mon/MonClient: send commands to a specific monitor

This implementation is limited: we direct our command by reopening
a session with the specific monitor.  If there is more than one of these
queued we will fail to reach either.

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

diff --git a/src/mon/MonClient.cc b/src/mon/MonClient.cc
index 181d06883112b9454256e381e3de16be3a7d857d..c0d2b5183c567faf5c7dbb465aac5d8264f9a611 100644 (file)
--- a/src/mon/MonClient.cc
+++ b/src/mon/MonClient.cc
@@ -479,11 +479,18 @@ string MonClient::_pick_random_mon()
   }
 }
 
-void MonClient::_pick_new_mon()
+void MonClient::_reopen_session(int rank, string name)
 {
   assert(monc_lock.is_locked());
+  ldout(cct, 10) << "_reopen_session rank " << rank << " name " << name << dendl;
 
-  cur_mon = _pick_random_mon();
+  if (rank < 0 && name.length() == 0) {
+    cur_mon = _pick_random_mon();
+  } else if (name.length()) {
+    cur_mon = name;
+  } else {
+    cur_mon = monmap.get_name(rank);
+  }
 
   if (cur_con) {
     messenger->mark_down(cur_con);
@@ -491,18 +498,9 @@ void MonClient::_pick_new_mon()
   }
   cur_con = messenger->get_connection(monmap.get_inst(cur_mon));
        
-  ldout(cct, 10) << "_pick_new_mon picked mon." << cur_mon << " con " << cur_con
+  ldout(cct, 10) << "picked mon." << cur_mon << " con " << cur_con
                 << " addr " << cur_con->get_peer_addr()
                 << dendl;
-}
-
-
-void MonClient::_reopen_session()
-{
-  assert(monc_lock.is_locked());
-  ldout(cct, 10) << "_reopen_session" << dendl;
-
-  _pick_new_mon();
 
   // throw out old queued messages
   while (!waiting_for_session.empty()) {
@@ -724,6 +722,37 @@ int MonClient::wait_auth_rotating(double timeout)
 void MonClient::_send_command(MonCommand *r)
 {
   version_t last_seen_version = 0;
+
+  if (r->target_rank >= 0 &&
+      r->target_rank != monmap.get_rank(cur_mon)) {
+    ldout(cct, 10) << "_send_command " << r->tid << " " << r->cmd
+                  << " wants rank " << r->target_rank
+                  << ", reopening session"
+                  << dendl;
+    if (r->target_rank >= (int)monmap.size()) {
+      ldout(cct, 10) << " target " << r->target_rank << " >= max mon " << monmap.size() << dendl;
+      _finish_command(r, -ENOENT, "mon rank dne");
+      return;
+    }
+    _reopen_session(r->target_rank, string());
+    return;
+  }
+
+  if (r->target_name.length() &&
+      r->target_name != cur_mon) {
+    ldout(cct, 10) << "_send_command " << r->tid << " " << r->cmd
+                  << " wants mon " << r->target_name
+                  << ", reopening session"
+                  << dendl;
+    if (!monmap.contains(r->target_name)) {
+      ldout(cct, 10) << " target " << r->target_name << " not present in monmap" << dendl;
+      _finish_command(r, -ENOENT, "mon dne");
+      return;
+    }
+    _reopen_session(-1, r->target_name);
+    return;
+  }
+
   ldout(cct, 10) << "_send_command " << r->tid << " " << r->cmd << dendl;
   MMonCommand *m = new MMonCommand(monmap.fsid, last_seen_version);
   m->set_tid(r->tid);
@@ -798,6 +827,43 @@ int MonClient::start_mon_command(const vector<string>& cmd, bufferlist& inbl,
   return 0;
 }
 
+int MonClient::start_mon_command(string name,
+                                const vector<string>& cmd, bufferlist& inbl,
+                                bufferlist *outbl, string *outs,
+                                Context *onfinish)
+{
+  Mutex::Locker l(monc_lock);
+  MonCommand *r = new MonCommand(++last_mon_command_tid);
+  r->target_name = name;
+  r->cmd = cmd;
+  r->inbl = inbl;
+  r->poutbl = outbl;
+  r->prs = outs;
+  r->onfinish = onfinish;
+  mon_commands[r->tid] = r;
+  _send_command(r);
+  // can't fail
+  return 0;
+}
+
+int MonClient::start_mon_command(int rank,
+                                const vector<string>& cmd, bufferlist& inbl,
+                                bufferlist *outbl, string *outs,
+                                Context *onfinish)
+{
+  Mutex::Locker l(monc_lock);
+  MonCommand *r = new MonCommand(++last_mon_command_tid);
+  r->target_rank = rank;
+  r->cmd = cmd;
+  r->inbl = inbl;
+  r->poutbl = outbl;
+  r->prs = outs;
+  r->onfinish = onfinish;
+  mon_commands[r->tid] = r;
+  _send_command(r);
+  return 0;
+}
+
 // ---------
 
 void MonClient::get_version(string map, version_t *newest, version_t *oldest, Context *onfinish)

diff --git a/src/mon/MonClient.h b/src/mon/MonClient.h
index 04e6b0e44b5b8b6c8f7c6d4d92dc7e7e83ad4447..7d4a0548f9d02230d4f07fee435173ba45feb0af 100644 (file)
--- a/src/mon/MonClient.h
+++ b/src/mon/MonClient.h
@@ -129,8 +129,10 @@ private:
 
   string _pick_random_mon();
   void _finish_hunting();
-  void _reopen_session();
-  void _pick_new_mon();
+  void _reopen_session(int rank, string name);
+  void _reopen_session() {
+    _reopen_session(-1, string());
+  }
   void _send_mon_message(Message *m, bool force=false);
 
 public:
@@ -270,6 +272,8 @@ public:
 private:
   uint64_t last_mon_command_tid;
   struct MonCommand {
+    string target_name;
+    int target_rank;
     uint64_t tid;
     vector<string> cmd;
     bufferlist inbl;
@@ -279,7 +283,8 @@ private:
     Context *onfinish;
 
     MonCommand(uint64_t t)
-      : tid(t),
+      : target_rank(-1),
+       tid(t),
        poutbl(NULL), prs(NULL), prval(NULL), onfinish(NULL)
     {}
   };
@@ -294,6 +299,14 @@ public:
   int start_mon_command(const vector<string>& cmd, bufferlist& inbl,
                        bufferlist *outbl, string *outs,
                        Context *onfinish);
+  int start_mon_command(int mon_rank,
+                       const vector<string>& cmd, bufferlist& inbl,
+                       bufferlist *outbl, string *outs,
+                       Context *onfinish);
+  int start_mon_command(const string mon_name,  ///< mon name, with mon. prefix
+                       const vector<string>& cmd, bufferlist& inbl,
+                       bufferlist *outbl, string *outs,
+                       Context *onfinish);
 
   // version requests
 public: