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Diffstat (limited to 'src/mon/Paxos.cc')
| -rw-r--r-- | src/mon/Paxos.cc | 1584 |
1 files changed, 1584 insertions, 0 deletions
diff --git a/src/mon/Paxos.cc b/src/mon/Paxos.cc new file mode 100644 index 00000000..a62b028b --- /dev/null +++ b/src/mon/Paxos.cc @@ -0,0 +1,1584 @@ +// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- +// vim: ts=8 sw=2 smarttab +/* + * Ceph - scalable distributed file system + * + * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net> + * + * This is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License version 2.1, as published by the Free Software + * Foundation. See file COPYING. + * + */ + +#include <sstream> +#include "Paxos.h" +#include "Monitor.h" +#include "messages/MMonPaxos.h" + +#include "mon/mon_types.h" +#include "common/config.h" +#include "include/ceph_assert.h" +#include "include/stringify.h" +#include "common/Timer.h" +#include "messages/PaxosServiceMessage.h" + +#define dout_subsys ceph_subsys_paxos +#undef dout_prefix +#define dout_prefix _prefix(_dout, mon, mon->name, mon->rank, paxos_name, state, first_committed, last_committed) +static ostream& _prefix(std::ostream *_dout, Monitor *mon, const string& name, + int rank, const string& paxos_name, int state, + version_t first_committed, version_t last_committed) +{ + return *_dout << "mon." << name << "@" << rank + << "(" << mon->get_state_name() << ")" + << ".paxos(" << paxos_name << " " << Paxos::get_statename(state) + << " c " << first_committed << ".." << last_committed + << ") "; +} + +class Paxos::C_Trimmed : public Context { + Paxos *paxos; +public: + explicit C_Trimmed(Paxos *p) : paxos(p) { } + void finish(int r) override { + paxos->trimming = false; + } +}; + +MonitorDBStore *Paxos::get_store() +{ + return mon->store; +} + +void Paxos::read_and_prepare_transactions(MonitorDBStore::TransactionRef tx, + version_t first, version_t last) +{ + dout(10) << __func__ << " first " << first << " last " << last << dendl; + for (version_t v = first; v <= last; ++v) { + dout(30) << __func__ << " apply version " << v << dendl; + bufferlist bl; + int err = get_store()->get(get_name(), v, bl); + ceph_assert(err == 0); + ceph_assert(bl.length()); + decode_append_transaction(tx, bl); + } + dout(15) << __func__ << " total versions " << (last-first) << dendl; +} + +void Paxos::init() +{ + // load paxos variables from stable storage + last_pn = get_store()->get(get_name(), "last_pn"); + accepted_pn = get_store()->get(get_name(), "accepted_pn"); + last_committed = get_store()->get(get_name(), "last_committed"); + first_committed = get_store()->get(get_name(), "first_committed"); + + dout(10) << __func__ << " last_pn: " << last_pn << " accepted_pn: " + << accepted_pn << " last_committed: " << last_committed + << " first_committed: " << first_committed << dendl; + + dout(10) << "init" << dendl; + ceph_assert(is_consistent()); +} + +void Paxos::init_logger() +{ + PerfCountersBuilder pcb(g_ceph_context, "paxos", l_paxos_first, l_paxos_last); + + // Because monitors are so few in number, the resource cost of capturing + // almost all their perf counters at USEFUL is trivial. + pcb.set_prio_default(PerfCountersBuilder::PRIO_USEFUL); + + pcb.add_u64_counter(l_paxos_start_leader, "start_leader", "Starts in leader role"); + pcb.add_u64_counter(l_paxos_start_peon, "start_peon", "Starts in peon role"); + pcb.add_u64_counter(l_paxos_restart, "restart", "Restarts"); + pcb.add_u64_counter(l_paxos_refresh, "refresh", "Refreshes"); + pcb.add_time_avg(l_paxos_refresh_latency, "refresh_latency", "Refresh latency"); + pcb.add_u64_counter(l_paxos_begin, "begin", "Started and handled begins"); + pcb.add_u64_avg(l_paxos_begin_keys, "begin_keys", "Keys in transaction on begin"); + pcb.add_u64_avg(l_paxos_begin_bytes, "begin_bytes", "Data in transaction on begin", NULL, 0, unit_t(UNIT_BYTES)); + pcb.add_time_avg(l_paxos_begin_latency, "begin_latency", "Latency of begin operation"); + pcb.add_u64_counter(l_paxos_commit, "commit", + "Commits", "cmt"); + pcb.add_u64_avg(l_paxos_commit_keys, "commit_keys", "Keys in transaction on commit"); + pcb.add_u64_avg(l_paxos_commit_bytes, "commit_bytes", "Data in transaction on commit", NULL, 0, unit_t(UNIT_BYTES)); + pcb.add_time_avg(l_paxos_commit_latency, "commit_latency", + "Commit latency", "clat"); + pcb.add_u64_counter(l_paxos_collect, "collect", "Peon collects"); + pcb.add_u64_avg(l_paxos_collect_keys, "collect_keys", "Keys in transaction on peon collect"); + pcb.add_u64_avg(l_paxos_collect_bytes, "collect_bytes", "Data in transaction on peon collect", NULL, 0, unit_t(UNIT_BYTES)); + pcb.add_time_avg(l_paxos_collect_latency, "collect_latency", "Peon collect latency"); + pcb.add_u64_counter(l_paxos_collect_uncommitted, "collect_uncommitted", "Uncommitted values in started and handled collects"); + pcb.add_u64_counter(l_paxos_collect_timeout, "collect_timeout", "Collect timeouts"); + pcb.add_u64_counter(l_paxos_accept_timeout, "accept_timeout", "Accept timeouts"); + pcb.add_u64_counter(l_paxos_lease_ack_timeout, "lease_ack_timeout", "Lease acknowledgement timeouts"); + pcb.add_u64_counter(l_paxos_lease_timeout, "lease_timeout", "Lease timeouts"); + pcb.add_u64_counter(l_paxos_store_state, "store_state", "Store a shared state on disk"); + pcb.add_u64_avg(l_paxos_store_state_keys, "store_state_keys", "Keys in transaction in stored state"); + pcb.add_u64_avg(l_paxos_store_state_bytes, "store_state_bytes", "Data in transaction in stored state", NULL, 0, unit_t(UNIT_BYTES)); + pcb.add_time_avg(l_paxos_store_state_latency, "store_state_latency", "Storing state latency"); + pcb.add_u64_counter(l_paxos_share_state, "share_state", "Sharings of state"); + pcb.add_u64_avg(l_paxos_share_state_keys, "share_state_keys", "Keys in shared state"); + pcb.add_u64_avg(l_paxos_share_state_bytes, "share_state_bytes", "Data in shared state", NULL, 0, unit_t(UNIT_BYTES)); + pcb.add_u64_counter(l_paxos_new_pn, "new_pn", "New proposal number queries"); + pcb.add_time_avg(l_paxos_new_pn_latency, "new_pn_latency", "New proposal number getting latency"); + logger = pcb.create_perf_counters(); + g_ceph_context->get_perfcounters_collection()->add(logger); +} + +void Paxos::dump_info(Formatter *f) +{ + f->open_object_section("paxos"); + f->dump_unsigned("first_committed", first_committed); + f->dump_unsigned("last_committed", last_committed); + f->dump_unsigned("last_pn", last_pn); + f->dump_unsigned("accepted_pn", accepted_pn); + f->close_section(); +} + +// --------------------------------- + +// PHASE 1 + +// leader +void Paxos::collect(version_t oldpn) +{ + // we're recoverying, it seems! + state = STATE_RECOVERING; + ceph_assert(mon->is_leader()); + + // reset the number of lasts received + uncommitted_v = 0; + uncommitted_pn = 0; + uncommitted_value.clear(); + peer_first_committed.clear(); + peer_last_committed.clear(); + + // look for uncommitted value + if (get_store()->exists(get_name(), last_committed+1)) { + version_t v = get_store()->get(get_name(), "pending_v"); + version_t pn = get_store()->get(get_name(), "pending_pn"); + if (v && pn && v == last_committed + 1) { + uncommitted_pn = pn; + } else { + dout(10) << "WARNING: no pending_pn on disk, using previous accepted_pn " << accepted_pn + << " and crossing our fingers" << dendl; + uncommitted_pn = accepted_pn; + } + uncommitted_v = last_committed+1; + + get_store()->get(get_name(), last_committed+1, uncommitted_value); + ceph_assert(uncommitted_value.length()); + dout(10) << "learned uncommitted " << (last_committed+1) + << " pn " << uncommitted_pn + << " (" << uncommitted_value.length() << " bytes) from myself" + << dendl; + + logger->inc(l_paxos_collect_uncommitted); + } + + // pick new pn + accepted_pn = get_new_proposal_number(std::max(accepted_pn, oldpn)); + accepted_pn_from = last_committed; + num_last = 1; + dout(10) << "collect with pn " << accepted_pn << dendl; + + // send collect + for (set<int>::const_iterator p = mon->get_quorum().begin(); + p != mon->get_quorum().end(); + ++p) { + if (*p == mon->rank) continue; + + MMonPaxos *collect = new MMonPaxos(mon->get_epoch(), MMonPaxos::OP_COLLECT, + ceph_clock_now()); + collect->last_committed = last_committed; + collect->first_committed = first_committed; + collect->pn = accepted_pn; + mon->send_mon_message(collect, *p); + } + + // set timeout event + collect_timeout_event = mon->timer.add_event_after( + g_conf()->mon_accept_timeout_factor * + g_conf()->mon_lease, + new C_MonContext(mon, [this](int r) { + if (r == -ECANCELED) + return; + collect_timeout(); + })); +} + + +// peon +void Paxos::handle_collect(MonOpRequestRef op) +{ + + op->mark_paxos_event("handle_collect"); + + MMonPaxos *collect = static_cast<MMonPaxos*>(op->get_req()); + dout(10) << "handle_collect " << *collect << dendl; + + ceph_assert(mon->is_peon()); // mon epoch filter should catch strays + + // we're recoverying, it seems! + state = STATE_RECOVERING; + + //update the peon recovery timeout + reset_lease_timeout(); + + if (collect->first_committed > last_committed+1) { + dout(2) << __func__ + << " leader's lowest version is too high for our last committed" + << " (theirs: " << collect->first_committed + << "; ours: " << last_committed << ") -- bootstrap!" << dendl; + op->mark_paxos_event("need to bootstrap"); + mon->bootstrap(); + return; + } + + // reply + MMonPaxos *last = new MMonPaxos(mon->get_epoch(), MMonPaxos::OP_LAST, + ceph_clock_now()); + last->last_committed = last_committed; + last->first_committed = first_committed; + + version_t previous_pn = accepted_pn; + + // can we accept this pn? + if (collect->pn > accepted_pn) { + // ok, accept it + accepted_pn = collect->pn; + accepted_pn_from = collect->pn_from; + dout(10) << "accepting pn " << accepted_pn << " from " + << accepted_pn_from << dendl; + + auto t(std::make_shared<MonitorDBStore::Transaction>()); + t->put(get_name(), "accepted_pn", accepted_pn); + + dout(30) << __func__ << " transaction dump:\n"; + JSONFormatter f(true); + t->dump(&f); + f.flush(*_dout); + *_dout << dendl; + + logger->inc(l_paxos_collect); + logger->inc(l_paxos_collect_keys, t->get_keys()); + logger->inc(l_paxos_collect_bytes, t->get_bytes()); + + auto start = ceph::coarse_mono_clock::now(); + get_store()->apply_transaction(t); + auto end = ceph::coarse_mono_clock::now(); + + logger->tinc(l_paxos_collect_latency, to_timespan(end - start)); + } else { + // don't accept! + dout(10) << "NOT accepting pn " << collect->pn << " from " << collect->pn_from + << ", we already accepted " << accepted_pn + << " from " << accepted_pn_from << dendl; + } + last->pn = accepted_pn; + last->pn_from = accepted_pn_from; + + // share whatever committed values we have + if (collect->last_committed < last_committed) + share_state(last, collect->first_committed, collect->last_committed); + + // do we have an accepted but uncommitted value? + // (it'll be at last_committed+1) + bufferlist bl; + if (collect->last_committed <= last_committed && + get_store()->exists(get_name(), last_committed+1)) { + get_store()->get(get_name(), last_committed+1, bl); + ceph_assert(bl.length() > 0); + dout(10) << " sharing our accepted but uncommitted value for " + << last_committed+1 << " (" << bl.length() << " bytes)" << dendl; + last->values[last_committed+1] = bl; + + version_t v = get_store()->get(get_name(), "pending_v"); + version_t pn = get_store()->get(get_name(), "pending_pn"); + if (v && pn && v == last_committed + 1) { + last->uncommitted_pn = pn; + } else { + // previously we didn't record which pn a value was accepted + // under! use the pn value we just had... :( + dout(10) << "WARNING: no pending_pn on disk, using previous accepted_pn " << previous_pn + << " and crossing our fingers" << dendl; + last->uncommitted_pn = previous_pn; + } + + logger->inc(l_paxos_collect_uncommitted); + } + + // send reply + collect->get_connection()->send_message(last); +} + +/** + * @note This is Okay. We share our versions between peer_last_committed and + * our last_committed (inclusive), and add their bufferlists to the + * message. It will be the peer's job to apply them to its store, as + * these bufferlists will contain raw transactions. + * This function is called by both the Peon and the Leader. The Peon will + * share the state with the Leader during handle_collect(), sharing any + * values the leader may be missing (i.e., the leader's last_committed is + * lower than the peon's last_committed). The Leader will share the state + * with the Peon during handle_last(), if the peon's last_committed is + * lower than the leader's last_committed. + */ +void Paxos::share_state(MMonPaxos *m, version_t peer_first_committed, + version_t peer_last_committed) +{ + ceph_assert(peer_last_committed < last_committed); + + dout(10) << "share_state peer has fc " << peer_first_committed + << " lc " << peer_last_committed << dendl; + version_t v = peer_last_committed + 1; + + // include incrementals + uint64_t bytes = 0; + for ( ; v <= last_committed; v++) { + if (get_store()->exists(get_name(), v)) { + get_store()->get(get_name(), v, m->values[v]); + ceph_assert(m->values[v].length()); + dout(10) << " sharing " << v << " (" + << m->values[v].length() << " bytes)" << dendl; + bytes += m->values[v].length() + 16; // paxos_ + 10 digits = 16 + } + } + logger->inc(l_paxos_share_state); + logger->inc(l_paxos_share_state_keys, m->values.size()); + logger->inc(l_paxos_share_state_bytes, bytes); + + m->last_committed = last_committed; +} + +/** + * Store on disk a state that was shared with us + * + * Basically, we received a set of version. Or just one. It doesn't matter. + * What matters is that we have to stash it in the store. So, we will simply + * write every single bufferlist into their own versions on our side (i.e., + * onto paxos-related keys), and then we will decode those same bufferlists + * we just wrote and apply the transactions they hold. We will also update + * our first and last committed values to point to the new values, if need + * be. All all this is done tightly wrapped in a transaction to ensure we + * enjoy the atomicity guarantees given by our awesome k/v store. + */ +bool Paxos::store_state(MMonPaxos *m) +{ + auto t(std::make_shared<MonitorDBStore::Transaction>()); + map<version_t,bufferlist>::iterator start = m->values.begin(); + bool changed = false; + + // build map of values to store + // we want to write the range [last_committed, m->last_committed] only. + if (start != m->values.end() && + start->first > last_committed + 1) { + // ignore everything if values start in the future. + dout(10) << "store_state ignoring all values, they start at " << start->first + << " > last_committed+1" << dendl; + return false; + } + + // push forward the start position on the message's values iterator, up until + // we run out of positions or we find a position matching 'last_committed'. + while (start != m->values.end() && start->first <= last_committed) { + ++start; + } + + // make sure we get the right interval of values to apply by pushing forward + // the 'end' iterator until it matches the message's 'last_committed'. + map<version_t,bufferlist>::iterator end = start; + while (end != m->values.end() && end->first <= m->last_committed) { + last_committed = end->first; + ++end; + } + + if (start == end) { + dout(10) << "store_state nothing to commit" << dendl; + } else { + dout(10) << "store_state [" << start->first << ".." + << last_committed << "]" << dendl; + t->put(get_name(), "last_committed", last_committed); + + // we should apply the state here -- decode every single bufferlist in the + // map and append the transactions to 't'. + map<version_t,bufferlist>::iterator it; + for (it = start; it != end; ++it) { + // write the bufferlist as the version's value + t->put(get_name(), it->first, it->second); + // decode the bufferlist and append it to the transaction we will shortly + // apply. + decode_append_transaction(t, it->second); + } + + // discard obsolete uncommitted value? + if (uncommitted_v && uncommitted_v <= last_committed) { + dout(10) << " forgetting obsolete uncommitted value " << uncommitted_v + << " pn " << uncommitted_pn << dendl; + uncommitted_v = 0; + uncommitted_pn = 0; + uncommitted_value.clear(); + } + } + if (!t->empty()) { + dout(30) << __func__ << " transaction dump:\n"; + JSONFormatter f(true); + t->dump(&f); + f.flush(*_dout); + *_dout << dendl; + + logger->inc(l_paxos_store_state); + logger->inc(l_paxos_store_state_bytes, t->get_bytes()); + logger->inc(l_paxos_store_state_keys, t->get_keys()); + + auto start = ceph::coarse_mono_clock::now(); + get_store()->apply_transaction(t); + auto end = ceph::coarse_mono_clock::now(); + + logger->tinc(l_paxos_store_state_latency, to_timespan(end-start)); + + // refresh first_committed; this txn may have trimmed. + first_committed = get_store()->get(get_name(), "first_committed"); + + _sanity_check_store(); + changed = true; + } + + return changed; +} + +void Paxos::_sanity_check_store() +{ + version_t lc = get_store()->get(get_name(), "last_committed"); + ceph_assert(lc == last_committed); +} + + +// leader +void Paxos::handle_last(MonOpRequestRef op) +{ + op->mark_paxos_event("handle_last"); + MMonPaxos *last = static_cast<MMonPaxos*>(op->get_req()); + bool need_refresh = false; + int from = last->get_source().num(); + + dout(10) << "handle_last " << *last << dendl; + + if (!mon->is_leader()) { + dout(10) << "not leader, dropping" << dendl; + return; + } + + // note peer's first_ and last_committed, in case we learn a new + // commit and need to push it to them. + peer_first_committed[from] = last->first_committed; + peer_last_committed[from] = last->last_committed; + + if (last->first_committed > last_committed + 1) { + dout(5) << __func__ + << " mon." << from + << " lowest version is too high for our last committed" + << " (theirs: " << last->first_committed + << "; ours: " << last_committed << ") -- bootstrap!" << dendl; + op->mark_paxos_event("need to bootstrap"); + mon->bootstrap(); + return; + } + + ceph_assert(g_conf()->paxos_kill_at != 1); + + // store any committed values if any are specified in the message + need_refresh = store_state(last); + + ceph_assert(g_conf()->paxos_kill_at != 2); + + // is everyone contiguous and up to date? + for (map<int,version_t>::iterator p = peer_last_committed.begin(); + p != peer_last_committed.end(); + ++p) { + if (p->second + 1 < first_committed && first_committed > 1) { + dout(5) << __func__ + << " peon " << p->first + << " last_committed (" << p->second + << ") is too low for our first_committed (" << first_committed + << ") -- bootstrap!" << dendl; + op->mark_paxos_event("need to bootstrap"); + mon->bootstrap(); + return; + } + if (p->second < last_committed) { + // share committed values + dout(10) << " sending commit to mon." << p->first << dendl; + MMonPaxos *commit = new MMonPaxos(mon->get_epoch(), + MMonPaxos::OP_COMMIT, + ceph_clock_now()); + share_state(commit, peer_first_committed[p->first], p->second); + mon->send_mon_message(commit, p->first); + } + } + + // do they accept your pn? + if (last->pn > accepted_pn) { + // no, try again. + dout(10) << " they had a higher pn than us, picking a new one." << dendl; + + // cancel timeout event + mon->timer.cancel_event(collect_timeout_event); + collect_timeout_event = 0; + + collect(last->pn); + } else if (last->pn == accepted_pn) { + // yes, they accepted our pn. great. + num_last++; + dout(10) << " they accepted our pn, we now have " + << num_last << " peons" << dendl; + + // did this person send back an accepted but uncommitted value? + if (last->uncommitted_pn) { + if (last->uncommitted_pn >= uncommitted_pn && + last->last_committed >= last_committed && + last->last_committed + 1 >= uncommitted_v) { + uncommitted_v = last->last_committed+1; + uncommitted_pn = last->uncommitted_pn; + uncommitted_value = last->values[uncommitted_v]; + dout(10) << "we learned an uncommitted value for " << uncommitted_v + << " pn " << uncommitted_pn + << " " << uncommitted_value.length() << " bytes" + << dendl; + } else { + dout(10) << "ignoring uncommitted value for " << (last->last_committed+1) + << " pn " << last->uncommitted_pn + << " " << last->values[last->last_committed+1].length() << " bytes" + << dendl; + } + } + + // is that everyone? + if (num_last == mon->get_quorum().size()) { + // cancel timeout event + mon->timer.cancel_event(collect_timeout_event); + collect_timeout_event = 0; + peer_first_committed.clear(); + peer_last_committed.clear(); + + // almost... + + // did we learn an old value? + if (uncommitted_v == last_committed+1 && + uncommitted_value.length()) { + dout(10) << "that's everyone. begin on old learned value" << dendl; + state = STATE_UPDATING_PREVIOUS; + begin(uncommitted_value); + } else { + // active! + dout(10) << "that's everyone. active!" << dendl; + extend_lease(); + + need_refresh = false; + if (do_refresh()) { + finish_round(); + } + } + } + } else { + // no, this is an old message, discard + dout(10) << "old pn, ignoring" << dendl; + } + + if (need_refresh) + (void)do_refresh(); +} + +void Paxos::collect_timeout() +{ + dout(1) << "collect timeout, calling fresh election" << dendl; + collect_timeout_event = 0; + logger->inc(l_paxos_collect_timeout); + ceph_assert(mon->is_leader()); + mon->bootstrap(); +} + + +// leader +void Paxos::begin(bufferlist& v) +{ + dout(10) << "begin for " << last_committed+1 << " " + << v.length() << " bytes" + << dendl; + + ceph_assert(mon->is_leader()); + ceph_assert(is_updating() || is_updating_previous()); + + // we must already have a majority for this to work. + ceph_assert(mon->get_quorum().size() == 1 || + num_last > (unsigned)mon->monmap->size()/2); + + // and no value, yet. + ceph_assert(new_value.length() == 0); + + // accept it ourselves + accepted.clear(); + accepted.insert(mon->rank); + new_value = v; + + if (last_committed == 0) { + auto t(std::make_shared<MonitorDBStore::Transaction>()); + // initial base case; set first_committed too + t->put(get_name(), "first_committed", 1); + decode_append_transaction(t, new_value); + + bufferlist tx_bl; + t->encode(tx_bl); + + new_value = tx_bl; + } + + // store the proposed value in the store. IF it is accepted, we will then + // have to decode it into a transaction and apply it. + auto t(std::make_shared<MonitorDBStore::Transaction>()); + t->put(get_name(), last_committed+1, new_value); + + // note which pn this pending value is for. + t->put(get_name(), "pending_v", last_committed + 1); + t->put(get_name(), "pending_pn", accepted_pn); + + dout(30) << __func__ << " transaction dump:\n"; + JSONFormatter f(true); + t->dump(&f); + f.flush(*_dout); + auto debug_tx(std::make_shared<MonitorDBStore::Transaction>()); + auto new_value_it = new_value.cbegin(); + debug_tx->decode(new_value_it); + debug_tx->dump(&f); + *_dout << "\nbl dump:\n"; + f.flush(*_dout); + *_dout << dendl; + + logger->inc(l_paxos_begin); + logger->inc(l_paxos_begin_keys, t->get_keys()); + logger->inc(l_paxos_begin_bytes, t->get_bytes()); + + auto start = ceph::coarse_mono_clock::now(); + get_store()->apply_transaction(t); + auto end = ceph::coarse_mono_clock::now(); + + logger->tinc(l_paxos_begin_latency, to_timespan(end - start)); + + ceph_assert(g_conf()->paxos_kill_at != 3); + + if (mon->get_quorum().size() == 1) { + // we're alone, take it easy + commit_start(); + return; + } + + // ask others to accept it too! + for (set<int>::const_iterator p = mon->get_quorum().begin(); + p != mon->get_quorum().end(); + ++p) { + if (*p == mon->rank) continue; + + dout(10) << " sending begin to mon." << *p << dendl; + MMonPaxos *begin = new MMonPaxos(mon->get_epoch(), MMonPaxos::OP_BEGIN, + ceph_clock_now()); + begin->values[last_committed+1] = new_value; + begin->last_committed = last_committed; + begin->pn = accepted_pn; + + mon->send_mon_message(begin, *p); + } + + // set timeout event + accept_timeout_event = mon->timer.add_event_after( + g_conf()->mon_accept_timeout_factor * g_conf()->mon_lease, + new C_MonContext(mon, [this](int r) { + if (r == -ECANCELED) + return; + accept_timeout(); + })); +} + +// peon +void Paxos::handle_begin(MonOpRequestRef op) +{ + op->mark_paxos_event("handle_begin"); + MMonPaxos *begin = static_cast<MMonPaxos*>(op->get_req()); + dout(10) << "handle_begin " << *begin << dendl; + + // can we accept this? + if (begin->pn < accepted_pn) { + dout(10) << " we accepted a higher pn " << accepted_pn << ", ignoring" << dendl; + op->mark_paxos_event("have higher pn, ignore"); + return; + } + ceph_assert(begin->pn == accepted_pn); + ceph_assert(begin->last_committed == last_committed); + + ceph_assert(g_conf()->paxos_kill_at != 4); + + logger->inc(l_paxos_begin); + + // set state. + state = STATE_UPDATING; + lease_expire = utime_t(); // cancel lease + + // yes. + version_t v = last_committed+1; + dout(10) << "accepting value for " << v << " pn " << accepted_pn << dendl; + // store the accepted value onto our store. We will have to decode it and + // apply its transaction once we receive permission to commit. + auto t(std::make_shared<MonitorDBStore::Transaction>()); + t->put(get_name(), v, begin->values[v]); + + // note which pn this pending value is for. + t->put(get_name(), "pending_v", v); + t->put(get_name(), "pending_pn", accepted_pn); + + dout(30) << __func__ << " transaction dump:\n"; + JSONFormatter f(true); + t->dump(&f); + f.flush(*_dout); + *_dout << dendl; + + logger->inc(l_paxos_begin_bytes, t->get_bytes()); + + auto start = ceph::coarse_mono_clock::now(); + get_store()->apply_transaction(t); + auto end = ceph::coarse_mono_clock::now(); + + logger->tinc(l_paxos_begin_latency, to_timespan(end - start)); + + ceph_assert(g_conf()->paxos_kill_at != 5); + + // reply + MMonPaxos *accept = new MMonPaxos(mon->get_epoch(), MMonPaxos::OP_ACCEPT, + ceph_clock_now()); + accept->pn = accepted_pn; + accept->last_committed = last_committed; + begin->get_connection()->send_message(accept); +} + +// leader +void Paxos::handle_accept(MonOpRequestRef op) +{ + op->mark_paxos_event("handle_accept"); + MMonPaxos *accept = static_cast<MMonPaxos*>(op->get_req()); + dout(10) << "handle_accept " << *accept << dendl; + int from = accept->get_source().num(); + + if (accept->pn != accepted_pn) { + // we accepted a higher pn, from some other leader + dout(10) << " we accepted a higher pn " << accepted_pn << ", ignoring" << dendl; + op->mark_paxos_event("have higher pn, ignore"); + return; + } + if (last_committed > 0 && + accept->last_committed < last_committed-1) { + dout(10) << " this is from an old round, ignoring" << dendl; + op->mark_paxos_event("old round, ignore"); + return; + } + ceph_assert(accept->last_committed == last_committed || // not committed + accept->last_committed == last_committed-1); // committed + + ceph_assert(is_updating() || is_updating_previous()); + ceph_assert(accepted.count(from) == 0); + accepted.insert(from); + dout(10) << " now " << accepted << " have accepted" << dendl; + + ceph_assert(g_conf()->paxos_kill_at != 6); + + // only commit (and expose committed state) when we get *all* quorum + // members to accept. otherwise, they may still be sharing the now + // stale state. + // FIXME: we can improve this with an additional lease revocation message + // that doesn't block for the persist. + if (accepted == mon->get_quorum()) { + // yay, commit! + dout(10) << " got majority, committing, done with update" << dendl; + op->mark_paxos_event("commit_start"); + commit_start(); + } +} + +void Paxos::accept_timeout() +{ + dout(1) << "accept timeout, calling fresh election" << dendl; + accept_timeout_event = 0; + ceph_assert(mon->is_leader()); + ceph_assert(is_updating() || is_updating_previous() || is_writing() || + is_writing_previous()); + logger->inc(l_paxos_accept_timeout); + mon->bootstrap(); +} + +struct C_Committed : public Context { + Paxos *paxos; + explicit C_Committed(Paxos *p) : paxos(p) {} + void finish(int r) override { + ceph_assert(r >= 0); + std::lock_guard l(paxos->mon->lock); + if (paxos->is_shutdown()) { + paxos->abort_commit(); + return; + } + paxos->commit_finish(); + } +}; + +void Paxos::abort_commit() +{ + ceph_assert(commits_started > 0); + --commits_started; + if (commits_started == 0) + shutdown_cond.Signal(); +} + +void Paxos::commit_start() +{ + dout(10) << __func__ << " " << (last_committed+1) << dendl; + + ceph_assert(g_conf()->paxos_kill_at != 7); + + auto t(std::make_shared<MonitorDBStore::Transaction>()); + + // commit locally + t->put(get_name(), "last_committed", last_committed + 1); + + // decode the value and apply its transaction to the store. + // this value can now be read from last_committed. + decode_append_transaction(t, new_value); + + dout(30) << __func__ << " transaction dump:\n"; + JSONFormatter f(true); + t->dump(&f); + f.flush(*_dout); + *_dout << dendl; + + logger->inc(l_paxos_commit); + logger->inc(l_paxos_commit_keys, t->get_keys()); + logger->inc(l_paxos_commit_bytes, t->get_bytes()); + commit_start_stamp = ceph_clock_now(); + + get_store()->queue_transaction(t, new C_Committed(this)); + + if (is_updating_previous()) + state = STATE_WRITING_PREVIOUS; + else if (is_updating()) + state = STATE_WRITING; + else + ceph_abort(); + ++commits_started; + + if (mon->get_quorum().size() > 1) { + // cancel timeout event + mon->timer.cancel_event(accept_timeout_event); + accept_timeout_event = 0; + } +} + +void Paxos::commit_finish() +{ + dout(20) << __func__ << " " << (last_committed+1) << dendl; + utime_t end = ceph_clock_now(); + logger->tinc(l_paxos_commit_latency, end - commit_start_stamp); + + ceph_assert(g_conf()->paxos_kill_at != 8); + + // cancel lease - it was for the old value. + // (this would only happen if message layer lost the 'begin', but + // leader still got a majority and committed with out us.) + lease_expire = utime_t(); // cancel lease + + last_committed++; + last_commit_time = ceph_clock_now(); + + // refresh first_committed; this txn may have trimmed. + first_committed = get_store()->get(get_name(), "first_committed"); + + _sanity_check_store(); + + // tell everyone + for (set<int>::const_iterator p = mon->get_quorum().begin(); + p != mon->get_quorum().end(); + ++p) { + if (*p == mon->rank) continue; + + dout(10) << " sending commit to mon." << *p << dendl; + MMonPaxos *commit = new MMonPaxos(mon->get_epoch(), MMonPaxos::OP_COMMIT, + ceph_clock_now()); + commit->values[last_committed] = new_value; + commit->pn = accepted_pn; + commit->last_committed = last_committed; + + mon->send_mon_message(commit, *p); + } + + ceph_assert(g_conf()->paxos_kill_at != 9); + + // get ready for a new round. + new_value.clear(); + + // WRITING -> REFRESH + // among other things, this lets do_refresh() -> mon->bootstrap() -> + // wait_for_paxos_write() know that it doesn't need to flush the store + // queue. and it should not, as we are in the async completion thread now! + ceph_assert(is_writing() || is_writing_previous()); + state = STATE_REFRESH; + ceph_assert(commits_started > 0); + --commits_started; + + if (do_refresh()) { + commit_proposal(); + if (mon->get_quorum().size() > 1) { + extend_lease(); + } + + ceph_assert(g_conf()->paxos_kill_at != 10); + + finish_round(); + } +} + + +void Paxos::handle_commit(MonOpRequestRef op) +{ + op->mark_paxos_event("handle_commit"); + MMonPaxos *commit = static_cast<MMonPaxos*>(op->get_req()); + dout(10) << "handle_commit on " << commit->last_committed << dendl; + + logger->inc(l_paxos_commit); + + if (!mon->is_peon()) { + dout(10) << "not a peon, dropping" << dendl; + ceph_abort(); + return; + } + + op->mark_paxos_event("store_state"); + store_state(commit); + + (void)do_refresh(); +} + +void Paxos::extend_lease() +{ + ceph_assert(mon->is_leader()); + //assert(is_active()); + + lease_expire = ceph_clock_now(); + lease_expire += g_conf()->mon_lease; + acked_lease.clear(); + acked_lease.insert(mon->rank); + + dout(7) << "extend_lease now+" << g_conf()->mon_lease + << " (" << lease_expire << ")" << dendl; + + // bcast + for (set<int>::const_iterator p = mon->get_quorum().begin(); + p != mon->get_quorum().end(); ++p) { + + if (*p == mon->rank) continue; + MMonPaxos *lease = new MMonPaxos(mon->get_epoch(), MMonPaxos::OP_LEASE, + ceph_clock_now()); + lease->last_committed = last_committed; + lease->lease_timestamp = lease_expire; + lease->first_committed = first_committed; + mon->send_mon_message(lease, *p); + } + + // set timeout event. + // if old timeout is still in place, leave it. + if (!lease_ack_timeout_event) { + lease_ack_timeout_event = mon->timer.add_event_after( + g_conf()->mon_lease_ack_timeout_factor * g_conf()->mon_lease, + new C_MonContext(mon, [this](int r) { + if (r == -ECANCELED) + return; + lease_ack_timeout(); + })); + } + + // set renew event + utime_t at = lease_expire; + at -= g_conf()->mon_lease; + at += g_conf()->mon_lease_renew_interval_factor * g_conf()->mon_lease; + lease_renew_event = mon->timer.add_event_at( + at, new C_MonContext(mon, [this](int r) { + if (r == -ECANCELED) + return; + lease_renew_timeout(); + })); +} + +void Paxos::warn_on_future_time(utime_t t, entity_name_t from) +{ + utime_t now = ceph_clock_now(); + if (t > now) { + utime_t diff = t - now; + if (diff > g_conf()->mon_clock_drift_allowed) { + utime_t warn_diff = now - last_clock_drift_warn; + if (warn_diff > + pow(g_conf()->mon_clock_drift_warn_backoff, clock_drift_warned)) { + mon->clog->warn() << "message from " << from << " was stamped " << diff + << "s in the future, clocks not synchronized"; + last_clock_drift_warn = ceph_clock_now(); + ++clock_drift_warned; + } + } + } + +} + +bool Paxos::do_refresh() +{ + bool need_bootstrap = false; + + // make sure we have the latest state loaded up + auto start = ceph::coarse_mono_clock::now(); + mon->refresh_from_paxos(&need_bootstrap); + auto end = ceph::coarse_mono_clock::now(); + + logger->inc(l_paxos_refresh); + logger->tinc(l_paxos_refresh_latency, to_timespan(end - start)); + + if (need_bootstrap) { + dout(10) << " doing requested bootstrap" << dendl; + mon->bootstrap(); + return false; + } + + return true; +} + +void Paxos::commit_proposal() +{ + dout(10) << __func__ << dendl; + ceph_assert(mon->is_leader()); + ceph_assert(is_refresh()); + + finish_contexts(g_ceph_context, committing_finishers); +} + +void Paxos::finish_round() +{ + dout(10) << __func__ << dendl; + ceph_assert(mon->is_leader()); + + // ok, now go active! + state = STATE_ACTIVE; + + dout(20) << __func__ << " waiting_for_acting" << dendl; + finish_contexts(g_ceph_context, waiting_for_active); + dout(20) << __func__ << " waiting_for_readable" << dendl; + finish_contexts(g_ceph_context, waiting_for_readable); + dout(20) << __func__ << " waiting_for_writeable" << dendl; + finish_contexts(g_ceph_context, waiting_for_writeable); + + dout(10) << __func__ << " done w/ waiters, state " << get_statename(state) << dendl; + + if (should_trim()) { + trim(); + } + + if (is_active() && pending_proposal) { + propose_pending(); + } +} + + +// peon +void Paxos::handle_lease(MonOpRequestRef op) +{ + op->mark_paxos_event("handle_lease"); + MMonPaxos *lease = static_cast<MMonPaxos*>(op->get_req()); + // sanity + if (!mon->is_peon() || + last_committed != lease->last_committed) { + dout(10) << "handle_lease i'm not a peon, or they're not the leader," + << " or the last_committed doesn't match, dropping" << dendl; + op->mark_paxos_event("invalid lease, ignore"); + return; + } + + warn_on_future_time(lease->sent_timestamp, lease->get_source()); + + // extend lease + if (lease_expire < lease->lease_timestamp) { + lease_expire = lease->lease_timestamp; + + utime_t now = ceph_clock_now(); + if (lease_expire < now) { + utime_t diff = now - lease_expire; + derr << "lease_expire from " << lease->get_source_inst() << " is " << diff << " seconds in the past; mons are probably laggy (or possibly clocks are too skewed)" << dendl; + } + } + + state = STATE_ACTIVE; + + dout(10) << "handle_lease on " << lease->last_committed + << " now " << lease_expire << dendl; + + // ack + MMonPaxos *ack = new MMonPaxos(mon->get_epoch(), MMonPaxos::OP_LEASE_ACK, + ceph_clock_now()); + ack->last_committed = last_committed; + ack->first_committed = first_committed; + ack->lease_timestamp = ceph_clock_now(); + encode(mon->session_map.feature_map, ack->feature_map); + lease->get_connection()->send_message(ack); + + // (re)set timeout event. + reset_lease_timeout(); + + // kick waiters + finish_contexts(g_ceph_context, waiting_for_active); + if (is_readable()) + finish_contexts(g_ceph_context, waiting_for_readable); +} + +void Paxos::handle_lease_ack(MonOpRequestRef op) +{ + op->mark_paxos_event("handle_lease_ack"); + MMonPaxos *ack = static_cast<MMonPaxos*>(op->get_req()); + int from = ack->get_source().num(); + + if (!lease_ack_timeout_event) { + dout(10) << "handle_lease_ack from " << ack->get_source() + << " -- stray (probably since revoked)" << dendl; + + } else if (acked_lease.count(from) == 0) { + acked_lease.insert(from); + if (ack->feature_map.length()) { + auto p = ack->feature_map.cbegin(); + FeatureMap& t = mon->quorum_feature_map[from]; + decode(t, p); + } + if (acked_lease == mon->get_quorum()) { + // yay! + dout(10) << "handle_lease_ack from " << ack->get_source() + << " -- got everyone" << dendl; + mon->timer.cancel_event(lease_ack_timeout_event); + lease_ack_timeout_event = 0; + + + } else { + dout(10) << "handle_lease_ack from " << ack->get_source() + << " -- still need " + << mon->get_quorum().size() - acked_lease.size() + << " more" << dendl; + } + } else { + dout(10) << "handle_lease_ack from " << ack->get_source() + << " dup (lagging!), ignoring" << dendl; + } + + warn_on_future_time(ack->sent_timestamp, ack->get_source()); +} + +void Paxos::lease_ack_timeout() +{ + dout(1) << "lease_ack_timeout -- calling new election" << dendl; + ceph_assert(mon->is_leader()); + ceph_assert(is_active()); + logger->inc(l_paxos_lease_ack_timeout); + lease_ack_timeout_event = 0; + mon->bootstrap(); +} + +void Paxos::reset_lease_timeout() +{ + dout(20) << "reset_lease_timeout - setting timeout event" << dendl; + if (lease_timeout_event) + mon->timer.cancel_event(lease_timeout_event); + lease_timeout_event = mon->timer.add_event_after( + g_conf()->mon_lease_ack_timeout_factor * g_conf()->mon_lease, + new C_MonContext(mon, [this](int r) { + if (r == -ECANCELED) + return; + lease_timeout(); + })); +} + +void Paxos::lease_timeout() +{ + dout(1) << "lease_timeout -- calling new election" << dendl; + ceph_assert(mon->is_peon()); + logger->inc(l_paxos_lease_timeout); + lease_timeout_event = 0; + mon->bootstrap(); +} + +void Paxos::lease_renew_timeout() +{ + lease_renew_event = 0; + extend_lease(); +} + + +/* + * trim old states + */ +void Paxos::trim() +{ + ceph_assert(should_trim()); + version_t end = std::min(get_version() - g_conf()->paxos_min, + get_first_committed() + g_conf()->paxos_trim_max); + + if (first_committed >= end) + return; + + dout(10) << "trim to " << end << " (was " << first_committed << ")" << dendl; + + MonitorDBStore::TransactionRef t = get_pending_transaction(); + + for (version_t v = first_committed; v < end; ++v) { + dout(10) << "trim " << v << dendl; + t->erase(get_name(), v); + } + t->put(get_name(), "first_committed", end); + if (g_conf()->mon_compact_on_trim) { + dout(10) << " compacting trimmed range" << dendl; + t->compact_range(get_name(), stringify(first_committed - 1), stringify(end)); + } + + trimming = true; + queue_pending_finisher(new C_Trimmed(this)); +} + +/* + * return a globally unique, monotonically increasing proposal number + */ +version_t Paxos::get_new_proposal_number(version_t gt) +{ + if (last_pn < gt) + last_pn = gt; + + // update. make it unique among all monitors. + last_pn /= 100; + last_pn++; + last_pn *= 100; + last_pn += (version_t)mon->rank; + + // write + auto t(std::make_shared<MonitorDBStore::Transaction>()); + t->put(get_name(), "last_pn", last_pn); + + dout(30) << __func__ << " transaction dump:\n"; + JSONFormatter f(true); + t->dump(&f); + f.flush(*_dout); + *_dout << dendl; + + logger->inc(l_paxos_new_pn); + + auto start = ceph::coarse_mono_clock::now(); + get_store()->apply_transaction(t); + auto end = ceph::coarse_mono_clock::now(); + + logger->tinc(l_paxos_new_pn_latency, to_timespan(end - start)); + + dout(10) << "get_new_proposal_number = " << last_pn << dendl; + return last_pn; +} + + +void Paxos::cancel_events() +{ + if (collect_timeout_event) { + mon->timer.cancel_event(collect_timeout_event); + collect_timeout_event = 0; + } + if (accept_timeout_event) { + mon->timer.cancel_event(accept_timeout_event); + accept_timeout_event = 0; + } + if (lease_renew_event) { + mon->timer.cancel_event(lease_renew_event); + lease_renew_event = 0; + } + if (lease_ack_timeout_event) { + mon->timer.cancel_event(lease_ack_timeout_event); + lease_ack_timeout_event = 0; + } + if (lease_timeout_event) { + mon->timer.cancel_event(lease_timeout_event); + lease_timeout_event = 0; + } +} + +void Paxos::shutdown() +{ + dout(10) << __func__ << " cancel all contexts" << dendl; + + state = STATE_SHUTDOWN; + + // discard pending transaction + pending_proposal.reset(); + + // Let store finish commits in progress + // XXX: I assume I can't use finish_contexts() because the store + // is going to trigger + while(commits_started > 0) + shutdown_cond.Wait(mon->lock); + + finish_contexts(g_ceph_context, waiting_for_writeable, -ECANCELED); + finish_contexts(g_ceph_context, waiting_for_readable, -ECANCELED); + finish_contexts(g_ceph_context, waiting_for_active, -ECANCELED); + finish_contexts(g_ceph_context, pending_finishers, -ECANCELED); + finish_contexts(g_ceph_context, committing_finishers, -ECANCELED); + if (logger) + g_ceph_context->get_perfcounters_collection()->remove(logger); +} + +void Paxos::leader_init() +{ + cancel_events(); + new_value.clear(); + + // discard pending transaction + pending_proposal.reset(); + + reset_pending_committing_finishers(); + + logger->inc(l_paxos_start_leader); + + if (mon->get_quorum().size() == 1) { + state = STATE_ACTIVE; + return; + } + + state = STATE_RECOVERING; + lease_expire = utime_t(); + dout(10) << "leader_init -- starting paxos recovery" << dendl; + collect(0); +} + +void Paxos::peon_init() +{ + cancel_events(); + new_value.clear(); + + state = STATE_RECOVERING; + lease_expire = utime_t(); + dout(10) << "peon_init -- i am a peon" << dendl; + + // start a timer, in case the leader never manages to issue a lease + reset_lease_timeout(); + + // discard pending transaction + pending_proposal.reset(); + + // no chance to write now! + reset_pending_committing_finishers(); + finish_contexts(g_ceph_context, waiting_for_writeable, -EAGAIN); + + logger->inc(l_paxos_start_peon); +} + +void Paxos::restart() +{ + dout(10) << "restart -- canceling timeouts" << dendl; + cancel_events(); + new_value.clear(); + + if (is_writing() || is_writing_previous()) { + dout(10) << __func__ << " flushing" << dendl; + mon->lock.Unlock(); + mon->store->flush(); + mon->lock.Lock(); + dout(10) << __func__ << " flushed" << dendl; + } + state = STATE_RECOVERING; + + // discard pending transaction + pending_proposal.reset(); + + reset_pending_committing_finishers(); + finish_contexts(g_ceph_context, waiting_for_active, -EAGAIN); + + logger->inc(l_paxos_restart); +} + +void Paxos::reset_pending_committing_finishers() +{ + committing_finishers.splice(committing_finishers.end(), pending_finishers); + finish_contexts(g_ceph_context, committing_finishers, -EAGAIN); +} + +void Paxos::dispatch(MonOpRequestRef op) +{ + ceph_assert(op->is_type_paxos()); + op->mark_paxos_event("dispatch"); + PaxosServiceMessage *m = static_cast<PaxosServiceMessage*>(op->get_req()); + // election in progress? + if (!mon->is_leader() && !mon->is_peon()) { + dout(5) << "election in progress, dropping " << *m << dendl; + return; + } + + // check sanity + ceph_assert(mon->is_leader() || + (mon->is_peon() && m->get_source().num() == mon->get_leader())); + + switch (m->get_type()) { + + case MSG_MON_PAXOS: + { + MMonPaxos *pm = reinterpret_cast<MMonPaxos*>(m); + + // NOTE: these ops are defined in messages/MMonPaxos.h + switch (pm->op) { + // learner + case MMonPaxos::OP_COLLECT: + handle_collect(op); + break; + case MMonPaxos::OP_LAST: + handle_last(op); + break; + case MMonPaxos::OP_BEGIN: + handle_begin(op); + break; + case MMonPaxos::OP_ACCEPT: + handle_accept(op); + break; + case MMonPaxos::OP_COMMIT: + handle_commit(op); + break; + case MMonPaxos::OP_LEASE: + handle_lease(op); + break; + case MMonPaxos::OP_LEASE_ACK: + handle_lease_ack(op); + break; + default: + ceph_abort(); + } + } + break; + + default: + ceph_abort(); + } +} + + +// ----------------- +// service interface + +// -- READ -- + +bool Paxos::is_readable(version_t v) +{ + bool ret; + if (v > last_committed) + ret = false; + else + ret = + (mon->is_peon() || mon->is_leader()) && + (is_active() || is_updating() || is_writing()) && + last_committed > 0 && is_lease_valid(); // must have a value alone, or have lease + dout(5) << __func__ << " = " << (int)ret + << " - now=" << ceph_clock_now() + << " lease_expire=" << lease_expire + << " has v" << v << " lc " << last_committed + << dendl; + return ret; +} + +bool Paxos::read(version_t v, bufferlist &bl) +{ + if (!get_store()->get(get_name(), v, bl)) + return false; + return true; +} + +version_t Paxos::read_current(bufferlist &bl) +{ + if (read(last_committed, bl)) + return last_committed; + return 0; +} + + +bool Paxos::is_lease_valid() +{ + return ((mon->get_quorum().size() == 1) + || (ceph_clock_now() < lease_expire)); +} + +// -- WRITE -- + +bool Paxos::is_writeable() +{ + return + mon->is_leader() && + is_active() && + is_lease_valid(); +} + +void Paxos::propose_pending() +{ + ceph_assert(is_active()); + ceph_assert(pending_proposal); + + cancel_events(); + + bufferlist bl; + pending_proposal->encode(bl); + + dout(10) << __func__ << " " << (last_committed + 1) + << " " << bl.length() << " bytes" << dendl; + dout(30) << __func__ << " transaction dump:\n"; + JSONFormatter f(true); + pending_proposal->dump(&f); + f.flush(*_dout); + *_dout << dendl; + + pending_proposal.reset(); + + committing_finishers.swap(pending_finishers); + state = STATE_UPDATING; + begin(bl); +} + +void Paxos::queue_pending_finisher(Context *onfinished) +{ + dout(5) << __func__ << " " << onfinished << dendl; + ceph_assert(onfinished); + pending_finishers.push_back(onfinished); +} + +MonitorDBStore::TransactionRef Paxos::get_pending_transaction() +{ + ceph_assert(mon->is_leader()); + if (!pending_proposal) { + pending_proposal.reset(new MonitorDBStore::Transaction); + ceph_assert(pending_finishers.empty()); + } + return pending_proposal; +} + +bool Paxos::trigger_propose() +{ + if (plugged) { + dout(10) << __func__ << " plugged, not proposing now" << dendl; + return false; + } else if (is_active()) { + dout(10) << __func__ << " active, proposing now" << dendl; + propose_pending(); + return true; + } else { + dout(10) << __func__ << " not active, will propose later" << dendl; + return false; + } +} + +bool Paxos::is_consistent() +{ + return (first_committed <= last_committed); +} + |