Repository: VictoriaMetrics/VictoriaMetrics
Pull request #1005 (2021-01-09 18:09:18)

docker-compose: provide the example list of alerting rules for vm components
List contains examples for the alerting rules which might be executed
via `vmalert` to track the health state of VM components. It is assumed
that list will be revised and calibrated for each system individually.

codecov[bot]: # [Codecov](https://codecov.io/gh/VictoriaMetrics/VictoriaMetrics/pull/1005?src=pr&el=h1) Report
> Merging [#1005](https://codecov.io/gh/VictoriaMetrics/VictoriaMetrics/pull/1005?src=pr&el=desc) (c752a87) into [master](https://codecov.io/gh/VictoriaMetrics/VictoriaMetrics/commit/9dcb18e03d1ef04901feca2232b609ca2803adb7?el=desc) (9dcb18e) will **increase** coverage by `0.02%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/VictoriaMetrics/VictoriaMetrics/pull/1005/graphs/tree.svg?width=650&height=150&src=pr&token=YND8dYVcXn)](https://codecov.io/gh/VictoriaMetrics/VictoriaMetrics/pull/1005?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master    #1005      +/-   ##
==========================================
+ Coverage   60.37%   60.40%   +0.02%     
==========================================
  Files         202      202              
  Lines       22983    22983              
==========================================
+ Hits        13877    13882       +5     
+ Misses       7784     7781       -3     
+ Partials     1322     1320       -2     
```


| [Impacted Files](https://codecov.io/gh/VictoriaMetrics/VictoriaMetrics/pull/1005?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [lib/storage/index\_db.go](https://codecov.io/gh/VictoriaMetrics/VictoriaMetrics/pull/1005/diff?src=pr&el=tree#diff-bGliL3N0b3JhZ2UvaW5kZXhfZGIuZ28=) | `63.96% <0.00%> (-0.16%)` | :arrow_down: |
| [app/vmselect/promql/aggr\_incremental.go](https://codecov.io/gh/VictoriaMetrics/VictoriaMetrics/pull/1005/diff?src=pr&el=tree#diff-YXBwL3Ztc2VsZWN0L3Byb21xbC9hZ2dyX2luY3JlbWVudGFsLmdv) | `86.43% <0.00%> (+1.55%)` | :arrow_up: |
| [app/vmalert/remotewrite/remotewrite.go](https://codecov.io/gh/VictoriaMetrics/VictoriaMetrics/pull/1005/diff?src=pr&el=tree#diff-YXBwL3ZtYWxlcnQvcmVtb3Rld3JpdGUvcmVtb3Rld3JpdGUuZ28=) | `60.37% <0.00%> (+3.77%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/VictoriaMetrics/VictoriaMetrics/pull/1005?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/VictoriaMetrics/VictoriaMetrics/pull/1005?src=pr&el=footer). Last update [9dcb18e...c752a87](https://codecov.io/gh/VictoriaMetrics/VictoriaMetrics/pull/1005?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).


Patch:
diff --git a/README.md b/README.md
index 67db1496c..b0df5c4e6 100644
--- a/README.md
+++ b/README.md
@@ -1279,6 +1279,7 @@ The most interesting metrics are:
 
 VictoriaMetrics also exposes currently running queries with their execution times at `/api/v1/status/active_queries` page.
 
+See the example of alerting rules for VM components [here](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/deployment/docker/alerts.yml).
 
 ## Troubleshooting
 
diff --git a/app/vmagent/remotewrite/statconn.go b/app/vmagent/remotewrite/statconn.go
index 93cbf0a15..3c227dc19 100644
--- a/app/vmagent/remotewrite/statconn.go
+++ b/app/vmagent/remotewrite/statconn.go
@@ -5,9 +5,9 @@ import (
 	"net"
 	"strings"
 	"sync/atomic"
+	"time"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/netutil"
-	"github.com/VictoriaMetrics/fasthttp"
 	"github.com/VictoriaMetrics/metrics"
 )
 
@@ -15,11 +15,10 @@ func statDial(network, addr string) (conn net.Conn, err error) {
 	if !strings.HasPrefix(network, "tcp") {
 		return nil, fmt.Errorf("unexpected network passed to statDial: %q; it must start from `tcp`", network)
 	}
-	if netutil.TCP6Enabled() {
-		conn, err = fasthttp.DialDualStack(addr)
-	} else {
-		conn, err = fasthttp.Dial(addr)
+	if !netutil.TCP6Enabled() {
+		network = "tcp4"
 	}
+	conn, err = net.DialTimeout(network, addr, 5*time.Second)
 	dialsTotal.Inc()
 	if err != nil {
 		dialErrors.Inc()
diff --git a/app/vmalert/notifier/template_func.go b/app/vmalert/notifier/template_func.go
index 043339b87..8751abcc7 100644
--- a/app/vmalert/notifier/template_func.go
+++ b/app/vmalert/notifier/template_func.go
@@ -178,7 +178,9 @@ func InitTemplateFunc(externalURL *url.URL) {
 		// it is present here only for validation purposes, when there is no
 		// provided datasource.
 		"query": func(q string) ([]datasource.Metric, error) {
-			return nil, nil
+			// return non-empty slice to pass validation with chained functions in template
+			// see issue #989 for details
+			return []datasource.Metric{{}}, nil
 		},
 		"first": func(metrics []datasource.Metric) (datasource.Metric, error) {
 			if len(metrics) > 0 {
diff --git a/deployment/docker/alerts.yml b/deployment/docker/alerts.yml
index 1d2e3398e..77f72854b 100644
--- a/deployment/docker/alerts.yml
+++ b/deployment/docker/alerts.yml
@@ -1,23 +1,174 @@
+# File contains default list of alerts for vm-single and vmagent services.
+# The alerts below are just recommendations and may require some updates
+# and threshold calibration according to every specific setup.
 groups:
-  - name: groupGorSingleAlert
+  - name: serviceHealth
     rules:
-      - alert: VMRows
-        for: 10s
-        expr: vm_rows > 0
+      # note the `job` filter and update accordingly to your setup
+      - alert: TooManyRestarts
+        expr: changes(process_start_time_seconds{job=~"victoriametrics|vmagent|vmalert"}[15m]) > 2
         labels:
-          label: bar
-          host: "{{ $labels.instance }}"
+          severity: critical
         annotations:
-          summary: "{{ $value|humanize }}"
-          description: "{{$labels}}"
-  - name: TestGroup
+          summary: "{{ $labels.job }} too many restarts (instance {{ $labels.instance }})"
+          description: "Job {{ $labels.job }} has restarted more than twice in the last 15 minutes.
+            It might be crashlooping."
+
+  # Alerts group for VM single assumes that Grafana dashboard
+  # https://grafana.com/grafana/dashboards/10229 is installed.
+  # Pls update the `dashboard` annotation according to your setup.
+  - name: vmsingle
+    interval: 30s
+    concurrency: 2
     rules:
-      - alert: Conns
-        expr: sum(vm_tcplistener_conns) by(instance) > 1
-        for: 5s
-        annotations:
-          summary: "Too high connection number for {{$labels.instance}}"
-          description: "It is {{ $value }} connections for {{$labels.instance}}"
-      - alert: ExampleAlertAlwaysFiring
-        expr: sum by(job)
-          (up == 1)
+      - alert: DiskRunsOutOfSpaceIn3Days
+        expr: |
+          vm_free_disk_space_bytes / ignoring(path) (
+           (
+            sum(rate(vm_rows_added_to_storage_total[1d])) -
+            sum(rate(vm_deduplicated_samples_total[1d])) without(type)
+           )
+          *
+           (
+            sum(vm_data_size_bytes{type!="indexdb"}) /
+            sum(vm_rows{type!="indexdb"})
+           )
+          ) < 3 * 24 * 3600
+        for: 30m
+        labels:
+          severity: critical
+        annotations:
+          dashboard: "http://localhost:3000/d/wNf0q_kZk?viewPanel=73&var-instance={{ $labels.instance }}"
+          summary: "Instance {{ $labels.instance }} will run out of disk space soon"
+          description: "Taking into account current ingestion rate, free disk space will be enough only
+            for {{ $value | humanizeDuration }} on instance {{ $labels.instance }}.\n
+            Consider to limit the ingestion rate, decrease retention or scale the disk space if possible."
+
+      - alert: RequestErrorsToAPI
+        expr: increase(vm_http_request_errors_total[5m]) > 0
+        for: 15m
+        labels:
+          severity: warning
+        annotations:
+          dashboard: "http://localhost:3000/d/wNf0q_kZk?viewPanel=35&var-instance={{ $labels.instance }}"
+          summary: "Too many errors served for path {{ $labels.path }} (instance {{ $labels.instance }})"
+          description: "Requests to path {{ $labels.path }} are receiving errors.
+            Please verify if clients are sending correct requests."
+
+      - alert: ConcurrentFlushesHitTheLimit
+        expr: vm_concurrent_addrows_current >= vm_concurrent_addrows_capacity
+        for: 15m
+        labels:
+          severity: warning
+        annotations:
+          dashboard: "http://localhost:3000/d/wNf0q_kZk?viewPanel=59&var-instance={{ $labels.instance }}"
+          summary: "VictoriMetrics on instance {{ $labels.instance }} is constantly hitting concurrent flushes limit"
+          description: "The limit of concurrent flushes on instance {{ $labels.instance }} is equal to number of CPUs.\n
+            When VictoriaMetrics constantly hits the limit it means that storage is overloaded and requires more CPU."
+
+      - alert: TooManyLogs
+        expr: sum(increase(vm_log_messages_total{level!="info"}[5m])) by (job, instance) > 0
+        for: 15m
+        labels:
+          severity: warning
+        annotations:
+          dashboard: "http://localhost:3000/d/wNf0q_kZk?viewPanel=67&var-instance={{ $labels.instance }}"
+          summary: "Too many logs printed for job \"{{ $labels.job }}\" ({{ $labels.instance }})"
+          description: "Logging rate for job \"{{ $labels.job }}\" ({{ $labels.instance }}) is {{ $value }} for last 15m.\n
+           Worth to check logs for specific error messages."
+
+      - alert: RowsRejectedOnIngestion
+        expr: sum(rate(vm_rows_ignored_total[5m])) by (instance, reason) > 0
+        for: 15m
+        labels:
+          severity: warning
+        annotations:
+          dashboard: "http://localhost:3000/d/wNf0q_kZk?viewPanel=58&var-instance={{ $labels.instance }}"
+          summary: "Some rows are rejected on \"{{ $labels.instance }}\" on ingestion attempt"
+          description: "VM is rejecting to ingest rows on \"{{ $labels.instance }}\" due to the
+            following reason: \"{{ $labels.reason }}\""
+
+      - alert: TooHighChurnRate
+        expr: |
+          (
+             sum(rate(vm_new_timeseries_created_total[5m])) by(instance)
+             /
+             sum(rate(vm_rows_inserted_total[5m])) by (instance)
+           ) > 0.1
+        for: 15m
+        labels:
+          severity: warning
+        annotations:
+          dashboard: "http://localhost:3000/d/wNf0q_kZk?viewPanel=66&var-instance={{ $labels.instance }}"
+          summary: "Churn rate is more than 10% on \"{{ $labels.instance }}\" for the last 15m"
+          description: "VM constantly creates new time series on \"{{ $labels.instance }}\".\n
+            This effect is known as Churn Rate.\n
+            High Churn Rate tightly connected with database performance and may
+            result in unexpected OOM's or slow queries."
+
+      - alert: TooHighSlowInsertsRate
+        expr: |
+          (
+             sum(rate(vm_slow_row_inserts_total[5m])) by(instance)
+             /
+             sum(rate(vm_rows_inserted_total[5m])) by (instance)
+           ) > 0.5
+        for: 15m
+        labels:
+          severity: warning
+        annotations:
+          dashboard: "http://localhost:3000/d/wNf0q_kZk?viewPanel=68&var-instance={{ $labels.instance }}"
+          summary: "Percentage of slow inserts is more than 50% on \"{{ $labels.instance }}\" for the last 15m"
+          description: "High rate of slow inserts on \"{{ $labels.instance }}\" may be a sign of resource exhaustion
+            for the current load. It is likely more RAM is needed for optimal handling of the current number of active time series."
+
+  # Alerts group for vmagent assumes that Grafana dashboard
+  # https://grafana.com/grafana/dashboards/12683 is installed.
+  # Pls update the `dashboard` annotation according to your setup.
+  - name: vmagent
+    interval: 30s
+    concurrency: 2
+    rules:
+      - alert: PersistentQueueIsDroppingData
+        expr: sum(increase(vm_persistentqueue_bytes_dropped_total[5m])) by (job, instance) > 0
+        for: 10m
+        labels:
+          severity: critical
+        annotations:
+          dashboard: "http://localhost:3000/d/G7Z9GzMGz?viewPanel=49&var-instance={{ $labels.instance }}"
+          summary: "Instance {{ $labels.instance }} is dropping data from persistent queue"
+          description: "Vmagent dropped {{ $value | humanize1024 }} from persistent queue
+              on instance {{ $labels.instance }} for the last 10m."
+
+      - alert: TooManyScrapeErrors
+        expr: sum(increase(vm_promscrape_scrapes_failed_total[5m])) by (job, instance) > 0
+        for: 15m
+        labels:
+          severity: warning
+        annotations:
+          dashboard: "http://localhost:3000/d/G7Z9GzMGz?viewPanel=31&var-instance={{ $labels.instance }}"
+          summary: "Job \"{{ $labels.job }}\" on instance {{ $labels.instance }} fails to scrape targets for last 15m"
+
+      - alert: TooManyWriteErrors
+        expr: |
+          (sum(increase(vm_ingestserver_request_errors_total[5m])) by (job, instance)
+          +
+          sum(increase(vmagent_http_request_errors_total[5m])) by (job, instance)) > 0
+        for: 15m
+        labels:
+          severity: warning
+        annotations:
+          dashboard: "http://localhost:3000/d/G7Z9GzMGz?viewPanel=77&var-instance={{ $labels.instance }}"
+          summary: "Job \"{{ $labels.job }}\" on instance {{ $labels.instance }} responds with errors to write requests for last 15m."
+
+      - alert: TooManyRemoteWriteErrors
+        expr: sum(rate(vmagent_remotewrite_retries_count_total[5m])) by(job, instance, url) > 0
+        for: 15m
+        labels:
+          severity: warning
+        annotations:
+          dashboard: "http://localhost:3000/d/G7Z9GzMGz?viewPanel=61&var-instance={{ $labels.instance }}"
+          summary: "Job \"{{ $labels.job }}\" on instance {{ $labels.instance }} fails to push to remote storage"
+          description: "Vmagent fails to push data via remote write protocol to destination \"{{ $labels.url }}\"\n
+            Ensure that destination is up and reachable."
+
diff --git a/deployment/docker/prometheus.yml b/deployment/docker/prometheus.yml
index 17e46a943..451ed70ae 100644
--- a/deployment/docker/prometheus.yml
+++ b/deployment/docker/prometheus.yml
@@ -1,5 +1,5 @@
 global:
-  scrape_interval:     10s
+  scrape_interval: 10s
 
 scrape_configs:
   - job_name: 'vmagent'
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 4ef7a1d49..11cb74908 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 # tip
 
+* BUGFIX: vmagent: prevent from `dialing to the given TCP address time out` error when scraping big number of unavailable targets. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/987
+
 * FEATURE: disable final merge for data for the previous month at the beginning of new month, since it may result in high disk IO and CPU usage. Final merge can be enabled by setting `-finalMergeDelay` command-line flag to positive duration.
 
 
diff --git a/go.mod b/go.mod
index 04862cc14..6a1f20561 100644
--- a/go.mod
+++ b/go.mod
@@ -7,7 +7,7 @@ require (
 
 	// Do not use the original github.com/valyala/fasthttp because of issues
 	// like https://github.com/valyala/fasthttp/commit/996610f021ff45fdc98c2ce7884d5fa4e7f9199b
-	github.com/VictoriaMetrics/fasthttp v1.0.9
+	github.com/VictoriaMetrics/fasthttp v1.0.11
 	github.com/VictoriaMetrics/metrics v1.12.3
 	github.com/VictoriaMetrics/metricsql v0.9.1
 	github.com/aws/aws-sdk-go v1.36.23
diff --git a/go.sum b/go.sum
index 1961d66ca..1d48c9e86 100644
--- a/go.sum
+++ b/go.sum
@@ -41,8 +41,8 @@ github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/VictoriaMetrics/fastcache v1.5.7 h1:4y6y0G8PRzszQUYIQHHssv/jgPHAb5qQuuDNdCbyAgw=
 github.com/VictoriaMetrics/fastcache v1.5.7/go.mod h1:ptDBkNMQI4RtmVo8VS/XwRY6RoTu1dAWCbrk+6WsEM8=
-github.com/VictoriaMetrics/fasthttp v1.0.9 h1:Fja1tfcNMNoUD7RJDYpjGx2CsSfXkUbISKY4kNafdN4=
-github.com/VictoriaMetrics/fasthttp v1.0.9/go.mod h1:3SeUL4zwB/p/a9aEeRc6gdlbrtNHXBJR6N376EgiSHU=
+github.com/VictoriaMetrics/fasthttp v1.0.11 h1:6XOvE1pF/EhW8qoi7V5qJQJ2rhNV+UGrb1/a9vMbTiw=
+github.com/VictoriaMetrics/fasthttp v1.0.11/go.mod h1:3SeUL4zwB/p/a9aEeRc6gdlbrtNHXBJR6N376EgiSHU=
 github.com/VictoriaMetrics/metrics v1.12.2/go.mod h1:Z1tSfPfngDn12bTfZSCqArT3OPY3u88J12hSoOhuiRE=
 github.com/VictoriaMetrics/metrics v1.12.3 h1:Fe6JHC6MSEKa+BtLhPN8WIvS+HKPzMc2evEpNeCGy7I=
 github.com/VictoriaMetrics/metrics v1.12.3/go.mod h1:Z1tSfPfngDn12bTfZSCqArT3OPY3u88J12hSoOhuiRE=
diff --git a/lib/proxy/proxy.go b/lib/proxy/proxy.go
index 82cb7b46a..bb3c339ef 100644
--- a/lib/proxy/proxy.go
+++ b/lib/proxy/proxy.go
@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"net"
 	"net/url"
+	"time"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/netutil"
 	"github.com/VictoriaMetrics/fasthttp"
@@ -80,10 +81,12 @@ func (u *URL) NewDialFunc(tlsConfig *tls.Config) (fasthttp.DialFunc, error) {
 }
 
 func defaultDialFunc(addr string) (net.Conn, error) {
+	network := "tcp4"
 	if netutil.TCP6Enabled() {
-		return fasthttp.DialDualStack(addr)
+		network = "tcp"
 	}
-	return fasthttp.Dial(addr)
+	// Do not use fasthttp.Dial because of https://github.com/VictoriaMetrics/VictoriaMetrics/issues/987
+	return net.DialTimeout(network, addr, 5*time.Second)
 }
 
 // sendConnectRequest sends CONNECT request to proxyConn for the given addr and authHeader and returns the established connection to dstAddr.
diff --git a/vendor/modules.txt b/vendor/modules.txt
index c07ffa30f..4c80dec6f 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -10,7 +10,7 @@ cloud.google.com/go/internal/version
 cloud.google.com/go/storage
 # github.com/VictoriaMetrics/fastcache v1.5.7
 github.com/VictoriaMetrics/fastcache
-# github.com/VictoriaMetrics/fasthttp v1.0.9
+# github.com/VictoriaMetrics/fasthttp v1.0.11
 github.com/VictoriaMetrics/fasthttp
 github.com/VictoriaMetrics/fasthttp/fasthttputil
 github.com/VictoriaMetrics/fasthttp/stackless


Test patch:
diff --git a/app/vmalert/config/testdata/rules2-good.rules b/app/vmalert/config/testdata/rules2-good.rules
index 6c9141e90..00e4cb8ee 100644
--- a/app/vmalert/config/testdata/rules2-good.rules
+++ b/app/vmalert/config/testdata/rules2-good.rules
@@ -17,6 +17,7 @@ groups:
           (up == 1)
         labels:
           job: '{{ $labels.job }}'
+          dynamic: '{{ $x := query "up" | first | value }}{{ if eq 1.0 $x }}one{{ else }}unknown{{ end }}'
         annotations:
           description: Job {{ $labels.job }} is up!
           summary: All instances up {{ range query "up" }}