From b4776ea4e0dfab9e9b67e14f29088dab96052b90 Mon Sep 17 00:00:00 2001
From: Jakob Borg <jakob@kastelo.net>
Date: Sat, 12 Apr 2025 17:18:06 +0200
Subject: [PATCH] feat(stdiscosrv): configurable desired not-found rate

---
 cmd/stdiscosrv/apisrv.go      |  6 +++---
 cmd/stdiscosrv/apisrv_test.go |  2 +-
 cmd/stdiscosrv/main.go        | 15 ++++++++-------
 3 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/cmd/stdiscosrv/apisrv.go b/cmd/stdiscosrv/apisrv.go
index e714937fa..ec0c3520e 100644
--- a/cmd/stdiscosrv/apisrv.go
+++ b/cmd/stdiscosrv/apisrv.go
@@ -66,7 +66,7 @@ type contextKey int
 
 const idKey contextKey = iota
 
-func newAPISrv(addr string, cert tls.Certificate, db database, repl replicator, useHTTP, compression bool) *apiSrv {
+func newAPISrv(addr string, cert tls.Certificate, db database, repl replicator, useHTTP, compression bool, desiredNotFoundRate float64) *apiSrv {
 	return &apiSrv{
 		addr:        addr,
 		cert:        cert,
@@ -77,13 +77,13 @@ func newAPISrv(addr string, cert tls.Certificate, db database, repl replicator,
 		seenTracker: &retryAfterTracker{
 			name:         "seenTracker",
 			bucketStarts: time.Now(),
-			desiredRate:  250,
+			desiredRate:  desiredNotFoundRate / 2,
 			currentDelay: notFoundRetryUnknownMinSeconds,
 		},
 		notSeenTracker: &retryAfterTracker{
 			name:         "notSeenTracker",
 			bucketStarts: time.Now(),
-			desiredRate:  250,
+			desiredRate:  desiredNotFoundRate / 2,
 			currentDelay: notFoundRetryUnknownMaxSeconds / 2,
 		},
 	}
diff --git a/cmd/stdiscosrv/apisrv_test.go b/cmd/stdiscosrv/apisrv_test.go
index 272c0ca12..07dfa2f17 100644
--- a/cmd/stdiscosrv/apisrv_test.go
+++ b/cmd/stdiscosrv/apisrv_test.go
@@ -111,7 +111,7 @@ func BenchmarkAPIRequests(b *testing.B) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 	go db.Serve(ctx)
-	api := newAPISrv("127.0.0.1:0", tls.Certificate{}, db, nil, true, true)
+	api := newAPISrv("127.0.0.1:0", tls.Certificate{}, db, nil, true, true, 1000)
 	srv := httptest.NewServer(http.HandlerFunc(api.handler))
 
 	kf := b.TempDir() + "/cert"
diff --git a/cmd/stdiscosrv/main.go b/cmd/stdiscosrv/main.go
index 027c4978d..a870651d1 100644
--- a/cmd/stdiscosrv/main.go
+++ b/cmd/stdiscosrv/main.go
@@ -60,12 +60,13 @@ const (
 var debug = false
 
 type CLI struct {
-	Cert          string `group:"Listen" help:"Certificate file" default:"./cert.pem" env:"DISCOVERY_CERT_FILE"`
-	Key           string `group:"Listen" help:"Key file" default:"./key.pem" env:"DISCOVERY_KEY_FILE"`
-	HTTP          bool   `group:"Listen" help:"Listen on HTTP (behind an HTTPS proxy)" env:"DISCOVERY_HTTP"`
-	Compression   bool   `group:"Listen" help:"Enable GZIP compression of responses" env:"DISCOVERY_COMPRESSION"`
-	Listen        string `group:"Listen" help:"Listen address" default:":8443" env:"DISCOVERY_LISTEN"`
-	MetricsListen string `group:"Listen" help:"Metrics listen address" env:"DISCOVERY_METRICS_LISTEN"`
+	Cert                string  `group:"Listen" help:"Certificate file" default:"./cert.pem" env:"DISCOVERY_CERT_FILE"`
+	Key                 string  `group:"Listen" help:"Key file" default:"./key.pem" env:"DISCOVERY_KEY_FILE"`
+	HTTP                bool    `group:"Listen" help:"Listen on HTTP (behind an HTTPS proxy)" env:"DISCOVERY_HTTP"`
+	Compression         bool    `group:"Listen" help:"Enable GZIP compression of responses" env:"DISCOVERY_COMPRESSION"`
+	Listen              string  `group:"Listen" help:"Listen address" default:":8443" env:"DISCOVERY_LISTEN"`
+	MetricsListen       string  `group:"Listen" help:"Metrics listen address" env:"DISCOVERY_METRICS_LISTEN"`
+	DesiredNotFoundRate float64 `group:"Listen" help:"Desired maximum rate of not-found replies (/s)" default:"1000"`
 
 	DBDir           string        `group:"Database" help:"Database directory" default:"." env:"DISCOVERY_DB_DIR"`
 	DBFlushInterval time.Duration `group:"Database" help:"Interval between database flushes" default:"5m" env:"DISCOVERY_DB_FLUSH_INTERVAL"`
@@ -149,7 +150,7 @@ func main() {
 	}
 
 	// Start the main API server.
-	qs := newAPISrv(cli.Listen, cert, db, repl, cli.HTTP, cli.Compression)
+	qs := newAPISrv(cli.Listen, cert, db, repl, cli.HTTP, cli.Compression, cli.DesiredNotFoundRate)
 	main.Add(qs)
 
 	// If we have a metrics port configured, start a metrics handler.