* Can add, remove and modify labels (aka tags) via Prometheus relabeling. Can filter data before sending it to remote storage. See [these docs](#relabeling) for details.
* Accepts data via all the ingestion protocols supported by VictoriaMetrics:
* Influx line protocol via `http://<vmagent>:8429/write`. See [these docs](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md#how-to-send-data-from-influxdb-compatible-agents-such-as-telegraf).
* Graphite plaintext protocol if `-graphiteListenAddr` command-line flag is set. See [these docs](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md#how-to-send-data-from-graphite-compatible-agents-such-as-statsd).
* OpenTSDB telnet and http protocols if `-opentsdbListenAddr` command-line flag is set. See [these docs](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md#how-to-send-data-from-opentsdb-compatible-agents).
* Prometheus remote write protocol via `http://<vmagent>:8429/api/v1/write`.
* JSON lines import protocol via `http://<vmagent>:8429/api/v1/import`. See [these docs](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md#how-to-import-data-in-json-line-format).
* Native data import protocol via `http://<vmagent>:8429/api/v1/import/native`. See [these docs](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md#how-to-import-data-in-native-format).
* Data in Prometheus exposition format. See [these docs](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md#how-to-import-data-in-prometheus-exposition-format) for details.
* Arbitrary CSV data via `http://<vmagent>:8429/api/v1/import/csv`. See [these docs](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md#how-to-import-csv-data).
*`-remoteWrite.url` with the remote storage endpoint such as VictoriaMetrics. The `-remoteWrite.url` argument can be specified multiple times in order to replicate data concurrently to an arbitrary number of remote storage systems.
Then send Influx data to `http://vmagent-host:8429`. See [these docs](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md#how-to-send-data-from-influxdb-compatible-agents-such-as-telegraf) for more details.
`vmagent` should be restarted in order to update config options set via command-line args.
`vmagent` supports multiple approaches for reloading configs from updated config files such as `-promscrape.config`, `-remoteWrite.relabelConfig` and `-remoteWrite.urlRelabelConfig`:
* Sending `SUGHUP` signal to `vmagent` process:
```bash
kill -SIGHUP `pidof vmagent`
```
* Sending HTTP request to `http://vmagent:8429/-/reload` endpoint.
There is also `-promscrape.configCheckInterval` command-line option, which can be used for automatic reloading configs from of updated `-promscrape.config` file.
then `vmagent` can replace such Prometheus setup. Usually `vmagent` requires lower amounts of RAM, CPU and network bandwidth comparing to Prometheus for such a setup.
which is applied independently for each configured `-remoteWrite.url` destination. For instance, it is possible to replicate or split
data among long-term remote storage, short-term remote storage and real-time analytical system [built on top of Kafka](https://github.com/Telefonica/prometheus-kafka-adapter).
Note that each destination can receive its own subset of the collected data thanks to per-destination relabeling via `-remoteWrite.urlRelabelConfig`.
Pass the path to `prometheus.yml` to `-promscrape.config` command-line flag. `vmagent` takes into account the following
sections from [Prometheus config file](https://prometheus.io/docs/prometheus/latest/configuration/configuration/):
*`global`
*`scrape_configs`
All the other sections are ignored, including [remote_write](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#remote_write) section.
The following scrape types in [scrape_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config) section are supported:
*`static_configs` - for scraping statically defined targets. See [these docs](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#static_config) for details.
*`file_sd_configs` - for scraping targets defined in external files aka file-based service discover.
See [these docs](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#file_sd_config) for details.
File feature requests at [our issue tracker](https://github.com/VictoriaMetrics/VictoriaMetrics/issues) if you need other service discovery mechanisms to be supported by `vmagent`.
`vmagent` also support the following additional options in `scrape_config` section:
*`disable_compression: true` - for disabling response compression on a per-job basis. By default `vmagent` requests compressed responses from scrape targets
in order to save network bandwidth.
*`disable_keepalive: true` - for disabling [HTTP keep-alive connections](https://en.wikipedia.org/wiki/HTTP_persistent_connection) on a per-job basis.
By default `vmagent` uses keep-alive connections to scrape targets in order to reduce overhead on connection re-establishing.
The file pointed by `-promscrape.config` may contain `%{ENV_VAR}` placeholders, which are substituted by the corresponding `ENV_VAR` environment variable values.
Labels can be added to metrics via the following mechanisms:
* Via `global -> external_labels` section in `-promscrape.config` file. These labels are added only to metrics scraped from targets configured in `-promscrape.config` file.
* Via `-remoteWrite.label` command-line flag. These labels are added to all the collected metrics before sending them to `-remoteWrite.url`.
Additionally it provides the following extra actions:
*`replace_all`: replaces all the occurences of `regex` in the values of `source_labels` with the `replacement` and stores the result in the `target_label`.
*`labelmap_all`: replaces all the occurences of `regex` in all the label names with the `replacement`.
* At `scrape_config -> relabel_configs` section in `-promscrape.config` file. This relabeling is applied to target labels.
* At `scrape_config -> metric_relabel_configs` section in `-promscrape.config` file. This relabeling is applied to all the scraped metrics in the given `scrape_config`.
Read more about relabeling in the following articles:
* [Life of a label](https://www.robustperception.io/life-of-a-label)
* [Discarding targets and timeseries with relabeling](https://www.robustperception.io/relabelling-can-discard-targets-timeseries-and-alerts)
* [Dropping labels at scrape time](https://www.robustperception.io/dropping-metrics-at-scrape-time-with-prometheus)
* [Extracting labels from legacy metric names](https://www.robustperception.io/extracting-labels-from-legacy-metric-names)
* [relabel_configs vs metric_relabel_configs](https://www.robustperception.io/relabel_configs-vs-metric_relabel_configs)
### Monitoring
`vmagent` exports various metrics in Prometheus exposition format at `http://vmagent-host:8429/metrics` page. It is recommended setting up regular scraping of this page
either via `vmagent` itself or via Prometheus, so the exported metrics could be analyzed later.
`vmagent` also exports target statuses at the following handlers:
*`http://vmagent-host:8429/targets`. This handler returns human-readable plaintext status for every active target.
This page is convenient to query from command line with `wget`, `curl` or similar tools.
It accepts optional `show_original_labels=1` query arg, which shows the original labels per each target before applying relabeling.
This information may be useful for debugging target relabeling.
*`http://vmagent-host:8429/api/v1/targets`. This handler returns data compatible with [the corresponding page from Prometheus API](https://prometheus.io/docs/prometheus/latest/querying/api/#targets).
by passing `-promscrape.suppressScrapeErrors` command-line flag to `vmagent`. The most recent scrape error per each target can be observed at `http://vmagent-host:8429/targets`
* The `/api/v1/targets` page could be useful for debugging relabeling process for scrape targets.
This page contains original labels for targets dropped during relabeling (see "droppedTargets" section in the page output). By default up to `-promscrape.maxDroppedTargets` targets are shown here. If your setup drops more targets during relabeling, then increase `-promscrape.maxDroppedTargets` command-line flag value in order to see all the dropped targets. Note that tracking each dropped target requires up to 10Kb of RAM, so big values for `-promscrape.maxDroppedTargets` may result in increased memory usage if big number of scrape targets are dropped during relabeling.
* If `vmagent` scrapes big number of targets, then `-promscrape.dropOriginalLabels` command-line option may be passed to `vmagent` in order to reduce memory usage.
This option drops `"discoveredLabels"` and `"droppedTargets"` lists at `/api/v1/targets` page, which may result in reduced debuggability for improperly configured per-target relabeling.
* If `vmagent` scrapes targets with millions of metrics per each target (for instance, when scraping [federation endpoints](https://prometheus.io/docs/prometheus/latest/federation/)),
then it is recommended enabling `stream parsing mode` in order to reduce memory usage during scraping. This mode may be enabled either globally for all the scrape targets
by passing `-promscrape.streamParse` command-line flag or on a per-scrape target basis with `stream_parse: true` option. For example:
* It is recommended to increase `-remoteWrite.queues` if `vmagent_remotewrite_pending_data_bytes` metric exported at `http://vmagent-host:8429/metrics` page constantly grows.
* If you see gaps on the data pushed by `vmagent` to remote storage when `-remoteWrite.maxDiskUsagePerURL` is set, then try increasing `-remoteWrite.queues`.
Such gaps may appear because `vmagent` cannot keep up with sending the collected data to remote storage, so it starts dropping the buffered data
if the on-disk buffer size exceeds `-remoteWrite.maxDiskUsagePerURL`.
* If you see `skipping duplicate scrape target with identical labels` errors when scraping Kubernetes pods, then it is likely these pods listen multiple ports
It is recommended using [binary releases](https://github.com/VictoriaMetrics/VictoriaMetrics/releases) - `vmagent` is located in `vmutils-*` archives there.
by setting it via `<ROOT_IMAGE>` environment variable. For example, the following command builds the image on top of [scratch](https://hub.docker.com/_/scratch) image:
