osd/PG: indicate in pg query output whether ignore_history_les would help

Put a hint in the PG query output if setting the
osd_find_best_info_ignore_history_les = true would allow peering to
proceed.  This is difficult to diagnose even for a developer (you need
to read the peer info *very* carefully) but is easy to hint.

Signed-off-by: Sage Weil <sage@redhat.com>

diff --git a/src/osd/PG.cc b/src/osd/PG.cc
index 682f41569ba33639c53a32f690f84b8e735432e9..b2cad0b76861ccc6f8fcf1c8af7f5f95788b584c 100644 (file)
--- a/src/osd/PG.cc
+++ b/src/osd/PG.cc
@@ -970,8 +970,9 @@ PG::Scrubber::~Scrubber() {}
  *  3) Prefer current primary
  */
 map<pg_shard_t, pg_info_t>::const_iterator PG::find_best_info(
-  const map<pg_shard_t, pg_info_t> &infos) const
+  const map<pg_shard_t, pg_info_t> &infos, bool *history_les_bound) const
 {
+  assert(history_les_bound);
   /* See doc/dev/osd_internals/last_epoch_started.rst before attempting
    * to make changes to this process.  Also, make sure to update it
    * when you find bugs! */
@@ -982,6 +983,7 @@ map<pg_shard_t, pg_info_t>::const_iterator PG::find_best_info(
        ++i) {
     if (!cct->_conf->osd_find_best_info_ignore_history_les &&
        max_last_epoch_started_found < i->second.history.last_epoch_started) {
+      *history_les_bound = true;
       max_last_epoch_started_found = i->second.history.last_epoch_started;
     }
     if (!i->second.is_incomplete() &&
@@ -1287,7 +1289,7 @@ void PG::calc_replicated_acting(
  * calculate the desired acting, and request a change with the monitor
  * if it differs from the current acting.
  */
-bool PG::choose_acting(pg_shard_t &auth_log_shard_id)
+bool PG::choose_acting(pg_shard_t &auth_log_shard_id, bool *history_les_bound)
 {
   map<pg_shard_t, pg_info_t> all_info(peer_info.begin(), peer_info.end());
   all_info[pg_whoami] = info;
@@ -1299,7 +1301,7 @@ bool PG::choose_acting(pg_shard_t &auth_log_shard_id)
   }
 
   map<pg_shard_t, pg_info_t>::const_iterator auth_log_shard =
-    find_best_info(all_info);
+    find_best_info(all_info, history_les_bound);
 
   if (auth_log_shard == all_info.end()) {
     if (up != acting) {
@@ -1328,7 +1330,8 @@ bool PG::choose_acting(pg_shard_t &auth_log_shard_id)
        complete_infos.insert(*i);
     }
     map<pg_shard_t, pg_info_t>::const_iterator i = find_best_info(
-      complete_infos);
+      complete_infos,
+      history_les_bound);
     if (i != complete_infos.end()) {
       auth_log_shard = all_info.find(i->first);
     }
@@ -5902,7 +5905,8 @@ void PG::RecoveryState::Primary::exit()
 /*---------Peering--------*/
 PG::RecoveryState::Peering::Peering(my_context ctx)
   : my_base(ctx),
-    NamedState(context< RecoveryMachine >().pg->cct, "Started/Primary/Peering")
+    NamedState(context< RecoveryMachine >().pg->cct, "Started/Primary/Peering"),
+    history_les_bound(false)
 {
   context< RecoveryMachine >().log_enter(state_name);
 
@@ -5975,6 +5979,14 @@ boost::statechart::result PG::RecoveryState::Peering::react(const QueryState& q)
   }
   q.f->close_section();
 
+  if (history_les_bound) {
+    q.f->open_array_section("peering_blocked_by_detail");
+    q.f->open_object_section("item");
+    q.f->dump_string("detail","peering_blocked_by_history_les_bound");
+    q.f->close_section();
+    q.f->close_section();
+  }
+
   q.f->close_section();
   return forward_event();
 }
@@ -6510,7 +6522,9 @@ PG::RecoveryState::Recovered::Recovered(my_context ctx)
     pg->state_clear(PG_STATE_DEGRADED);
 
   // adjust acting set?  (e.g. because backfill completed...)
-  if (pg->acting != pg->up && !pg->choose_acting(auth_log_shard))
+  bool history_les_bound = false;
+  if (pg->acting != pg->up && !pg->choose_acting(auth_log_shard,
+                                                &history_les_bound))
     assert(pg->want_acting.size());
 
   if (context< Active >().all_replicas_activated)
@@ -7299,7 +7313,8 @@ PG::RecoveryState::GetLog::GetLog(my_context ctx)
   PG *pg = context< RecoveryMachine >().pg;
 
   // adjust acting?
-  if (!pg->choose_acting(auth_log_shard)) {
+  if (!pg->choose_acting(auth_log_shard,
+      &context< Peering >().history_les_bound)) {
     if (!pg->want_acting.empty()) {
       post_event(NeedActingChange());
     } else {

diff --git a/src/osd/PG.h b/src/osd/PG.h
index 87b0d996028d6d4b7fea62e662b9c8f50e79146e..16d58bd9ebc04237927fab0a298096eb57657d50 100644 (file)
--- a/src/osd/PG.h
+++ b/src/osd/PG.h
@@ -1041,7 +1041,8 @@ public:
   void trim_write_ahead();
 
   map<pg_shard_t, pg_info_t>::const_iterator find_best_info(
-    const map<pg_shard_t, pg_info_t> &infos) const;
+    const map<pg_shard_t, pg_info_t> &infos,
+    bool *history_les_bound) const;
   static void calc_ec_acting(
     map<pg_shard_t, pg_info_t>::const_iterator auth_log_shard,
     unsigned size,
@@ -1070,7 +1071,8 @@ public:
     set<pg_shard_t> *acting_backfill,
     pg_shard_t *want_primary,
     ostream &ss);
-  bool choose_acting(pg_shard_t &auth_log_shard);
+  bool choose_acting(pg_shard_t &auth_log_shard,
+                    bool *history_les_bound);
   void build_might_have_unfound();
   void replay_queued_ops();
   void activate(
@@ -1732,6 +1734,7 @@ public:
 
     struct Peering : boost::statechart::state< Peering, Primary, GetInfo >, NamedState {
       std::unique_ptr< PriorSet > prior_set;
+      bool history_les_bound;  //< need osd_find_best_info_ignore_history_les
 
       explicit Peering(my_context ctx);
       void exit();