Add ability to reset metrics between crawl to limit payload absorbed (#5)

by the prometheus/victoria metric crawlers.

Makefile

@@ -11,7 +11,7 @@ help:  ## display this help
 
 .PHONY: run
 run: build ## run application
-	@LOG_LEVEL=debug BLOCK_SCHEMA_INTROSPECTION=false CACHE_TTL=10 JWT_ROLE_RATE_LIMIT=false JWT_ROLE_CLAIM_PATH="Hasura.x-hasura-default-role" JWT_USER_CLAIM_PATH="Hasura.x-hasura-user-id" HOST_GRAPHQL=https://hasura8.lan/ HEALTHCHECK_GRAPHQL_URL=https://hasura8.lan/v1/graphql ./graphql-proxy
+	@LOG_LEVEL=debug PURGE_METRICS_ON_CRAWL=true BLOCK_SCHEMA_INTROSPECTION=false CACHE_TTL=10 JWT_ROLE_RATE_LIMIT=false JWT_ROLE_CLAIM_PATH="Hasura.x-hasura-default-role" JWT_USER_CLAIM_PATH="Hasura.x-hasura-user-id" HOST_GRAPHQL=https://hasura8.lan/ HEALTHCHECK_GRAPHQL_URL=https://hasura8.lan/v1/graphql ./graphql-proxy
 
 .PHONY: build
 build: ## build the binary

README.md

@@ -23,6 +23,7 @@ This project is in active use by [telegram-bot.app](https://telegram-bot.app), a
   - [API endpoints](#api-endpoints)
     - [Ban or unban the user](#ban-or-unban-the-user)
   - [General](#general)
+    - [Metrics which matter](#metrics-which-matter)
     - [Healthcheck](#healthcheck)
     - [Monitoring endpoint](#monitoring-endpoint)
 
@@ -123,6 +124,7 @@ In this case, both proxy and websockets will be available under the `/v1/graphql
 | `API_PORT`                | The port to expose the monitoring API   | `9090`                     |
 | `BANNED_USERS_FILE`       | The path to the file with banned users  | `/go/src/app/banned_users.json`   |
 | `PROXIED_CLIENT_TIMEOUT` | The timeout for the proxied client in seconds     | `120`                      |
+| `PURGE_METRICS_ON_CRAWL` | Purge metrics on each /metrics crawl    | `false`                      |
 
 ### Speed
 
@@ -227,6 +229,12 @@ Ban details will be stored in the `banned_users.json` file, which you can mount
 
 ### General
 
+#### Metrics which matter
+
+You can always enable `PURGE_METRICS_ON_CRAWL` environment variable to purge the metrics on each `/metrics` crawl. This will allow you to see only the current metrics, without potential leftovers from the previous crawls. This is useful if you want to monitor the metrics in real-time and / or limit the amount of data ingested into the monitoring system. When enabled you will most likely need to update your monitoring queries.
+
+With the `PURGE_METRICS_ON_CRAWL` enabled, the `graphql_proxy_requests_failed`, `graphql_proxy_requests_skipped` and `graphql_proxy_requests_succesful` metrics will remain between resets.
+
 #### Healthcheck
 
 If you'd like the `/healthz` endpoint to perform actual check for the connectivity to the graphql endpoint - set the `HEALTHCHECK_GRAPHQL_URL` environment variable to the exact URL of the graphql endpoint. The query executed will be `query { __typename }` and if the response is not `200 OK` - the healthcheck will fail. Remember that the endpoint is a full URL which you'd like to check, so it should include the protocol, host and path - for example `http://localhost:8080/v1/graphql` and it's NOT the same as value of `HOST_GRAPHQL` environment variable which should provide only the host, without path, ending with slash.

main.go

@@ -55,6 +55,7 @@ func parseConfig() {
 	c.Server.EnableApi = envutil.GetBool("ENABLE_API", false)
 	c.Server.ApiPort = envutil.GetInt("API_PORT", 9090)
 	c.Api.BannedUsersFile = envutil.Getenv("BANNED_USERS_FILE", "/go/src/app/banned_users.json")
+	c.Server.PurgeOnCrawl = envutil.GetBool("PURGE_METRICS_ON_CRAWL", false)
 	cfg = &c
 	enableCache() // takes close to no resources, but can be used with dynamic query cache
 	loadRatelimitConfig()

monitoring.go

@@ -5,7 +5,7 @@ import (
 )
 
 func StartMonitoringServer() {
-	cfg.Monitoring = libpack_monitoring.NewMonitoring()
+	cfg.Monitoring = libpack_monitoring.NewMonitoring(cfg.Server.PurgeOnCrawl)
 	cfg.Monitoring.AddMetricsPrefix("graphql_proxy")
 	cfg.Monitoring.RegisterDefaultMetrics()
 }

monitoring/monitoring.go

@@ -15,18 +15,22 @@ import (
 )
 
 type MetricsSetup struct {
-	metrics_prefix string
-	metrics_set    *metrics.Set
+	metrics_prefix     string
+	metrics_set        *metrics.Set
+	metrics_set_custom *metrics.Set
 }
 
 var (
-	log *logging.LogConfig
+	log                 *logging.LogConfig
+	purgeMetricsOnCrawl bool
 )
 
-func NewMonitoring() *MetricsSetup {
+func NewMonitoring(purgeOnCrawl bool) *MetricsSetup {
+	purgeMetricsOnCrawl = purgeOnCrawl
 	log = logging.NewLogger()
 	ms := &MetricsSetup{}
 	ms.metrics_set = metrics.NewSet()
+	ms.metrics_set_custom = metrics.NewSet()
 	go ms.startPrometheusEndpoint()
 	return ms
 }
@@ -45,6 +49,10 @@ func (ms *MetricsSetup) startPrometheusEndpoint() {
 
 func (ms *MetricsSetup) metricsEndpoint(c *fiber.Ctx) error {
 	ms.metrics_set.WritePrometheus(c.Response().BodyWriter())
+	ms.metrics_set_custom.WritePrometheus(c.Response().BodyWriter())
+	if purgeMetricsOnCrawl {
+		ms.PurgeMetrics()
+	}
 	return nil
 }
 
@@ -61,7 +69,7 @@ func (ms *MetricsSetup) RegisterMetricsGauge(metric_name string, labels map[stri
 		log.Critical("RegisterMetricsGauge() error", map[string]interface{}{"_error": "Invalid metric name", "_metric_name": metric_name})
 		return nil
 	}
-	return ms.metrics_set.GetOrCreateGauge(ms.get_metrics_name(metric_name, labels), func() float64 {
+	return ms.metrics_set_custom.GetOrCreateGauge(ms.get_metrics_name(metric_name, labels), func() float64 {
 		// get current value of the gauge and add val to it
 		return val
 	})
@@ -72,7 +80,10 @@ func (ms *MetricsSetup) RegisterMetricsCounter(metric_name string, labels map[st
 		log.Critical("RegisterMetricsCounter() error", map[string]interface{}{"_error": "Invalid metric name", "_metric_name": metric_name})
 		return nil
 	}
-	return ms.metrics_set.GetOrCreateCounter(ms.get_metrics_name(metric_name, labels))
+	if metric_name == MetricsSucceeded || metric_name == MetricsFailed || metric_name == MetricsSkipped {
+		return ms.metrics_set.GetOrCreateCounter(ms.get_metrics_name(metric_name, labels))
+	}
+	return ms.metrics_set_custom.GetOrCreateCounter(ms.get_metrics_name(metric_name, labels))
 }
 
 func (ms *MetricsSetup) RegisterFloatCounter(metric_name string, labels map[string]string) *metrics.FloatCounter {
@@ -80,7 +91,7 @@ func (ms *MetricsSetup) RegisterFloatCounter(metric_name string, labels map[stri
 		log.Critical("RegisterFloatCounter() error", map[string]interface{}{"_error": "Invalid metric name", "_metric_name": metric_name})
 		return nil
 	}
-	return ms.metrics_set.GetOrCreateFloatCounter(ms.get_metrics_name(metric_name, labels))
+	return ms.metrics_set_custom.GetOrCreateFloatCounter(ms.get_metrics_name(metric_name, labels))
 }
 
 func (ms *MetricsSetup) RegisterMetricsSummary(metric_name string, labels map[string]string) *metrics.Summary {
@@ -88,7 +99,7 @@ func (ms *MetricsSetup) RegisterMetricsSummary(metric_name string, labels map[st
 		log.Critical("RegisterMetricsSummary() error", map[string]interface{}{"_error": "Invalid metric name", "_metric_name": metric_name})
 		return nil
 	}
-	return ms.metrics_set.GetOrCreateSummary(ms.get_metrics_name(metric_name, labels))
+	return ms.metrics_set_custom.GetOrCreateSummary(ms.get_metrics_name(metric_name, labels))
 }
 
 func (ms *MetricsSetup) RegisterMetricsHistogram(metric_name string, labels map[string]string) *metrics.Histogram {
@@ -96,7 +107,7 @@ func (ms *MetricsSetup) RegisterMetricsHistogram(metric_name string, labels map[
 		log.Critical("RegisterMetricsHistogram() error", map[string]interface{}{"_error": "Invalid metric name", "_metric_name": metric_name})
 		return nil
 	}
-	return ms.metrics_set.GetOrCreateHistogram(ms.get_metrics_name(metric_name, labels))
+	return ms.metrics_set_custom.GetOrCreateHistogram(ms.get_metrics_name(metric_name, labels))
 }
 
 func (ms *MetricsSetup) Increment(metric_name string, labels map[string]string) {
@@ -124,9 +135,9 @@ func (ms *MetricsSetup) UpdateSummary(metric_name string, labels map[string]stri
 }
 
 func (ms *MetricsSetup) RemoveMetrics(metric_name string, labels map[string]string) {
-	ms.metrics_set.UnregisterMetric(ms.get_metrics_name(metric_name, labels))
+	ms.metrics_set_custom.UnregisterMetric(ms.get_metrics_name(metric_name, labels))
 }
 
 func (ms *MetricsSetup) PurgeMetrics() {
-	ms.metrics_set.UnregisterAllMetrics()
+	ms.metrics_set_custom.UnregisterAllMetrics()
 }

struct_config.go

@@ -24,6 +24,7 @@ type config struct {
 		AllowURLs          []string
 		EnableApi          bool
 		ApiPort            int
+		PurgeOnCrawl       bool
 	}
 
 	Client struct {