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-rw-r--r--lib/mnesia/doc/src/Mnesia_chap5.xmlsrc1
-rw-r--r--lib/mnesia/doc/src/mnesia.xml8
-rw-r--r--lib/mnesia/src/mnesia_recover.erl31
3 files changed, 34 insertions, 6 deletions
diff --git a/lib/mnesia/doc/src/Mnesia_chap5.xmlsrc b/lib/mnesia/doc/src/Mnesia_chap5.xmlsrc
index 65b950bd46..127c23e0f7 100644
--- a/lib/mnesia/doc/src/Mnesia_chap5.xmlsrc
+++ b/lib/mnesia/doc/src/Mnesia_chap5.xmlsrc
@@ -867,6 +867,7 @@ ok
</section>
<section>
+ <marker id="event_handling"></marker>
<title>Mnesia Event Handling</title>
<p>System events and table events are the two categories of events
that Mnesia will generate in various situations.
diff --git a/lib/mnesia/doc/src/mnesia.xml b/lib/mnesia/doc/src/mnesia.xml
index b2de8b6946..ed5b879f7f 100644
--- a/lib/mnesia/doc/src/mnesia.xml
+++ b/lib/mnesia/doc/src/mnesia.xml
@@ -2188,12 +2188,13 @@ mnesia:create_table(employee,
</desc>
</func>
<func>
- <name>subscribe(EventCategory)</name>
+ <name>subscribe(EventCategory) -> {ok, Node} | {error, Reason} </name>
<fsummary>Subscribe to events of type <c>EventCategory</c>.</fsummary>
<desc>
<p>Ensures that a copy of all events of type
<c>EventCategory</c> are sent to the caller. The event
- types available are described in the Mnesia User's Guide.</p>
+ types available are described in the Mnesia User's Guide at <seealso marker="Mnesia_chap5#event_handling">Mnesia Event Handling</seealso>.</p>
+ <p><c>Node</c> is the local node. For table events to be subscribed, mnesia must have a readable local copy of the table on the node.</p>
</desc>
</func>
<func>
@@ -2861,11 +2862,12 @@ raise(Name, Amount) ->
</desc>
</func>
<func>
- <name>unsubscribe(EventCategory)</name>
+ <name>unsubscribe(EventCategory) -> {ok, Node} | {error, Reason} </name>
<fsummary>Subscribe to events of type <c>EventCategory</c>.</fsummary>
<desc>
<p>Stops sending events of type
<c>EventCategory</c> to the caller.</p>
+ <p><c>Node</c> is the local node.</p>
</desc>
</func>
<func>
diff --git a/lib/mnesia/src/mnesia_recover.erl b/lib/mnesia/src/mnesia_recover.erl
index b6492707e2..eeb4fa0ced 100644
--- a/lib/mnesia/src/mnesia_recover.erl
+++ b/lib/mnesia/src/mnesia_recover.erl
@@ -689,12 +689,29 @@ handle_call({connect_nodes, Ns}, From, State) ->
%% called from handle_info
gen_server:reply(From, {[], AlreadyConnected}),
{noreply, State};
- GoodNodes ->
+ ProbablyGoodNodes ->
%% Now we have agreed upon a protocol with some new nodes
- %% and we may use them when we recover transactions
+ %% and we may use them when we recover transactions.
+ %%
+ %% Just in case Mnesia was stopped on some of those nodes
+ %% between the protocol negotiation and now, we check one
+ %% more time the state of Mnesia.
+ %%
+ %% Of course, there is still a chance that mnesia_down
+ %% events occur during this check and we miss them. To
+ %% prevent it, handle_cast({mnesia_down, ...}, ...) removes
+ %% the down node again, in addition to mnesia_down/1.
+ %%
+ %% See a comment in handle_cast({mnesia_down, ...}, ...).
+ Verify = fun(N) ->
+ Run = mnesia_lib:is_running(N),
+ Run =:= yes orelse Run =:= starting
+ end,
+ GoodNodes = [N || N <- ProbablyGoodNodes, Verify(N)],
+
mnesia_lib:add_list(recover_nodes, GoodNodes),
cast({announce_all, GoodNodes}),
- case get_master_nodes(schema) of
+ case get_master_nodes(schema) of
[] ->
Context = starting_partitioned_network,
mnesia_monitor:detect_inconcistency(GoodNodes, Context);
@@ -842,6 +859,14 @@ handle_cast({what_decision, Node, OtherD}, State) ->
{noreply, State};
handle_cast({mnesia_down, Node}, State) ->
+ %% The node was already removed from recover_nodes in mnesia_down/1,
+ %% but we do it again here in the mnesia_recover process, in case
+ %% another event incorrectly added it back. This can happen during
+ %% Mnesia startup which takes time betweenthe connection, the
+ %% protocol negotiation and the merge of the schema.
+ %%
+ %% See a comment in handle_call({connect_nodes, ...), ...).
+ mnesia_lib:del(recover_nodes, Node),
case State#state.unclear_decision of
undefined ->
{noreply, State};