From f98f89848c7f8b37d9ae3fa6931f544e372e8743 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gabriel=20D=C3=ADaz?= <g.diaz.lopezllave@bbva.com>
Date: Fri, 23 Nov 2018 16:31:09 +0100
Subject: [PATCH] Fix topology peerlist update() and shuffle()

---
 cmd/agent_auditor.go |  2 +-
 gossip/topology.go   | 23 ++++++++++++++---------
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/cmd/agent_auditor.go b/cmd/agent_auditor.go
index 42bb362eb..b8f6a8911 100644
--- a/cmd/agent_auditor.go
+++ b/cmd/agent_auditor.go
@@ -48,7 +48,7 @@ func newAgentAuditorCommand(ctx *agentContext) *cobra.Command {
 			if err != nil {
 				log.Fatalf("Failed to join the cluster: %v", err)
 			}
-			log.Debugf("Number of nodes contacted: %d", contacted)
+			log.Debugf("Number of nodes contacted: %d (%v)", contacted, agentConfig.StartJoin)
 
 			agent.Start()
 			defer agent.Shutdown()
diff --git a/gossip/topology.go b/gossip/topology.go
index fcadaff81..4d023d9d0 100644
--- a/gossip/topology.go
+++ b/gossip/topology.go
@@ -17,7 +17,6 @@ import (
 	"sync"
 
 	"github.com/bbva/qed/gossip/member"
-	"github.com/bbva/qed/log"
 )
 
 type PeerList struct {
@@ -39,6 +38,9 @@ func (l *PeerList) Filter(f Filter) *PeerList {
 }
 
 func (l *PeerList) Exclude(list *PeerList) *PeerList {
+	if list == nil {
+		return l
+	}
 	return l.Filter(func(p *member.Peer) bool {
 		for _, x := range list.L {
 			if x.Name == p.Name {
@@ -54,20 +56,23 @@ func (l PeerList) All() PeerList {
 }
 
 func (l *PeerList) Shuffle() *PeerList {
-	var s PeerList
-	s.L = l.L[:0]
 	rand.Shuffle(len(l.L), func(i, j int) {
-		s.L[i], s.L[j] = s.L[j], s.L[i]
+		l.L[i], l.L[j] = l.L[j], l.L[i]
 	})
-	return &s
+	return l
 }
 
 func (l *PeerList) Update(m *member.Peer) error {
+	var add bool = true
 	for _, e := range l.L {
 		if e.Name == m.Name {
 			e = m
+			add = false
 		}
 	}
+	if add {
+		l.L = append(l.L, m)
+	}
 	return nil
 }
 
@@ -102,7 +107,6 @@ func NewTopology() *Topology {
 func (t *Topology) Update(p *member.Peer) error {
 	t.Lock()
 	defer t.Unlock()
-	log.Debugf("Updating topology with member: %+v", p)
 	t.m[p.Meta.Role].Update(p)
 	return nil
 }
@@ -123,9 +127,9 @@ func (t *Topology) Get(kind member.Type) PeerList {
 func (t *Topology) Each(n int, p *PeerList) *PeerList {
 	var b PeerList
 
-	auditors := t.m[member.Auditor].Exclude(p)
-	monitors := t.m[member.Monitor].Exclude(p)
-	publishers := t.m[member.Publisher].Exclude(p)
+	auditors := t.m[member.Auditor].Exclude(p).Shuffle()
+	monitors := t.m[member.Monitor].Exclude(p).Shuffle()
+	publishers := t.m[member.Publisher].Exclude(p).Shuffle()
 
 	if len(auditors.L) > n {
 		auditors.L = auditors.L[:n]
@@ -139,5 +143,6 @@ func (t *Topology) Each(n int, p *PeerList) *PeerList {
 	b.L = append(b.L, auditors.L...)
 	b.L = append(b.L, auditors.L...)
 	b.L = append(b.L, auditors.L...)
+
 	return &b
 }