diff --git a/app/vmauth/README.md b/app/vmauth/README.md
index 335c2804e..0afa6fb9d 100644
--- a/app/vmauth/README.md
+++ b/app/vmauth/README.md
@@ -1,8 +1,8 @@
 # vmauth
 
-`vmauth` is a simple auth proxy and router for [VictoriaMetrics](https://github.com/VictoriaMetrics/VictoriaMetrics).
-It reads username and password from [Basic Auth headers](https://en.wikipedia.org/wiki/Basic_access_authentication),
-matches them against configs pointed by `-auth.config` command-line flag and proxies incoming HTTP requests to the configured per-user `url_prefix` on successful match.
+`vmauth` is a simple auth proxy, router and [load balancer](#load-balancing) for [VictoriaMetrics](https://github.com/VictoriaMetrics/VictoriaMetrics).
+It reads auth credentials from `Authorization` http header ([Basic Auth](https://en.wikipedia.org/wiki/Basic_access_authentication) and `Bearer token` is supported),
+matches them against configs pointed by [-auth.config](#auth-config) command-line flag and proxies incoming HTTP requests to the configured per-user `url_prefix` on successful match.
 
 
 ## Quick start
@@ -27,9 +27,14 @@ Feel free [contacting us](mailto:info@victoriametrics.com) if you need customize
 accounting and rate limiting such as [vmgateway](https://docs.victoriametrics.com/vmgateway.html).
 
 
+## Load balancing
+
+Each `url_prefix` in the [-auth.config](#auth-config) may contain either a single url or a list of urls. In the latter case `vmauth` balances load among the configured urls in a round-robin manner. This feature is useful for balancing the load among multiple `vmselect` and/or `vminsert` nodes in [VictoriaMetrics cluster](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html).
+
+
 ## Auth config
 
-Auth config is represented in the following simple `yml` format:
+`-auth.config` is represented in the following simple `yml` format:
 
 ```yml
 
@@ -61,31 +66,44 @@ users:
   # The user for querying account 123 in VictoriaMetrics cluster
   # See https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#url-format
   # All the requests to http://vmauth:8427 with the given Basic Auth (username:password)
-  # will be proxied to http://vmselect:8481/select/123/prometheus .
-  # For example, http://vmauth:8427/api/v1/query is proxied to http://vmselect:8481/select/123/prometheus/api/v1/select
+  # will be load-balanced among http://vmselect1:8481/select/123/prometheus and http://vmselect2:8481/select/123/prometheus
+  # For example, http://vmauth:8427/api/v1/query is proxied to the following urls in a round-robin manner:
+  #   - http://vmselect1:8481/select/123/prometheus/api/v1/select
+  #   - http://vmselect2:8481/select/123/prometheus/api/v1/select
 - username: "cluster-select-account-123"
   password: "***"
-  url_prefix: "http://vmselect:8481/select/123/prometheus"
+  url_prefix:
+  - "http://vmselect1:8481/select/123/prometheus"
+  - "http://vmselect2:8481/select/123/prometheus"
 
   # The user for inserting Prometheus data into VictoriaMetrics cluster under account 42
   # See https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#url-format
   # All the requests to http://vmauth:8427 with the given Basic Auth (username:password)
-  # will be proxied to http://vminsert:8480/insert/42/prometheus .
-  # For example, http://vmauth:8427/api/v1/write is proxied to http://vminsert:8480/insert/42/prometheus/api/v1/write
+  # will be load-balanced between http://vminsert1:8480/insert/42/prometheus and http://vminsert2:8480/insert/42/prometheus
+  # For example, http://vmauth:8427/api/v1/write is proxied to the following urls in a round-robin manner:
+  #   - http://vminsert1:8480/insert/42/prometheus/api/v1/write
+  #   - http://vminsert2:8480/insert/42/prometheus/api/v1/write
 - username: "cluster-insert-account-42"
   password: "***"
-  url_prefix: "http://vminsert:8480/insert/42/prometheus"
+  url_prefix:
+  - "http://vminsert1:8480/insert/42/prometheus"
+  - "http://vminsert2:8480/insert/42/prometheus"
 
 
   # A single user for querying and inserting data:
   # - Requests to http://vmauth:8427/api/v1/query, http://vmauth:8427/api/v1/query_range
-  #   and http://vmauth:8427/api/v1/label/<label_name>/values are proxied to http://vmselect:8481/select/42/prometheus.
-  #   For example, http://vmauth:8427/api/v1/query is proxied to http://vmselect:8480/select/42/prometheus/api/v1/query
+  #   and http://vmauth:8427/api/v1/label/<label_name>/values are proxied to the following urls in a round-robin manner:
+  #     - http://vmselect1:8481/select/42/prometheus
+  #     - http://vmselect2:8481/select/42/prometheus
+  #   For example, http://vmauth:8427/api/v1/query is proxied to http://vmselect1:8480/select/42/prometheus/api/v1/query
+  #   or to http://vmselect2:8480/select/42/prometheus/api/v1/query .
   # - Requests to http://vmauth:8427/api/v1/write are proxied to http://vminsert:8480/insert/42/prometheus/api/v1/write
 - username: "foobar"
   url_map:
   - src_paths: ["/api/v1/query", "/api/v1/query_range", "/api/v1/label/[^/]+/values"]
-    url_prefix: "http://vmselect:8481/select/42/prometheus"
+    url_prefix:
+    - "http://vmselect1:8481/select/42/prometheus"
+    - "http://vmselect2:8481/select/42/prometheus"
   - src_paths: ["/api/v1/write"]
     url_prefix: "http://vminsert:8480/insert/42/prometheus"
 ```
diff --git a/app/vmauth/auth_config.go b/app/vmauth/auth_config.go
index a5ac3186d..d368bb766 100644
--- a/app/vmauth/auth_config.go
+++ b/app/vmauth/auth_config.go
@@ -8,6 +8,7 @@ import (
 	"net/url"
 	"os"
 	"regexp"
+	"strconv"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -31,11 +32,11 @@ type AuthConfig struct {
 
 // UserInfo is user information read from authConfigPath
 type UserInfo struct {
-	BearerToken string   `yaml:"bearer_token"`
-	Username    string   `yaml:"username"`
-	Password    string   `yaml:"password"`
-	URLPrefix   *yamlURL `yaml:"url_prefix"`
-	URLMap      []URLMap `yaml:"url_map"`
+	BearerToken string     `yaml:"bearer_token"`
+	Username    string     `yaml:"username"`
+	Password    string     `yaml:"password"`
+	URLPrefix   *URLPrefix `yaml:"url_prefix"`
+	URLMap      []URLMap   `yaml:"url_map"`
 
 	requests *metrics.Counter
 }
@@ -43,7 +44,7 @@ type UserInfo struct {
 // URLMap is a mapping from source paths to target urls.
 type URLMap struct {
 	SrcPaths  []*SrcPath `yaml:"src_paths"`
-	URLPrefix *yamlURL   `yaml:"url_prefix"`
+	URLPrefix *URLPrefix `yaml:"url_prefix"`
 }
 
 // SrcPath represents an src path
@@ -52,25 +53,74 @@ type SrcPath struct {
 	re        *regexp.Regexp
 }
 
-type yamlURL struct {
-	u *url.URL
+// URLPrefix represents pased `url_prefix`
+type URLPrefix struct {
+	n    uint32
+	urls []*url.URL
 }
 
-func (yu *yamlURL) UnmarshalYAML(f func(interface{}) error) error {
-	var s string
-	if err := f(&s); err != nil {
+func (up *URLPrefix) getNextURL() *url.URL {
+	n := atomic.AddUint32(&up.n, 1)
+	idx := n % uint32(len(up.urls))
+	return up.urls[idx]
+}
+
+// UnmarshalYAML unmarshals up from yaml.
+func (up *URLPrefix) UnmarshalYAML(f func(interface{}) error) error {
+	var v interface{}
+	if err := f(&v); err != nil {
 		return err
 	}
-	u, err := url.Parse(s)
-	if err != nil {
-		return fmt.Errorf("cannot unmarshal %q into url: %w", s, err)
+	var urls []string
+	switch x := v.(type) {
+	case string:
+		urls = []string{x}
+	case []interface{}:
+		if len(x) == 0 {
+			return fmt.Errorf("`url_prefix` must contain at least a single url")
+		}
+		us := make([]string, len(x))
+		for i, xx := range x {
+			s, ok := xx.(string)
+			if !ok {
+				return fmt.Errorf("`url_prefix` must contain array of strings; got %T", xx)
+			}
+			us[i] = s
+		}
+		urls = us
+	default:
+		return fmt.Errorf("unexpected type for `url_prefix`: %T; want string or []string", v)
 	}
-	yu.u = u
+	pus := make([]*url.URL, len(urls))
+	for i, u := range urls {
+		pu, err := url.Parse(u)
+		if err != nil {
+			return fmt.Errorf("cannot unmarshal %q into url: %w", u, err)
+		}
+		pus[i] = pu
+	}
+	up.urls = pus
 	return nil
 }
 
-func (yu *yamlURL) MarshalYAML() (interface{}, error) {
-	return yu.u.String(), nil
+// MarshalYAML marshals up to yaml.
+func (up *URLPrefix) MarshalYAML() (interface{}, error) {
+	var b []byte
+	if len(up.urls) == 1 {
+		u := up.urls[0].String()
+		b = strconv.AppendQuote(b, u)
+		return string(b), nil
+	}
+	b = append(b, '[')
+	for i, pu := range up.urls {
+		u := pu.String()
+		b = strconv.AppendQuote(b, u)
+		if i+1 < len(up.urls) {
+			b = append(b, ',')
+		}
+	}
+	b = append(b, ']')
+	return string(b), nil
 }
 
 func (sp *SrcPath) match(s string) bool {
@@ -201,11 +251,9 @@ func parseAuthConfig(data []byte) (map[string]*UserInfo, error) {
 			return nil, fmt.Errorf("duplicate auth token found for bearer_token=%q, username=%q: %q", authToken, ui.BearerToken, ui.Username)
 		}
 		if ui.URLPrefix != nil {
-			urlPrefix, err := sanitizeURLPrefix(ui.URLPrefix.u)
-			if err != nil {
+			if err := ui.URLPrefix.sanitize(); err != nil {
 				return nil, err
 			}
-			ui.URLPrefix.u = urlPrefix
 		}
 		for _, e := range ui.URLMap {
 			if len(e.SrcPaths) == 0 {
@@ -214,11 +262,9 @@ func parseAuthConfig(data []byte) (map[string]*UserInfo, error) {
 			if e.URLPrefix == nil {
 				return nil, fmt.Errorf("missing `url_prefix` in `url_map`")
 			}
-			urlPrefix, err := sanitizeURLPrefix(e.URLPrefix.u)
-			if err != nil {
+			if err := e.URLPrefix.sanitize(); err != nil {
 				return nil, err
 			}
-			e.URLPrefix.u = urlPrefix
 		}
 		if len(ui.URLMap) == 0 && ui.URLPrefix == nil {
 			return nil, fmt.Errorf("missing `url_prefix`")
@@ -248,6 +294,17 @@ func getAuthToken(bearerToken, username, password string) string {
 	return "Basic " + token64
 }
 
+func (up *URLPrefix) sanitize() error {
+	for i, pu := range up.urls {
+		puNew, err := sanitizeURLPrefix(pu)
+		if err != nil {
+			return err
+		}
+		up.urls[i] = puNew
+	}
+	return nil
+}
+
 func sanitizeURLPrefix(urlPrefix *url.URL) (*url.URL, error) {
 	// Remove trailing '/' from urlPrefix
 	for strings.HasSuffix(urlPrefix.Path, "/") {
diff --git a/app/vmauth/auth_config_test.go b/app/vmauth/auth_config_test.go
index e192189c5..1b6ad3d4a 100644
--- a/app/vmauth/auth_config_test.go
+++ b/app/vmauth/auth_config_test.go
@@ -59,7 +59,21 @@ users:
 	f(`
 users:
 - username: foo
-  url_prefix: [bar]
+  url_prefix:
+    bar: baz
+`)
+	f(`
+users:
+- username: foo
+  url_prefix:
+  - [foo]
+`)
+
+	// empty url_prefix
+	f(`
+users:
+- username: foo
+  url_prefix: []
 `)
 
 	// Username and bearer_token in a single config
@@ -117,6 +131,15 @@ users:
     url_prefix: foo.bar
 `)
 
+	// empty url_prefix in url_map
+	f(`
+users:
+- username: a
+  url_map:
+  - src_paths: ['/foo/bar']
+    url_prefix: []
+`)
+
 	// Missing src_paths in url_map
 	f(`
 users:
@@ -162,6 +185,25 @@ users:
 		},
 	})
 
+	// Multiple url_prefix entries
+	f(`
+users:
+- username: foo
+  password: bar
+  url_prefix:
+  - http://node1:343/bbb
+  - http://node2:343/bbb
+`, map[string]*UserInfo{
+		getAuthToken("", "foo", "bar"): {
+			Username: "foo",
+			Password: "bar",
+			URLPrefix: mustParseURLs([]string{
+				"http://node1:343/bbb",
+				"http://node2:343/bbb",
+			}),
+		},
+	})
+
 	// Multiple users
 	f(`
 users:
@@ -188,7 +230,7 @@ users:
   - src_paths: ["/api/v1/query","/api/v1/query_range","/api/v1/label/[^./]+/.+"]
     url_prefix: http://vmselect/select/0/prometheus
   - src_paths: ["/api/v1/write"]
-    url_prefix: http://vminsert/insert/0/prometheus
+    url_prefix: ["http://vminsert1/insert/0/prometheus","http://vminsert2/insert/0/prometheus"]
 `, map[string]*UserInfo{
 		getAuthToken("foo", "", ""): {
 			BearerToken: "foo",
@@ -198,8 +240,11 @@ users:
 					URLPrefix: mustParseURL("http://vmselect/select/0/prometheus"),
 				},
 				{
-					SrcPaths:  getSrcPaths([]string{"/api/v1/write"}),
-					URLPrefix: mustParseURL("http://vminsert/insert/0/prometheus"),
+					SrcPaths: getSrcPaths([]string{"/api/v1/write"}),
+					URLPrefix: mustParseURLs([]string{
+						"http://vminsert1/insert/0/prometheus",
+						"http://vminsert2/insert/0/prometheus",
+					}),
 				},
 			},
 		},
@@ -238,12 +283,20 @@ func areEqualConfigs(a, b map[string]*UserInfo) error {
 	return nil
 }
 
-func mustParseURL(u string) *yamlURL {
-	pu, err := url.Parse(u)
-	if err != nil {
-		panic(fmt.Errorf("BUG: cannot parse %q: %w", u, err))
+func mustParseURL(u string) *URLPrefix {
+	return mustParseURLs([]string{u})
+}
+
+func mustParseURLs(us []string) *URLPrefix {
+	pus := make([]*url.URL, len(us))
+	for i, u := range us {
+		pu, err := url.Parse(u)
+		if err != nil {
+			panic(fmt.Errorf("BUG: cannot parse %q: %w", u, err))
+		}
+		pus[i] = pu
 	}
-	return &yamlURL{
-		u: pu,
+	return &URLPrefix{
+		urls: pus,
 	}
 }
diff --git a/app/vmauth/example_config.yml b/app/vmauth/example_config.yml
index 31877984e..ece9b9994 100644
--- a/app/vmauth/example_config.yml
+++ b/app/vmauth/example_config.yml
@@ -26,30 +26,43 @@ users:
   # The user for querying account 123 in VictoriaMetrics cluster
   # See https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#url-format
   # All the requests to http://vmauth:8427 with the given Basic Auth (username:password)
-  # will be proxied to http://vmselect:8481/select/123/prometheus .
-  # For example, http://vmauth:8427/api/v1/query is proxied to http://vmselect:8481/select/123/prometheus/api/v1/select
+  # will be load-balanced among http://vmselect1:8481/select/123/prometheus and http://vmselect2:8481/select/123/prometheus
+  # For example, http://vmauth:8427/api/v1/query is proxied to the following urls in a round-robin manner:
+  #   - http://vmselect1:8481/select/123/prometheus/api/v1/select
+  #   - http://vmselect2:8481/select/123/prometheus/api/v1/select
 - username: "cluster-select-account-123"
   password: "***"
-  url_prefix: "http://vmselect:8481/select/123/prometheus"
+  url_prefix:
+  - "http://vmselect1:8481/select/123/prometheus"
+  - "http://vmselect2:8481/select/123/prometheus"
 
   # The user for inserting Prometheus data into VictoriaMetrics cluster under account 42
   # See https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#url-format
   # All the requests to http://vmauth:8427 with the given Basic Auth (username:password)
-  # will be proxied to http://vminsert:8480/insert/42/prometheus .
-  # For example, http://vmauth:8427/api/v1/write is proxied to http://vminsert:8480/insert/42/prometheus/api/v1/write
+  # will be load-balanced between http://vminsert1:8480/insert/42/prometheus and http://vminsert2:8480/insert/42/prometheus
+  # For example, http://vmauth:8427/api/v1/write is proxied to the following urls in a round-robin manner:
+  #   - http://vminsert1:8480/insert/42/prometheus/api/v1/write
+  #   - http://vminsert2:8480/insert/42/prometheus/api/v1/write
 - username: "cluster-insert-account-42"
   password: "***"
-  url_prefix: "http://vminsert:8480/insert/42/prometheus"
+  url_prefix:
+  - "http://vminsert1:8480/insert/42/prometheus"
+  - "http://vminsert2:8480/insert/42/prometheus"
 
 
   # A single user for querying and inserting data:
   # - Requests to http://vmauth:8427/api/v1/query, http://vmauth:8427/api/v1/query_range
-  #   and http://vmauth:8427/api/v1/label/<label_name>/values are proxied to http://vmselect:8481/select/42/prometheus.
-  #   For example, http://vmauth:8427/api/v1/query is proxied to http://vmselect:8480/select/42/prometheus/api/v1/query
+  #   and http://vmauth:8427/api/v1/label/<label_name>/values are proxied to the following urls in a round-robin manner:
+  #     - http://vmselect1:8481/select/42/prometheus
+  #     - http://vmselect2:8481/select/42/prometheus
+  #   For example, http://vmauth:8427/api/v1/query is proxied to http://vmselect1:8480/select/42/prometheus/api/v1/query
+  #   or to http://vmselect2:8480/select/42/prometheus/api/v1/query .
   # - Requests to http://vmauth:8427/api/v1/write are proxied to http://vminsert:8480/insert/42/prometheus/api/v1/write
 - username: "foobar"
   url_map:
   - src_paths: ["/api/v1/query", "/api/v1/query_range", "/api/v1/label/[^/]+/values"]
-    url_prefix: "http://vmselect:8481/select/42/prometheus"
+    url_prefix:
+    - "http://vmselect1:8481/select/42/prometheus"
+    - "http://vmselect2:8481/select/42/prometheus"
   - src_paths: ["/api/v1/write"]
     url_prefix: "http://vminsert:8480/insert/42/prometheus"
diff --git a/app/vmauth/target_url.go b/app/vmauth/target_url.go
index a361b561f..5e5d81f56 100644
--- a/app/vmauth/target_url.go
+++ b/app/vmauth/target_url.go
@@ -7,6 +7,11 @@ import (
 	"strings"
 )
 
+func (up *URLPrefix) mergeURLs(requestURI *url.URL) *url.URL {
+	pu := up.getNextURL()
+	return mergeURLs(pu, requestURI)
+}
+
 func mergeURLs(uiURL, requestURI *url.URL) *url.URL {
 	targetURL := *uiURL
 	targetURL.Path += requestURI.Path
@@ -40,12 +45,12 @@ func createTargetURL(ui *UserInfo, uOrig *url.URL) (*url.URL, error) {
 	for _, e := range ui.URLMap {
 		for _, sp := range e.SrcPaths {
 			if sp.match(u.Path) {
-				return mergeURLs(e.URLPrefix.u, &u), nil
+				return e.URLPrefix.mergeURLs(&u), nil
 			}
 		}
 	}
 	if ui.URLPrefix != nil {
-		return mergeURLs(ui.URLPrefix.u, &u), nil
+		return ui.URLPrefix.mergeURLs(&u), nil
 	}
 	return nil, fmt.Errorf("missing route for %q", u.String())
 }
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index f04c803b2..39f144b43 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -8,6 +8,7 @@ sort: 15
 
 * FEATURE: vmalert: add a command-line flag `-rule.configCheckInterval` for automatic re-reading of `-rule` files without the need to send SIGHUP signal. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/512).
 * FEATURE: vmagent: respect the `sample_limit` and `-promscrape.maxScrapeSize` values when scraping targets in [stream parsing mode](https://docs.victoriametrics.com/vmagent.html#stream-parsing-mode). See [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/1331).
+* FEATURE: vmauth: add ability to specify mutliple `url_prefix` entries for balancing the load among multiple `vmselect` and/or `vminsert` nodes in a cluster. See [these docs](https://docs.victoriametrics.com/vmauth.html#load-balancing).
 
 * BUGFIX: reduce CPU usage by up to 2x during querying a database with big number of active daily time series. The issue has been introduced in `v1.59.0`.
 
diff --git a/docs/Cluster-VictoriaMetrics.md b/docs/Cluster-VictoriaMetrics.md
index 9aa8eedbf..30728c421 100644
--- a/docs/Cluster-VictoriaMetrics.md
+++ b/docs/Cluster-VictoriaMetrics.md
@@ -138,7 +138,7 @@ A minimal cluster must contain the following nodes:
 It is recommended to run at least two nodes for each service
 for high availability purposes.
 
-An http load balancer such as `nginx` must be put in front of `vminsert` and `vmselect` nodes:
+An http load balancer such as [vmauth](https://docs.victoriametrics.com/vmauth.html) or `nginx` must be put in front of `vminsert` and `vmselect` nodes:
 - requests starting with `/insert` must be routed to port `8480` on `vminsert` nodes.
 - requests starting with `/select` must be routed to port `8481` on `vmselect` nodes.
 
diff --git a/docs/vmauth.md b/docs/vmauth.md
index dfe62be62..cbca61e7a 100644
--- a/docs/vmauth.md
+++ b/docs/vmauth.md
@@ -4,9 +4,9 @@ sort: 5
 
 # vmauth
 
-`vmauth` is a simple auth proxy and router for [VictoriaMetrics](https://github.com/VictoriaMetrics/VictoriaMetrics).
-It reads username and password from [Basic Auth headers](https://en.wikipedia.org/wiki/Basic_access_authentication),
-matches them against configs pointed by `-auth.config` command-line flag and proxies incoming HTTP requests to the configured per-user `url_prefix` on successful match.
+`vmauth` is a simple auth proxy, router and [load balancer](#load-balancing) for [VictoriaMetrics](https://github.com/VictoriaMetrics/VictoriaMetrics).
+It reads auth credentials from `Authorization` http header ([Basic Auth](https://en.wikipedia.org/wiki/Basic_access_authentication) and `Bearer token` is supported),
+matches them against configs pointed by [-auth.config](#auth-config) command-line flag and proxies incoming HTTP requests to the configured per-user `url_prefix` on successful match.
 
 
 ## Quick start
@@ -31,9 +31,14 @@ Feel free [contacting us](mailto:info@victoriametrics.com) if you need customize
 accounting and rate limiting such as [vmgateway](https://docs.victoriametrics.com/vmgateway.html).
 
 
+## Load balancing
+
+Each `url_prefix` in the [-auth.config](#auth-config) may contain either a single url or a list of urls. In the latter case `vmauth` balances load among the configured urls in a round-robin manner. This feature is useful for balancing the load among multiple `vmselect` and/or `vminsert` nodes in [VictoriaMetrics cluster](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html).
+
+
 ## Auth config
 
-Auth config is represented in the following simple `yml` format:
+`-auth.config` is represented in the following simple `yml` format:
 
 ```yml
 
@@ -65,31 +70,44 @@ users:
   # The user for querying account 123 in VictoriaMetrics cluster
   # See https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#url-format
   # All the requests to http://vmauth:8427 with the given Basic Auth (username:password)
-  # will be proxied to http://vmselect:8481/select/123/prometheus .
-  # For example, http://vmauth:8427/api/v1/query is proxied to http://vmselect:8481/select/123/prometheus/api/v1/select
+  # will be load-balanced among http://vmselect1:8481/select/123/prometheus and http://vmselect2:8481/select/123/prometheus
+  # For example, http://vmauth:8427/api/v1/query is proxied to the following urls in a round-robin manner:
+  #   - http://vmselect1:8481/select/123/prometheus/api/v1/select
+  #   - http://vmselect2:8481/select/123/prometheus/api/v1/select
 - username: "cluster-select-account-123"
   password: "***"
-  url_prefix: "http://vmselect:8481/select/123/prometheus"
+  url_prefix:
+  - "http://vmselect1:8481/select/123/prometheus"
+  - "http://vmselect2:8481/select/123/prometheus"
 
   # The user for inserting Prometheus data into VictoriaMetrics cluster under account 42
   # See https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#url-format
   # All the requests to http://vmauth:8427 with the given Basic Auth (username:password)
-  # will be proxied to http://vminsert:8480/insert/42/prometheus .
-  # For example, http://vmauth:8427/api/v1/write is proxied to http://vminsert:8480/insert/42/prometheus/api/v1/write
+  # will be load-balanced between http://vminsert1:8480/insert/42/prometheus and http://vminsert2:8480/insert/42/prometheus
+  # For example, http://vmauth:8427/api/v1/write is proxied to the following urls in a round-robin manner:
+  #   - http://vminsert1:8480/insert/42/prometheus/api/v1/write
+  #   - http://vminsert2:8480/insert/42/prometheus/api/v1/write
 - username: "cluster-insert-account-42"
   password: "***"
-  url_prefix: "http://vminsert:8480/insert/42/prometheus"
+  url_prefix:
+  - "http://vminsert1:8480/insert/42/prometheus"
+  - "http://vminsert2:8480/insert/42/prometheus"
 
 
   # A single user for querying and inserting data:
   # - Requests to http://vmauth:8427/api/v1/query, http://vmauth:8427/api/v1/query_range
-  #   and http://vmauth:8427/api/v1/label/<label_name>/values are proxied to http://vmselect:8481/select/42/prometheus.
-  #   For example, http://vmauth:8427/api/v1/query is proxied to http://vmselect:8480/select/42/prometheus/api/v1/query
+  #   and http://vmauth:8427/api/v1/label/<label_name>/values are proxied to the following urls in a round-robin manner:
+  #     - http://vmselect1:8481/select/42/prometheus
+  #     - http://vmselect2:8481/select/42/prometheus
+  #   For example, http://vmauth:8427/api/v1/query is proxied to http://vmselect1:8480/select/42/prometheus/api/v1/query
+  #   or to http://vmselect2:8480/select/42/prometheus/api/v1/query .
   # - Requests to http://vmauth:8427/api/v1/write are proxied to http://vminsert:8480/insert/42/prometheus/api/v1/write
 - username: "foobar"
   url_map:
   - src_paths: ["/api/v1/query", "/api/v1/query_range", "/api/v1/label/[^/]+/values"]
-    url_prefix: "http://vmselect:8481/select/42/prometheus"
+    url_prefix:
+    - "http://vmselect1:8481/select/42/prometheus"
+    - "http://vmselect2:8481/select/42/prometheus"
   - src_paths: ["/api/v1/write"]
     url_prefix: "http://vminsert:8480/insert/42/prometheus"
 ```