This commit is contained in:
parent
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110
lib/paxos.ex
110
lib/paxos.ex
@ -1,3 +1,51 @@
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defmodule Ballot do
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def init(name, number \\ 0) do
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{name, number}
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end
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def inc(b, name \\ nil) do
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{old_name, number} = b
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{
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if name == nil do
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old_name
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else
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name
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end,
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number + 1
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}
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end
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defp lexicographical_compare(a, b) do
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cond do
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a == b -> 0
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a > b -> 1
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true -> -1
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end
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end
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defp diff({name1, number1}, {name2, number2}) do
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diff = number1 - number2
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if diff == 0 do
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lexicographical_compare(name1, name2)
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else
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diff
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end
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end
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def compare(b1, operator, b2) do
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operator.(diff(b1, b2), 0)
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end
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end
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#
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#
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# Possible actions
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@ -42,7 +90,8 @@ defmodule Paxos do
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instmap =
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Map.put(state.instmap, inst, %{
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value: value,
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ballot: 0,
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ballot: Ballot.init(state.name, 0),
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aborted: false,
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ballot_value: nil,
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prepared_values: [],
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accepted: 0,
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@ -58,8 +107,13 @@ defmodule Paxos do
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end
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end
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def has_finished(state, inst) do
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Map.has_key?(state.decided, inst)
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def has_finished(state, inst, ignore_aborted \\ false) do
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cond do
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Map.has_key?(state.decided, inst) -> true
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ignore_aborted -> false
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Map.has_key?(state.instmap, inst) -> state.instmap[inst].aborted
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true -> false
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end
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end
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def run(state) do
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@ -77,7 +131,7 @@ defmodule Paxos do
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IO.puts("#{state.name} - Propose #{inspect(inst)} with action #{inspect(action)}")
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cond do
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has_finished(state, inst) ->
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has_finished(state, inst, true) ->
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IO.puts("#{state.name} - Has already decided for #{inspect(inst)} sending #{inspect(state.decided[inst])}")
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send(pid_to_inform, {:decision, inst, state.decided[inst]})
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state
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@ -90,7 +144,7 @@ defmodule Paxos do
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# Inform the pid with timeout right way
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send(pid_to_inform, {:timeout, inst});
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set_instmap(state, inst, fn map -> %{map| ballot: map.ballot + 1} end)
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set_instmap(state, inst, fn map -> %{map| ballot: Ballot.inc(map.ballot)} end)
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not Map.has_key?(state.instmap, inst) ->
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EagerReliableBroadcast.broadcast(state.name, {:other_propose, inst, value})
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@ -121,7 +175,7 @@ defmodule Paxos do
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state = %{state | other_values: Map.put(state.other_values, inst, value)}
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cond do
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has_finished(state, inst) ->
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has_finished(state, inst, true) ->
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EagerReliableBroadcast.broadcast(
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state.name,
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{:decide, inst, state.decided[inst]}
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@ -154,7 +208,7 @@ defmodule Paxos do
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| ballot: ballot
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} end)
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ballot > state.instmap[inst].ballot ->
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Ballot.compare(ballot, &>/2, state.instmap[inst].ballot) ->
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Utils.unicast(
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{:prepared, inst, ballot, state.instmap[inst].accepted_ballot,
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state.instmap[inst].accepted_value},
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@ -167,7 +221,7 @@ defmodule Paxos do
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} end)
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true ->
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Utils.unicast({:nack, inst, ballot, state.instmap[inst].ballot}, proc)
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Utils.unicast({:nack, inst, ballot}, proc)
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state
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end
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@ -178,14 +232,14 @@ defmodule Paxos do
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state
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{:nack, inst, ballot, new_ballot} ->
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IO.puts("#{state.name} - nack #{inspect(inst)} #{inspect(ballot)} #{inspect(new_ballot)}")
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{:nack, inst, ballot} ->
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IO.puts("#{state.name} - nack #{inspect(inst)} #{inspect(ballot)}")
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cond do
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has_finished(state, inst) ->
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state
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state.leader == state.name and state.instmap[inst].ballot == ballot ->
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state.leader == state.name and Ballot.compare(state.instmap[inst].ballot, &==/2, ballot) ->
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if Map.has_key?(state.instmap, inst) and state.instmap[inst].pid_to_inform != nil do
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send(state.instmap[inst].pid_to_inform, {:abort, inst})
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end
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@ -194,8 +248,9 @@ defmodule Paxos do
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set_instmap(state, inst, fn map -> %{
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map | has_sent_accept: false,
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ballot: new_ballot + 1,
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has_sent_prepare: false,
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ballot: Ballot.inc(map.ballot),
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aborted: true,
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} end)
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true ->
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@ -227,7 +282,7 @@ defmodule Paxos do
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has_finished(state, inst) ->
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state
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ballot == state.instmap[inst].ballot ->
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Ballot.compare(ballot, &==/2, state.instmap[inst].ballot) ->
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state =
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set_instmap(state, inst, fn map -> %{
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map
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@ -236,7 +291,7 @@ defmodule Paxos do
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prepared(state, inst)
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ballot > state.instmap[inst].ballot ->
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Ballot.compare(ballot, &>/2, state.instmap[inst].ballot) ->
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IO.puts("#{state.name} - Probably recieved this before preare came to self sending with delay")
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Process.send_after(self(), {:prepared, inst, ballot, accepted_ballot, accepted_value}, 100)
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state
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@ -253,7 +308,7 @@ defmodule Paxos do
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true ->
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state = has_or_create(state, inst)
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if ballot >= state.instmap[inst].ballot do
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if Ballot.compare(ballot, &>=/2, state.instmap[inst].ballot) do
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IO.puts("#{state.name} - accept #{inspect(inst)} #{inspect(ballot)} #{inspect(value)}")
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Utils.unicast({:accepted, inst, ballot}, proc)
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@ -266,7 +321,7 @@ defmodule Paxos do
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} end)
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else
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IO.puts("#{state.name} -> #{proc} nack")
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Utils.unicast({:nack, inst, ballot, state.instmap[inst].ballot}, proc)
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Utils.unicast({:nack, inst, ballot}, proc)
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state
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end
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end
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@ -278,7 +333,7 @@ defmodule Paxos do
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has_finished(state, inst) ->
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state
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state.leader == state.name and state.instmap[inst].ballot == ballot ->
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state.leader == state.name and Ballot.compare(state.instmap[inst].ballot, &==/2, ballot) ->
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accepted(
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set_instmap(state, inst, fn map -> %{
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map
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@ -298,7 +353,7 @@ defmodule Paxos do
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t < 0 ->
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send(pid_to_inform, {:get_value_res, inst})
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has_finished(state, inst) ->
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has_finished(state, inst, true) ->
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send(pid_to_inform, {:get_value_res_actual, inst, state.decided[inst]})
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true ->
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@ -341,24 +396,28 @@ defmodule Paxos do
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def prepare(state, inst) do
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cond do
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Map.get(state.instmap, inst) == nil and Map.get(state.other_values, inst) == nil ->
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state.instmap[inst] == nil ->
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state
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Map.get(state.instmap, inst) != nil and state.instmap[inst].has_sent_prepare ->
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state.instmap[inst].value == nil and state.other_values[inst] == nil ->
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state
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Map.get(state.instmap, inst) != nil and state.instmap[inst].has_sent_accept ->
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state.instmap[inst] != nil and state.instmap[inst].has_sent_prepare ->
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state
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state.instmap[inst] != nil and state.instmap[inst].has_sent_accept ->
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state
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true ->
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ballot = state.instmap[inst].ballot + 1
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IO.puts("#{state.name} - sending all prepare #{inst} #{ballot}")
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ballot = Ballot.inc(state.instmap[inst].ballot)
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IO.puts("#{state.name} - sending all prepare #{inst} #{inspect(ballot)}")
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EagerReliableBroadcast.broadcast(state.name, {:prepare, state.name, inst, ballot})
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set_instmap(state, inst, fn map -> %{
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map
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| prepared_values: [],
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accepted: 0,
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aborted: false,
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ballot_value: nil,
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has_sent_prepare: true,
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has_sent_accept: false
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@ -375,12 +434,12 @@ defmodule Paxos do
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if length(state.instmap[inst].prepared_values) >= floor(length(state.processes) / 2) + 1 and
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not state.instmap[inst].has_sent_accept do
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{_, a_val} =
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Enum.reduce(state.instmap[inst].prepared_values, {0, nil}, fn {bal, val},
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Enum.reduce(state.instmap[inst].prepared_values, {Ballot.init(state.name, 0), nil}, fn {bal, val},
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{acc_bal, acc_val} ->
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cond do
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val == nil ->
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{acc_bal, acc_val}
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acc_bal > bal ->
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Ballot.compare(acc_bal, &>/2, bal) ->
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{acc_bal, acc_val}
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true ->
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{bal, val}
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@ -496,3 +555,4 @@ defmodule Paxos do
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end
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end
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end
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@ -71,7 +71,7 @@ defmodule PaxosTestAditional do
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IO.puts("#{inspect(name)}: started")
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[leader | spare] = Enum.sort(participants)
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increase_ballot = Enum.take(spare, floor(length(participants) / 2))
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increase_ballot = Enum.take(spare, floor(length(participants) / 2) + 1)
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if name == leader do
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# Propose when passed with :kill_before_decision will die right before a decision is selected
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@ -145,7 +145,7 @@ defmodule PaxosTestAditional do
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participants = Enum.sort(participants)
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[leader | spare ] = participants
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increase_ballot = Enum.take(spare, floor(length(participants) / 2))
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increase_ballot = Enum.take(spare, floor(length(participants) / 2) + 1)
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[non_leader | _] = Enum.reverse(spare)
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if name == non_leader do
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@ -22,57 +22,57 @@ test_suite = [
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# Use TestUtil.get_local_config(n) to generate a single-node configuration
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# consisting of n processes, all running on the same node.
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{&PaxosTest.run_simple/3, TestUtil.get_local_config(3), 10,
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"No failures, no concurrent ballots, 3 local procs"},
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{&PaxosTest.run_simple/3, TestUtil.get_dist_config(host, 3), 10,
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"No failures, no concurrent ballots, 3 nodes"},
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{&PaxosTest.run_simple/3, TestUtil.get_local_config(5), 10,
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"No failures, no concurrent ballots, 5 local procs"},
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{&PaxosTest.run_simple_2/3, TestUtil.get_dist_config(host, 3), 10,
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"No failures, 2 concurrent ballots, 3 nodes"},
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{&PaxosTest.run_simple_2/3, TestUtil.get_local_config(3), 10,
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"No failures, 2 concurrent ballots, 3 local procs"},
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{&PaxosTest.run_simple_3/3, TestUtil.get_local_config(3), 10,
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"No failures, 2 concurrent instances, 3 local procs"},
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{&PaxosTest.run_simple_many_1/3, TestUtil.get_dist_config(host, 5), 10,
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"No failures, many concurrent ballots 1, 5 nodes"},
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{&PaxosTest.run_simple_many_1/3, TestUtil.get_local_config(5), 10,
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"No failures, many concurrent ballots 1, 5 local procs"},
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{&PaxosTest.run_simple_many_2/3, TestUtil.get_dist_config(host, 5), 10,
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"No failures, many concurrent ballots 2, 5 nodes"},
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{&PaxosTest.run_simple_many_2/3, TestUtil.get_local_config(5), 10,
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"No failures, many concurrent ballots 2, 5 local procs"},
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{&PaxosTest.run_non_leader_crash/3, TestUtil.get_dist_config(host, 3), 10,
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"One non-leader crashes, no concurrent ballots, 3 nodes"},
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{&PaxosTest.run_non_leader_crash/3, TestUtil.get_local_config(3), 10,
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"One non-leader crashes, no concurrent ballots, 3 local procs"},
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{&PaxosTest.run_minority_non_leader_crash/3, TestUtil.get_dist_config(host, 5), 10,
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"Minority non-leader crashes, no concurrent ballots"},
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{&PaxosTest.run_minority_non_leader_crash/3, TestUtil.get_local_config(5), 10,
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"Minority non-leader crashes, no concurrent ballots"},
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{&PaxosTest.run_leader_crash_simple/3, TestUtil.get_dist_config(host, 5), 10,
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"Leader crashes, no concurrent ballots, 5 nodes"},
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{&PaxosTest.run_leader_crash_simple/3, TestUtil.get_local_config(5), 10,
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"Leader crashes, no concurrent ballots, 5 local procs"},
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{&PaxosTest.run_leader_crash_simple_2/3, TestUtil.get_dist_config(host, 7), 10,
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"Leader and some non-leaders crash, no concurrent ballots, 7 nodes"},
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{&PaxosTest.run_leader_crash_simple_2/3, TestUtil.get_local_config(7), 10,
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"Leader and some non-leaders crash, no concurrent ballots, 7 local procs"},
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{&PaxosTest.run_leader_crash_complex/3, TestUtil.get_dist_config(host, 11), 10,
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"Cascading failures of leaders and non-leaders, 11 nodes"},
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{&PaxosTest.run_leader_crash_complex/3, TestUtil.get_local_config(11), 10,
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"Cascading failures of leaders and non-leaders, 11 local procs"},
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{&PaxosTest.run_leader_crash_complex_2/3, TestUtil.get_dist_config(host, 11), 10,
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"Cascading failures of leaders and non-leaders, random delays, 7 nodes"},
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{&PaxosTest.run_leader_crash_complex_2/3, TestUtil.get_local_config(11), 10,
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"Cascading failures of leaders and non-leaders, random delays, 7 local procs"},
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# {&PaxosTest.run_simple/3, TestUtil.get_local_config(3), 10,
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# "No failures, no concurrent ballots, 3 local procs"},
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# {&PaxosTest.run_simple/3, TestUtil.get_dist_config(host, 3), 10,
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# "No failures, no concurrent ballots, 3 nodes"},
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# {&PaxosTest.run_simple/3, TestUtil.get_local_config(5), 10,
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# "No failures, no concurrent ballots, 5 local procs"},
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# {&PaxosTest.run_simple_2/3, TestUtil.get_dist_config(host, 3), 10,
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# "No failures, 2 concurrent ballots, 3 nodes"},
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# {&PaxosTest.run_simple_2/3, TestUtil.get_local_config(3), 10,
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# "No failures, 2 concurrent ballots, 3 local procs"},
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# {&PaxosTest.run_simple_3/3, TestUtil.get_local_config(3), 10,
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# "No failures, 2 concurrent instances, 3 local procs"},
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# {&PaxosTest.run_simple_many_1/3, TestUtil.get_dist_config(host, 5), 10,
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# "No failures, many concurrent ballots 1, 5 nodes"},
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# {&PaxosTest.run_simple_many_1/3, TestUtil.get_local_config(5), 10,
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# "No failures, many concurrent ballots 1, 5 local procs"},
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# {&PaxosTest.run_simple_many_2/3, TestUtil.get_dist_config(host, 5), 10,
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# "No failures, many concurrent ballots 2, 5 nodes"},
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# {&PaxosTest.run_simple_many_2/3, TestUtil.get_local_config(5), 10,
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# "No failures, many concurrent ballots 2, 5 local procs"},
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# {&PaxosTest.run_non_leader_crash/3, TestUtil.get_dist_config(host, 3), 10,
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# "One non-leader crashes, no concurrent ballots, 3 nodes"},
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# {&PaxosTest.run_non_leader_crash/3, TestUtil.get_local_config(3), 10,
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# "One non-leader crashes, no concurrent ballots, 3 local procs"},
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# {&PaxosTest.run_minority_non_leader_crash/3, TestUtil.get_dist_config(host, 5), 10,
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# "Minority non-leader crashes, no concurrent ballots"},
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# {&PaxosTest.run_minority_non_leader_crash/3, TestUtil.get_local_config(5), 10,
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# "Minority non-leader crashes, no concurrent ballots"},
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# {&PaxosTest.run_leader_crash_simple/3, TestUtil.get_dist_config(host, 5), 10,
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# "Leader crashes, no concurrent ballots, 5 nodes"},
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# {&PaxosTest.run_leader_crash_simple/3, TestUtil.get_local_config(5), 10,
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# "Leader crashes, no concurrent ballots, 5 local procs"},
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# {&PaxosTest.run_leader_crash_simple_2/3, TestUtil.get_dist_config(host, 7), 10,
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# "Leader and some non-leaders crash, no concurrent ballots, 7 nodes"},
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# {&PaxosTest.run_leader_crash_simple_2/3, TestUtil.get_local_config(7), 10,
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# "Leader and some non-leaders crash, no concurrent ballots, 7 local procs"},
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# {&PaxosTest.run_leader_crash_complex/3, TestUtil.get_dist_config(host, 11), 10,
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# "Cascading failures of leaders and non-leaders, 11 nodes"},
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# {&PaxosTest.run_leader_crash_complex/3, TestUtil.get_local_config(11), 10,
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# "Cascading failures of leaders and non-leaders, 11 local procs"},
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# {&PaxosTest.run_leader_crash_complex_2/3, TestUtil.get_dist_config(host, 11), 10,
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# "Cascading failures of leaders and non-leaders, random delays, 7 nodes"},
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# {&PaxosTest.run_leader_crash_complex_2/3, TestUtil.get_local_config(11), 10,
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# "Cascading failures of leaders and non-leaders, random delays, 7 local procs"},
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# Aditional Test functions
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# # Aditional Test functions
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{&PaxosTestAditional.run_leader_crash_simple_before_decision/3, TestUtil.get_dist_config(host, 5), 10,
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"Leader crashes right before decision, no concurrent ballots, 5 nodes"},
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{&PaxosTestAditional.run_leader_crash_simple_before_decision/3, TestUtil.get_local_config(5), 10,
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"Leader crashes right before decision, no concurrent ballots, 5 local procs"},
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# {&PaxosTestAditional.run_leader_crash_simple_before_decision/3, TestUtil.get_dist_config(host, 5), 10,
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# "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_should_nack_simple/3, TestUtil.get_dist_config(host, 5), 10,
|
||||
"Leader should nack before decision and then come to decision, no concurrent ballots, 5 nodes"},
|
||||
|
Reference in New Issue
Block a user