Merged default into bug24323

4 files changed, 96 insertions, 66 deletions

diff --git a/docs/rabbitmqctl.1.xml b/docs/rabbitmqctl.1.xml
index 3291c44d..29d9032b 100644
--- a/docs/rabbitmqctl.1.xml
+++ b/docs/rabbitmqctl.1.xml
@@ -390,44 +390,6 @@
     </refsect2>
 
     <refsect2>
-      <title>Closing individual connections</title>
-
-      <variablelist>
-        <varlistentry>
-          <term><cmdsynopsis><command>close_connection</command> <arg choice="req"><replaceable>connectionpid</replaceable></arg> <arg choice="req"><replaceable>explanation</replaceable></arg></cmdsynopsis></term>
-          <listitem>
-            <variablelist>
-              <varlistentry>
-                <term>connectionpid</term>
-                <listitem><para>Id of the Erlang process associated with the connection to close.</para></listitem>
-              </varlistentry>
-              <varlistentry>
-                <term>explanation</term>
-                <listitem><para>Explanation string.</para></listitem>
-              </varlistentry>
-            </variablelist>
-            <para>
-              Instruct the broker to close the connection associated
-              with the Erlang process id <option>connectionpid</option> (see also the
-              <link linkend="list_connections"><command>list_connections</command></link>
-              command), passing the <option>explanation</option> string to the
-              connected client as part of the AMQP connection shutdown
-              protocol.
-            </para>
-            <para role="example-prefix">For example:</para>
-            <screen role="example">rabbitmqctl close_connection "&lt;rabbit@tanto.4262.0&gt;" "go away"</screen>
-            <para role="example">
-              This command instructs the RabbitMQ broker to close the
-              connection associated with the Erlang process
-              id <command>&lt;rabbit@tanto.4262.0&gt;</command>, passing the
-              explanation <command>go away</command> to the connected client.
-            </para>
-          </listitem>
-        </varlistentry>
-      </variablelist>
-    </refsect2>
-
-    <refsect2>
       <title>User management</title>
       <para>
         Note that <command>rabbitmqctl</command> manages the RabbitMQ
@@ -1306,9 +1268,14 @@
             <para>
               Displays broker status information such as the running
               applications on the current Erlang node, RabbitMQ and
-              Erlang versions and OS name.  (See
-              the <command>cluster_status</command> command to find
-              out which nodes are clustered and running.)
+              Erlang versions, OS name and memory statistics.
+              In this context <varname>vm_memory_high_watermark</varname>
+              indicates the fraction of memory at which flow control is
+              triggered. <varname>vm_memory_limit</varname> refers to the
+              absolute memory threshhold at which flow control is triggered.
+              The unit of this number and those listed in the <varname>memory</varname>
+              section is bytes. (See the <command>cluster_status</command>
+              command to find out which nodes are clustered and running.)
             </para>
             <para role="example-prefix">For example:</para>
             <screen role="example">rabbitmqctl status</screen>
@@ -1352,9 +1319,40 @@
     </refsect2>
 
     <refsect2>
-      <title>Message Tracing</title>
+      <title>Miscellaneous</title>
       <variablelist>
         <varlistentry>
+          <term><cmdsynopsis><command>close_connection</command> <arg choice="req"><replaceable>connectionpid</replaceable></arg> <arg choice="req"><replaceable>explanation</replaceable></arg></cmdsynopsis></term>
+          <listitem>
+            <variablelist>
+              <varlistentry>
+                <term>connectionpid</term>
+                <listitem><para>Id of the Erlang process associated with the connection to close.</para></listitem>
+              </varlistentry>
+              <varlistentry>
+                <term>explanation</term>
+                <listitem><para>Explanation string.</para></listitem>
+              </varlistentry>
+            </variablelist>
+            <para>
+              Instruct the broker to close the connection associated
+              with the Erlang process id <option>connectionpid</option> (see also the
+              <link linkend="list_connections"><command>list_connections</command></link>
+              command), passing the <option>explanation</option> string to the
+              connected client as part of the AMQP connection shutdown
+              protocol.
+            </para>
+            <para role="example-prefix">For example:</para>
+            <screen role="example">rabbitmqctl close_connection "&lt;rabbit@tanto.4262.0&gt;" "go away"</screen>
+            <para role="example">
+              This command instructs the RabbitMQ broker to close the
+              connection associated with the Erlang process
+              id <command>&lt;rabbit@tanto.4262.0&gt;</command>, passing the
+              explanation <command>go away</command> to the connected client.
+            </para>
+          </listitem>
+        </varlistentry>
+        <varlistentry>
           <term><cmdsynopsis><command>trace_on</command> <arg choice="opt">-p <replaceable>vhost</replaceable></arg></cmdsynopsis></term>
           <listitem>
             <variablelist>
@@ -1383,7 +1381,18 @@
             </para>
           </listitem>
         </varlistentry>
-
+        <varlistentry>
+          <term><cmdsynopsis><command>set_vm_memory_high_watermark</command> <arg choice="req"><replaceable>fraction</replaceable></arg></cmdsynopsis></term>
+          <listitem>
+            <variablelist>
+              <varlistentry>
+                <term>fraction</term>
+                <listitem><para>The new memory threshhold fraction at which flow control is triggered, as a
+                                floating point number between 0.0 and 1.0 with a mandatory fractional part.</para></listitem>
+              </varlistentry>
+            </variablelist>
+          </listitem>
+        </varlistentry>
       </variablelist>
     </refsect2>
   </refsect1>
diff --git a/src/rabbit.erl b/src/rabbit.erl
index b8dbccc7..2403d027 100644
--- a/src/rabbit.erl
+++ b/src/rabbit.erl
@@ -239,7 +239,13 @@ status() ->
      {running_applications, application:which_applications(infinity)},
      {os, os:type()},
      {erlang_version, erlang:system_info(system_version)},
-     {memory, erlang:memory()}].
+     {memory, erlang:memory()}] ++
+    case is_running() of
+        true  -> [{vm_memory_high_watermark,
+                       vm_memory_monitor:get_vm_memory_high_watermark()},
+                  {vm_memory_limit, vm_memory_monitor:get_memory_limit()}];
+        false -> []
+    end.
 
 is_running() -> is_running(node()).
 
diff --git a/src/rabbit_control.erl b/src/rabbit_control.erl
index 1163ae9d..9034c81f 100644
--- a/src/rabbit_control.erl
+++ b/src/rabbit_control.erl
@@ -321,6 +321,11 @@ action(trace_off, Node, [], Opts, Inform) ->
     Inform("Stopping tracing for vhost ~p", [VHost]),
     rpc_call(Node, rabbit_trace, stop, [list_to_binary(VHost)]);
 
+action(set_vm_memory_high_watermark, Node, [Arg], _Opts, Inform) ->
+    Frac = list_to_float("0" ++ Arg),
+    Inform("Setting memory threshhold on ~p to ~p", [Node, Frac]),
+    rpc_call(Node, vm_memory_monitor, set_vm_memory_high_watermark, [Frac]);
+
 action(set_permissions, Node, [Username, CPerm, WPerm, RPerm], Opts, Inform) ->
     VHost = proplists:get_value(?VHOST_OPT, Opts),
     Inform("Setting permissions for user ~p in vhost ~p", [Username, VHost]),
diff --git a/src/vm_memory_monitor.erl b/src/vm_memory_monitor.erl
index fb2fa267..3b955914 100644
--- a/src/vm_memory_monitor.erl
+++ b/src/vm_memory_monitor.erl
@@ -40,6 +40,7 @@
 
 -define(SERVER, ?MODULE).
 -define(DEFAULT_MEMORY_CHECK_INTERVAL, 1000).
+-define(ONE_MB, 1048576).
 
 %% For an unknown OS, we assume that we have 1GB of memory. It'll be
 %% wrong. Scale by vm_memory_high_watermark in configuration to get a
@@ -106,35 +107,20 @@ start_link(Args) ->
     gen_server:start_link({local, ?SERVER}, ?MODULE, [Args], []).
 
 init([MemFraction]) ->
-    TotalMemory =
-        case get_total_memory() of
-            unknown ->
-                error_logger:warning_msg(
-                  "Unknown total memory size for your OS ~p. "
-                  "Assuming memory size is ~pMB.~n",
-                  [os:type(), trunc(?MEMORY_SIZE_FOR_UNKNOWN_OS/1048576)]),
-                ?MEMORY_SIZE_FOR_UNKNOWN_OS;
-            M -> M
-        end,
-    MemLimit = get_mem_limit(MemFraction, TotalMemory),
-    error_logger:info_msg("Memory limit set to ~pMB.~n",
-                          [trunc(MemLimit/1048576)]),
     TRef = start_timer(?DEFAULT_MEMORY_CHECK_INTERVAL),
-    State = #state { total_memory = TotalMemory,
-                     memory_limit = MemLimit,
-                     timeout = ?DEFAULT_MEMORY_CHECK_INTERVAL,
+    State = #state { timeout = ?DEFAULT_MEMORY_CHECK_INTERVAL,
                      timer = TRef,
                      alarmed = false},
-    {ok, internal_update(State)}.
+    {ok, internal_update(set_mem_limits(State, MemFraction))}.
 
 handle_call(get_vm_memory_high_watermark, _From, State) ->
     {reply, State#state.memory_limit / State#state.total_memory, State};
 
 handle_call({set_vm_memory_high_watermark, MemFraction}, _From, State) ->
-    MemLimit = get_mem_limit(MemFraction, State#state.total_memory),
+    State1 = set_mem_limits(State, MemFraction),
     error_logger:info_msg("Memory alarm changed to ~p, ~p bytes.~n",
-                          [MemFraction, MemLimit]),
-    {reply, ok, State#state{memory_limit = MemLimit}};
+                          [MemFraction, State1#state.memory_limit]),
+    {reply, ok, State1};
 
 handle_call(get_check_interval, _From, State) ->
     {reply, State#state.timeout, State};
@@ -168,6 +154,30 @@ code_change(_OldVsn, State, _Extra) ->
 %% Server Internals
 %%----------------------------------------------------------------------------
 
+set_mem_limits(State, MemFraction) ->
+    TotalMemory =
+        case get_total_memory() of
+            unknown ->
+                case State of
+                    #state { total_memory = undefined,
+                             memory_limit = undefined } ->
+                        error_logger:warning_msg(
+                          "Unknown total memory size for your OS ~p. "
+                          "Assuming memory size is ~pMB.~n",
+                          [os:type(),
+                           trunc(?MEMORY_SIZE_FOR_UNKNOWN_OS/?ONE_MB)]);
+                    _ ->
+                        ok
+                end,
+                ?MEMORY_SIZE_FOR_UNKNOWN_OS;
+            M -> M
+        end,
+    MemLim = get_mem_limit(MemFraction, TotalMemory),
+    error_logger:info_msg("Memory limit set to ~pMB of ~pMB total.~n",
+                          [trunc(MemLim/?ONE_MB), trunc(TotalMemory/?ONE_MB)]),
+    State #state { total_memory = TotalMemory,
+                   memory_limit = MemLim }.
+
 internal_update(State = #state { memory_limit = MemLimit,
                                  alarmed = Alarmed}) ->
     MemUsed = erlang:memory(total),
@@ -322,9 +332,9 @@ parse_line_sunos(Line) ->
             [Value1 | UnitsRest] = string:tokens(RHS, " "),
             Value2 = case UnitsRest of
                          ["Gigabytes"] ->
-                             list_to_integer(Value1) * 1024 * 1024 * 1024;
+                             list_to_integer(Value1) * ?ONE_MB * 1024;
                          ["Megabytes"] ->
-                             list_to_integer(Value1) * 1024 * 1024;
+                             list_to_integer(Value1) * ?ONE_MB;
                          ["Kilobytes"] ->
                              list_to_integer(Value1) * 1024;
                          _ ->