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authorDan Gudmundsson <[email protected]>2014-02-12 14:50:49 +0100
committerDan Gudmundsson <[email protected]>2014-02-20 12:38:51 +0100
commit70373f8cb0a3fe404c1e51e0ade0c98b83aa0014 (patch)
tree32fc44566f344b8d1b3196ee74902d6afb584a5c /lib/mnesia/doc
parentfdcdaca338849d7f63d4300e489318f6ee275d82 (diff)
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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/mnesia/doc')
-rw-r--r--lib/mnesia/doc/src/mnesia.xml26
1 files changed, 22 insertions, 4 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>