Improve logging of ring merge

Turn some Sprint() calls into `%v` in the outer format string.
Remove one debug log line on duplicate token, since that info is already logged.

Add an Info log line when we accept another peer's token, since that
should be a rare event, and it's important if we've made a mistake.

ipam/ring/ring.go

@@ -284,7 +284,7 @@ func (es entries) merge(other entries, ourPeer mesh.PeerName, r *Ring, hasAlloca
 	var i, j int
 	for i < len(es) && j < len(other) {
 		mine, theirs = es[i], other[j]
-		common.Log.Debugln(fmt.Sprintf("[ring %s]: Merge mine.Token=%s theirs.Token=%s mine.Peer=%s theirs.Peer=%s mine.Version=%s theirs.Version=%s", ourPeer, mine.Token, theirs.Token, mine.Peer, theirs.Peer, fmt.Sprint(mine.Version), fmt.Sprint(theirs.Version)))
+		common.Log.Debugf("[ring %s]: Merge mine.Token=%s theirs.Token=%s mine.Peer=%s theirs.Peer=%s mine.Version=%v theirs.Version=%v", ourPeer, mine.Token, theirs.Token, mine.Peer, theirs.Peer, mine.Version, theirs.Version)
 		switch {
 		case mine.Token < theirs.Token:
 			addToResult(*mine)
@@ -302,7 +302,6 @@ func (es entries) merge(other entries, ourPeer mesh.PeerName, r *Ring, hasAlloca
 			addTheirs(*theirs)
 			j++
 		case mine.Token == theirs.Token:
-			common.Log.Debugln(fmt.Sprintf("[ring %s]: Merge token=%s mine.Peer=%s theirs.Peer=%s mine.Version=%s theirs.Version=%s", ourPeer, mine.Token, mine.Peer, theirs.Peer, fmt.Sprint(mine.Version), fmt.Sprint(theirs.Version)))
 			// merge
 			switch {
 			case mine.Version >= theirs.Version:
@@ -333,6 +332,7 @@ func (es entries) merge(other entries, ourPeer mesh.PeerName, r *Ring, hasAlloca
 					// which case we should set our version to the one received plus one,
 					// effectively imposing our existing entry.
 					if theirs.Peer != ourPeer && !hasAllocations(r.makeRanges(mine.Token, es.entry(i+1).Token)) {
+						common.Log.Infof("ring: repair inconsistent data by accepting token %v from %v - no allocations up to %v", theirs.Token, theirs.Peer, es.entry(i+1).Token)
 						addTheirs(*theirs)
 					} else if theirs.Peer == ourPeer {
 						mine.Version = theirs.Version + 1
@@ -528,7 +528,7 @@ func (r *Ring) ReportFree(freespace map[address.Address]address.Count) (updated
 
 		entries[i].Free = free
 		entries[i].Version++
-		common.Log.Debugln(fmt.Sprintf("[ring %s]: ReportFree token=%s peer=%s version=%s", r.Peer, entries[i].Token, entries[i].Peer, fmt.Sprint(entries[i].Version)))
+		common.Log.Debugf("[ring %s]: ReportFree token=%s peer=%s version=%v", r.Peer, entries[i].Token, entries[i].Peer, entries[i].Version)
 		updated = true
 	}
 	return
@@ -612,7 +612,7 @@ func (r *Ring) Transfer(from, to mesh.PeerName) []address.Range {
 			// bump version by large value so that transfer of range takes precedence (if there is any conflict in merging entry)
 			// over other opertaions on the entry that increments the version
 			entry.Version = entry.Version + 100
-			common.Log.Debugln(fmt.Sprintf("[ring %s]: Transfer token=%s from=%s to=%s version=%s", r.Peer, entry.Token, from, to, fmt.Sprint(entry.Version)))
+			common.Log.Debugf("[ring %s]: Transfer token=%s from=%s to=%s version=%v", r.Peer, entry.Token, from, to, entry.Version)
 			newRanges = append(newRanges, address.Range{Start: entry.Token, End: r.Entries.entry(i + 1).Token})
 		}
 	}