From ae171ba134b6e4bc2f7445a080025a80d07773ba Mon Sep 17 00:00:00 2001
From: Jae Kwon <jkwon.work@gmail.com>
Date: Wed, 6 May 2015 10:50:57 -0700
Subject: [PATCH] random dialing

---
 common/random.go   |  4 ++++
 node/node.go       | 14 +++++++++-----
 p2p/pex_reactor.go |  4 ++++
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/common/random.go b/common/random.go
index b767dcdb4..12ce8a24d 100644
--- a/common/random.go
+++ b/common/random.go
@@ -95,6 +95,10 @@ func RandUint64Exp() uint64 {
 	return n
 }
 
+func RandFloat32() float32 {
+	return rand.Float32()
+}
+
 func RandTime() time.Time {
 	return time.Unix(int64(RandUint64Exp()), 0)
 }
diff --git a/node/node.go b/node/node.go
index 143b0a789..9f533e518 100644
--- a/node/node.go
+++ b/node/node.go
@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"os"
 	"strconv"
+	"time"
 
 	bc "github.com/tendermint/tendermint/blockchain"
 	. "github.com/tendermint/tendermint/common"
@@ -152,6 +153,7 @@ func (n *Node) AddListener(l p2p.Listener) {
 	n.book.AddOurAddress(l.ExternalAddress())
 }
 
+// NOTE: Blocking
 func (n *Node) DialSeed() {
 	// if the single seed node is available, use only it
 	prioritySeed := config.App().GetString("SeedNode")
@@ -161,14 +163,16 @@ func (n *Node) DialSeed() {
 		return
 	}
 
-	// permute the list, dial half of them
+	// permute the list, dial them in random order.
 	seeds := config.App().GetStringSlice("SeedNodes")
 	perm := rand.Perm(len(seeds))
-	// TODO: we shouldn't necessarily connect to all of them every time ...
 	for i := 0; i < len(perm); i++ {
-		j := perm[i]
-		addr := p2p.NewNetAddressString(seeds[j])
-		n.dialSeed(addr)
+		go func(i int) {
+			time.Sleep(time.Duration(rand.Int63n(3000)) * time.Millisecond)
+			j := perm[i]
+			addr := p2p.NewNetAddressString(seeds[j])
+			n.dialSeed(addr)
+		}(i)
 	}
 }
 
diff --git a/p2p/pex_reactor.go b/p2p/pex_reactor.go
index f5d26d573..b6a070f46 100644
--- a/p2p/pex_reactor.go
+++ b/p2p/pex_reactor.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"math/rand"
 	"reflect"
 	"sync/atomic"
 	"time"
@@ -130,6 +131,9 @@ func (pexR *PEXReactor) SendAddrs(peer *Peer, addrs []*NetAddress) {
 
 // Ensures that sufficient peers are connected. (continuous)
 func (pexR *PEXReactor) ensurePeersRoutine() {
+	// Randomize when routine starts
+	time.Sleep(time.Duration(rand.Int63n(500*ensurePeersPeriodSeconds)) * time.Millisecond)
+
 	// fire once immediately.
 	pexR.ensurePeers()
 	// fire periodically