# Elect node 1, then add node 4 as a new voter. AddNode commits under the old quorum {1,2,3} and
# every existing node's conf_state becomes {1,2,3,4} on apply (apply-time membership: the
# conf-changed event fires on apply, not append). The joining observer node 4 starts empty; the
# leader probes it on the next heartbeat and catches it up to the committed log.
add-nodes 3 voters=(1,2,3)
----
n1: created voters={1,2,3} term=0 commit=0 last=0
n2: created voters={1,2,3} term=0 commit=0 last=0
n3: created voters={1,2,3} term=0 commit=0 last=0

campaign 1
----
n1 candidate term=1
RequestVote term=1 last=0/0 prevote=false
RequestVote term=1 last=0/0 prevote=false

stabilize
----
> n2 recv RequestVote term=1 last=0/0 prevote=false
> n3 recv RequestVote term=1 last=0/0 prevote=false
> n2 ready
  VoteResponse term=1 prevote=false reject=false
> n3 ready
  VoteResponse term=1 prevote=false reject=false
> n1 recv VoteResponse term=1 prevote=false reject=false
> n1 recv VoteResponse term=1 prevote=false reject=false
> n1 ready
  Heartbeat term=1 commit=0
  Heartbeat term=1 commit=0
  AppendEntries term=1 prev=0/0 commit=0 entries=[1/1 empty]
  AppendEntries term=1 prev=0/0 commit=0 entries=[1/1 empty]
  n1 leader-changed term=1 lead=1
> n2 recv Heartbeat term=1 commit=0
> n3 recv Heartbeat term=1 commit=0
> n2 recv AppendEntries term=1 prev=0/0 commit=0 entries=[1/1 empty]
> n3 recv AppendEntries term=1 prev=0/0 commit=0 entries=[1/1 empty]
> n2 ready
  HeartbeatResponse term=1
  AppendResponse term=1 match=1
  n2 leader-changed term=1 lead=1
> n3 ready
  HeartbeatResponse term=1
  AppendResponse term=1 match=1
  n3 leader-changed term=1 lead=1
> n1 recv HeartbeatResponse term=1
> n1 recv AppendResponse term=1 match=1
> n1 recv HeartbeatResponse term=1
> n1 recv AppendResponse term=1 match=1
> n1 ready
  AppendEntries term=1 prev=0/0 commit=0 entries=[1/1 empty]
  AppendEntries term=1 prev=1/1 commit=1 entries=[]
  AppendEntries term=1 prev=0/0 commit=1 entries=[1/1 empty]
  AppendEntries term=1 prev=1/1 commit=1 entries=[]
> n2 recv AppendEntries term=1 prev=0/0 commit=0 entries=[1/1 empty]
> n2 recv AppendEntries term=1 prev=1/1 commit=1 entries=[]
> n3 recv AppendEntries term=1 prev=0/0 commit=1 entries=[1/1 empty]
> n3 recv AppendEntries term=1 prev=1/1 commit=1 entries=[]
> n2 ready
  AppendResponse term=1 match=1
  AppendResponse term=1 match=1
> n3 ready
  AppendResponse term=1 match=1
  AppendResponse term=1 match=1
> n1 recv AppendResponse term=1 match=1
> n1 recv AppendResponse term=1 match=1
> n1 recv AppendResponse term=1 match=1
> n1 recv AppendResponse term=1 match=1

propose-conf-change 1 add 4
----
n1 proposed conf-change add n4 at index 2
AppendEntries term=1 prev=1/1 commit=1 entries=[1/2 conf-change 0x120a12080400000000000000]
AppendEntries term=1 prev=1/1 commit=1 entries=[1/2 conf-change 0x120a12080400000000000000]

stabilize
----
> n2 recv AppendEntries term=1 prev=1/1 commit=1 entries=[1/2 conf-change 0x120a12080400000000000000]
> n3 recv AppendEntries term=1 prev=1/1 commit=1 entries=[1/2 conf-change 0x120a12080400000000000000]
> n2 ready
  AppendResponse term=1 match=2
> n3 ready
  AppendResponse term=1 match=2
> n1 recv AppendResponse term=1 match=2
> n1 recv AppendResponse term=1 match=2
> n1 ready
  AppendEntries term=1 prev=1/2 commit=2 entries=[]
  AppendEntries term=1 prev=1/2 commit=2 entries=[]
  n1 conf-changed index=2 voters={1,2,3,4}
> n2 recv AppendEntries term=1 prev=1/2 commit=2 entries=[]
> n3 recv AppendEntries term=1 prev=1/2 commit=2 entries=[]
> n2 ready
  AppendResponse term=1 match=2
  n2 conf-changed index=2 voters={1,2,3,4}
> n3 ready
  AppendResponse term=1 match=2
  n3 conf-changed index=2 voters={1,2,3,4}
> n1 recv AppendResponse term=1 match=2
> n1 recv AppendResponse term=1 match=2

tick-heartbeat 1
----
Heartbeat term=1 commit=2
Heartbeat term=1 commit=2
Heartbeat term=1 commit=0

stabilize
----
> n2 recv Heartbeat term=1 commit=2
> n3 recv Heartbeat term=1 commit=2
> n4 recv Heartbeat term=1 commit=0
> n2 ready
  HeartbeatResponse term=1
> n3 ready
  HeartbeatResponse term=1
> n4 ready
  HeartbeatResponse term=1
  n4 leader-changed term=1 lead=1
> n1 recv HeartbeatResponse term=1
> n1 recv HeartbeatResponse term=1
> n1 recv HeartbeatResponse term=1
> n1 ready
  AppendEntries term=1 prev=1/2 commit=2 entries=[]
  AppendEntries term=1 prev=1/2 commit=2 entries=[]
  AppendEntries term=1 prev=1/1 commit=2 entries=[1/2 conf-change 0x120a12080400000000000000]
> n2 recv AppendEntries term=1 prev=1/2 commit=2 entries=[]
> n3 recv AppendEntries term=1 prev=1/2 commit=2 entries=[]
> n4 recv AppendEntries term=1 prev=1/1 commit=2 entries=[1/2 conf-change 0x120a12080400000000000000]
> n2 ready
  AppendResponse term=1 match=2
> n3 ready
  AppendResponse term=1 match=2
> n4 ready
  AppendResponse term=1 reject hint=0/0
> n1 recv AppendResponse term=1 match=2
> n1 recv AppendResponse term=1 match=2
> n1 recv AppendResponse term=1 reject hint=0/0
> n1 ready
  AppendEntries term=1 prev=0/0 commit=2 entries=[1/1 empty, 1/2 conf-change 0x120a12080400000000000000]
> n4 recv AppendEntries term=1 prev=0/0 commit=2 entries=[1/1 empty, 1/2 conf-change 0x120a12080400000000000000]
> n4 ready
  AppendResponse term=1 match=2
  n4 conf-changed index=2 voters={1,2,3,4}
> n1 recv AppendResponse term=1 match=2
> n1 ready
  AppendEntries term=1 prev=1/2 commit=2 entries=[]
> n4 recv AppendEntries term=1 prev=1/2 commit=2 entries=[]
> n4 ready
  AppendResponse term=1 match=2
> n1 recv AppendResponse term=1 match=2

raft-state
----
n1: leader term=1 lead=1
n2: follower term=1 lead=1
n3: follower term=1 lead=1
n4: follower term=1 lead=1

raft-log 4
----
n4: commit=2 applied=2 last=2
  1/1 empty
  1/2 conf-change 0x120a12080400000000000000

