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author | Dan Gudmundsson <dgud@erlang.org> | 2014-02-12 14:50:49 +0100 |
---|---|---|
committer | Dan Gudmundsson <dgud@erlang.org> | 2014-02-20 12:38:51 +0100 |
commit | 70373f8cb0a3fe404c1e51e0ade0c98b83aa0014 (patch) | |
tree | 32fc44566f344b8d1b3196ee74902d6afb584a5c /lib | |
parent | fdcdaca338849d7f63d4300e489318f6ee275d82 (diff) | |
download | otp-70373f8cb0a3fe404c1e51e0ade0c98b83aa0014.tar.gz otp-70373f8cb0a3fe404c1e51e0ade0c98b83aa0014.tar.bz2 otp-70373f8cb0a3fe404c1e51e0ade0c98b83aa0014.zip |
mnesia: Add explicit sync_log command
For performance reasons the file data is not synced to disk in mnesia,
data loss can happen between each dump.
mnesia:dump_log() can be used explicitly to ensure data is written to disk.
But that can take a long time, so mnesia:sync_log() which just
sync the log have been added.
Diffstat (limited to 'lib')
-rw-r--r-- | lib/mnesia/doc/src/mnesia.xml | 26 | ||||
-rw-r--r-- | lib/mnesia/src/mnesia.erl | 6 | ||||
-rw-r--r-- | lib/mnesia/src/mnesia_monitor.erl | 7 | ||||
-rw-r--r-- | lib/mnesia/test/mnesia_nice_coverage_test.erl | 3 |
4 files changed, 36 insertions, 6 deletions
diff --git a/lib/mnesia/doc/src/mnesia.xml b/lib/mnesia/doc/src/mnesia.xml index 914ec77721..72e9bd7e8f 100644 --- a/lib/mnesia/doc/src/mnesia.xml +++ b/lib/mnesia/doc/src/mnesia.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2013</year> + <year>1996</year><year>2014</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -1204,7 +1204,11 @@ mnesia:create_table(person, <desc> <p>Performs a user initiated dump of the local log file. This is usually not necessary since Mnesia, by default, - manages this automatically.</p> + manages this automatically. + See configuration parameters + <seealso marker="#dump_log_time_threshold">dump_log_time_threshold</seealso> and + <seealso marker="#dump_log_write_threshold">dump_log_write_threshold</seealso>. + </p> </desc> </func> <func> @@ -2208,6 +2212,18 @@ mnesia:create_table(employee, </desc> </func> <func> + <name>sync_log() -> ok | {error, Reason} </name> + <fsummary>Perform a file sync of the local log file.</fsummary> + <desc> + <p>Ensures that the local transaction log file is synced to disk. + On a single node system data written to disk tables, since the last dump, + can be lost in case of a power outage. + See <seealso marker="#dump_log/0">dump_log/0</seealso>. + </p> + </desc> + </func> + + <func> <name>sync_transaction(Fun, [[, Args], Retries]) -> {aborted, Reason} | {atomic, ResultOfFun} </name> <fsummary>Synchronously execute a transaction.</fsummary> <desc> @@ -2445,7 +2461,7 @@ mnesia:create_table(employee, <name>table(Tab [,[Option]]) -> QueryHandle </name> <fsummary>Return a QLC query handle.</fsummary> <desc> - <p> <marker id="qlc_table"></marker> + <p><marker id="qlc_table"></marker> Returns a QLC (Query List Comprehension) query handle, see <seealso marker="stdlib:qlc">qlc(3)</seealso>.The module <c>qlc</c> implements a query language, it can use mnesia tables as sources of data. Calling @@ -3015,6 +3031,7 @@ raise(Name, Amount) -> performed on the original data file. The default is <c>true</c></p> </item> <item> + <marker id=" dump_log_write_threshold"></marker> <p><c>-mnesia dump_log_write_threshold Max</c>, where <c>Max</c> is an integer which specifies the maximum number of writes allowed to the transaction log before a new dump of the log @@ -3022,13 +3039,14 @@ raise(Name, Amount) -> </p> </item> <item> + <marker id=" dump_log_time_threshold"></marker> <p><c>-mnesia dump_log_time_threshold Max</c>, where <c>Max</c> is an integer which specifies the dump log interval in milliseconds. It defaults to 3 minutes. If a dump has not been performed within <c>dump_log_time_threshold</c> milliseconds, then a new dump is performed regardless of how many writes have been - performed. + performed. </p> </item> <item> diff --git a/lib/mnesia/src/mnesia.erl b/lib/mnesia/src/mnesia.erl index 70466d10d7..b791e1221f 100644 --- a/lib/mnesia/src/mnesia.erl +++ b/lib/mnesia/src/mnesia.erl @@ -104,7 +104,8 @@ set_master_nodes/1, set_master_nodes/2, %% Misc admin - dump_log/0, subscribe/1, unsubscribe/1, report_event/1, + dump_log/0, sync_log/0, + subscribe/1, unsubscribe/1, report_event/1, %% Snmp snmp_open_table/2, snmp_close_table/1, @@ -2554,6 +2555,9 @@ set_master_nodes(Tab, Nodes) -> dump_log() -> mnesia_controller:sync_dump_log(user). +sync_log() -> + mnesia_monitor:sync_log(latest_log). + subscribe(What) -> mnesia_subscr:subscribe(self(), What). diff --git a/lib/mnesia/src/mnesia_monitor.erl b/lib/mnesia/src/mnesia_monitor.erl index c7b905a1bf..7b56613ad7 100644 --- a/lib/mnesia/src/mnesia_monitor.erl +++ b/lib/mnesia/src/mnesia_monitor.erl @@ -44,6 +44,7 @@ set_env/2, start/0, start_proc/4, + sync_log/1, terminate_proc/3, unsafe_close_dets/1, unsafe_close_log/1, @@ -118,6 +119,9 @@ open_log(Args) -> reopen_log(Name, Fname, Head) -> unsafe_call({reopen_log, Name, Fname, Head}). +sync_log(Name) -> + unsafe_call({sync_log, Name}). + close_log(Name) -> unsafe_call({close_log, Name}). @@ -382,6 +386,9 @@ handle_call({reopen_log, Name, Fname, Head}, _From, State) -> {noreply, State} end; +handle_call({sync_log, Name}, _From, State) -> + {reply, disk_log:sync(Name), State}; + handle_call({close_log, Name}, _From, State) -> case disk_log:close(Name) of ok -> diff --git a/lib/mnesia/test/mnesia_nice_coverage_test.erl b/lib/mnesia/test/mnesia_nice_coverage_test.erl index 78eab67b11..4b28ac634f 100644 --- a/lib/mnesia/test/mnesia_nice_coverage_test.erl +++ b/lib/mnesia/test/mnesia_nice_coverage_test.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 1996-2010. All Rights Reserved. +%% Copyright Ericsson AB 1996-2014. All Rights Reserved. %% %% The contents of this file are subject to the Erlang Public License, %% Version 1.1, (the "License"); you may not use this file except in @@ -189,6 +189,7 @@ adm(Attrs, Node1, Node2) -> ?match({atomic, ok}, mnesia:move_table_copy(nice_tab, Node2, Node1)), ?match(yes, mnesia:force_load_table(nice_counter_tab)), + ?match(ok, mnesia:sync_log()), ?match(dumped, mnesia:dump_log()), ok. |