Author: paul
Date: 2008-11-14 02:41:32 +0100 (Fri, 14 Nov 2008)
New Revision: 12468
Log:
Modified:
trunk/refman-6.0/replication-solutions.xml
Property changes on: trunk
___________________________________________________________________
Name: svk:merge
- 4767c598-dc10-0410-bea0-d01b485662eb:/mysqldoc-local/mysqldoc/trunk:39854
7d8d2c4e-af1d-0410-ab9f-b038ce55645b:/mysqldoc-local/mysqldoc:35700
b5ec3a16-e900-0410-9ad2-d183a3acac99:/mysqldoc-local/mysqldoc/trunk:14218
bf112a9c-6c03-0410-a055-ad865cd57414:/mysqldoc-local/mysqldoc/trunk:34365
+ 4767c598-dc10-0410-bea0-d01b485662eb:/mysqldoc-local/mysqldoc/trunk:39854
7d8d2c4e-af1d-0410-ab9f-b038ce55645b:/mysqldoc-local/mysqldoc:35706
b5ec3a16-e900-0410-9ad2-d183a3acac99:/mysqldoc-local/mysqldoc/trunk:14218
bf112a9c-6c03-0410-a055-ad865cd57414:/mysqldoc-local/mysqldoc/trunk:34365
Modified: trunk/refman-6.0/replication-solutions.xml
===================================================================
--- trunk/refman-6.0/replication-solutions.xml 2008-11-14 00:29:07 UTC (rev 12467)
+++ trunk/refman-6.0/replication-solutions.xml 2008-11-14 01:41:32 UTC (rev 12468)
Changed blocks: 3, Lines Added: 46, Lines Deleted: 12; 4010 bytes
@@ -1559,6 +1559,41 @@
processes other than the one you are using to
perform tasks on C relating to the software upgrade.
</para>
+
+ <para>
+ You can prevent any application clients from
+ reconnecting to C by executing the following
+ statement as MySQL <literal>root</literal> (or
+ another user having the
+ <literal role="priv">SUPER</literal> privilege):
+
+<programlisting>
+SET @@GLOBAL.MAX_CONNECTIONS = 1;
+</programlisting>
+ </para>
+
+ <para>
+ Once this has been done, only a single client,
+ having the <literal role="priv">SUPER</literal>
+ privilege, may connect to C. This works because
+ <literal>max_connections + 1</literal> clients are
+ allowed to connect to the server, with one of these
+ connections being reserved for a client having the
+ <literal role="priv">SUPER</literal> privilege.
+ Therefore, when <literal>max_connections</literal>
+ is equal to 1, and no other clients are connected, a
+ maximum of 1 client <emphasis>not</emphasis> having
+ <literal role="priv">SUPER</literal> may connect.
+ However, a client not having the
+ <literal>SUPER</literal> privilege cannot use the
+ extra connection. This means that, when
+ <literal>max_connections</literal> is
+ <literal>1</literal> and a client having
+ <literal role="priv">SUPER</literal> is already
+ connected, no
+ non-<literal role="priv">SUPER</literal> clients may
+ connect connect to the server.
+ </para>
</listitem>
<listitem>
@@ -1748,13 +1783,12 @@
<para>
Start server C', insuring that all its tables are in
- read-only mode. You can do this by starting
- <command>mysqld</command> with the
- <option>--read_only</option> option. Using this option
- allows only slave threads or clients having the
- <literal role="priv">SUPER</literal> privilege to perform
- any updates on the server. (For more information about
- this option, see
+ read-only mode, and that no MySQL clients (with the
+ exception of a single connection from a superuser account)
+ can connect to it. You can do this by starting
+ <command>mysqld</command> with the options
+ <option>--read_only --max_connections=1</option>. (For
+ more information about these options, see
<xref linkend="server-system-variables"/>.)
</para>
@@ -1938,11 +1972,11 @@
<para>
This can be done by setting
- <literal>@@GLOBAL.READ_ONLY</literal> to
- <literal>0</literal> or <literal>OFF</literal>, thereby
- permitting regular clients other than those having the
- <literal role="priv">SUPER</literal> privilege once again
- to connect.
+ <literal>@@GLOBAL.MAX_CONNECTIONS</literal> to an
+ appropriate value greater than <literal>1</literal>,
+ thereby once again permitting regular clients not having
+ the <literal role="priv">SUPER</literal> privilege to
+ connect.
</para>
</formalpara>
| Thread |
|---|
| • svn commit - mysqldoc@docsrva: r12468 - in trunk: . refman-6.0 | paul.dubois | 14 Nov |
