support MaxConnsPerHost

.gitignore

@@ -8,7 +8,8 @@ sha256sum.txt
 # Test binary, build with `go test -c`
 *.test
 .coverprofile
-prometheus-data
+prometheus-data/
+redis-data/
 trickster-data
 trips_*.gz
 

Makefile

@@ -290,11 +290,11 @@ developer-stop:
 
 .PHONY: developer-delete
 developer-delete:
-	@cd docs/developer/environment && docker compose down
+	@cd docs/developer/environment && docker compose down -v --remove-orphans
 
-.PHONY: developer-restart
-developer-restart:
-	@cd docs/developer/environment && docker compose down && docker compose up -d
+.PHONY: developer-recreate
+developer-recreate: developer-delete
+	@cd docs/developer/environment && docker compose up -d
 
 .PHONY: developer-seed-data
 developer-seed-data:

docs/developer/environment/docker-compose-data/grafana-config/provisioning/datasources/datasource.yaml

@@ -63,6 +63,16 @@ datasources:
   editable: true
   jsonData:
     httpMethod: POST
+- name: "7: Trickster | ALB 1"
+  type: prometheus
+  access: proxy
+  orgId: 1
+  uid: ds_prom_trickster_alb_1
+  url: http://host.docker.internal:8480/alb1
+  version: 1
+  editable: true
+  jsonData:
+    httpMethod: POST
 
 # Mockster (Prom API Simulator)
 - name: sim-direct

docs/developer/environment/docker-compose.yml

@@ -11,7 +11,7 @@ services:
     ports:
      - 6379:6379
     volumes:
-     - redis-data:/data
+     - ./docker-compose-data/redis-data:/data
     command: redis-server --appendonly yes --stop-writes-on-bgsave-error no
 
   # ui's
@@ -40,6 +40,7 @@ services:
     image: prom/prometheus:v3.2.1
     volumes:
       - ./docker-compose-data/prometheus-config:/etc/prometheus
+      - ./docker-compose-data/prometheus-data:/prometheus
     command:
       - '--config.file=/etc/prometheus/prometheus.yml'
       - '--storage.tsdb.path=/prometheus'
@@ -153,4 +154,3 @@ services:
 
 volumes:
   influxdbv2:
-  redis-data:

examples/conf/example.full.yaml

@@ -308,9 +308,13 @@ backends:
 #     keep_alive_timeout: 120s
 
 #     # max_idle_conns set the maximum concurrent keep-alive connections Trickster may have opened to this backend
-#     # additional requests will be queued. Default: 20
+#     # while no clients are being served. Default: 20
 #     max_idle_conns: 20
 
+#     # max_concurrent_conns set the maximum number of concurrent connections Trickster may have opened to this backend
+#     # additional requests will be queued. Default: 20
+#     max_concurrent_conns: 20
+
 #     # max_ttl defines the maximum allowed TTL for any object cached for this backend. default is 24 hours
 #     max_ttl: 24h
 

pkg/backends/healthcheck/target.go

@@ -297,9 +297,17 @@ func newHTTPClient(timeout time.Duration) *http.Client {
 			return http.ErrUseLastResponse
 		},
 		Transport: &http.Transport{
-			Dial:                (&net.Dialer{KeepAlive: 5 * time.Second}).Dial,
-			MaxIdleConns:        32,
-			MaxIdleConnsPerHost: 32,
+			Dial: (&net.Dialer{
+				Timeout:   timeout,
+				KeepAlive: time.Second * 30,
+			}).Dial,
+			MaxIdleConns:          1,
+			MaxIdleConnsPerHost:   1,
+			MaxConnsPerHost:       1,
+			IdleConnTimeout:       time.Second * 30,
+			TLSHandshakeTimeout:   timeout,
+			ExpectContinueTimeout: timeout,
+			ResponseHeaderTimeout: timeout,
 		},
 	}
 }

pkg/backends/options/defaults.go

@@ -57,6 +57,8 @@ const (
 	DefaultKeepAliveTimeout = 2 * time.Minute
 	// DefaultMaxIdleConns is the default number of Idle Connections in Backends' upstream client pools
 	DefaultMaxIdleConns = 20
+	// DefaultMaxConcurrentConns is the default max number of concurrent connections to the origin the Backend can use
+	DefaultMaxConcurrentConns = 20
 	// DefaultForwardedHeaders defines which class of 'Forwarded' headers are attached to upstream requests
 	DefaultForwardedHeaders = "standard"
 	// DefaultALBMechanismName defines the default ALB Mechanism Name

pkg/backends/options/options.go

@@ -69,6 +69,8 @@ type Options struct {
 	Timeout time.Duration `yaml:"timeout,omitempty"`
 	// KeepAliveTimeout defines how long an open keep-alive HTTP connection remains idle before closing
 	KeepAliveTimeout time.Duration `yaml:"keep_alive_timeout,omitempty"`
+	// MaxConcurrentConns defines maximum number of open concurrent connections to maintain to the backend
+	MaxConcurrentConns int `yaml:"max_concurrent_conns,omitempty"`
 	// MaxIdleConns defines maximum number of open keep-alive connections to maintain
 	MaxIdleConns int `yaml:"max_idle_conns,omitempty"`
 	// CacheName provides the name of the configured cache where the backend client will store it's cache data
@@ -237,6 +239,7 @@ func New() *Options {
 		HealthCheck:                  ho.New(),
 		KeepAliveTimeout:             DefaultKeepAliveTimeout,
 		MaxIdleConns:                 DefaultMaxIdleConns,
+		MaxConcurrentConns:           DefaultMaxConcurrentConns,
 		MaxObjectSizeBytes:           DefaultMaxObjectSizeBytes,
 		MaxTTL:                       DefaultMaxTTL,
 		NegativeCache:                make(map[int]time.Duration),

pkg/config/testdata/example.alb.yaml

@@ -4,6 +4,7 @@ backends:
   default:
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     chunk_read_concurrency_limit: 16
@@ -37,6 +38,7 @@ backends:
     origin_url: https://origin1/
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     cache_key_prefix: origin1
@@ -73,6 +75,7 @@ backends:
     origin_url: http://origin2
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     cache_key_prefix: origin2
@@ -109,6 +112,7 @@ backends:
     origin_url: http://prom1:9090
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     cache_key_prefix: prom1:9090
@@ -144,6 +148,7 @@ backends:
     origin_url: http://prom2:9090
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     cache_key_prefix: prom2:9090
@@ -178,6 +183,7 @@ backends:
     provider: alb
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     chunk_read_concurrency_limit: 16
@@ -216,6 +222,7 @@ backends:
     provider: alb
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     chunk_read_concurrency_limit: 16

pkg/config/testdata/example.auth.yaml

@@ -6,6 +6,7 @@ backends:
     origin_url: https://example.com/
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     cache_key_prefix: example.com
@@ -41,6 +42,7 @@ backends:
     origin_url: https://example.com/
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     cache_key_prefix: example.com
@@ -76,6 +78,7 @@ backends:
     origin_url: https://example.com/
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     cache_key_prefix: example.com
@@ -109,6 +112,7 @@ backends:
   default:
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     chunk_read_concurrency_limit: 16

pkg/config/testdata/example.full.yaml

@@ -6,6 +6,7 @@ backends:
     origin_url: http://prometheus:9090
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     cache_key_prefix: prometheus:9090

pkg/config/testdata/exmple.sharding.yaml

@@ -6,6 +6,7 @@ backends:
     origin_url: http://prometheus:9090
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     cache_key_prefix: prometheus:9090

pkg/config/testdata/simple.prometheus.yaml

@@ -6,6 +6,7 @@ backends:
     origin_url: http://prometheus:9090
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     cache_key_prefix: prometheus:9090

pkg/config/testdata/simple.reverseproxycache.yaml

@@ -6,6 +6,7 @@ backends:
     origin_url: https://www.example.com
     timeout: 1m0s
     keep_alive_timeout: 2m0s
+    max_concurrent_conns: 20
     max_idle_conns: 20
     cache_name: default
     cache_key_prefix: www.example.com

pkg/proxy/proxy.go

@@ -90,6 +90,7 @@ func NewHTTPClient(o *bo.Options) (*http.Client, error) {
 			}).Dial,
 			MaxIdleConns:          o.MaxIdleConns,
 			MaxIdleConnsPerHost:   o.MaxIdleConns,
+			MaxConnsPerHost:       o.MaxConcurrentConns,
 			IdleConnTimeout:       o.KeepAliveTimeout,
 			TLSHandshakeTimeout:   connectTimeout,
 			ExpectContinueTimeout: o.Timeout,