed as a silver bullet for the correlation between metrics, traces and logs -
just click the exemplar dot on some graph in Grafana and instantly see the corresponding trace or log entry!
This doesn't work as expected in production as shown above. Are there better solutions, which work in production?
Yes - just use time-based and label-based correlation between metrics, traces and logs. Assign the same `job`
and `instance` labels to metrics, logs and traces, so you can quickly find the needed trace or log entry
by these labes on the time range with the anomaly on metrics' graph.
- Export streamaggr.LoadFromData() function, so it could be used in tests outside the lib/streamaggr package.
This allows removing a hack with creation of temporary files at TestRemoteWriteContext_TryPush_ImmutableTimeseries.
- Move common code for mustParsePromMetrics() function into lib/prompbmarshal package,
so it could be used in tests for building []prompbmarshal.TimeSeries from string.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6205
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6206
Move the code responsible for relabelCtx clearing into deferred function.
This allows making more clear the remoteWriteCtx.TryPush code.
This is a follow-up for 879771808b
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6205
While at it, clarify the description of the bugfix at docs/CHANGELOG.md
### Describe Your Changes
- added stale metrics counters for input and output samples
- added labels for aggregator metrics =>
`name="{rwctx}:{aggrId}:{aggrSuffix}"`
- rwctx - global or number starting from 1
- aggrid - aggregator id starting from 1
- aggrSuffix - <interval>_(by|without)_label1_label2_labeln
e.g: `name="global:1:1m_without_instance_pod"`
### Checklist
The following checks are **mandatory**:
- [ ] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
Prevent excessive resource usage when stream aggregation config file
contains no matchers by prevent pushing data into Aggregators object.
Before this change a lot of extra work was invoked without reason.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Occasionally, vmagent sends empty blocks to downstream servers. If a
downstream server returns an unexpected response, vmagent gets stuck in
a retry loop. While vmagent handles 400 and 409 errors, there are
various prometheus remote write implementations that return different
error codes. For example, vector returns a 422 error. To mitigate the
risk of vmagent getting stuck in a retry loop, it is advisable to skip
sending empty blocks to downstream servers.
Co-authored-by: hao.peng <hao.peng@smartx.com>
Co-authored-by: Zhu Jiekun <jiekun.dev@gmail.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
* adds datadog extensions for statsd:
- multiple packed values (v1.1)
- additional types distribution, histogram
* adds type check and append metric type to the labels with special tag
name `__statsd_metric_type__`. It simplifies streaming aggregation
config.
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
* FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html):
allow configuring `-remoteWrite.disableOnDiskQueue` and
`-remoteWrite.dropSamplesOnOverload` cmd-line flags per each
`-remoteWrite.url`. See this [pull
request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6065).
Thanks to @rbizos for implementaion!
* FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): add
labels `path` and `url` to metrics
`vmagent_remotewrite_push_failures_total` and
`vmagent_remotewrite_samples_dropped_total`. Now number of failed pushes
and dropped samples can be tracked per `-remoteWrite.url`.
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Raphael Bizos <r.bizos@criteo.com>
### Describe Your Changes
Added makefile rule for `GOARCH=loong64` to support building all
VictoriaMetrics components on the `loongarch64` platform.
### Checklist
The following checks are **mandatory**:
* [X] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
Signed-off-by: qiangxuhui <qiangxuhui@loongson.cn>
This code adds Exemplars to VMagent and the promscrape parser adhering
to OpenMetrics Specifications. This will allow forwarding of exemplars
to Prometheus and other third party apps that support OpenMetrics specs.
---------
Signed-off-by: Ted Possible <ted_possible@cable.comcast.com>
When at least one remote write has deduplication configured it cleans up
timeseries while they can be in use by another remote write without
deduplication
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6205
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6140
We don't cover this corner case as it has low chance for reproduction.
Precisely, the requirements are following:
1. vmagent need to be configured with multiple identical `remoteWrite.url` flags;
2. At least one of the persistent queues need to be non-empty, which already
signalizes about issues with setup;
3. vmagent need to be restarted with removing of one of `remoteWrite.url` flags.
We do not document this case in vmagent.md as it seems to be a rare corner case
and its explanation will require too much of explanation and confuse users.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Stream aggregation may yield inaccurate results if it processes incomplete data.
This issue can arise when data is sourced from clients that maintain a queue of unsent data, such as Prometheus or vmagent.
If the queue isn't fully cleared within the aggregation interval, only a portion of the time series may be included in that period, leading to distorted calculations.
To mitigate this we add an option to ignore first N aggregation intervals. It is expected, that client queues
will be cleared during the time while aggregation ignores first N intervals and all subsequent aggregations
will be correct.
Data ingestion benchmark doesn't show memory usage difference between two approaches,
so let's use simpler approach in order to improve code readability and maintainability.
This is a follow-up for 77c597738c
This scheme was used for reducing memory usage when vmagent runs on a machine with big number of CPU cores
and the ingestion rate isn't too big. The scheme with channel-based pool could reduce memory usage,
since it minimizes the number of PushCtx structs in the pool in this case.
Performance tests didn't reveal significant difference in memory usage under both low and high ingestion rate
between plain sync.Pool and the current hybrid scheme, so replace the scheme with plain sync.Pool in order
to simplify the code.
