dnsforward: imp code, docs

CHANGELOG.md

@@ -33,7 +33,7 @@ NOTE: Add new changes BELOW THIS COMMENT.
 
 ### Fixed
 
-- Load balancing algorithm ([#6480]).
+- Load balancing algorithm stuck on a single server ([#6480]).
 - Names defined in the `/etc/hosts` for a single address family wrongly
   considered undefined for another family ([#6541]).
 - Omitted CNAME records in safe search results, which can cause YouTube to not

internal/dnsforward/config.go

@@ -154,7 +154,7 @@ type Config struct {
 
 	// MaxGoroutines is the max number of parallel goroutines for processing
 	// incoming requests.
-	MaxGoroutines uint32 `yaml:"max_goroutines"`
+	MaxGoroutines uint `yaml:"max_goroutines"`
 
 	// HandleDDR, if true, handle DDR requests
 	HandleDDR bool `yaml:"handle_ddr"`
@@ -313,7 +313,7 @@ func (s *Server) newProxyConfig() (conf *proxy.Config, err error) {
 		RequestHandler:         s.handleDNSRequest,
 		HTTPSServerName:        aghhttp.UserAgent(),
 		EnableEDNSClientSubnet: srvConf.EDNSClientSubnet.Enabled,
-		MaxGoroutines:          uint(srvConf.MaxGoroutines),
+		MaxGoroutines:          srvConf.MaxGoroutines,
 		UseDNS64:               srvConf.UseDNS64,
 		DNS64Prefs:             srvConf.DNS64Prefixes,
 	}

internal/dnsforward/dnsforward.go

@@ -470,10 +470,11 @@ func (s *Server) startLocked() error {
 	return err
 }
 
-// prepareUpstreamSettings initializes the local upstreams configuration using b
-// as bootstrap.  It assumes that s.serverLock is locked or the Server not
-// running.
-func (s *Server) prepareLocalResolvers(b upstream.Resolver) (uc *proxy.UpstreamConfig, err error) {
+// prepareLocalResolvers initializes the local upstreams configuration using
+// boot as bootstrap.  It assumes that s.serverLock is locked or s not running.
+func (s *Server) prepareLocalResolvers(
+	boot upstream.Resolver,
+) (uc *proxy.UpstreamConfig, err error) {
 	set, err := s.conf.ourAddrsSet()
 	if err != nil {
 		// Don't wrap the error because it's informative enough as is.
@@ -495,7 +496,7 @@ func (s *Server) prepareLocalResolvers(b upstream.Resolver) (uc *proxy.UpstreamC
 	log.Debug("dnsforward: upstreams to resolve ptr for local addresses: %v", resolvers)
 
 	uc, err = s.prepareUpstreamConfig(resolvers, nil, &upstream.Options{
-		Bootstrap: b,
+		Bootstrap: boot,
 		Timeout:   defaultLocalTimeout,
 		// TODO(e.burkov): Should we verify server's certificates?
 		PreferIPv6: s.conf.BootstrapPreferIPv6,
@@ -515,7 +516,7 @@ func (s *Server) prepareLocalResolvers(b upstream.Resolver) (uc *proxy.UpstreamC
 }
 
 // setupLocalResolvers initializes and sets the resolvers for local addresses.
-// It assumes s.serverLock is locked or the Server not running.
+// It assumes s.serverLock is locked or s not running.
 func (s *Server) setupLocalResolvers(boot upstream.Resolver) (err error) {
 	uc, err := s.prepareLocalResolvers(boot)
 	if err != nil {
@@ -719,7 +720,7 @@ func (s *Server) prepareInternalProxy() (err error) {
 		CacheEnabled:   true,
 		CacheSizeBytes: 4096,
 		UpstreamConfig: srvConf.UpstreamConfig,
-		MaxGoroutines:  uint(s.conf.MaxGoroutines),
+		MaxGoroutines:  s.conf.MaxGoroutines,
 	}
 
 	setProxyUpstreamMode(