void
client_view::advance_leader (
std::vector <boost::asio::ip::tcp::endpoint> const & live_servers)
{
if (live_servers.empty () == true)
{
next_leader_ = boost::none;
return;
}
for (auto const & i : live_servers)
{
PAXOS_DEBUG (i);
}
/*!
If the server was is found, this returns an iterator to the server, otherwise
it returns the iterator *before* the last server.
*/
std::vector <boost::asio::ip::tcp::endpoint>::const_iterator pos;
if (next_leader_.is_initialized () == false)
{
pos = live_servers.begin ();
}
else
{
pos = std::find (live_servers.begin (),
live_servers.end (),
*next_leader_);
if (pos == live_servers.end ())
{
/*!
Server we determined to be the next leader was not in live_servers array anymore,
the best thing to do is to just return to the beginning of the array.
*/
pos = live_servers.begin ();
}
}
PAXOS_ASSERT (pos != live_servers.end ());
++pos;
if (pos == live_servers.end ())
{
/*!
Uh-oh, we're at the end of the vector. Let's start at the beginning again.
*/
pos = live_servers.begin ();
}
PAXOS_ASSERT (pos != live_servers.end ());
/*!
The next time we call this function, we want to immediately select the server
we return here.
*/
next_leader_ = *pos;
}
void
heap::remove (
int64_t proposal_id)
{
PAXOS_ASSERT (proposal_id >= 0);
if (data_.find (proposal_id) == data_.end ())
{
/*!
This is weird, likely caused by some manual copying / fiddling with the data
backend. Only sensible thing to do is to ignore this remove command.
*/
PAXOS_WARN ("proposal_id " << proposal_id << " not found in history, ignoring remove!");
return;
}
PAXOS_DEBUG (this << " deleting all data since " << proposal_id);
data_.erase (data_.begin (),
data_.find (proposal_id));
data_.erase (proposal_id);
PAXOS_ASSERT_EQ (lowest_proposal_id (), proposal_id + 1);
}
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");
}
