svn commit - mysqldoc@oter02: r25785 - trunk/dynamic-docs/glossary

[john.russell]

Author: jdrussel
Date: 2011-04-07 21:05:59 +0200 (Thu, 07 Apr 2011)
New Revision: 25785

Log:
Add a reference to innodb_print_all_deadlocks.


Modified:
   trunk/dynamic-docs/glossary/innodb.xml


Modified: trunk/dynamic-docs/glossary/innodb.xml
===================================================================
--- trunk/dynamic-docs/glossary/innodb.xml	2011-04-07 18:51:10 UTC (rev 25784)
+++ trunk/dynamic-docs/glossary/innodb.xml	2011-04-07 19:05:59 UTC (rev 25785)
Changed blocks: 2, Lines Added: 14, Lines Deleted: 9; 2201 bytes

@@ -1958,13 +1958,13 @@
         available, neither will ever release the locks it holds.
       </para>
       <para>
-        A deadlock can occur when the transactions acquire locks on
-        multiple tables, but in the opposite order. A deadlock can also
-        occur when statements such as <literal>UPDATE</literal> or
-        <literal>SELECT ... FOR UPDATE</literal> lock ranges of index
-        records and <emphasis role="bold">gaps</emphasis>, with each
-        transaction acquiring some locks but not others due to a timing
-        issue.
+        A deadlock can occur when the transactions lock rows in multiple
+        tables (through statements such as <literal>UPDATE</literal> or
+        <literal>SELECT ... FOR UPDATE</literal>), but in the opposite
+        order. A deadlock can also occur when such statements lock
+        ranges of index records and
+        <emphasis role="bold">gaps</emphasis>, with each transaction
+        acquiring some locks but not others due to a timing issue.
       </para>
       <para>
         To reduce the possibility of deadlocks, use transactions rather

@@ -1987,8 +1987,13 @@
         transactions (the <emphasis role="bold">victim</emphasis>).
         Thus, even if your application logic is perfectly correct, you
         must still handle the case where a transaction must be retried.
-        To monitor how frequently deadlocks occur, use the command
-        <literal>SHOW ENGINE INNODB STATUS</literal>.
+        To see the last deadlock in an InnoDB user transaction, use the
+        command <literal>SHOW ENGINE INNODB STATUS</literal>. If
+        frequent deadlocks highlight a problem with transaction
+        structure or application error handling, run with the
+        <literal role="sysvar">innodb_print_all_deadlocks</literal>
+        setting enabled to print information about all deadlocks to the
+        <literal>mysqld</literal> error log.
       </para>
 
     </def>