started making paxos more nack registant

lib/leader_elector.ex

@@ -56,7 +56,7 @@ defmodule EventualLeaderElector do
 
         {:timeout} ->
           state =
-            if MapSet.size(state.heard_back) == 0 do
+            if MapSet.size(state.heard_back) < floor(length(state.processes)/2) + 1 do
               state
             else
               to_trust = Enum.at(Enum.sort(MapSet.to_list(state.heard_back)), 0)

lib/paxos.ex

@@ -42,6 +42,7 @@ defmodule Paxos do
           pid_to_inform: pid_to_inform,
           has_sent_accept: false,
           action: action,
+          has_sent_prepare: false,
         })
 
       %{state | instmap: instmap}
@@ -146,7 +147,7 @@ defmodule Paxos do
               } end)
 
             true ->
-              Utils.unicast({:nack, inst, ballot}, proc)
+              Utils.unicast({:nack, inst, ballot, state.instmap[inst].ballot}, proc)
               state
           end
 
@@ -157,8 +158,8 @@ defmodule Paxos do
 
           state
 
-        {:nack, inst, ballot} ->
-          IO.puts("#{state.name} - nack #{inspect(inst)} #{inspect(ballot)}")
+        {:nack, inst, ballot, new_ballot} ->
+          IO.puts("#{state.name} - nack #{inspect(inst)} #{inspect(ballot)} #{inspect(new_ballot)}")
 
           cond do
             has_finished(state, inst) ->
@@ -169,14 +170,35 @@ defmodule Paxos do
                 send(state.instmap[inst].pid_to_inform, {:abort, inst})
               end
 
+              EagerReliableBroadcast.broadcast(state.name, {:abort, inst, ballot, new_ballot})
+
               set_instmap(state, inst, fn map -> %{
-                map | has_sent_accept: false
+                map | has_sent_accept: false, 
+                ballot: new_ballot + 1,
+                has_sent_prepare: false,
               } end)
 
             true ->
               state
           end
 
+        {:rb_deliver, _proc, {:abort, inst, ballot}} ->
+          cond do
+            has_finished(state, inst) ->
+              state
+
+            state.instmap[inst].ballot == ballot ->
+              if Map.has_key?(state.instmap, inst) and state.instmap[inst].pid_to_inform != nil do
+                send(state.instmap[inst].pid_to_inform, {:abort, inst})
+              end
+
+              state
+
+            true ->
+              state
+
+          end
+
         {:prepared, inst, ballot, accepted_ballot, accepted_value} ->
           IO.puts(
             "#{state.name} - prepared #{inspect(inst)} #{inspect(ballot)} #{inspect(accepted_ballot)} #{inspect(accepted_value)}"
@@ -225,7 +247,7 @@ defmodule Paxos do
                 } end)
               else
                 IO.puts("#{state.name} -> #{proc} nack")
-                Utils.unicast({:nack, inst, ballot}, proc)
+                Utils.unicast({:nack, inst, ballot, state.instmap[inst].ballot}, proc)
                 state
               end
           end
@@ -233,10 +255,11 @@ defmodule Paxos do
         {:accepted, inst, ballot} ->
           IO.puts("#{state.name} accepted #{inspect(inst)} #{inspect(ballot)}")
 
-          if has_finished(state, inst) do
-            state
-          else
-            if state.leader == state.name and state.instmap[inst].ballot == ballot do
+          cond do
+            has_finished(state, inst) ->
+              state
+
+            state.leader == state.name and state.instmap[inst].ballot == ballot ->
               accepted(
                 set_instmap(state, inst, fn map -> %{
                   map
@@ -244,9 +267,9 @@ defmodule Paxos do
                 } end),
                 inst
               )
-            else
+
+            true ->
               state
-            end
           end
 
         {:get_value, inst, pid_to_inform, t} ->
@@ -302,6 +325,9 @@ defmodule Paxos do
       Map.get(state.instmap, inst) == nil and Map.get(state.other_values, inst) == nil ->
         state
 
+      Map.get(state.instmap, inst) != nil and state.instmap[inst].has_sent_prepare ->
+        state
+
       Map.get(state.instmap, inst) != nil and state.instmap[inst].has_sent_accept ->
         state
 
@@ -315,6 +341,7 @@ defmodule Paxos do
           |  prepared_values: [],
             accepted: 0,
             ballot_value: nil,
+            has_sent_prepare: true,
             has_sent_accept: false
         } end)
     end
@@ -330,11 +357,14 @@ defmodule Paxos do
          not state.instmap[inst].has_sent_accept do
       {_, a_val} =
         Enum.reduce(state.instmap[inst].prepared_values, {0, nil}, fn {bal, val},
-                                                                      {a_bal, a_val} ->
-          if a_bal > bal do
-            {a_bal, a_val}
-          else
-            {bal, val}
+                                                                      {acc_bal, acc_val} ->
+          cond do 
+            val == nil ->
+              {acc_bal, acc_val}
+            acc_bal > bal ->
+              {acc_bal, acc_val}
+            true ->
+              {bal, val}
           end
         end)
 

lib/test_script.exs

@@ -22,42 +22,42 @@ test_suite = [
   # Use TestUtil.get_local_config(n) to generate a single-node configuration 
   # consisting of n processes, all running on the same node.
 
-  # {&PaxosTest.run_simple/3, TestUtil.get_local_config(3), 10,
-  #  "No failures, no concurrent ballots, 3 local procs"},
-  # {&PaxosTest.run_simple/3, TestUtil.get_dist_config(host, 3), 10,
-  #  "No failures, no concurrent ballots, 3 nodes"},
-  # {&PaxosTest.run_simple/3, TestUtil.get_local_config(5), 10,
-  #  "No failures, no concurrent ballots, 5 local procs"},
-  # {&PaxosTest.run_simple_2/3, TestUtil.get_dist_config(host, 3), 10,
-  #  "No failures, 2 concurrent ballots, 3 nodes"},
-  # {&PaxosTest.run_simple_2/3, TestUtil.get_local_config(3), 10,
-  #  "No failures, 2 concurrent ballots, 3 local procs"},
-  # {&PaxosTest.run_simple_3/3, TestUtil.get_local_config(3), 10,
-  #  "No failures, 2 concurrent instances, 3 local procs"},
-  # {&PaxosTest.run_simple_many_1/3, TestUtil.get_dist_config(host, 5), 10,
-  #  "No failures, many concurrent ballots 1, 5 nodes"},
-  # {&PaxosTest.run_simple_many_1/3, TestUtil.get_local_config(5), 10,
-  #  "No failures, many concurrent ballots 1, 5 local procs"},
-  # {&PaxosTest.run_simple_many_2/3, TestUtil.get_dist_config(host, 5), 10,
-  #  "No failures, many concurrent ballots 2, 5 nodes"},
-  # {&PaxosTest.run_simple_many_2/3, TestUtil.get_local_config(5), 10,
-  #  "No failures, many concurrent ballots 2, 5 local procs"},
-  # {&PaxosTest.run_non_leader_crash/3, TestUtil.get_dist_config(host, 3), 10,
-  #  "One non-leader crashes, no concurrent ballots, 3 nodes"},
-  # {&PaxosTest.run_non_leader_crash/3, TestUtil.get_local_config(3), 10,
-  #  "One non-leader crashes, no concurrent ballots, 3 local procs"},
-  # {&PaxosTest.run_minority_non_leader_crash/3, TestUtil.get_dist_config(host, 5), 10,
-  #  "Minority non-leader crashes, no concurrent ballots"},
-  # {&PaxosTest.run_minority_non_leader_crash/3, TestUtil.get_local_config(5), 10,
-  #  "Minority non-leader crashes, no concurrent ballots"},
-  # {&PaxosTest.run_leader_crash_simple/3, TestUtil.get_dist_config(host, 5), 10,
-  #  "Leader crashes, no concurrent ballots, 5 nodes"},
-  # {&PaxosTest.run_leader_crash_simple/3, TestUtil.get_local_config(5), 10,
-  #  "Leader crashes, no concurrent ballots, 5 local procs"},
-  # {&PaxosTest.run_leader_crash_simple_2/3, TestUtil.get_dist_config(host, 7), 10,
-  #  "Leader and some non-leaders crash, no concurrent ballots, 7 nodes"},
-  # {&PaxosTest.run_leader_crash_simple_2/3, TestUtil.get_local_config(7), 10,
-  #  "Leader and some non-leaders crash, no concurrent ballots, 7 local procs"},
+  {&PaxosTest.run_simple/3, TestUtil.get_local_config(3), 10,
+   "No failures, no concurrent ballots, 3 local procs"},
+  {&PaxosTest.run_simple/3, TestUtil.get_dist_config(host, 3), 10,
+   "No failures, no concurrent ballots, 3 nodes"},
+  {&PaxosTest.run_simple/3, TestUtil.get_local_config(5), 10,
+   "No failures, no concurrent ballots, 5 local procs"},
+  {&PaxosTest.run_simple_2/3, TestUtil.get_dist_config(host, 3), 10,
+   "No failures, 2 concurrent ballots, 3 nodes"},
+  {&PaxosTest.run_simple_2/3, TestUtil.get_local_config(3), 10,
+   "No failures, 2 concurrent ballots, 3 local procs"},
+  {&PaxosTest.run_simple_3/3, TestUtil.get_local_config(3), 10,
+   "No failures, 2 concurrent instances, 3 local procs"},
+  {&PaxosTest.run_simple_many_1/3, TestUtil.get_dist_config(host, 5), 10,
+   "No failures, many concurrent ballots 1, 5 nodes"},
+  {&PaxosTest.run_simple_many_1/3, TestUtil.get_local_config(5), 10,
+   "No failures, many concurrent ballots 1, 5 local procs"},
+  {&PaxosTest.run_simple_many_2/3, TestUtil.get_dist_config(host, 5), 10,
+   "No failures, many concurrent ballots 2, 5 nodes"},
+  {&PaxosTest.run_simple_many_2/3, TestUtil.get_local_config(5), 10,
+   "No failures, many concurrent ballots 2, 5 local procs"},
+  {&PaxosTest.run_non_leader_crash/3, TestUtil.get_dist_config(host, 3), 10,
+   "One non-leader crashes, no concurrent ballots, 3 nodes"},
+  {&PaxosTest.run_non_leader_crash/3, TestUtil.get_local_config(3), 10,
+   "One non-leader crashes, no concurrent ballots, 3 local procs"},
+  {&PaxosTest.run_minority_non_leader_crash/3, TestUtil.get_dist_config(host, 5), 10,
+   "Minority non-leader crashes, no concurrent ballots"},
+  {&PaxosTest.run_minority_non_leader_crash/3, TestUtil.get_local_config(5), 10,
+   "Minority non-leader crashes, no concurrent ballots"},
+  {&PaxosTest.run_leader_crash_simple/3, TestUtil.get_dist_config(host, 5), 10,
+   "Leader crashes, no concurrent ballots, 5 nodes"},
+  {&PaxosTest.run_leader_crash_simple/3, TestUtil.get_local_config(5), 10,
+   "Leader crashes, no concurrent ballots, 5 local procs"},
+  {&PaxosTest.run_leader_crash_simple_2/3, TestUtil.get_dist_config(host, 7), 10,
+   "Leader and some non-leaders crash, no concurrent ballots, 7 nodes"},
+  {&PaxosTest.run_leader_crash_simple_2/3, TestUtil.get_local_config(7), 10,
+   "Leader and some non-leaders crash, no concurrent ballots, 7 local procs"},
   {&PaxosTest.run_leader_crash_complex/3, TestUtil.get_dist_config(host, 11), 10,
    "Cascading failures of leaders and non-leaders, 11 nodes"},
   {&PaxosTest.run_leader_crash_complex/3, TestUtil.get_local_config(11), 10,
@@ -69,10 +69,10 @@ test_suite = [
 
   # Aditional Test functions
   
-  # {&PaxosTestAditional.run_leader_crash_simple_before_decision/3, TestUtil.get_dist_config(host, 5), 10,
-  #  "Leader crashes right before decision, no concurrent ballots, 5 nodes"},
-  # {&PaxosTestAditional.run_leader_crash_simple_before_decision/3, TestUtil.get_local_config(5), 10,
-  #  "Leader crashes right before decision, no concurrent ballots, 5 local procs"},
+  {&PaxosTestAditional.run_leader_crash_simple_before_decision/3, TestUtil.get_dist_config(host, 5), 10,
+   "Leader crashes right before decision, no concurrent ballots, 5 nodes"},
+  {&PaxosTestAditional.run_leader_crash_simple_before_decision/3, TestUtil.get_local_config(5), 10,
+   "Leader crashes right before decision, no concurrent ballots, 5 local procs"},
 ]
 
 Node.stop()