Initial Store & Forward Implementation (#2917)

This adds store & forward relays into dendrite for p2p.
A few things have changed:
- new relay api serves new http endpoints for s&f federation
- updated outbound federation queueing which will attempt to forward
using s&f if appropriate
- database entries to track s&f relays for other nodes

federationapi/statistics/statistics_test.go

@@ -4,17 +4,26 @@ import (
 	"math"
 	"testing"
 	"time"
+
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/stretchr/testify/assert"
+)
+
+const (
+	FailuresUntilAssumedOffline = 3
+	FailuresUntilBlacklist      = 8
 )
 
 func TestBackoff(t *testing.T) {
-	stats := NewStatistics(nil, 7)
+	stats := NewStatistics(nil, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
 	server := ServerStatistics{
 		statistics: &stats,
 		serverName: "test.com",
 	}
 
 	// Start by checking that counting successes works.
-	server.Success()
+	server.Success(SendDirect)
 	if successes := server.SuccessCount(); successes != 1 {
 		t.Fatalf("Expected success count 1, got %d", successes)
 	}
@@ -31,9 +40,8 @@ func TestBackoff(t *testing.T) {
 		// side effects since a backoff is already in progress. If it does
 		// then we'll fail.
 		until, blacklisted := server.Failure()
-
-		// Get the duration.
-		_, blacklist := server.BackoffInfo()
+		blacklist := server.Blacklisted()
+		assumedOffline := server.AssumedOffline()
 		duration := time.Until(until)
 
 		// Unset the backoff, or otherwise our next call will think that
@@ -41,16 +49,43 @@ func TestBackoff(t *testing.T) {
 		server.cancel()
 		server.backoffStarted.Store(false)
 
+		if i >= stats.FailuresUntilAssumedOffline {
+			if !assumedOffline {
+				t.Fatalf("Backoff %d should have resulted in assuming the destination was offline but didn't", i)
+			}
+		}
+
+		// Check if we should be assumed offline by now.
+		if i >= stats.FailuresUntilAssumedOffline {
+			if !assumedOffline {
+				t.Fatalf("Backoff %d should have resulted in assumed offline but didn't", i)
+			} else {
+				t.Logf("Backoff %d is assumed offline as expected", i)
+			}
+		} else {
+			if assumedOffline {
+				t.Fatalf("Backoff %d should not have resulted in assumed offline but did", i)
+			} else {
+				t.Logf("Backoff %d is not assumed offline as expected", i)
+			}
+		}
+
 		// Check if we should be blacklisted by now.
 		if i >= stats.FailuresUntilBlacklist {
 			if !blacklist {
 				t.Fatalf("Backoff %d should have resulted in blacklist but didn't", i)
 			} else if blacklist != blacklisted {
-				t.Fatalf("BackoffInfo and Failure returned different blacklist values")
+				t.Fatalf("Blacklisted and Failure returned different blacklist values")
 			} else {
 				t.Logf("Backoff %d is blacklisted as expected", i)
 				continue
 			}
+		} else {
+			if blacklist {
+				t.Fatalf("Backoff %d should not have resulted in blacklist but did", i)
+			} else {
+				t.Logf("Backoff %d is not blacklisted as expected", i)
+			}
 		}
 
 		// Check if the duration is what we expect.
@@ -69,3 +104,14 @@ func TestBackoff(t *testing.T) {
 		}
 	}
 }
+
+func TestRelayServersListing(t *testing.T) {
+	stats := NewStatistics(test.NewInMemoryFederationDatabase(), FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	server := ServerStatistics{statistics: &stats}
+	server.AddRelayServers([]gomatrixserverlib.ServerName{"relay1", "relay1", "relay2"})
+	relayServers := server.KnownRelayServers()
+	assert.Equal(t, []gomatrixserverlib.ServerName{"relay1", "relay2"}, relayServers)
+	server.AddRelayServers([]gomatrixserverlib.ServerName{"relay1", "relay1", "relay2"})
+	relayServers = server.KnownRelayServers()
+	assert.Equal(t, []gomatrixserverlib.ServerName{"relay1", "relay2"}, relayServers)
+}