diff options
Diffstat (limited to 'lib/mnesia')
| -rw-r--r-- | lib/mnesia/doc/src/Mnesia_chap5.xmlsrc | 1 | ||||
| -rw-r--r-- | lib/mnesia/doc/src/mnesia.xml | 16 | ||||
| -rw-r--r-- | lib/mnesia/src/mnesia_recover.erl | 31 |
3 files changed, 38 insertions, 10 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 268dc18e65..ed5b879f7f 100644 --- a/lib/mnesia/doc/src/mnesia.xml +++ b/lib/mnesia/doc/src/mnesia.xml @@ -151,9 +151,9 @@ If a new item is inserted with the same key as </item> <item> <p><c>local_content</c> When an application requires - tables whose contents is local to each node, + tables whose contents are local to each node, <c>local_content</c> tables may be used. The name of the - table is known to all Mnesia nodes, but its contents is + table is known to all Mnesia nodes, but its contents are unique on each node. This means that access to such a table must be done locally. Set the <c>local_content</c> field to <c>true</c> if you want to enable the <c>local_content</c> @@ -579,7 +579,7 @@ mnesia:add_table_index(person, age) <desc> <p>The tables are backed up to external media using the backup module <c>BackupMod</c>. Tables with the local contents - property is being backed up as they exist on the current + property are backed up as they exist on the current node. <c>BackupMod</c> is the default backup callback module obtained by <c>mnesia:system_info(backup_module)</c>. See the User's @@ -863,7 +863,7 @@ mnesia:create_table(person, {attributes, record_info(fields,person)}]). </code> <p>The specification of <c>index</c> and <c>attributes</c> may be - hard coded as <c>{index, [2]}</c> and + hard coded as <c>{index, [4]}</c> and <c>{attributes, [name, age, address, salary, children]}</c> respectively. </p> @@ -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}; |