Make usage of relays optional, avoid DB roundtrips (#3337)

This should avoid 2 additional DB roundtrips if we don't want to use
relays.

So instead of possibly doing roughly 20k trips to the DB, we are now
"only" doing ~6600.

---------

Co-authored-by: devonh <devon.dmytro@gmail.com>

7 files changed, 32 insertions, 17 deletions

diff --git a/federationapi/federationapi.go b/federationapi/federationapi.go
index efbfa331..d3730c7c 100644
--- a/federationapi/federationapi.go
+++ b/federationapi/federationapi.go
@@ -113,10 +113,7 @@ func NewInternalAPI(
 		_ = federationDB.RemoveAllServersFromBlacklist()
 	}
 
-	stats := statistics.NewStatistics(
-		federationDB,
-		cfg.FederationMaxRetries+1,
-		cfg.P2PFederationRetriesUntilAssumedOffline+1)
+	stats := statistics.NewStatistics(federationDB, cfg.FederationMaxRetries+1, cfg.P2PFederationRetriesUntilAssumedOffline+1, cfg.EnableRelays)
 
 	js, nats := natsInstance.Prepare(processContext, &cfg.Matrix.JetStream)
 
diff --git a/federationapi/internal/federationclient_test.go b/federationapi/internal/federationclient_test.go
index fe8d84ff..47efb11d 100644
--- a/federationapi/internal/federationclient_test.go
+++ b/federationapi/internal/federationclient_test.go
@@ -61,7 +61,7 @@ func TestFederationClientQueryKeys(t *testing.T) {
 		},
 	}
 	fedClient := &testFedClient{}
-	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline, false)
 	queues := queue.NewOutgoingQueues(
 		testDB, process.NewProcessContext(),
 		false,
@@ -92,7 +92,7 @@ func TestFederationClientQueryKeysBlacklisted(t *testing.T) {
 		},
 	}
 	fedClient := &testFedClient{}
-	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline, false)
 	queues := queue.NewOutgoingQueues(
 		testDB, process.NewProcessContext(),
 		false,
@@ -122,7 +122,7 @@ func TestFederationClientQueryKeysFailure(t *testing.T) {
 		},
 	}
 	fedClient := &testFedClient{shouldFail: true}
-	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline, false)
 	queues := queue.NewOutgoingQueues(
 		testDB, process.NewProcessContext(),
 		false,
@@ -152,7 +152,7 @@ func TestFederationClientClaimKeys(t *testing.T) {
 		},
 	}
 	fedClient := &testFedClient{}
-	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline, false)
 	queues := queue.NewOutgoingQueues(
 		testDB, process.NewProcessContext(),
 		false,
@@ -183,7 +183,7 @@ func TestFederationClientClaimKeysBlacklisted(t *testing.T) {
 		},
 	}
 	fedClient := &testFedClient{}
-	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline, false)
 	queues := queue.NewOutgoingQueues(
 		testDB, process.NewProcessContext(),
 		false,
diff --git a/federationapi/internal/perform_test.go b/federationapi/internal/perform_test.go
index 2795a018..82f9b9db 100644
--- a/federationapi/internal/perform_test.go
+++ b/federationapi/internal/perform_test.go
@@ -66,7 +66,7 @@ func TestPerformWakeupServers(t *testing.T) {
 		},
 	}
 	fedClient := &testFedClient{}
-	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline, true)
 	queues := queue.NewOutgoingQueues(
 		testDB, process.NewProcessContext(),
 		false,
@@ -112,7 +112,7 @@ func TestQueryRelayServers(t *testing.T) {
 		},
 	}
 	fedClient := &testFedClient{}
-	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline, false)
 	queues := queue.NewOutgoingQueues(
 		testDB, process.NewProcessContext(),
 		false,
@@ -153,7 +153,7 @@ func TestRemoveRelayServers(t *testing.T) {
 		},
 	}
 	fedClient := &testFedClient{}
-	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline, false)
 	queues := queue.NewOutgoingQueues(
 		testDB, process.NewProcessContext(),
 		false,
@@ -193,7 +193,7 @@ func TestPerformDirectoryLookup(t *testing.T) {
 		},
 	}
 	fedClient := &testFedClient{}
-	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline, false)
 	queues := queue.NewOutgoingQueues(
 		testDB, process.NewProcessContext(),
 		false,
@@ -232,7 +232,7 @@ func TestPerformDirectoryLookupRelaying(t *testing.T) {
 		},
 	}
 	fedClient := &testFedClient{}
-	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline, true)
 	queues := queue.NewOutgoingQueues(
 		testDB, process.NewProcessContext(),
 		false,
diff --git a/federationapi/queue/queue_test.go b/federationapi/queue/queue_test.go
index 73d3b059..6da86342 100644
--- a/federationapi/queue/queue_test.go
+++ b/federationapi/queue/queue_test.go
@@ -117,7 +117,7 @@ func testSetup(failuresUntilBlacklist uint32, failuresUntilAssumedOffline uint32
 		txRelayCount:         *atomic.NewUint32(0),
 	}
 
-	stats := statistics.NewStatistics(db, failuresUntilBlacklist, failuresUntilAssumedOffline)
+	stats := statistics.NewStatistics(db, failuresUntilBlacklist, failuresUntilAssumedOffline, false)
 	signingInfo := []*fclient.SigningIdentity{
 		{
 			KeyID:      "ed21019:auto",
diff --git a/federationapi/statistics/statistics.go b/federationapi/statistics/statistics.go
index e5fc4b94..e133fc9c 100644
--- a/federationapi/statistics/statistics.go
+++ b/federationapi/statistics/statistics.go
@@ -34,12 +34,15 @@ type Statistics struct {
 	// mark the destination as offline. At this point we should attempt
 	// to send messages to the user's async relay servers if we know them.
 	FailuresUntilAssumedOffline uint32
+
+	enableRelays bool
 }
 
 func NewStatistics(
 	db storage.Database,
 	failuresUntilBlacklist uint32,
 	failuresUntilAssumedOffline uint32,
+	enableRelays bool,
 ) Statistics {
 	return Statistics{
 		DB:                          db,
@@ -47,6 +50,7 @@ func NewStatistics(
 		FailuresUntilAssumedOffline: failuresUntilAssumedOffline,
 		backoffTimers:               make(map[spec.ServerName]*time.Timer),
 		servers:                     make(map[spec.ServerName]*ServerStatistics),
+		enableRelays:                enableRelays,
 	}
 }
 
@@ -73,6 +77,13 @@ func (s *Statistics) ForServer(serverName spec.ServerName) *ServerStatistics {
 		} else {
 			server.blacklisted.Store(blacklisted)
 		}
+
+		// Don't bother hitting the database 2 additional times
+		// if we don't want to use relays.
+		if !s.enableRelays {
+			return server
+		}
+
 		assumedOffline, err := s.DB.IsServerAssumedOffline(context.Background(), serverName)
 		if err != nil {
 			logrus.WithError(err).Errorf("Failed to get assumed offline entry %q", serverName)
diff --git a/federationapi/statistics/statistics_test.go b/federationapi/statistics/statistics_test.go
index a930bc3b..4376a905 100644
--- a/federationapi/statistics/statistics_test.go
+++ b/federationapi/statistics/statistics_test.go
@@ -16,7 +16,7 @@ const (
 )
 
 func TestBackoff(t *testing.T) {
-	stats := NewStatistics(nil, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	stats := NewStatistics(nil, FailuresUntilBlacklist, FailuresUntilAssumedOffline, false)
 	server := ServerStatistics{
 		statistics: &stats,
 		serverName: "test.com",
@@ -106,7 +106,7 @@ func TestBackoff(t *testing.T) {
 }
 
 func TestRelayServersListing(t *testing.T) {
-	stats := NewStatistics(test.NewInMemoryFederationDatabase(), FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	stats := NewStatistics(test.NewInMemoryFederationDatabase(), FailuresUntilBlacklist, FailuresUntilAssumedOffline, false)
 	server := ServerStatistics{statistics: &stats}
 	server.AddRelayServers([]spec.ServerName{"relay1", "relay1", "relay2"})
 	relayServers := server.KnownRelayServers()
diff --git a/setup/config/config_federationapi.go b/setup/config/config_federationapi.go
index a72eee36..073c46e0 100644
--- a/setup/config/config_federationapi.go
+++ b/setup/config/config_federationapi.go
@@ -18,6 +18,13 @@ type FederationAPI struct {
 	// The default value is 16 if not specified, which is circa 18 hours.
 	FederationMaxRetries uint32 `yaml:"send_max_retries"`
 
+	// P2P Feature: Whether relaying to specific nodes should be enabled.
+	// Defaults to false.
+	// Note: Enabling relays introduces a huge startup delay, if you are not using
+	// relays and have many servers to re-hydrate on start. Only enable this
+	// if you are using relays!
+	EnableRelays bool `yaml:"enable_relays"`
+
 	// P2P Feature: How many consecutive failures that we should tolerate when
 	// sending federation requests to a specific server until we should assume they
 	// are offline. If we assume they are offline then we will attempt to send