Network: Penalize peer/class rankings when peer does not have catchpo…

…int (algorand#5959)

catchup/catchpointService.go

@@ -824,6 +824,8 @@ func (cs *CatchpointCatchupService) checkLedgerDownload() error {
 		if err == nil {
 			return nil
 		}
+		// a non-nil error means that the catchpoint is not available, so we should rank it accordingly
+		cs.blocksDownloadPeerSelector.rankPeer(psp, peerRankNoCatchpointForRound)
 	}
 	return fmt.Errorf("checkLedgerDownload(): catchpoint '%s' unavailable from peers: %s", cs.stats.CatchpointLabel, err)
 }

catchup/peerSelector.go

@@ -55,6 +55,10 @@ const (
 	// This indicates a peer is either behind or a block has not happened yet, or does not have a block that is old enough.
 	peerRankNoBlockForRound = 2000
 
+	// peerRankNoCatchpointForRound is used for responses failed because of no catchpoint for round
+	// This indicates a peer is either behind or a catchpoint has not been produced, or this node did not retain this catchpoint (aged out).
+	peerRankNoCatchpointForRound = 2000
+
 	// peerRankDownloadFailed is used for responses which could be temporary, such as missing files, or such that we don't
 	// have clear resolution
 	peerRankDownloadFailed = 10000