Author: jstephens
Date: 2006-08-09 16:43:05 +0200 (Wed, 09 Aug 2006)
New Revision: 2981
Log:
Fixing Docs Bug #19931.
UndoDataBuffer, UndoIndexBuffer parameters no longer present in 5.1.
(Thanks, Martin & Hartmut!)
Modified:
trunk/refman-4.1/mysql-cluster.xml
trunk/refman-5.0/mysql-cluster.xml
trunk/refman-5.1/mysql-cluster.xml
Modified: trunk/refman-4.1/mysql-cluster.xml
===================================================================
--- trunk/refman-4.1/mysql-cluster.xml 2006-08-09 13:47:16 UTC (rev 2980)
+++ trunk/refman-4.1/mysql-cluster.xml 2006-08-09 14:43:05 UTC (rev 2981)
Changed blocks: 4, Lines Added: 20, Lines Deleted: 4; 2193 bytes
@@ -5234,8 +5234,7 @@
<listitem>
<indexterm>
- <primary><literal>UndoIndexBuffer</literal> (MySQL Cluster configuration
- parameter)</primary>
+ <primary><literal>UndoIndexBuffer</literal></primary>
</indexterm>
<para id="mysql-cluster-param-ndbd-definition-undoindexbuffer">
@@ -5282,12 +5281,17 @@
engine issues internal error code 677 (<literal>Index UNDO
buffers overloaded</literal>).
</para>
+
+ <para>
+ <emphasis role="bold">Important</emphasis>: It is not safe
+ to decrease the value of this parameter during a rolling
+ restart.
+ </para>
</listitem>
<listitem>
<indexterm>
- <primary><literal>UndoDataBuffer</literal> (MySQL Cluster configuration
- parameter)</primary>
+ <primary><literal>UndoDataBuffer</literal></primary>
</indexterm>
<para id="mysql-cluster-param-ndbd-definition-undodatabuffer">
@@ -5329,6 +5333,12 @@
storage engine issues internal error code 891
(<errortext>Data UNDO buffers overloaded</errortext>).
</para>
+
+ <para>
+ <emphasis role="bold">Important</emphasis>: It is not safe
+ to decrease the value of this parameter during a rolling
+ restart.
+ </para>
</listitem>
<listitem>
@@ -5360,6 +5370,12 @@
error code 1221 (<literal>REDO log buffers
overloaded</literal>).
</para>
+
+ <para>
+ <emphasis role="bold">Important</emphasis>: It is not safe
+ to decrease the value of this parameter during a rolling
+ restart.
+ </para>
</listitem>
</itemizedlist>
Modified: trunk/refman-5.0/mysql-cluster.xml
===================================================================
--- trunk/refman-5.0/mysql-cluster.xml 2006-08-09 13:47:16 UTC (rev 2980)
+++ trunk/refman-5.0/mysql-cluster.xml 2006-08-09 14:43:05 UTC (rev 2981)
Changed blocks: 4, Lines Added: 20, Lines Deleted: 4; 2193 bytes
@@ -5217,8 +5217,7 @@
<listitem>
<indexterm>
- <primary><literal>UndoIndexBuffer</literal> (MySQL Cluster configuration
- parameter)</primary>
+ <primary><literal>UndoIndexBuffer</literal></primary>
</indexterm>
<para id="mysql-cluster-param-ndbd-definition-undoindexbuffer">
@@ -5265,12 +5264,17 @@
engine issues internal error code 677 (<literal>Index UNDO
buffers overloaded</literal>).
</para>
+
+ <para>
+ <emphasis role="bold">Important</emphasis>: It is not safe
+ to decrease the value of this parameter during a rolling
+ restart.
+ </para>
</listitem>
<listitem>
<indexterm>
- <primary><literal>UndoDataBuffer</literal> (MySQL Cluster configuration
- parameter)</primary>
+ <primary><literal>UndoDataBuffer</literal></primary>
</indexterm>
<para id="mysql-cluster-param-ndbd-definition-undodatabuffer">
@@ -5312,6 +5316,12 @@
storage engine issues internal error code 891
(<errortext>Data UNDO buffers overloaded</errortext>).
</para>
+
+ <para>
+ <emphasis role="bold">Important</emphasis>: It is not safe
+ to decrease the value of this parameter during a rolling
+ restart.
+ </para>
</listitem>
<listitem>
@@ -5343,6 +5353,12 @@
error code 1221 (<literal>REDO log buffers
overloaded</literal>).
</para>
+
+ <para>
+ <emphasis role="bold">Important</emphasis>: It is not safe
+ to decrease the value of this parameter during a rolling
+ restart.
+ </para>
</listitem>
</itemizedlist>
Modified: trunk/refman-5.1/mysql-cluster.xml
===================================================================
--- trunk/refman-5.1/mysql-cluster.xml 2006-08-09 13:47:16 UTC (rev 2980)
+++ trunk/refman-5.1/mysql-cluster.xml 2006-08-09 14:43:05 UTC (rev 2981)
Changed blocks: 4, Lines Added: 32, Lines Deleted: 144; 8961 bytes
@@ -5207,126 +5207,8 @@
<emphasis role="bold">Buffering and Logging</emphasis>
</para>
- <para>
- Several <literal>[NDBD]</literal> configuration parameters
- corresponding to former compile-time parameters are also
- available. These enable the advanced user to have more control
- over the resources used by node processes and to adjust
- various buffer sizes at need.
- </para>
-
- <para>
- These buffers are used as front ends to the file system when
- writing log records to disk. If the node is running in
- diskless mode, these parameters can be set to their minimum
- values without penalty due to the fact that disk writes are
- <quote>faked</quote> by the <literal>NDB</literal> storage
- engine's filesystem abstraction layer.
- </para>
-
- <itemizedlist>
-
- <listitem>
+
<indexterm>
- <primary><literal>UndoIndexBuffer</literal> (MySQL Cluster configuration
- parameter)</primary>
- </indexterm>
-
- <para id="mysql-cluster-param-ndbd-definition-undoindexbuffer">
- <literal>UndoIndexBuffer</literal>
- </para>
-
- <para>
- The UNDO index buffer, whose size is set by this
- parameter, is used during local checkpoints. The
- <literal>NDB</literal> storage engine uses a recovery
- scheme based on checkpoint consistency in conjunction with
- an operational REDO log. To produce a consistent
- checkpoint without blocking the entire system for writes,
- UNDO logging is done while performing the local
- checkpoint. UNDO logging is activated on a single table
- fragment at a time. This optimization is possible because
- tables are stored entirely in main memory.
- </para>
-
- <para>
- The UNDO index buffer is used for the updates on the
- primary key hash index. Inserts and deletes rearrange the
- hash index; the NDB storage engine writes UNDO log records
- that map all physical changes to an index page so that
- they can be undone at system restart. It also logs all
- active insert operations for each fragment at the start of
- a local checkpoint.
- </para>
-
- <para>
- Reads and updates set lock bits and update a header in the
- hash index entry. These changes are handled by the
- page-writing algorithm to ensure that these operations
- need no UNDO logging.
- </para>
-
- <para>
- This buffer is 2MB by default. The minimum value is 1MB,
- which is sufficient for most applications. For
- applications doing extremely large or numerous inserts and
- deletes together with large transactions and large primary
- keys, it may be necessary to increase the size of this
- buffer. If this buffer is too small, the NDB storage
- engine issues internal error code 677 (<literal>Index UNDO
- buffers overloaded</literal>).
- </para>
- </listitem>
-
- <listitem>
- <indexterm>
- <primary><literal>UndoDataBuffer</literal> (MySQL Cluster configuration
- parameter)</primary>
- </indexterm>
-
- <para id="mysql-cluster-param-ndbd-definition-undodatabuffer">
- <literal>UndoDataBuffer</literal>
- </para>
-
- <para>
- This parameter sets the size of the UNDO data buffer,
- which performs a function similar to that of the UNDO
- index buffer, except the UNDO data buffer is used with
- regard to data memory rather than index memory. This
- buffer is used during the local checkpoint phase of a
- fragment for inserts, deletes, and updates.
- </para>
-
- <para>
- Because UNDO log entries tend to grow larger as more
- operations are logged, this buffer is also larger than its
- index memory counterpart, with a default value of 16MB.
- </para>
-
- <para>
- This amount of memory may be unnecessarily large for some
- applications. In such cases, it is possible to decrease
- this size to a minimum of 1MB.
- </para>
-
- <para>
- It is rarely necessary to increase the size of this
- buffer. If there is such a need, it is a good idea to
- check whether the disks can actually handle the load
- caused by database update activity. A lack of sufficient
- disk space cannot be overcome by increasing the size of
- this buffer.
- </para>
-
- <para>
- If this buffer is too small and gets congested, the NDB
- storage engine issues internal error code 891
- (<errortext>Data UNDO buffers overloaded</errortext>).
- </para>
- </listitem>
-
- <listitem>
- <indexterm>
<primary><literal>RedoBuffer</literal></primary>
</indexterm>
@@ -5335,7 +5217,7 @@
</para>
<para>
- All update activities also need to be logged. The REDO log
+ All update activities need to be logged. The REDO log
makes it possible to replay these updates whenever the
system is restarted. The NDB recovery algorithm uses a
<quote>fuzzy</quote> checkpoint of the data together with
@@ -5346,18 +5228,40 @@
<para>
<literal>RedoBuffer</literal> sets the size of the buffer
inwhich the REDO log is written, and is 8MB by default.
- The minimum value is 1MB.
- </para>
-
- <para>
- If this buffer is too small, the NDB storage engine issues
+ This buffer is used as a front end to the file system when
+ writing REDO log records to disk. If this buffer is too
+ small, the <literal>NDB</literal> storage engine issues
error code 1221 (<literal>REDO log buffers
overloaded</literal>).
</para>
- </listitem>
+ <para>
+ The minimum value is 1MB. If the node is running in
+ diskless mode, these parameters can be set to their minimum
+ values without penalty due to the fact that disk writes are
+ <quote>faked</quote> by the <literal>NDB</literal> storage
+ engine's filesystem abstraction layer.
+ </para>
+
+ <para>
+ <emphasis role="bold">Important</emphasis>: It is not safe
+ to decrease the value of this parameter during a rolling
+ restart.
+ </para>
+ <indexterm>
+ <primary><literal>UndoDataBuffer</literal></primary>
+ </indexterm>
+ <indexterm>
+ <primary><literal>UndoIndexBuffer</literal></primary>
+ </indexterm>
+
+ <para>
+ <emphasis role="bold">Note</emphasis>: The
+ <literal>UndoIndexBuffer</literal> and
+ <literal>UndoDataBuffer</literal> parameters which appeared in
+ earlier versions of MySQL Cluster are no longer necessary (or
+ even present) in MySQL 5.1.
+ </para>
- </itemizedlist>
-
<para id="mysql-cluster-controlling-log-messages">
<emphasis role="bold">Controlling Log Messages</emphasis>
</para>
@@ -7216,22 +7120,6 @@
<entry>4294967039</entry>
<entry>N</entry>
</row>
- <row>
- <entry><literal><link linkend="mysql-cluster-param-ndbd-definition-undodatabuffer">UndoDataBuffer</link></literal></entry>
- <entry>bytes</entry>
- <entry>16M</entry>
- <entry>1M</entry>
- <entry>4294967039</entry>
- <entry>N</entry>
- </row>
- <row>
- <entry><literal><link linkend="mysql-cluster-param-ndbd-definition-undoindexbuffer">UndoIndexBuffer</link></literal></entry>
- <entry>bytes</entry>
- <entry>2M</entry>
- <entry>1M</entry>
- <entry>4294967039</entry>
- <entry>N</entry>
- </row>
</tbody>
</tgroup>
</informaltable>
| Thread |
|---|
| • svn commit - mysqldoc@docsrva: r2981 - in trunk: refman-4.1 refman-5.0 refman-5.1 | jon | 9 Aug |
