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Age	Commit message (Collapse)	Author
2011-09-15	[mnesia] Fix schema conversion to previous versions	Dan Gudmundsson

2011-09-15	[mnesia] Mnesia schema merge tested with 2 nodes, r13b04 -> r14b (dev)	Ulf Wiger
	The do_merge_schema function now converts cstructs from a remote node when it detects that they are different. In order to be compatible the other way around, mnesia_controller:get_cstructs() detects a remote caller, and converts the cstructs before sending them.
2011-05-16	where_to_wlock optimization + change_table_majority/2	Ulf Wiger

2011-04-04	Mnesia sometimes failed to tell all nodes that it had started.	Dan Gudmundsson

2010-09-15	mnesia: Do not auto-import error/2	Tuncer Ayaz
	Resolve name clash with auto-imported BIF error/2.
2010-06-04	Merge branch 'uw/mnesia-overload' into dev	Erlang/OTP
	* uw/mnesia-overload: Enable continuous monitoring of mnesia overload status
2010-06-04	Merge branch 'uw/mnesia-schema-merge' into dev	Erlang/OTP
	* uw/mnesia-schema-merge: remove debug printout and accidental variable name reuse Allow a user_defined function to wrap mnesia_schema:merge_schema()
2010-06-02	Allow a user_defined function to wrap mnesia_schema:merge_schema()	Ulf Wiger
	Mnesia currently notifies the user if it detects a partitioned network, but the options for resolving the situation are limited. In practice, the only safe options are: - set master_nodes and restart one of the affected 'islands' - restart the entire system from backup This patch introduces a way to resolve the situation without restarting any nodes. The key to doing this safely is to lock affected tables and run the merge function inside the same transaction that merges the schema. Otherwise, one transaction will merge the schema, after which writes to the database will be replicated across the (potentially) inconsistent copies; the transaction triggered by the asynchronous inconsistency event will have to race to be the first to access the tables. The normal call to merge the schema is done from mnesia_controller. Previously, this was mnesia_schema:merge_schema(). The new function is merge_schema(UserFun), with the following behaviour: merge_schema(UserFun) -> schema_transaction( fun() -> UserFun(fun(Arg) -> do_merge_schema(Arg) end) end). Where do_merge_schema(LockTabs) will execute the schema merge as before, but also lock all tables in the list LockTabs which have copies on the affected nodes (that is, everywhere the schema table is locked). The effect of this is to allow a wrapper function that calls the merge and, if successful, continues to resolve the inconsistency on the tables, knowing that they have now been locked on all affected nodes. The function that is actually called by the deconflict function is mnesia_controller:connect_nodes(Nodes, UserFun), as in: Tables = tables_to_deconflict(Node), mnesia_controller:connect_nodes( [Node], fun(MergeF) -> case MergeF(Tables) of {merged,_,_} -> deconflict(Tables, Node); Other -> Other end). In the case where the merge fails, it is probably wise to restart from a backup... I have not run the mnesia test suite, as it is not available. I have not updated documentation, as these functions are not documented in the first place.
2010-05-09	Enable continuous monitoring of mnesia overload status	Ulf Wiger
	Mnesia currently issues an event whenever it detects an overload condition. It recognizes two different types of overload: - whenever the message queue of mnesia_tm process grows large - when a log dump interval triggers before the previous dump is done These events could be used to trigger a load regulation mechanism to reduce the load until the condition seizes. The missing piece is that there is no facility to ask mnesia whether the overload condition still exists. This patch implements a couple of functions in mnesia_lib that can be used to sample the overload status. It has been tested in a load regulator component being developed by Erlang Solutions. No mnesia test suites have been run, since they are not available. No documentation has been updated. The functions in mnesia_lib are at any rate undocumented (as are all other functions in that module). A decision would have to be made about whether to provide a documented API on top of these functions. The internal state record of mnesia_recover has been modified. For this reason, a code change hook has been provided.
2009-11-20	The R13B03 release.OTP_R13B03	Erlang/OTP