configure community filter cutoff

pkg/config/config.go

@@ -69,22 +69,28 @@ const (
 	// DefaultHTTPTimeout is the time in seconds after which the
 	// server will timeout.
 	DefaultHTTPTimeout = 120
+
+	// DefaultPrefixLookupCommunityFilterCutoff is the number of
+	// routes after which the community filter will not be
+	// available.
+	DefaultPrefixLookupCommunityFilterCutoff = 100000
 )
 
 // A ServerConfig holds the runtime configuration
 // for the backend.
 type ServerConfig struct {
-	Listen                           string `ini:"listen_http"`
-	HTTPTimeout                      int    `ini:"http_timeout"`
-	EnablePrefixLookup               bool   `ini:"enable_prefix_lookup"`
-	NeighborsStoreRefreshInterval    int    `ini:"neighbors_store_refresh_interval"`
-	NeighborsStoreRefreshParallelism int    `ini:"neighbors_store_refresh_parallelism"`
-	RoutesStoreRefreshInterval       int    `ini:"routes_store_refresh_interval"`
-	RoutesStoreRefreshParallelism    int    `ini:"routes_store_refresh_parallelism"`
-	StoreBackend                     string `ini:"store_backend"`
-	DefaultAsn                       int    `ini:"asn"`
-	EnableNeighborsStatusRefresh     bool   `ini:"enable_neighbors_status_refresh"`
-	StreamParserThrottle             int    `ini:"stream_parser_throttle"`
+	Listen                            string `ini:"listen_http"`
+	HTTPTimeout                       int    `ini:"http_timeout"`
+	EnablePrefixLookup                bool   `ini:"enable_prefix_lookup"`
+	PrefixLookupCommunityFilterCutoff int    `ini:"prefix_lookup_community_filter_cutoff"`
+	NeighborsStoreRefreshInterval     int    `ini:"neighbors_store_refresh_interval"`
+	NeighborsStoreRefreshParallelism  int    `ini:"neighbors_store_refresh_parallelism"`
+	RoutesStoreRefreshInterval        int    `ini:"routes_store_refresh_interval"`
+	RoutesStoreRefreshParallelism     int    `ini:"routes_store_refresh_parallelism"`
+	StoreBackend                      string `ini:"store_backend"`
+	DefaultAsn                        int    `ini:"asn"`
+	EnableNeighborsStatusRefresh      bool   `ini:"enable_neighbors_status_refresh"`
+	StreamParserThrottle              int    `ini:"stream_parser_throttle"`
 }
 
 // PostgresConfig is the configuration for the database
@@ -928,10 +934,11 @@ func LoadConfig(file string) (*Config, error) {
 
 	// Map sections
 	server := ServerConfig{
-		HTTPTimeout:                      DefaultHTTPTimeout,
-		StoreBackend:                     "memory",
-		RoutesStoreRefreshParallelism:    1,
-		NeighborsStoreRefreshParallelism: 1,
+		HTTPTimeout:                       DefaultHTTPTimeout,
+		PrefixLookupCommunityFilterCutoff: DefaultPrefixLookupCommunityFilterCutoff,
+		StoreBackend:                      "memory",
+		RoutesStoreRefreshParallelism:     1,
+		NeighborsStoreRefreshParallelism:  1,
 	}
 	if err := parsedConfig.Section("server").MapTo(&server); err != nil {
 		return nil, err

pkg/config/config_test.go

@@ -38,6 +38,11 @@ func TestLoadConfigs(t *testing.T) {
 		t.Error("expcted to find example community 1:23 with 'some tag'",
 			"but got:", label)
 	}
+
+	// Check prefix lookup cutoff
+	if config.Server.PrefixLookupCommunityFilterCutoff != 123 {
+		t.Error("Expected PrefixLookupCommunityFilterCutoff to be 123")
+	}
 }
 
 // TestSourceConfig checks that the proper backend type was identified for each

pkg/config/testdata/alice.conf

@@ -18,6 +18,13 @@ enable_prefix_lookup = true
 enable_neighbors_status_refresh = false
 # this ASN is used as a fallback value in the RPKI feature and for route
 # filtering evaluation with large BGP communities
+#
+# Prefix lookup community filter cutoff defines an upper limit
+# of returned routes for which the community filters list is
+# available. If the number of routes exceeds this limit, the
+# communities filters become available if there is a specific
+# route server selected.
+prefix_lookup_community_filter_cutoff = 123
 
 # how many route servers will be refreshed at the same time
 # if set to 0 (or for the matter of fact 1), refresh will be

pkg/http/api_endpoints_search.go

@@ -78,9 +78,10 @@ func (s *Server) apiLookupPrefixGlobal(
 	imported := make(api.LookupRoutes, 0, totalResults)
 	filtered := make(api.LookupRoutes, 0, totalResults)
 
-	// TODO: Make configurable
-	communityFilterCutoff := 100000
-	canFilterCommunities := totalResults <= communityFilterCutoff
+	// Check if we should calculate community filter
+	// cardinalities.
+	filterCutoff := s.cfg.Server.PrefixLookupCommunityFilterCutoff
+	canFilterCommunities := totalResults <= filterCutoff
 
 	// In case there is a source filter applied, we can filter communities
 	if filtersApplied.HasGroup(api.SearchKeySources) {
@@ -89,7 +90,8 @@ func (s *Server) apiLookupPrefixGlobal(
 
 	filtersNotAvailable := []string{}
 	if !canFilterCommunities {
-		filtersNotAvailable = append(filtersNotAvailable, api.SearchKeyCommunities)
+		filtersNotAvailable = append(
+			filtersNotAvailable, api.SearchKeyCommunities)
 	}
 
 	// Now, as we have allocated even more space process routes by, splitting,

pkg/http/server.go

@@ -54,6 +54,15 @@ func (s *Server) Start(ctx context.Context) {
 
 	httpTimeout := time.Duration(s.cfg.Server.HTTPTimeout) * time.Second
 	log.Println("Web server HTTP timeout set to:", httpTimeout)
+	log.Println("Listening on:", s.cfg.Server.Listen)
+
+	if s.cfg.Server.EnablePrefixLookup {
+		log.Println("Prefix Lookup (Search): enabled")
+		log.Println("Prefix Lookup Community Filter Cutoff:",
+			s.cfg.Server.PrefixLookupCommunityFilterCutoff)
+	} else {
+		log.Println("Prefix Lookup (Search): disabled")
+	}
 
 	s.Server = &http.Server{
 		Addr:         s.cfg.Server.Listen,