--- sort: 4 --- # vmalert `vmalert` executes a list of the given [alerting](https://prometheus.io/docs/prometheus/latest/configuration/alerting_rules/) or [recording](https://prometheus.io/docs/prometheus/latest/configuration/recording_rules/) rules against configured `-datasource.url` compatible with Prometheus HTTP API. For sending alerting notifications vmalert relies on [Alertmanager](https://github.com/prometheus/alertmanager) configured via `-notifier.url` flag. Recording rules results are persisted via [remote write](https://prometheus.io/docs/prometheus/latest/storage/#remote-storage-integrations) protocol and require `-remoteWrite.url` to be configured. Vmalert is heavily inspired by [Prometheus](https://prometheus.io/docs/alerting/latest/overview/) implementation and aims to be compatible with its syntax. A [single-node](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#vmalert) or [cluster version](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#vmalert) of VictoriaMetrics are capable of proxying requests to vmalert via `-vmalert.proxyURL` command-line flag. Use this feature for the following cases: * for proxying requests from [Grafana Alerting UI](https://grafana.com/docs/grafana/latest/alerting/); * for accessing vmalert's UI through VictoriaMetrics Web interface. ## Features * Integration with [VictoriaMetrics](https://github.com/VictoriaMetrics/VictoriaMetrics) TSDB; * VictoriaMetrics [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html) support and expressions validation; * Prometheus [alerting rules definition format](https://prometheus.io/docs/prometheus/latest/configuration/alerting_rules/#defining-alerting-rules) support; * Integration with [Alertmanager](https://github.com/prometheus/alertmanager) starting from [Alertmanager v0.16.0-aplha](https://github.com/prometheus/alertmanager/releases/tag/v0.16.0-alpha.0); * Keeps the alerts [state on restarts](#alerts-state-on-restarts); * Graphite datasource can be used for alerting and recording rules. See [these docs](#graphite); * Recording and Alerting rules backfilling (aka `replay`). See [these docs](#rules-backfilling); * Lightweight and without extra dependencies. * Supports [reusable templates](#reusable-templates) for annotations; * Load of recording and alerting rules from local filesystem, GCS and S3. ## Limitations * `vmalert` execute queries against remote datasource which has reliability risks because of the network. It is recommended to configure alerts thresholds and rules expressions with the understanding that network requests may fail; * by default, rules execution is sequential within one group, but persistence of execution results to remote storage is asynchronous. Hence, user shouldn't rely on chaining of recording rules when result of previous recording rule is reused in the next one; ## QuickStart To build `vmalert` from sources: ```console git clone https://github.com/VictoriaMetrics/VictoriaMetrics cd VictoriaMetrics make vmalert ``` The build binary will be placed in `VictoriaMetrics/bin` folder. To start using `vmalert` you will need the following things: * list of rules - PromQL/MetricsQL expressions to execute; * datasource address - reachable endpoint with [Prometheus HTTP API](https://prometheus.io/docs/prometheus/latest/querying/api/#http-api) support for running queries against; * notifier address [optional] - reachable [Alert Manager](https://github.com/prometheus/alertmanager) instance for processing, aggregating alerts, and sending notifications. Please note, notifier address also supports Consul and DNS Service Discovery via [config file](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/app/vmalert/notifier/config.go). * remote write address [optional] - [remote write](https://prometheus.io/docs/prometheus/latest/storage/#remote-storage-integrations) compatible storage to persist rules and alerts state info. To persist results to multiple destinations use vmagent configured with multiple remote writes as a proxy; * remote read address [optional] - MetricsQL compatible datasource to restore alerts state from. Then configure `vmalert` accordingly: ```console ./bin/vmalert -rule=alert.rules \ # Path to the file with rules configuration. Supports wildcard -datasource.url=http://localhost:8428 \ # Prometheus HTTP API compatible datasource -notifier.url=http://localhost:9093 \ # AlertManager URL (required if alerting rules are used) -notifier.url=http://127.0.0.1:9093 \ # AlertManager replica URL -remoteWrite.url=http://localhost:8428 \ # Remote write compatible storage to persist rules and alerts state info (required if recording rules are used) -remoteRead.url=http://localhost:8428 \ # Prometheus HTTP API compatible datasource to restore alerts state from -external.label=cluster=east-1 \ # External label to be applied for each rule -external.label=replica=a # Multiple external labels may be set ``` Note there's a separate `-remoteWrite.url` command-line flag to allow writing results of alerting/recording rules into a different storage than the initial data that's queried. This allows using `vmalert` to aggregate data from a short-term, high-frequency, high-cardinality storage into a long-term storage with decreased cardinality and a bigger interval between samples. See also [stream aggregation](https://docs.victoriametrics.com/stream-aggregation.html). See the full list of configuration flags in [configuration](#configuration) section. If you run multiple `vmalert` services for the same datastore or AlertManager - do not forget to specify different `-external.label` command-line flags in order to define which `vmalert` generated rules or alerts. Configuration for [recording](https://prometheus.io/docs/prometheus/latest/configuration/recording_rules/) and [alerting](https://prometheus.io/docs/prometheus/latest/configuration/alerting_rules/) rules is very similar to Prometheus rules and configured using YAML. Configuration examples may be found in [testdata](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/app/vmalert/config/testdata) folder. Every `rule` belongs to a `group` and every configuration file may contain arbitrary number of groups: ```yaml groups: [ - ] ``` ### Groups Each group has the following attributes: ```yaml # The name of the group. Must be unique within a file. name: # How often rules in the group are evaluated. [ interval: | default = -evaluationInterval flag ] # Limit the number of alerts an alerting rule and series a recording # rule can produce. 0 is no limit. [ limit: | default = 0 ] # How many rules execute at once within a group. Increasing concurrency may speed # up round execution speed. [ concurrency: | default = 1 ] # Optional type for expressions inside the rules. Supported values: "graphite" and "prometheus". # By default "prometheus" type is used. [ type: ] # Optional list of HTTP URL parameters # applied for all rules requests within a group # For example: # params: # nocache: ["1"] # disable caching for vmselect # denyPartialResponse: ["true"] # fail if one or more vmstorage nodes returned an error # extra_label: ["env=dev"] # apply additional label filter "env=dev" for all requests # see more details at https://docs.victoriametrics.com#prometheus-querying-api-enhancements params: [ : [, ...]] # Optional list of HTTP headers in form `header-name: value` # applied for all rules requests within a group # For example: # headers: # - "CustomHeader: foo" # - "CustomHeader2: bar" # Headers set via this param have priority over headers set via `-datasource.headers` flag. headers: [ , ...] # Optional list of labels added to every rule within a group. # It has priority over the external labels. # Labels are commonly used for adding environment # or tenant-specific tag. labels: [ : ... ] rules: [ - ... ] ``` ### Rules Every rule contains `expr` field for [PromQL](https://prometheus.io/docs/prometheus/latest/querying/basics/) or [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html) expression. `vmalert` will execute the configured expression and then act according to the Rule type. There are two types of Rules: * [alerting](https://prometheus.io/docs/prometheus/latest/configuration/alerting_rules/) - Alerting rules allow defining alert conditions via `expr` field and to send notifications to [Alertmanager](https://github.com/prometheus/alertmanager) if execution result is not empty. * [recording](https://prometheus.io/docs/prometheus/latest/configuration/recording_rules/) - Recording rules allow defining `expr` which result will be then backfilled to configured `-remoteWrite.url`. Recording rules are used to precompute frequently needed or computationally expensive expressions and save their result as a new set of time series. `vmalert` forbids defining duplicates - rules with the same combination of name, expression, and labels within one group. #### Alerting rules The syntax for alerting rule is the following: ```yaml # The name of the alert. Must be a valid metric name. alert: # The expression to evaluate. The expression language depends on the type value. # By default, PromQL/MetricsQL expression is used. If group.type="graphite", then the expression # must contain valid Graphite expression. expr: # Alerts are considered firing once they have been returned for this long. # Alerts which have not yet been fired for long enough are considered pending. # If param is omitted or set to 0 then alerts will be immediately considered # as firing once they return. [ for: | default = 0s ] # Whether to print debug information into logs. # Information includes alerts state changes and requests sent to the datasource. # Please note, that if rule's query params contain sensitive # information - it will be printed to logs. # Is applicable to alerting rules only. [ debug: | default = false ] # Defines the number of rule's updates entries stored in memory # and available for view on rule's Details page. # Overrides `rule.updateEntriesLimit` value for this specific rule. [ update_entries_limit: | default 0 ] # Labels to add or overwrite for each alert. labels: [ : ] # Annotations to add to each alert. annotations: [ : ] ``` #### Templating It is allowed to use [Go templating](https://golang.org/pkg/text/template/) in annotations to format data, iterate over or execute expressions. The following variables are available in templating: | Variable | Description | Example | |------------------------------------|-----------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | $value or .Value | The current alert's value. Avoid using value in labels, it may cause unexpected issues. | {% raw %}Number of connections is {{ $value }}{% endraw %} | | $activeAt or .ActiveAt | The moment of [time](https://pkg.go.dev/time) when alert became active (`pending` or `firing`). | {% raw %}http://vm-grafana.com/panelId=xx?from={{($activeAt.Add (parseDurationTime \"1h\")).Unix}}&to={{($activeAt.Add (parseDurationTime \"-1h\")).Unix}}{% endraw %} | | $labels or .Labels | The list of labels of the current alert. Use as ".Labels.". | {% raw %}Too high number of connections for {{ .Labels.instance }}{% endraw %} | | $alertID or .AlertID | The current alert's ID generated by vmalert. | {% raw %}Link: vmalert/alert?group_id={{.GroupID}}&alert_id={{.AlertID}}{% endraw %} | | $groupID or .GroupID | The current alert's group ID generated by vmalert. | {% raw %}Link: vmalert/alert?group_id={{.GroupID}}&alert_id={{.AlertID}}{% endraw %} | | $expr or .Expr | Alert's expression. Can be used for generating links to Grafana or other systems. | {% raw %}/api/v1/query?query={{ $expr|queryEscape }}{% endraw %} | | $for or .For | Alert's configured for param. | {% raw %}Number of connections is too high for more than {{ .For }}{% endraw %} | | $externalLabels or .ExternalLabels | List of labels configured via `-external.label` command-line flag. | {% raw %}Issues with {{ $labels.instance }} (datacenter-{{ $externalLabels.dc }}){% endraw %} | | $externalURL or .ExternalURL | URL configured via `-external.url` command-line flag. Used for cases when vmalert is hidden behind proxy. | {% raw %}Visit {{ $externalURL }} for more details{% endraw %} | Additionally, `vmalert` provides some extra templating functions listed [here](#template-functions) and [reusable templates](#reusable-templates). #### Template functions `vmalert` provides the following template functions, which can be used during [templating](#templating): - `args arg0 ... argN` - converts the input args into a map with `arg0`, ..., `argN` keys. - `externalURL` - returns the value of `-external.url` command-line flag. - `first` - returns the first result from the input query results returned by `query` function. - `htmlEscape` - escapes special chars in input string, so it can be safely embedded as a plaintext into HTML. - `humanize` - converts the input number into human-readable format by adding [metric prefixes](https://en.wikipedia.org/wiki/Metric_prefix). For example, `100000` is converted into `100K`. - `humanize1024` - converts the input number into human-readable format with 1024 base. For example, `1024` is converted into 1ki`. - `humanizeDuration` - converts the input number in seconds into human-readable duration. - `humanizePercentage` - converts the input number to percentage. For example, `0.123` is converted into `12.3%`. - `humanizeTimestamp` - converts the input unix timestamp into human-readable time. - `jsonEscape` - JSON-encodes the input string. - `label name` - returns the value of the label with the given `name` from the input query result. - `match regex` - matches the input string against the provided `regex`. - `parseDuration` - parses the input string into duration in seconds. For example, `1h` is parsed into `3600`. - `parseDurationTime` - parses the input string into [time.Duration](https://pkg.go.dev/time#Duration). - `pathEscape` - escapes the input string, so it can be safely put inside path part of URL. - `pathPrefix` - returns the path part of the `-external.url` command-line flag. - `query` - executes the [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html) query against `-datasource.url` and returns the query result. For example, {% raw %}`{{ query "sort_desc(process_resident_memory_bytes)" | first | value }}`{% endraw %} executes the `sort_desc(process_resident_memory_bytes)` query at `-datasource.url` and returns the first result. - `queryEscape` - escapes the input string, so it can be safely put inside [query arg](https://en.wikipedia.org/wiki/Percent-encoding) part of URL. - `quotesEscape` - escapes the input string, so it can be safely embedded into JSON string. - `reReplaceAll regex repl` - replaces all the occurences of the `regex` in input string with the `repl`. - `safeHtml` - marks the input string as safe to use in HTML context without the need to html-escape it. - `sortByLabel name` - sorts the input query results by the label with the given `name`. - `stripDomain` - leaves the first part of the domain. For example, `foo.bar.baz` is converted to `foo`. The port part is left in the output string. E.g. `foo.bar:1234` is converted into `foo:1234`. - `stripPort` - strips `port` part from `host:port` input string. - `strvalue` - returns the metric name from the input query result. - `title` - converts the first letters of every input word to uppercase. - `toLower` - converts all the chars in the input string to lowercase. - `toTime` - converts the input unix timestamp to [time.Time](https://pkg.go.dev/time#Time). - `toUpper` - converts all the chars in the input string to uppercase. - `value` - returns the numeric value from the input query result. #### Reusable templates Like in Alertmanager you can define [reusable templates](https://prometheus.io/docs/prometheus/latest/configuration/template_examples/#defining-reusable-templates) to share same templates across annotations. Just define the templates in a file and set the path via `-rule.templates` flag. For example, template `grafana.filter` can be defined as following: {% raw %} ``` {{ define "grafana.filter" -}} {{- $labels := .arg0 -}} {{- range $name, $label := . -}} {{- if (ne $name "arg0") -}} {{- ( or (index $labels $label) "All" ) | printf "&var-%s=%s" $label -}} {{- end -}} {{- end -}} {{- end -}} ``` {% endraw %} And then used in annotations: {% raw %} ```yaml groups: - name: AlertGroupName rules: - alert: AlertName expr: any_metric > 100 for: 30s labels: alertname: 'Any metric is too high' severity: 'warning' annotations: dashboard: '{{ $externalURL }}/d/dashboard?orgId=1{{ template "grafana.filter" (args .CommonLabels "account_id" "any_label") }}' ``` {% endraw %} The `-rule.templates` flag supports wildcards so multiple files with templates can be loaded. The content of `-rule.templates` can be also [hot reloaded](#hot-config-reload). #### Recording rules The syntax for recording rules is following: ```yaml # The name of the time series to output to. Must be a valid metric name. record: # The expression to evaluate. The expression language depends on the type value. # By default, MetricsQL expression is used. If group.type="graphite", then the expression # must contain valid Graphite expression. expr: # Labels to add or overwrite before storing the result. labels: [ : ] # Defines the number of rule's updates entries stored in memory # and available for view on rule's Details page. # Overrides `rule.updateEntriesLimit` value for this specific rule. [ update_entries_limit: | default 0 ] ``` For recording rules to work `-remoteWrite.url` must be specified. ### Alerts state on restarts `vmalert` has no local storage, so alerts state is stored in the process memory. Hence, after restart of `vmalert` the process alerts state will be lost. To avoid this situation, `vmalert` should be configured via the following flags: * `-remoteWrite.url` - URL to VictoriaMetrics (Single) or vminsert (Cluster). `vmalert` will persist alerts state into the configured address in the form of time series named `ALERTS` and `ALERTS_FOR_STATE` via remote-write protocol. These are regular time series and maybe queried from VM just as any other time series. The state is stored to the configured address on every rule evaluation. * `-remoteRead.url` - URL to VictoriaMetrics (Single) or vmselect (Cluster). `vmalert` will try to restore alerts state from configured address by querying time series with name `ALERTS_FOR_STATE`. Both flags are required for proper state restoration. Restore process may fail if time series are missing in configured `-remoteRead.url`, weren't updated in the last `1h` (controlled by `-remoteRead.lookback`) or received state doesn't match current `vmalert` rules configuration. ### Multitenancy There are the following approaches exist for alerting and recording rules across [multiple tenants](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#multitenancy): * To run a separate `vmalert` instance per each tenant. The corresponding tenant must be specified in `-datasource.url` command-line flag according to [these docs](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#url-format). For example, `/path/to/vmalert -datasource.url=http://vmselect:8481/select/123/prometheus` would run alerts against `AccountID=123`. For recording rules the `-remoteWrite.url` command-line flag must contain the url for the specific tenant as well. For example, `-remoteWrite.url=http://vminsert:8480/insert/123/prometheus` would write recording rules to `AccountID=123`. * To specify `tenant` parameter per each alerting and recording group if [enterprise version of vmalert](https://docs.victoriametrics.com/enterprise.html) is used with `-clusterMode` command-line flag. For example: ```yaml groups: - name: rules_for_tenant_123 tenant: "123" rules: # Rules for accountID=123 - name: rules_for_tenant_456:789 tenant: "456:789" rules: # Rules for accountID=456, projectID=789 ``` The results of alerting and recording rules contain `vm_account_id` and `vm_project_id` labels if `-clusterMode` is enabled. These labels can be used during [templating](https://docs.victoriametrics.com/vmalert.html#templating), and help to identify to which account or project the triggered alert or produced recording belongs. If `-clusterMode` is enabled, then `-datasource.url`, `-remoteRead.url` and `-remoteWrite.url` must contain only the hostname without tenant id. For example: `-datasource.url=http://vmselect:8481`. `vmalert` automatically adds the specified tenant to urls per each recording rule in this case. If `-clusterMode` is enabled and the `tenant` in a particular group is missing, then the tenant value is obtained from `-defaultTenant.prometheus` or `-defaultTenant.graphite` depending on the `type` of the group. The enterprise version of vmalert is available in `vmutils-*-enterprise.tar.gz` files at [release page](https://github.com/VictoriaMetrics/VictoriaMetrics/releases) and in `*-enterprise` tags at [Docker Hub](https://hub.docker.com/r/victoriametrics/vmalert/tags). ### Reading rules from object storage [Enterprise version](https://docs.victoriametrics.com/enterprise.html) of `vmalert` may read alerting and recording rules from object storage: - `./bin/vmalert -rule=s3://bucket/dir/alert.rules` would read rules from the given path at S3 bucket - `./bin/vmalert -rule=gs://bucket/bir/alert.rules` would read rules from the given path at GCS bucket S3 and GCS paths support only matching by prefix, e.g. `s3://bucket/dir/rule_` matches all files with prefix `rule_` in the folder `dir`. The following [command-line flags](#flags) can be used for fine-tuning access to S3 and GCS: - `-s3.credsFilePath` - path to file with GCS or S3 credentials. Credentials are loaded from default locations if not set. - `-s3.configFilePath` - path to file with S3 configs. Configs are loaded from default location if not set. - `-s3.configProfile` - profile name for S3 configs. If no set, the value of the environment variable will be loaded (`AWS_PROFILE` or `AWS_DEFAULT_PROFILE`). - `-s3.customEndpoint` - custom S3 endpoint for use with S3-compatible storages (e.g. MinIO). S3 is used if not set. - `-s3.forcePathStyle` - prefixing endpoint with bucket name when set false, true by default. ### Topology examples The following sections are showing how `vmalert` may be used and configured for different scenarios. Please note, not all flags in examples are required: * `-remoteWrite.url` and `-remoteRead.url` are optional and are needed only if you have recording rules or want to store [alerts state](#alerts-state-on-restarts) on `vmalert` restarts; * `-notifier.url` is optional and is needed only if you have alerting rules. #### Single-node VictoriaMetrics The simplest configuration where one single-node VM server is used for rules execution, storing recording rules results and alerts state. `vmalert` configuration flags: ``` ./bin/vmalert -rule=rules.yml \ # Path to the file with rules configuration. Supports wildcard -datasource.url=http://victoriametrics:8428 \ # VM-single addr for executing rules expressions -remoteWrite.url=http://victoriametrics:8428 \ # VM-single addr to persist alerts state and recording rules results -remoteRead.url=http://victoriametrics:8428 \ # VM-single addr for restoring alerts state after restart -notifier.url=http://alertmanager:9093 # AlertManager addr to send alerts when they trigger ``` vmalert single #### Cluster VictoriaMetrics In [cluster mode](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html) VictoriaMetrics has separate components for writing and reading path: `vminsert` and `vmselect` components respectively. `vmselect` is used for executing rules expressions and `vminsert` is used to persist recording rules results and alerts state. Cluster mode could have multiple `vminsert` and `vmselect` components. `vmalert` configuration flags: ``` ./bin/vmalert -rule=rules.yml \ # Path to the file with rules configuration. Supports wildcard -datasource.url=http://vmselect:8481/select/0/prometheus # vmselect addr for executing rules expressions -remoteWrite.url=http://vminsert:8480/insert/0/prometheus # vminsert addr to persist alerts state and recording rules results -remoteRead.url=http://vmselect:8481/select/0/prometheus # vmselect addr for restoring alerts state after restart -notifier.url=http://alertmanager:9093 # AlertManager addr to send alerts when they trigger ``` vmalert cluster In case when you want to spread the load on these components - add balancers before them and configure `vmalert` with balancer's addresses. Please, see more about VM's cluster architecture [here](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#architecture-overview). #### HA vmalert For HA user can run multiple identically configured `vmalert` instances. It means all of them will execute the same rules, write state and results to the same destinations, and send alert notifications to multiple configured Alertmanagers. `vmalert` configuration flags: ``` ./bin/vmalert -rule=rules.yml \ # Path to the file with rules configuration. Supports wildcard -datasource.url=http://victoriametrics:8428 \ # VM-single addr for executing rules expressions -remoteWrite.url=http://victoriametrics:8428 \ # VM-single addr to persist alerts state and recording rules results -remoteRead.url=http://victoriametrics:8428 \ # VM-single addr for restoring alerts state after restart -notifier.url=http://alertmanager1:9093 \ # Multiple AlertManager addresses to send alerts when they trigger -notifier.url=http://alertmanagerN:9093 # The same alert will be sent to all configured notifiers ``` vmalert ha To avoid recording rules results and alerts state duplication in VictoriaMetrics server don't forget to configure [deduplication](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#deduplication). The recommended value for `-dedup.minScrapeInterval` must be greater or equal to vmalert's `evaluation_interval`. If you observe inconsistent or "jumping" values in series produced by vmalert, try disabling `-datasource.queryTimeAlignment` command line flag. Because of alignment, two or more vmalert HA pairs will produce results with the same timestamps. But due of backfilling (data delivered to the datasource with some delay) values of such results may differ, which would affect deduplication logic and result into "jumping" datapoints. Alertmanager will automatically deduplicate alerts with identical labels, so ensure that all `vmalert`s are having the same config. Don't forget to configure [cluster mode](https://prometheus.io/docs/alerting/latest/alertmanager/) for Alertmanagers for better reliability. List all Alertmanager URLs in vmalert's `-notifier.url` to ensure [high availability](https://github.com/prometheus/alertmanager#high-availability). This example uses single-node VM server for the sake of simplicity. Check how to replace it with [cluster VictoriaMetrics](#cluster-victoriametrics) if needed. #### Downsampling and aggregation via vmalert `vmalert` can't modify existing data. But it can run arbitrary PromQL/MetricsQL queries via [recording rules](#recording-rules) and backfill results to the configured `-remoteWrite.url`. This ability allows to aggregate data. For example, the following rule will calculate the average value for metric `http_requests` on the `5m` interval: ```yaml - record: http_requests:avg5m expr: avg_over_time(http_requests[5m]) ``` Every time this rule will be evaluated, `vmalert` will backfill its results as a new time series `http_requests:avg5m` to the configured `-remoteWrite.url`. `vmalert` executes rules with specified interval (configured via flag `-evaluationInterval` or as [group's](#groups) `interval` param). The interval helps to control "resolution" of the produced series. This ability allows to downsample data. For example, the following config will execute the rule only once every `5m`: ```yaml groups: - name: my_group interval: 5m rules: - record: http_requests:avg5m expr: avg_over_time(http_requests[5m]) ``` Ability of `vmalert` to be configured with different `-datasource.url` and `-remoteWrite.url` command-line flags allows reading data from one data source and backfilling results to another. This helps to build a system for aggregating and downsampling the data. The following example shows how to build a topology where `vmalert` will process data from one cluster and write results into another. Such clusters may be called as "hot" (low retention, high-speed disks, used for operative monitoring) and "cold" (long term retention, slower/cheaper disks, low resolution data). With help of `vmalert`, user can setup recording rules to process raw data from "hot" cluster (by applying additional transformations or reducing resolution) and push results to "cold" cluster. `vmalert` configuration flags: ``` ./bin/vmalert -rule=downsampling-rules.yml \ # Path to the file with rules configuration. Supports wildcard -datasource.url=http://raw-cluster-vmselect:8481/select/0/prometheus # vmselect addr for executing recording rules expressions -remoteWrite.url=http://aggregated-cluster-vminsert:8480/insert/0/prometheus # vminsert addr to persist recording rules results ``` vmalert multi cluster Please note, [replay](#rules-backfilling) feature may be used for transforming historical data. Flags `-remoteRead.url` and `-notifier.url` are omitted since we assume only recording rules are used. See also [stream aggregation](https://docs.victoriametrics.com/stream-aggregation.html) and [downsampling](https://docs.victoriametrics.com/#downsampling). #### Multiple remote writes For persisting recording or alerting rule results `vmalert` requires `-remoteWrite.url` to be set. But this flag supports only one destination. To persist rule results to multiple destinations we recommend using [vmagent](https://docs.victoriametrics.com/vmagent.html) as fan-out proxy: vmalert multiple remote write destinations In this topology, `vmalert` is configured to persist rule results to `vmagent`. And `vmagent` is configured to fan-out received data to two or more destinations. Using `vmagent` as a proxy provides additional benefits such as [data persisting when storage is unreachable](https://docs.victoriametrics.com/vmagent.html#replication-and-high-availability), or time series modification via [relabeling](https://docs.victoriametrics.com/vmagent.html#relabeling). ### Web `vmalert` runs a web-server (`-httpListenAddr`) for serving metrics and alerts endpoints: * `http://` - UI; * `http:///api/v1/rules` - list of all loaded groups and rules; * `http:///api/v1/alerts` - list of all active alerts; * `http:///vmalert/api/v1/alert?group_id=&alert_id=` - get alert status in JSON format. Used as alert source in AlertManager. * `http:///vmalert/alert?group_id=&alert_id=` - get alert status in web UI. * `http:///vmalert/rule?group_id=&rule_id=` - get rule status in web UI. * `http:///metrics` - application metrics. * `http:///-/reload` - hot configuration reload. `vmalert` web UI can be accessed from [single-node version of VictoriaMetrics](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html) and from [cluster version of VictoriaMetrics](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html). This may be used for better integraion with Grafana unified alerting system. See the following docs for details: * [How to query vmalert from single-node VictoriaMetrics](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#vmalert) * [How to query vmalert from VictoriaMetrics cluster](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#vmalert) ## Graphite vmalert sends requests to `<-datasource.url>/render?format=json` during evaluation of alerting and recording rules if the corresponding group or rule contains `type: "graphite"` config option. It is expected that the `<-datasource.url>/render` implements [Graphite Render API](https://graphite.readthedocs.io/en/stable/render_api.html) for `format=json`. When using vmalert with both `graphite` and `prometheus` rules configured against cluster version of VM do not forget to set `-datasource.appendTypePrefix` flag to `true`, so vmalert can adjust URL prefix automatically based on the query type. ## Rules backfilling vmalert supports alerting and recording rules backfilling (aka `replay`). In replay mode vmalert can read the same rules configuration as normal, evaluate them on the given time range and backfill results via remote write to the configured storage. vmalert supports any PromQL/MetricsQL compatible data source for backfilling. Please note, that response caching may lead to unexpected results during and after backfilling process. In order to avoid this you need to reset cache contents or disable caching when using backfilling as described in [backfilling docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#backfilling). See a blogpost about [Rules backfilling via vmalert](https://victoriametrics.com/blog/rules-replay/). ### How it works In `replay` mode vmalert works as a cli-tool and exits immediately after work is done. To run vmalert in `replay` mode: ``` ./bin/vmalert -rule=path/to/your.rules \ # path to files with rules you usually use with vmalert -datasource.url=http://localhost:8428 \ # Prometheus HTTP API compatible datasource -remoteWrite.url=http://localhost:8428 \ # remote write compatible storage to persist results -replay.timeFrom=2021-05-11T07:21:43Z \ # time from begin replay -replay.timeTo=2021-05-29T18:40:43Z # time to finish replay ``` The output of the command will look like the following: ``` Replay mode: from: 2021-05-11 07:21:43 +0000 UTC # set by -replay.timeFrom to: 2021-05-29 18:40:43 +0000 UTC # set by -replay.timeTo max data points per request: 1000 # set by -replay.maxDatapointsPerQuery Group "ReplayGroup" interval: 1m0s requests to make: 27 max range per request: 16h40m0s > Rule "type:vm_cache_entries:rate5m" (ID: 1792509946081842725) 27 / 27 [----------------------------------------------------------------------------------------------------] 100.00% 78 p/s > Rule "go_cgo_calls_count:rate5m" (ID: 17958425467471411582) 27 / 27 [-----------------------------------------------------------------------------------------------------] 100.00% ? p/s Group "vmsingleReplay" interval: 30s requests to make: 54 max range per request: 8h20m0s > Rule "RequestErrorsToAPI" (ID: 17645863024999990222) 54 / 54 [-----------------------------------------------------------------------------------------------------] 100.00% ? p/s > Rule "TooManyLogs" (ID: 9042195394653477652) 54 / 54 [-----------------------------------------------------------------------------------------------------] 100.00% ? p/s 2021-06-07T09:59:12.098Z info app/vmalert/replay.go:68 replay finished! Imported 511734 samples ``` In `replay` mode all groups are executed sequentially one-by-one. Rules within the group are executed sequentially as well (`concurrency` setting is ignored). Vmalert sends rule's expression to [/query_range](https://docs.victoriametrics.com/keyConcepts.html#range-query) endpoint of the configured `-datasource.url`. Returned data is then processed according to the rule type and backfilled to `-remoteWrite.url` via [remote Write protocol](https://prometheus.io/docs/prometheus/latest/storage/#remote-storage-integrations). Vmalert respects `evaluationInterval` value set by flag or per-group during the replay. Vmalert automatically disables caching on VictoriaMetrics side by sending `nocache=1` param. It allows to prevent cache pollution and unwanted time range boundaries adjustment during backfilling. #### Recording rules The result of recording rules `replay` should match with results of normal rules evaluation. #### Alerting rules The result of alerting rules `replay` is time series reflecting [alert's state](#alerts-state-on-restarts). To see if `replayed` alert has fired in the past use the following PromQL/MetricsQL expression: ``` ALERTS{alertname="your_alertname", alertstate="firing"} ``` Execute the query against storage which was used for `-remoteWrite.url` during the `replay`. ### Additional configuration There are following non-required `replay` flags: * `-replay.maxDatapointsPerQuery` - the max number of data points expected to receive in one request. In two words, it affects the max time range for every `/query_range` request. The higher the value, the fewer requests will be issued during `replay`. * `-replay.ruleRetryAttempts` - when datasource fails to respond vmalert will make this number of retries per rule before giving up. * `-replay.rulesDelay` - delay between sequential rules execution. Important in cases if there are chaining (rules which depend on each other) rules. It is expected, that remote storage will be able to persist previously accepted data during the delay, so data will be available for the subsequent queries. Keep it equal or bigger than `-remoteWrite.flushInterval`. * `-replay.disableProgressBar` - whether to disable progress bar which shows progress work. Progress bar may generate a lot of log records, which is not formatted as standard VictoriaMetrics logger. It could break logs parsing by external system and generate additional load on it. See full description for these flags in `./vmalert -help`. ### Limitations * Graphite engine isn't supported yet; * `query` template function is disabled for performance reasons (might be changed in future); * `limit` group's param has no effect during replay (might be changed in future); ## Monitoring `vmalert` exports various metrics in Prometheus exposition format at `http://vmalert-host:8880/metrics` page. The default list of alerting rules for these metric can be found [here](https://github.com/VictoriaMetrics/VictoriaMetrics/tree/master/deployment/docker). We recommend setting up regular scraping of this page either through `vmagent` or by Prometheus so that the exported metrics may be analyzed later. Use the official [Grafana dashboard](https://grafana.com/grafana/dashboards/14950-victoriametrics-vmalert/) for `vmalert` overview. Graphs on this dashboard contain useful hints - hover the `i` icon in the top left corner of each graph in order to read it. If you have suggestions for improvements or have found a bug - please open an issue on github or add a review to the dashboard. ## Troubleshooting ### Data delay Data delay is one of the most common issues with rules execution. vmalert executes configured rules within certain intervals at specifics timestamps. It expects that the data is already present in configured `-datasource.url` at the moment of time when rule is executed: vmalert expected evaluation Usually, troubles start to appear when data in `-datasource.url` is delayed or absent. In such cases, evaluations may get empty response from the datasource and produce empty recording rules or reset alerts state: vmalert evaluation when data is delayed Try the following recommendations to reduce the chance of hitting the data delay issue: * Always configure group's `evaluationInterval` to be bigger or at least equal to [time series resolution](https://docs.victoriametrics.com/keyConcepts.html#time-series-resolution); * Ensure that `[duration]` value is at least twice bigger than [time series resolution](https://docs.victoriametrics.com/keyConcepts.html#time-series-resolution). For example, if expression is `rate(my_metric[2m]) > 0` then ensure that `my_metric` resolution is at least `1m` or better `30s`. If you use VictoriaMetrics as datasource, `[duration]` can be omitted and VictoriaMetrics will adjust it automatically. * If you know in advance, that data in datasource is delayed - try changing vmalert's `-datasource.lookback` command-line flag to add a time shift for evaluations. Or extend `[duration]` to tolerate the delay. For example, `max_over_time(errors_total[10m]) > 0` will be active even if there is no data in datasource for last `9m`. * If [time series resolution](https://docs.victoriametrics.com/keyConcepts.html#time-series-resolution) in datasource is inconsistent or `>=5min` - try changing vmalert's `-datasource.queryStep` command-line flag to specify how far search query can lookback for the recent datapoint. The recommendation is to have the step at least two times bigger than the resolution. > Please note, data delay is inevitable in distributed systems. And it is better to account for it instead of ignoring. By default, recently written samples to VictoriaMetrics aren't visible for queries for up to 30s (see `-search.latencyOffset` command-line flag at vmselect). Such delay is needed to eliminate risk of incomplete data on the moment of querying, since metrics collectors won't be able to deliver the data in time. ### Alerts state Sometimes, it is not clear why some specific alert fired or didn't fire. It is very important to remember, that alerts with `for: 0` fire immediately when their expression becomes true. And alerts with `for > 0` will fire only after multiple consecutive evaluations, and at each evaluation their expression must be true. If at least one evaluation becomes false, then alert's state resets to the initial state. If `-remoteWrite.url` command-line flag is configured, vmalert will persist alert's state in form of time series `ALERTS` and `ALERTS_FOR_STATE` to the specified destination. Such time series can be then queried via [vmui](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#vmui) or Grafana to track how alerts state changed in time. vmalert stores last `-rule.updateEntriesLimit` (or `update_entries_limit` [per-rule config](https://docs.victoriametrics.com/vmalert.html#alerting-rules)) state updates for each rule. To check updates, click on `Details` link next to rule's name on `/vmalert/groups` page and check the `Last updates` section: vmalert state Rows in the section represent ordered rule evaluations and their results. The column `curl` contains an example of HTTP request sent by vmalert to the `-datasource.url` during evaluation. If specific state shows that there were no samples returned and curl command returns data - then it is very likely there was no data in datasource on the moment when rule was evaluated. ### Debug mode vmalert allows configuring more detailed logging for specific alerting rule. Just set `debug: true` in rule's configuration and vmalert will start printing additional log messages: ```terminal 2022-09-15T13:35:41.155Z DEBUG rule "TestGroup":"Conns" (2601299393013563564) at 2022-09-15T15:35:41+02:00: query returned 0 samples (elapsed: 5.896041ms) 2022-09-15T13:35:56.149Z DEBUG datasource request: executing POST request with params "denyPartialResponse=true&query=sum%28vm_tcplistener_conns%7Binstance%3D%22localhost%3A8429%22%7D%29+by%28instance%29+%3E+0&step=15s&time=1663248945" 2022-09-15T13:35:56.178Z DEBUG rule "TestGroup":"Conns" (2601299393013563564) at 2022-09-15T15:35:56+02:00: query returned 1 samples (elapsed: 28.368208ms) 2022-09-15T13:35:56.178Z DEBUG datasource request: executing POST request with params "denyPartialResponse=true&query=sum%28vm_tcplistener_conns%7Binstance%3D%22localhost%3A8429%22%7D%29&step=15s&time=1663248945" 2022-09-15T13:35:56.179Z DEBUG rule "TestGroup":"Conns" (2601299393013563564) at 2022-09-15T15:35:56+02:00: alert 10705778000901301787 {alertgroup="TestGroup",alertname="Conns",cluster="east-1",instance="localhost:8429",replica="a"} created in state PENDING ... 2022-09-15T13:36:56.153Z DEBUG rule "TestGroup":"Conns" (2601299393013563564) at 2022-09-15T15:36:56+02:00: alert 10705778000901301787 {alertgroup="TestGroup",alertname="Conns",cluster="east-1",instance="localhost:8429",replica="a"} PENDING => FIRING: 1m0s since becoming active at 2022-09-15 15:35:56.126006 +0200 CEST m=+39.384575417 ``` ## Profiling `vmalert` provides handlers for collecting the following [Go profiles](https://blog.golang.org/profiling-go-programs): * Memory profile. It can be collected with the following command (replace `0.0.0.0` with hostname if needed):
```console curl http://0.0.0.0:8880/debug/pprof/heap > mem.pprof ```
* CPU profile. It can be collected with the following command (replace `0.0.0.0` with hostname if needed):
```console curl http://0.0.0.0:8880/debug/pprof/profile > cpu.pprof ```
The command for collecting CPU profile waits for 30 seconds before returning. The collected profiles may be analyzed with [go tool pprof](https://github.com/google/pprof). It is safe sharing the collected profiles from security point of view, since they do not contain sensitive information. ## Configuration ### Flags Pass `-help` to `vmalert` in order to see the full list of supported command-line flags with their descriptions. The shortlist of configuration flags is the following: {% raw %} ``` -clusterMode If clusterMode is enabled, then vmalert automatically adds the tenant specified in config groups to -datasource.url, -remoteWrite.url and -remoteRead.url. See https://docs.victoriametrics.com/vmalert.html#multitenancy . This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html -configCheckInterval duration Interval for checking for changes in '-rule' or '-notifier.config' files. By default the checking is disabled. Send SIGHUP signal in order to force config check for changes. -datasource.appendTypePrefix Whether to add type prefix to -datasource.url based on the query type. Set to true if sending different query types to the vmselect URL. -datasource.basicAuth.password string Optional basic auth password for -datasource.url -datasource.basicAuth.passwordFile string Optional path to basic auth password to use for -datasource.url -datasource.basicAuth.username string Optional basic auth username for -datasource.url -datasource.bearerToken string Optional bearer auth token to use for -datasource.url. -datasource.bearerTokenFile string Optional path to bearer token file to use for -datasource.url. -datasource.disableKeepAlive Whether to disable long-lived connections to the datasource. If true, disables HTTP keep-alives and will only use the connection to the server for a single HTTP request. -datasource.headers string Optional HTTP extraHeaders to send with each request to the corresponding -datasource.url. For example, -datasource.headers='My-Auth:foobar' would send 'My-Auth: foobar' HTTP header with every request to the corresponding -datasource.url. Multiple headers must be delimited by '^^': -datasource.headers='header1:value1^^header2:value2' -datasource.lookback duration Lookback defines how far into the past to look when evaluating queries. For example, if the datasource.lookback=5m then param "time" with value now()-5m will be added to every query. -datasource.maxIdleConnections int Defines the number of idle (keep-alive connections) to each configured datasource. Consider setting this value equal to the value: groups_total * group.concurrency. Too low a value may result in a high number of sockets in TIME_WAIT state. (default 100) -datasource.oauth2.clientID string Optional OAuth2 clientID to use for -datasource.url. -datasource.oauth2.clientSecret string Optional OAuth2 clientSecret to use for -datasource.url. -datasource.oauth2.clientSecretFile string Optional OAuth2 clientSecretFile to use for -datasource.url. -datasource.oauth2.scopes string Optional OAuth2 scopes to use for -datasource.url. Scopes must be delimited by ';' -datasource.oauth2.tokenUrl string Optional OAuth2 tokenURL to use for -datasource.url. -datasource.queryStep duration How far a value can fallback to when evaluating queries. For example, if -datasource.queryStep=15s then param "step" with value "15s" will be added to every query. If set to 0, rule's evaluation interval will be used instead. (default 5m0s) -datasource.queryTimeAlignment Whether to align "time" parameter with evaluation interval.Alignment supposed to produce deterministic results despite of number of vmalert replicas or time they were started. See more details here https://github.com/VictoriaMetrics/VictoriaMetrics/pull/1257 (default true) -datasource.roundDigits int Adds "round_digits" GET param to datasource requests. In VM "round_digits" limits the number of digits after the decimal point in response values. -datasource.showURL Whether to show -datasource.url in the exported metrics. It is hidden by default, since it can contain sensitive info such as auth key -datasource.tlsCAFile string Optional path to TLS CA file to use for verifying connections to -datasource.url. By default, system CA is used -datasource.tlsCertFile string Optional path to client-side TLS certificate file to use when connecting to -datasource.url -datasource.tlsInsecureSkipVerify Whether to skip tls verification when connecting to -datasource.url -datasource.tlsKeyFile string Optional path to client-side TLS certificate key to use when connecting to -datasource.url -datasource.tlsServerName string Optional TLS server name to use for connections to -datasource.url. By default, the server name from -datasource.url is used -datasource.url string Datasource compatible with Prometheus HTTP API. It can be single node VictoriaMetrics or vmselect URL. Required parameter. E.g. http://127.0.0.1:8428 . See also -remoteRead.disablePathAppend and -datasource.showURL -defaultTenant.graphite string Default tenant for Graphite alerting groups. See https://docs.victoriametrics.com/vmalert.html#multitenancy .This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html -defaultTenant.prometheus string Default tenant for Prometheus alerting groups. See https://docs.victoriametrics.com/vmalert.html#multitenancy . This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html -disableAlertgroupLabel Whether to disable adding group's Name as label to generated alerts and time series. -dryRun Whether to check only config files without running vmalert. The rules file are validated. The -rule flag must be specified. -enableTCP6 Whether to enable IPv6 for listening and dialing. By default only IPv4 TCP and UDP is used -envflag.enable Whether to enable reading flags from environment variables additionally to command line. Command line flag values have priority over values from environment vars. Flags are read only from command line if this flag isn't set. See https://docs.victoriametrics.com/#environment-variables for more details -envflag.prefix string Prefix for environment variables if -envflag.enable is set -eula By specifying this flag, you confirm that you have an enterprise license and accept the EULA https://victoriametrics.com/assets/VM_EULA.pdf . This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html -evaluationInterval duration How often to evaluate the rules (default 1m0s) -external.alert.source string External Alert Source allows to override the Source link for alerts sent to AlertManager for cases where you want to build a custom link to Grafana, Prometheus or any other service. Supports templating - see https://docs.victoriametrics.com/vmalert.html#templating . For example, link to Grafana: -external.alert.source='explore?orgId=1&left=["now-1h","now","VictoriaMetrics",{"expr":{{$expr|jsonEscape|queryEscape}} },{"mode":"Metrics"},{"ui":[true,true,true,"none"]}]' . If empty 'vmalert/alert?group_id={{.GroupID}}&alert_id={{.AlertID}}' is used. -external.label array Optional label in the form 'Name=value' to add to all generated recording rules and alerts. Pass multiple -label flags in order to add multiple label sets. Supports an array of values separated by comma or specified via multiple flags. -external.url string External URL is used as alert's source for sent alerts to the notifier -flagsAuthKey string Auth key for /flags endpoint. It must be passed via authKey query arg. It overrides httpAuth.* settings -fs.disableMmap Whether to use pread() instead of mmap() for reading data files. By default mmap() is used for 64-bit arches and pread() is used for 32-bit arches, since they cannot read data files bigger than 2^32 bytes in memory. mmap() is usually faster for reading small data chunks than pread() -http.connTimeout duration Incoming http connections are closed after the configured timeout. This may help to spread the incoming load among a cluster of services behind a load balancer. Please note that the real timeout may be bigger by up to 10% as a protection against the thundering herd problem (default 2m0s) -http.disableResponseCompression Disable compression of HTTP responses to save CPU resources. By default compression is enabled to save network bandwidth -http.idleConnTimeout duration Timeout for incoming idle http connections (default 1m0s) -http.maxGracefulShutdownDuration duration The maximum duration for a graceful shutdown of the HTTP server. A highly loaded server may require increased value for a graceful shutdown (default 7s) -http.pathPrefix string An optional prefix to add to all the paths handled by http server. For example, if '-http.pathPrefix=/foo/bar' is set, then all the http requests will be handled on '/foo/bar/*' paths. This may be useful for proxied requests. See https://www.robustperception.io/using-external-urls-and-proxies-with-prometheus -http.shutdownDelay duration Optional delay before http server shutdown. During this delay, the server returns non-OK responses from /health page, so load balancers can route new requests to other servers -httpAuth.password string Password for HTTP Basic Auth. The authentication is disabled if -httpAuth.username is empty -httpAuth.username string Username for HTTP Basic Auth. The authentication is disabled if empty. See also -httpAuth.password -httpListenAddr string Address to listen for http connections. See also -httpListenAddr.useProxyProtocol (default ":8880") -httpListenAddr.useProxyProtocol Whether to use proxy protocol for connections accepted at -httpListenAddr . See https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt -insert.maxQueueDuration duration The maximum duration to wait in the queue when -maxConcurrentInserts concurrent insert requests are executed (default 1m0s) -internStringMaxLen int The maximum length for strings to intern. Lower limit may save memory at the cost of higher CPU usage. See https://en.wikipedia.org/wiki/String_interning (default 500) -loggerDisableTimestamps Whether to disable writing timestamps in logs -loggerErrorsPerSecondLimit int Per-second limit on the number of ERROR messages. If more than the given number of errors are emitted per second, the remaining errors are suppressed. Zero values disable the rate limit -loggerFormat string Format for logs. Possible values: default, json (default "default") -loggerJSONFields string Allows renaming fields in JSON formatted logs. Example: "ts:timestamp,msg:message" renames "ts" to "timestamp" and "msg" to "message". Supported fields: ts, level, caller, msg -loggerLevel string Minimum level of errors to log. Possible values: INFO, WARN, ERROR, FATAL, PANIC (default "INFO") -loggerOutput string Output for the logs. Supported values: stderr, stdout (default "stderr") -loggerTimezone string Timezone to use for timestamps in logs. Timezone must be a valid IANA Time Zone. For example: America/New_York, Europe/Berlin, Etc/GMT+3 or Local (default "UTC") -loggerWarnsPerSecondLimit int Per-second limit on the number of WARN messages. If more than the given number of warns are emitted per second, then the remaining warns are suppressed. Zero values disable the rate limit -maxConcurrentInserts int The maximum number of concurrent insert requests. Default value should work for most cases, since it minimizes the memory usage. The default value can be increased when clients send data over slow networks. See also -insert.maxQueueDuration (default 8) -memory.allowedBytes size Allowed size of system memory VictoriaMetrics caches may occupy. This option overrides -memory.allowedPercent if set to a non-zero value. Too low a value may increase the cache miss rate usually resulting in higher CPU and disk IO usage. Too high a value may evict too much data from OS page cache resulting in higher disk IO usage Supports the following optional suffixes for size values: KB, MB, GB, TB, KiB, MiB, GiB, TiB (default 0) -memory.allowedPercent float Allowed percent of system memory VictoriaMetrics caches may occupy. See also -memory.allowedBytes. Too low a value may increase cache miss rate usually resulting in higher CPU and disk IO usage. Too high a value may evict too much data from OS page cache which will result in higher disk IO usage (default 60) -metricsAuthKey string Auth key for /metrics endpoint. It must be passed via authKey query arg. It overrides httpAuth.* settings -notifier.basicAuth.password array Optional basic auth password for -notifier.url Supports an array of values separated by comma or specified via multiple flags. -notifier.basicAuth.passwordFile array Optional path to basic auth password file for -notifier.url Supports an array of values separated by comma or specified via multiple flags. -notifier.basicAuth.username array Optional basic auth username for -notifier.url Supports an array of values separated by comma or specified via multiple flags. -notifier.bearerToken array Optional bearer token for -notifier.url Supports an array of values separated by comma or specified via multiple flags. -notifier.bearerTokenFile array Optional path to bearer token file for -notifier.url Supports an array of values separated by comma or specified via multiple flags. -notifier.config string Path to configuration file for notifiers -notifier.oauth2.clientID array Optional OAuth2 clientID to use for -notifier.url. If multiple args are set, then they are applied independently for the corresponding -notifier.url Supports an array of values separated by comma or specified via multiple flags. -notifier.oauth2.clientSecret array Optional OAuth2 clientSecret to use for -notifier.url. If multiple args are set, then they are applied independently for the corresponding -notifier.url Supports an array of values separated by comma or specified via multiple flags. -notifier.oauth2.clientSecretFile array Optional OAuth2 clientSecretFile to use for -notifier.url. If multiple args are set, then they are applied independently for the corresponding -notifier.url Supports an array of values separated by comma or specified via multiple flags. -notifier.oauth2.scopes array Optional OAuth2 scopes to use for -notifier.url. Scopes must be delimited by ';'. If multiple args are set, then they are applied independently for the corresponding -notifier.url Supports an array of values separated by comma or specified via multiple flags. -notifier.oauth2.tokenUrl array Optional OAuth2 tokenURL to use for -notifier.url. If multiple args are set, then they are applied independently for the corresponding -notifier.url Supports an array of values separated by comma or specified via multiple flags. -notifier.suppressDuplicateTargetErrors Whether to suppress 'duplicate target' errors during discovery -notifier.tlsCAFile array Optional path to TLS CA file to use for verifying connections to -notifier.url. By default system CA is used Supports an array of values separated by comma or specified via multiple flags. -notifier.tlsCertFile array Optional path to client-side TLS certificate file to use when connecting to -notifier.url Supports an array of values separated by comma or specified via multiple flags. -notifier.tlsInsecureSkipVerify array Whether to skip tls verification when connecting to -notifier.url Supports array of values separated by comma or specified via multiple flags. -notifier.tlsKeyFile array Optional path to client-side TLS certificate key to use when connecting to -notifier.url Supports an array of values separated by comma or specified via multiple flags. -notifier.tlsServerName array Optional TLS server name to use for connections to -notifier.url. By default the server name from -notifier.url is used Supports an array of values separated by comma or specified via multiple flags. -notifier.url array Prometheus Alertmanager URL, e.g. http://127.0.0.1:9093. List all Alertmanager URLs if it runs in the cluster mode to ensure high availability. Supports an array of values separated by comma or specified via multiple flags. -pprofAuthKey string Auth key for /debug/pprof/* endpoints. It must be passed via authKey query arg. It overrides httpAuth.* settings -promscrape.consul.waitTime duration Wait time used by Consul service discovery. Default value is used if not set -promscrape.consulSDCheckInterval duration Interval for checking for changes in Consul. This works only if consul_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#consul_sd_configs for details (default 30s) -promscrape.discovery.concurrency int The maximum number of concurrent requests to Prometheus autodiscovery API (Consul, Kubernetes, etc.) (default 100) -promscrape.discovery.concurrentWaitTime duration The maximum duration for waiting to perform API requests if more than -promscrape.discovery.concurrency requests are simultaneously performed (default 1m0s) -promscrape.dnsSDCheckInterval duration Interval for checking for changes in dns. This works only if dns_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#dns_sd_configs for details (default 30s) -pushmetrics.extraLabel array Optional labels to add to metrics pushed to -pushmetrics.url . For example, -pushmetrics.extraLabel='instance="foo"' adds instance="foo" label to all the metrics pushed to -pushmetrics.url Supports an array of values separated by comma or specified via multiple flags. -pushmetrics.interval duration Interval for pushing metrics to -pushmetrics.url (default 10s) -pushmetrics.url array Optional URL to push metrics exposed at /metrics page. See https://docs.victoriametrics.com/#push-metrics . By default metrics exposed at /metrics page aren't pushed to any remote storage Supports an array of values separated by comma or specified via multiple flags. -remoteRead.basicAuth.password string Optional basic auth password for -remoteRead.url -remoteRead.basicAuth.passwordFile string Optional path to basic auth password to use for -remoteRead.url -remoteRead.basicAuth.username string Optional basic auth username for -remoteRead.url -remoteRead.bearerToken string Optional bearer auth token to use for -remoteRead.url. -remoteRead.bearerTokenFile string Optional path to bearer token file to use for -remoteRead.url. -remoteRead.disablePathAppend Whether to disable automatic appending of '/api/v1/query' path to the configured -datasource.url and -remoteRead.url -remoteRead.headers string Optional HTTP headers to send with each request to the corresponding -remoteRead.url. For example, -remoteRead.headers='My-Auth:foobar' would send 'My-Auth: foobar' HTTP header with every request to the corresponding -remoteRead.url. Multiple headers must be delimited by '^^': -remoteRead.headers='header1:value1^^header2:value2' -remoteRead.ignoreRestoreErrors Whether to ignore errors from remote storage when restoring alerts state on startup. DEPRECATED - this flag has no effect and will be removed in the next releases. (default true) -remoteRead.lookback duration Lookback defines how far to look into past for alerts timeseries. For example, if lookback=1h then range from now() to now()-1h will be scanned. (default 1h0m0s) -remoteRead.oauth2.clientID string Optional OAuth2 clientID to use for -remoteRead.url. -remoteRead.oauth2.clientSecret string Optional OAuth2 clientSecret to use for -remoteRead.url. -remoteRead.oauth2.clientSecretFile string Optional OAuth2 clientSecretFile to use for -remoteRead.url. -remoteRead.oauth2.scopes string Optional OAuth2 scopes to use for -remoteRead.url. Scopes must be delimited by ';'. -remoteRead.oauth2.tokenUrl string Optional OAuth2 tokenURL to use for -remoteRead.url. -remoteRead.showURL Whether to show -remoteRead.url in the exported metrics. It is hidden by default, since it can contain sensitive info such as auth key -remoteRead.tlsCAFile string Optional path to TLS CA file to use for verifying connections to -remoteRead.url. By default system CA is used -remoteRead.tlsCertFile string Optional path to client-side TLS certificate file to use when connecting to -remoteRead.url -remoteRead.tlsInsecureSkipVerify Whether to skip tls verification when connecting to -remoteRead.url -remoteRead.tlsKeyFile string Optional path to client-side TLS certificate key to use when connecting to -remoteRead.url -remoteRead.tlsServerName string Optional TLS server name to use for connections to -remoteRead.url. By default the server name from -remoteRead.url is used -remoteRead.url vmalert Optional URL to datasource compatible with Prometheus HTTP API. It can be single node VictoriaMetrics or vmselect.Remote read is used to restore alerts state.This configuration makes sense only if vmalert was configured with `remoteWrite.url` before and has been successfully persisted its state. E.g. http://127.0.0.1:8428. See also '-remoteRead.disablePathAppend', '-remoteRead.showURL'. -remoteWrite.basicAuth.password string Optional basic auth password for -remoteWrite.url -remoteWrite.basicAuth.passwordFile string Optional path to basic auth password to use for -remoteWrite.url -remoteWrite.basicAuth.username string Optional basic auth username for -remoteWrite.url -remoteWrite.bearerToken string Optional bearer auth token to use for -remoteWrite.url. -remoteWrite.bearerTokenFile string Optional path to bearer token file to use for -remoteWrite.url. -remoteWrite.concurrency int Defines number of writers for concurrent writing into remote querier (default 1) -remoteWrite.disablePathAppend Whether to disable automatic appending of '/api/v1/write' path to the configured -remoteWrite.url. -remoteWrite.flushInterval duration Defines interval of flushes to remote write endpoint (default 5s) -remoteWrite.headers string Optional HTTP headers to send with each request to the corresponding -remoteWrite.url. For example, -remoteWrite.headers='My-Auth:foobar' would send 'My-Auth: foobar' HTTP header with every request to the corresponding -remoteWrite.url. Multiple headers must be delimited by '^^': -remoteWrite.headers='header1:value1^^header2:value2' -remoteWrite.maxBatchSize int Defines defines max number of timeseries to be flushed at once (default 1000) -remoteWrite.maxQueueSize int Defines the max number of pending datapoints to remote write endpoint (default 100000) -remoteWrite.oauth2.clientID string Optional OAuth2 clientID to use for -remoteWrite.url. -remoteWrite.oauth2.clientSecret string Optional OAuth2 clientSecret to use for -remoteWrite.url. -remoteWrite.oauth2.clientSecretFile string Optional OAuth2 clientSecretFile to use for -remoteWrite.url. -remoteWrite.oauth2.scopes string Optional OAuth2 scopes to use for -notifier.url. Scopes must be delimited by ';'. -remoteWrite.oauth2.tokenUrl string Optional OAuth2 tokenURL to use for -notifier.url. -remoteWrite.sendTimeout duration Timeout for sending data to the configured -remoteWrite.url. (default 30s) -remoteWrite.showURL Whether to show -remoteWrite.url in the exported metrics. It is hidden by default, since it can contain sensitive info such as auth key -remoteWrite.tlsCAFile string Optional path to TLS CA file to use for verifying connections to -remoteWrite.url. By default system CA is used -remoteWrite.tlsCertFile string Optional path to client-side TLS certificate file to use when connecting to -remoteWrite.url -remoteWrite.tlsInsecureSkipVerify Whether to skip tls verification when connecting to -remoteWrite.url -remoteWrite.tlsKeyFile string Optional path to client-side TLS certificate key to use when connecting to -remoteWrite.url -remoteWrite.tlsServerName string Optional TLS server name to use for connections to -remoteWrite.url. By default the server name from -remoteWrite.url is used -remoteWrite.url string Optional URL to VictoriaMetrics or vminsert where to persist alerts state and recording rules results in form of timeseries. For example, if -remoteWrite.url=http://127.0.0.1:8428 is specified, then the alerts state will be written to http://127.0.0.1:8428/api/v1/write . See also -remoteWrite.disablePathAppend, '-remoteWrite.showURL'. -replay.disableProgressBar Whether to disable rendering progress bars during the replay. Progress bar rendering might be verbose or break the logs parsing, so it is recommended to be disabled when not used in interactive mode. -replay.maxDatapointsPerQuery /query_range Max number of data points expected in one request. It affects the max time range for every /query_range request during the replay. The higher the value, the less requests will be made during replay. (default 1000) -replay.ruleRetryAttempts int Defines how many retries to make before giving up on rule if request for it returns an error. (default 5) -replay.rulesDelay duration Delay between rules evaluation within the group. Could be important if there are chained rules inside of the groupand processing need to wait for previous rule results to be persisted by remote storage before evaluating the next rule.Keep it equal or bigger than -remoteWrite.flushInterval. (default 1s) -replay.timeFrom string The time filter in RFC3339 format to select time series with timestamp equal or higher than provided value. E.g. '2020-01-01T20:07:00Z' -replay.timeTo string The time filter in RFC3339 format to select timeseries with timestamp equal or lower than provided value. E.g. '2020-01-01T20:07:00Z' -rule array Path to the files with alerting and/or recording rules. Supports hierarchical patterns and regexpes. Examples: -rule="/path/to/file". Path to a single file with alerting rules -rule="dir/*.yaml" -rule="/*.yaml" -rule="gcs://vmalert-rules/tenant_%{TENANT_ID}/prod". Rule files may contain %{ENV_VAR} placeholders, which are substituted by the corresponding env vars. Enterprise version of vmalert supports S3 and GCS paths to rules. For example: gs://bucket/path/to/rules, s3://bucket/path/to/rules S3 and GCS paths support only matching by prefix, e.g. s3://bucket/dir/rule_ matches all files with prefix rule_ in folder dir. See https://docs.victoriametrics.com/vmalert.html#reading-rules-from-object-storage Supports an array of values separated by comma or specified via multiple flags. -rule.configCheckInterval duration Interval for checking for changes in '-rule' files. By default the checking is disabled. Send SIGHUP signal in order to force config check for changes. DEPRECATED - see '-configCheckInterval' instead -rule.maxResolveDuration duration Limits the maximum duration for automatic alert expiration, which by default is 4 times evaluationInterval of the parent group. -rule.resendDelay duration Minimum amount of time to wait before resending an alert to notifier -rule.templates array Path or glob pattern to location with go template definitions for rules annotations templating. Flag can be specified multiple times. Examples: -rule.templates="/path/to/file". Path to a single file with go templates -rule.templates="dir/*.tpl" -rule.templates="/*.tpl". Relative path to all .tpl files in "dir" folder, absolute path to all .tpl files in root. Supports an array of values separated by comma or specified via multiple flags. -rule.updateEntriesLimit int Defines the max number of rule's state updates stored in-memory. Rule's updates are available on rule's Details page and are used for debugging purposes. The number of stored updates can be overriden per rule via update_entries_limit param. (default 20) -rule.validateExpressions Whether to validate rules expressions via MetricsQL engine (default true) -rule.validateTemplates Whether to validate annotation and label templates (default true) -s3.configFilePath string Path to file with S3 configs. Configs are loaded from default location if not set. See https://docs.aws.amazon.com/general/latest/gr/aws-security-credentials.html . This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html -s3.configProfile string Profile name for S3 configs. If no set, the value of the environment variable will be loaded (AWS_PROFILE or AWS_DEFAULT_PROFILE), or if both not set, DefaultSharedConfigProfile is used. This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html -s3.credsFilePath string Path to file with GCS or S3 credentials. Credentials are loaded from default locations if not set. See https://cloud.google.com/iam/docs/creating-managing-service-account-keys and https://docs.aws.amazon.com/general/latest/gr/aws-security-credentials.html . This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html -s3.customEndpoint string Custom S3 endpoint for use with S3-compatible storages (e.g. MinIO). S3 is used if not set. This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html -s3.forcePathStyle Prefixing endpoint with bucket name when set false, true by default. This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html (default true) -tls Whether to enable TLS for incoming HTTP requests at -httpListenAddr (aka https). -tlsCertFile and -tlsKeyFile must be set if -tls is set -tlsCertFile string Path to file with TLS certificate if -tls is set. Prefer ECDSA certs instead of RSA certs as RSA certs are slower. The provided certificate file is automatically re-read every second, so it can be dynamically updated -tlsCipherSuites array Optional list of TLS cipher suites for incoming requests over HTTPS if -tls is set. See the list of supported cipher suites at https://pkg.go.dev/crypto/tls#pkg-constants Supports an array of values separated by comma or specified via multiple flags. -tlsKeyFile string Path to file with TLS key if -tls is set. The provided key file is automatically re-read every second, so it can be dynamically updated -tlsMinVersion string Optional minimum TLS version to use for incoming requests over HTTPS if -tls is set. Supported values: TLS10, TLS11, TLS12, TLS13 -version Show VictoriaMetrics version ``` {% endraw %} ### Hot config reload `vmalert` supports "hot" config reload via the following methods: * send SIGHUP signal to `vmalert` process; * send GET request to `/-/reload` endpoint; * configure `-configCheckInterval` flag for periodic reload on config change. ### URL params To set additional URL params for `datasource.url`, `remoteWrite.url` or `remoteRead.url` just add them in address: `-datasource.url=http://localhost:8428?nocache=1`. To set additional URL params for specific [group of rules](#Groups) modify the `params` group: ```yaml groups: - name: TestGroup params: denyPartialResponse: ["true"] extra_label: ["env=dev"] ``` Please note, `params` are used only for executing rules expressions (requests to `datasource.url`). If there would be a conflict between URL params set in `datasource.url` flag and params in group definition the latter will have higher priority. ### Notifier configuration file Notifier also supports configuration via file specified with flag `notifier.config`: ``` ./bin/vmalert -rule=app/vmalert/config/testdata/rules.good.rules \ -datasource.url=http://localhost:8428 \ -notifier.config=app/vmalert/notifier/testdata/consul.good.yaml ``` The configuration file allows to configure static notifiers, discover notifiers via [Consul](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#consul_sd_config) and [DNS](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#dns_sd_config): For example: ``` static_configs: - targets: - localhost:9093 - localhost:9095 consul_sd_configs: - server: localhost:8500 services: - alertmanager dns_sd_configs: - names: - my.domain.com type: 'A' port: 9093 ``` The list of configured or discovered Notifiers can be explored via [UI](#Web). If Alertmanager runs in cluster mode then all its URLs needs to be available during discovery to ensure [high availability](https://github.com/prometheus/alertmanager#high-availability). The configuration file [specification](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/app/vmalert/notifier/config.go) is the following: ``` # Per-target Notifier timeout when pushing alerts. [ timeout: | default = 10s ] # Prefix for the HTTP path alerts are pushed to. [ path_prefix: | default = / ] # Configures the protocol scheme used for requests. [ scheme: | default = http ] # Sets the `Authorization` header on every request with the # configured username and password. # password and password_file are mutually exclusive. basic_auth: [ username: ] [ password: ] [ password_file: ] # Optional `Authorization` header configuration. authorization: # Sets the authentication type. [ type: | default: Bearer ] # Sets the credentials. It is mutually exclusive with # `credentials_file`. [ credentials: ] # Sets the credentials to the credentials read from the configured file. # It is mutually exclusive with `credentials`. [ credentials_file: ] # Configures the scrape request's TLS settings. # see https://prometheus.io/docs/prometheus/latest/configuration/configuration/#tls_config tls_config: [ ] # Configures Bearer authentication token via string bearer_token: # or by passing path to the file with token. bearer_token_file: # Configures OAuth 2.0 authentication # see https://prometheus.io/docs/prometheus/latest/configuration/configuration/#oauth2 oauth2: [ ] # Optional list of HTTP headers in form `header-name: value` # applied for all requests to notifiers # For example: # headers: # - "CustomHeader: foo" # - "CustomHeader2: bar" headers: [ , ...] # List of labeled statically configured Notifiers. # # Each list of targets may be additionally instructed with # authorization params. Target's authorization params will # inherit params from global authorization params if there # are no conflicts. static_configs: [ - targets: ] [ - '' ] [ oauth2 ] [ basic_auth ] [ authorization ] [ tls_config ] [ bearer_token ] [ bearer_token_file ] [ headers ] # List of Consul service discovery configurations. # See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#consul_sd_config consul_sd_configs: [ - ... ] # List of DNS service discovery configurations. # See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#dns_sd_config dns_sd_configs: [ - ... ] # List of relabel configurations for entities discovered via service discovery. # Supports the same relabeling features as the rest of VictoriaMetrics components. # See https://docs.victoriametrics.com/vmagent.html#relabeling relabel_configs: [ - ... ] # List of relabel configurations for alert labels sent via Notifier. # Supports the same relabeling features as the rest of VictoriaMetrics components. # See https://docs.victoriametrics.com/vmagent.html#relabeling alert_relabel_configs: [ - ... ] ``` The configuration file can be [hot-reloaded](#hot-config-reload). ## Contributing `vmalert` is mostly designed and built by VictoriaMetrics community. Feel free to share your experience and ideas for improving this software. Please keep simplicity as the main priority. ## How to build from sources It is recommended using [binary releases](https://github.com/VictoriaMetrics/VictoriaMetrics/releases) * `vmalert` is located in `vmutils-*` archives there. ### Docker image You can build `vmalert` docker image from source and push it to your own docker repository. Run the following commands from the root folder of [the repository](https://github.com/VictoriaMetrics/VictoriaMetrics): ```console make package-vmalert docker tag victoria-metrics/vmalert:version my-repo:my-version-name docker push my-repo:my-version-name ``` To run the built image in `victoria-metrics-k8s-stack` or `VMAlert` CR object apply the following config change: ```yaml kind: VMAlert spec: image: repository: my-repo tag: my-version-name ``` ### Development build 1. [Install Go](https://golang.org/doc/install). The minimum supported version is Go 1.19. 2. Run `make vmalert` from the root folder of [the repository](https://github.com/VictoriaMetrics/VictoriaMetrics). It builds `vmalert` binary and puts it into the `bin` folder. ### Production build 1. [Install docker](https://docs.docker.com/install/). 2. Run `make vmalert-prod` from the root folder of [the repository](https://github.com/VictoriaMetrics/VictoriaMetrics). It builds `vmalert-prod` binary and puts it into the `bin` folder. ### ARM build ARM build may run on Raspberry Pi or on [energy-efficient ARM servers](https://blog.cloudflare.com/arm-takes-wing/). ### Development ARM build 1. [Install Go](https://golang.org/doc/install). The minimum supported version is Go 1.19. 2. Run `make vmalert-linux-arm` or `make vmalert-linux-arm64` from the root folder of [the repository](https://github.com/VictoriaMetrics/VictoriaMetrics). It builds `vmalert-linux-arm` or `vmalert-linux-arm64` binary respectively and puts it into the `bin` folder. ### Production ARM build 1. [Install docker](https://docs.docker.com/install/). 2. Run `make vmalert-linux-arm-prod` or `make vmalert-linux-arm64-prod` from the root folder of [the repository](https://github.com/VictoriaMetrics/VictoriaMetrics). It builds `vmalert-linux-arm-prod` or `vmalert-linux-arm64-prod` binary respectively and puts it into the `bin` folder.