int main ()
{
std::atomic <uint16_t> response_count (0);
paxos::server::callback_type callback =
[& response_count](int64_t, std::string const & workload) -> std::string
{
++response_count;
return "bar";
};
paxos::configuration configuration;
configuration.set_strategy_factory (new test_strategy_factory (configuration.durable_storage ()));
paxos::server server1 ("127.0.0.1", 1337, callback);
paxos::server server2 ("127.0.0.1", 1338, callback);
paxos::server server3 ("127.0.0.1", 1339, callback, configuration);
paxos::client client;
server1.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
server2.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
server3.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
client.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
/*!
This would be retried and shouldn't cause any troubles.
*/
PAXOS_ASSERT_EQ (client.send ("foo").get (), "bar");
PAXOS_ASSERT_EQ (response_count, 2);
PAXOS_INFO ("test succeeded");
}
int main ()
{
paxos::configuration configuration1;
paxos::configuration configuration2;
paxos::configuration configuration3;
configuration1.durable_storage ().set_history_size (5);
configuration2.durable_storage ().set_history_size (5);
configuration3.durable_storage ().set_history_size (5);
paxos::server::callback_type callback =
[](
int64_t promise_id,
std::string const & workload) -> std::string
{
return "bar";
};
paxos::client client;
client.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
paxos::server server1 ("127.0.0.1", 1337, callback, configuration1);
paxos::server server2 ("127.0.0.1", 1338, callback, configuration2);
server1.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
server2.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
{
paxos::server server3 ("127.0.0.1", 1339, callback, configuration3);
server3.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
/*!
Issue 10 calls, so we can verify that the lowest proposal id is in fact 10.
*/
for (size_t i = 0; i < 15; ++i)
{
PAXOS_ASSERT_EQ (client.send ("foo").get (), "bar");
}
PAXOS_ASSERT_EQ (configuration1.durable_storage ().lowest_proposal_id (), 11);
PAXOS_ASSERT_EQ (configuration2.durable_storage ().lowest_proposal_id (), 11);
PAXOS_ASSERT_EQ (configuration3.durable_storage ().lowest_proposal_id (), 11);
}
/*!
Now, since one host in our quorum is currently down, logs should *not* be cleaned
up further than the proposal that has been previously accepted by that host.
*/
for (size_t i = 0; i < 30; ++i)
{
PAXOS_ASSERT_EQ (client.send ("foo").get (), "bar");
}
PAXOS_ASSERT_GE (configuration1.durable_storage ().lowest_proposal_id (), 15);
PAXOS_ASSERT_GE (configuration2.durable_storage ().lowest_proposal_id (), 15);
PAXOS_ASSERT_EQ (configuration3.durable_storage ().lowest_proposal_id (), 11);
boost::this_thread::sleep (
boost::posix_time::milliseconds (
paxos::configuration ().timeout ()));
{
/*!
And after our server is back online, the history can be cleared again.
*/
paxos::server server3 ("127.0.0.1", 1339, callback, configuration3);
server3.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
for (size_t i = 0; i < 15; ++i)
{
PAXOS_ASSERT_EQ (client.send ("foo").get (), "bar");
}
PAXOS_ASSERT_EQ (configuration1.durable_storage ().lowest_proposal_id (), 56);
PAXOS_ASSERT_EQ (configuration2.durable_storage ().lowest_proposal_id (), 56);
PAXOS_ASSERT_EQ (configuration3.durable_storage ().lowest_proposal_id (), 56);
}
PAXOS_INFO ("test succeeded");
}
/*! static */ void
initiate_request::step1 (
std::string const & byte_array,
detail::quorum::client_view & quorum,
callback_type callback,
queue_guard_type guard)
{
boost::optional <boost::asio::ip::tcp::endpoint> leader = quorum.select_leader ();
if (leader.is_initialized () == false)
{
PAXOS_DEBUG ("leader.is_initialized () == false");
callback (detail::error_no_leader, "");
quorum.advance_leader ();
return;
}
PAXOS_DEBUG ("leader.is_initialized () == true");
quorum::server & server = quorum.lookup_server (*leader);
if (server.has_connection () == false)
{
PAXOS_DEBUG ("server.has_connection () == false");
callback (detail::error_no_leader, "");
quorum.advance_leader ();
return;
}
PAXOS_DEBUG ("server.has_connection () == true");
PAXOS_DEBUG ("sending request to host " << server.endpoint () << " with id = " << server.id ());
detail::tcp_connection_ptr connection = server.connection ();
/*!
Now that we have our leader's connection, let's send it our command to initiate
the request.
*/
command command;
command.set_type (command::type_request_initiate);
command.set_workload (byte_array);
connection->write_command (command);
PAXOS_INFO ("client initiating request!");
connection->read_command (
[connection,
& quorum,
& server,
callback,
guard] (
boost::optional <enum detail::error_code> error,
detail::command const & c)
{
if (error)
{
PAXOS_WARN ("client had problems communicating with leader: " << detail::to_string (*error));
quorum.connection_died (server.endpoint ());
quorum.advance_leader ();
callback (*error, "");
}
else
{
quorum.lookup_server (c.host_endpoint ()).set_id (c.host_id ());
quorum.lookup_server (c.host_endpoint ()).set_highest_proposal_id (c.highest_proposal_id ());
switch (c.type ())
{
case command::type_request_accepted:
PAXOS_DEBUG ("received command with workload = " << c.workload () << ", "
"now calling callback!");
callback (boost::none, c.workload ());
break;
case command::type_request_error:
if (c.error_code () == detail::error_no_leader)
{
quorum.advance_leader ();
}
PAXOS_WARN ("request error occured");
callback (c.error_code (), c.workload ());
break;
default:
PAXOS_UNREACHABLE ();
};
}
});
}
int main ()
{
std::map <int64_t, uint16_t> responses;
/*!
Synchronizes access to responses
*/
boost::mutex mutex;
paxos::configuration configuration1;
paxos::configuration configuration2;
paxos::configuration configuration3;
/*!
Note that the configuration objects below outlive the server objects declared later in
the test, thus providing semi-durable storage.
*/
configuration1.set_durable_storage (
new paxos::durable::heap ());
configuration2.set_durable_storage (
new paxos::durable::heap ());
configuration3.set_durable_storage (
new paxos::durable::heap ());
paxos::server::callback_type callback =
[& responses,
& mutex](
int64_t promise_id,
std::string const & workload) -> std::string
{
boost::mutex::scoped_lock lock (mutex);
if (responses.find (promise_id) == responses.end ())
{
responses[promise_id] = 1;
}
else
{
responses[promise_id]++;
}
PAXOS_ASSERT (responses[promise_id] <= 3);
return "bar";
};
paxos::client client;
client.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
{
paxos::server server1 ("127.0.0.1", 1337, callback, configuration1);
server1.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
{
paxos::server server2 ("127.0.0.1", 1338, callback, configuration2);
server2.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
{
paxos::server server3 ("127.0.0.1", 1339, callback, configuration3);
server3.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
PAXOS_ASSERT_EQ (client.send ("foo").get (), "bar");
PAXOS_ASSERT_EQ (client.send ("foo").get (), "bar");
PAXOS_ASSERT_EQ (all_responses_equal (responses, 3), true);
}
PAXOS_ASSERT_EQ (client.send ("foo").get (), "bar");
PAXOS_ASSERT_EQ (client.send ("foo").get (), "bar");
PAXOS_ASSERT_EQ (all_responses_equal (responses, 3), false);
}
PAXOS_ASSERT_THROW (client.send ("foo").get (), paxos::exception::no_majority);
}
/*!
Note that we're re-adding servers in reverse order here; this is to ensure that
server3 doesn't become our leader while it's lagging behind.
*/
paxos::server server3 ("127.0.0.1", 1339, callback, configuration3);
server3.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
PAXOS_ASSERT_THROW (client.send ("foo").get (), paxos::exception::no_majority);
paxos::server server2 ("127.0.0.1", 1338, callback, configuration2);
server2.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
boost::this_thread::sleep (
boost::posix_time::milliseconds (
paxos::configuration ().timeout ()));
PAXOS_ASSERT_EQ (client.send ("foo").get (), "bar");
PAXOS_ASSERT_EQ (client.send ("foo").get (), "bar");
paxos::server server1 ("127.0.0.1", 1337, callback, configuration1);
server1.add ({{"127.0.0.1", 1337}, {"127.0.0.1", 1338}, {"127.0.0.1", 1339}});
boost::this_thread::sleep (
boost::posix_time::milliseconds (
paxos::configuration ().timeout ()));
do
{
PAXOS_ASSERT_EQ (client.send ("foo").get (), "bar");
} while (all_responses_equal (responses, 3) == false);
PAXOS_INFO ("test succeeded");
}
