Author: paul
Date: 2008-05-05 00:50:12 +0200 (Mon, 05 May 2008)
New Revision: 10666
Log:
r31173@frost: paul | 2008-05-04 17:50:36 -0500
Add MC's ha-vm chapter
Added:
trunk/refman-common/ha-vm.xml
trunk/refman-common/images/published/ec2fig1.png
trunk/refman-common/images/published/ec2fig2.png
trunk/refman-common/images/published/ec2fig3.png
Modified:
trunk/refman-5.1/Makefile.depends
trunk/refman-5.1/manual.xml
trunk/refman-6.0/Makefile.depends
trunk/refman-6.0/manual.xml
Property changes on: trunk
___________________________________________________________________
Name: svk:merge
- 4767c598-dc10-0410-bea0-d01b485662eb:/mysqldoc-local/mysqldoc/trunk:35828
7d8d2c4e-af1d-0410-ab9f-b038ce55645b:/mysqldoc-local/mysqldoc:31159
b5ec3a16-e900-0410-9ad2-d183a3acac99:/mysqldoc-local/mysqldoc/trunk:14218
bf112a9c-6c03-0410-a055-ad865cd57414:/mysqldoc-local/mysqldoc/trunk:31090
+ 4767c598-dc10-0410-bea0-d01b485662eb:/mysqldoc-local/mysqldoc/trunk:35828
7d8d2c4e-af1d-0410-ab9f-b038ce55645b:/mysqldoc-local/mysqldoc:31173
b5ec3a16-e900-0410-9ad2-d183a3acac99:/mysqldoc-local/mysqldoc/trunk:14218
bf112a9c-6c03-0410-a055-ad865cd57414:/mysqldoc-local/mysqldoc/trunk:31090
Property changes on: trunk/refman-common/images/published/ec2fig1.png
___________________________________________________________________
Name: svn:mime-type
+ application/octet-stream
Property changes on: trunk/refman-common/images/published/ec2fig2.png
___________________________________________________________________
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+ application/octet-stream
Property changes on: trunk/refman-common/images/published/ec2fig3.png
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Name: svn:mime-type
+ application/octet-stream
Modified: trunk/refman-5.1/Makefile.depends
===================================================================
--- trunk/refman-5.1/Makefile.depends 2008-05-03 23:13:56 UTC (rev 10665)
+++ trunk/refman-5.1/Makefile.depends 2008-05-04 22:50:12 UTC (rev 10666)
Changed blocks: 3, Lines Added: 7, Lines Deleted: 0; 1570 bytes
@@ -1436,6 +1436,7 @@
../refman-common/credits.xml \
../refman-common/ha-drbd.xml \
../refman-common/ha-heartbeat.xml \
+ ../refman-common/ha-vm.xml \
../refman-common/ha.xml \
../refman-common/images/published/PSEArch.png \
../refman-common/images/published/active-master-mysql-server.png \
@@ -1456,6 +1457,9 @@
../refman-common/images/published/cnet-win-install-step4.png \
../refman-common/images/published/drbd-main.png \
../refman-common/images/published/drbd-sepinterface.png \
+ ../refman-common/images/published/ec2fig1.png \
+ ../refman-common/images/published/ec2fig2.png \
+ ../refman-common/images/published/ec2fig3.png \
../refman-common/images/published/ha-heartbeat-overview.png \
../refman-common/images/published/multi-comp-1.png \
../refman-common/images/published/multi-db.png \
@@ -1647,6 +1651,9 @@
../refman-common/images/published/cnet-win-install-step4.png \
../refman-common/images/published/drbd-main.png \
../refman-common/images/published/drbd-sepinterface.png \
+ ../refman-common/images/published/ec2fig1.png \
+ ../refman-common/images/published/ec2fig2.png \
+ ../refman-common/images/published/ec2fig3.png \
../refman-common/images/published/ha-heartbeat-overview.png \
../refman-common/images/published/multi-comp-1.png \
../refman-common/images/published/multi-db.png \
Modified: trunk/refman-5.1/manual.xml
===================================================================
--- trunk/refman-5.1/manual.xml 2008-05-03 23:13:56 UTC (rev 10665)
+++ trunk/refman-5.1/manual.xml 2008-05-04 22:50:12 UTC (rev 10666)
Changed blocks: 1, Lines Added: 2, Lines Deleted: 0; 625 bytes
@@ -60,6 +60,8 @@
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="../refman-common/ha.xml"/>
+ <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="../refman-common/ha-vm.xml"/>
+
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="../refman-common/load-balancer.xml"/>
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="replication.xml"/>
Modified: trunk/refman-6.0/Makefile.depends
===================================================================
--- trunk/refman-6.0/Makefile.depends 2008-05-03 23:13:56 UTC (rev 10665)
+++ trunk/refman-6.0/Makefile.depends 2008-05-04 22:50:12 UTC (rev 10666)
Changed blocks: 3, Lines Added: 7, Lines Deleted: 0; 1570 bytes
@@ -1253,6 +1253,7 @@
../refman-common/credits.xml \
../refman-common/ha-drbd.xml \
../refman-common/ha-heartbeat.xml \
+ ../refman-common/ha-vm.xml \
../refman-common/ha.xml \
../refman-common/images/published/PSEArch.png \
../refman-common/images/published/active-master-mysql-server.png \
@@ -1273,6 +1274,9 @@
../refman-common/images/published/cnet-win-install-step4.png \
../refman-common/images/published/drbd-main.png \
../refman-common/images/published/drbd-sepinterface.png \
+ ../refman-common/images/published/ec2fig1.png \
+ ../refman-common/images/published/ec2fig2.png \
+ ../refman-common/images/published/ec2fig3.png \
../refman-common/images/published/ha-heartbeat-overview.png \
../refman-common/images/published/multi-comp-1.png \
../refman-common/images/published/multi-db.png \
@@ -1463,6 +1467,9 @@
../refman-common/images/published/cnet-win-install-step4.png \
../refman-common/images/published/drbd-main.png \
../refman-common/images/published/drbd-sepinterface.png \
+ ../refman-common/images/published/ec2fig1.png \
+ ../refman-common/images/published/ec2fig2.png \
+ ../refman-common/images/published/ec2fig3.png \
../refman-common/images/published/ha-heartbeat-overview.png \
../refman-common/images/published/multi-comp-1.png \
../refman-common/images/published/multi-db.png \
Modified: trunk/refman-6.0/manual.xml
===================================================================
--- trunk/refman-6.0/manual.xml 2008-05-03 23:13:56 UTC (rev 10665)
+++ trunk/refman-6.0/manual.xml 2008-05-04 22:50:12 UTC (rev 10666)
Changed blocks: 1, Lines Added: 2, Lines Deleted: 0; 625 bytes
@@ -60,6 +60,8 @@
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="../refman-common/ha.xml"/>
+ <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="../refman-common/ha-vm.xml"/>
+
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="../refman-common/load-balancer.xml"/>
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="replication.xml"/>
Added: trunk/refman-common/ha-vm.xml
===================================================================
--- trunk/refman-common/ha-vm.xml (rev 0)
+++ trunk/refman-common/ha-vm.xml 2008-05-04 22:50:12 UTC (rev 10666)
Changed blocks: 1, Lines Added: 1049, Lines Deleted: 0; 39733 bytes
@@ -0,0 +1,1049 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
+"http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd"
+[
+<!ENTITY % all.entities SYSTEM "all-entities.ent">
+%all.entities;
+]>
+<chapter id="ha-vm">
+
+ <title>MySQL and Virtualization</title>
+
+ <para>
+ Using virtualization can be an effective way of better utilizing the
+ hardware of your machine when using with MySQL, or to provide
+ improved security or isolation of different instances of MySQL on
+ the same machine. In some circumstances, virtualization may be a
+ suitable solution for scaling out your database environment by
+ enabling you to easily deploy additional instances of a
+ pre-configured MySQL server and application environment to new
+ virtualization hosts.
+ </para>
+
+ <para>
+ With any virtualization solution there is often a trade off between
+ the flexibility and ease of deployment and performance, or between
+ the potential performance advantage and complexities of effectively
+ configuring multiple instances of MySQL to reside within a single
+ physical host.
+ </para>
+
+ <para>
+ Different issues are experienced according to the virtualization
+ environment you are using. Virtualization generally falls into one
+ of the following categories:
+ </para>
+
+ <itemizedlist>
+
+ <listitem>
+ <para>
+ <emphasis role="bold">Native virtualization</emphasis>,
+ including products like VMware Workstation, Parallels
+ Desktop/Parallels Workstation, Microsoft Virtual PC and
+ VirtualBox, all work by acting as an application that runs
+ within an existing operating system environment. Recent versions
+ can take advantage of the virtualization extensions in the Intel
+ and AMD CPUs to help improve performance.
+ </para>
+
+ <para>
+ The application based solutions have a number of advantages,
+ including the ability to prioritize CPU usage (including
+ multiple CPUs) and easily run multiple virtualized environment
+ simultaneously.
+ </para>
+
+ <para>
+ With these solutions, you also have the ability to easily create
+ a virtualized environment that can be packaged and shared among
+ different virtualization hosts. For example, you can create a
+ MySQL environment and configuration that can be deployed
+ multiple times to help extend an existing scalability or HA
+ environment.
+ </para>
+
+ <para>
+ The major disadvantage of this type of virtualization
+ environment is the effect of the host on the performance of the
+ virtualization instances. Disk storage is typically provided by
+ using one or more files on the host OS which are then emulated
+ to provide physical disks within the virtual instance. Other
+ resources on the host are similarly shared, including CPU,
+ network interfaces and additional devices (USB). It is also
+ difficult to directly share lower-level components, such as PCI
+ devices and that the ability to take advantage of RAID storage
+ solutions.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ <emphasis role="bold">Paravirtualization
+ (Hypervisor)</emphasis>, including Xen, Solaris xVM (based on
+ Xen), VMware ESX Server, Windows Server 2008 Hyper-V, and
+ Solaris Logical Domains (LDOM), work by running a specialized
+ version of the host operating system. The host OS then allows
+ slightly modified versions of different operating systems to run
+ within the virtualized environment.
+ </para>
+
+ <para>
+ With paravirtualization, the level of performance and the
+ control over the underlying hardware used to support the
+ virtualized environments is higher than native virtualization
+ solutions. For example, using paravirtualization you can
+ dedicate individual CPU cores, RAM, disk drives and even PCI
+ devices to be accessible to individual and specific virtual
+ instances.
+ </para>
+
+ <para>
+ For example, within a paravirtualized environment you could
+ dedicate a physical disk drive or subsystem to a particular
+ virtual environment and gain a performance benefit over a
+ typical file-based solution virtual disk.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ <emphasis role="bold">Operating system-level
+ virtualization</emphasis>, including BSD jails, and Solaris
+ Containers/Zones, offer methods for isolating different
+ instances of an operating system environment while sharing the
+ same hardware environment. Unlike the other virtualization
+ solutions, operating system level virtualization is not normally
+ used to run other operating systems, but instead to provide a
+ level of security isolation and resource control within the core
+ operating environment.
+ </para>
+
+ <para>
+ The isolation of these different instances is the key advantage
+ of this type of virtualization. Each virtualized instance sees
+ their environment as if it were completely different system. The
+ solution can be an effective method to provide isolated
+ computing resources for different departments or users, or to
+ provide unique instances for testing and development.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ <para>
+ The main reasons for using virtualization, particularly with a
+ database or an application stack that includes a database component,
+ include:
+ </para>
+
+ <itemizedlist>
+
+ <listitem>
+ <para>
+ <emphasis role="bold">Security</emphasis> — separate
+ instances of different operating systems running within a single
+ host but with effective isolation from each other. When used
+ with MySQL you can provide an increased level of security
+ between different instances of each server.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ <emphasis role="bold">Consolidation</emphasis> — merging a
+ number of individual systems with a relatively small load onto a
+ single, larger, server. This can help reduce footprint and
+ energy costs, or make more efficient use of a larger machine.
+ Performance is the main issue with this solution as the load of
+ many MySQL databases running in individual virtual instances on
+ a single machine can be considerable.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ <emphasis role="bold">Development/QA/Testing</emphasis> —
+ by creating different instances of different environments and
+ operating systems you can test your MySQL-based application in
+ different environments.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ <emphasis role="bold">Scalability</emphasis> — although
+ using virtualization imposes a performance hit, many
+ virtualization solutions allow you to create a packaged version
+ of an environment, including MySQL and the other application
+ components. By distributing the virtualization environment
+ package to new hosts you can often very quickly scale out by
+ adding new hosts and deploying the virtualized environment.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ <para>
+ The remainder of this chapter looks at common issues with using
+ MySQL in a virtualized environment and tips for using MySQL within
+ different virtualization tools.
+ </para>
+
+ <para>
+ For advice on common issues and problems, including performance and
+ configuration issues, when using virtualized instances, see
+ <xref linkend="ha-vm-commonissues"/>.
+ </para>
+
+ <section id="ha-vm-commonissues">
+
+ <title>Common Issues with Virtualization</title>
+
+ <para>
+ There are many issues related to using MySQL within a virtualized
+ environment that are common across the different virtualization
+ types. Most are directly related to the performance or security of
+ the environment in which you are deploying the MySQL server
+ compared to the host on which you are running the virtualization
+ solution.
+ </para>
+
+ <para>
+ Before deciding to use virtualization as a solution for your
+ database, you should ensure that the expected load for the server
+ and the expected performance when run in a virtualized environment
+ meet your needs and requirements.
+ </para>
+
+ <para>
+ To help you determine the issues and some of the potential
+ solutions, use the following sections:
+ </para>
+
+ <itemizedlist>
+
+ <listitem>
+ <para>
+ For general performance issues and the problems and probably
+ causes of performance issues, see
+ <xref linkend="ha-vm-commonissues-performance"/>.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Disk and storage concerns directly affect database storage
+ because most database access is limited by the I/O bandwidth.
+ For some examples and issues, see
+ <xref linkend="ha-vm-commonissues-storage"/>.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Issues related to network configuration and performance may
+ need more careful planning, especially if you are using
+ network-specific technologies such as MySQL replication. For
+ further examples and details, see
+ <xref linkend="ha-vm-commonissues-networking"/>.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ <section id="ha-vm-commonissues-performance">
+
+ <title>Virtualization Performance Issues</title>
+
+ <para>
+ Often the biggest consideration is the performance of a
+ virtualized environment once hosted. In most cases, the
+ virtualized environment involves some level of emulation of one
+ or more of the hardware interfaces (CPU, network or disk) of the
+ host environment. The effect is to reduce the effective
+ performance of the virtualized environment compared to running
+ an application natively on the host.
+ </para>
+
+ <para>
+ Some core resourcing issues to be aware of include:
+ </para>
+
+ <itemizedlist>
+
+ <listitem>
+ <para>
+ Using virtualization does not reduce the amount of CPU
+ required to support a particular application or environment.
+ If your application stack requires 2GB of RAM on an
+ individual machine, then you will need the same RAM
+ requirement within your virtualized environment. The
+ additional overhead of the virtualization layer and host
+ operating system or environment often mean that you will
+ need 2.5GB or 3GB of RAM to run the same application within
+ the virtualized environment.
+ </para>
+
+ <para>
+ You should configure your virtualization environment with
+ the correct RAM allocation according to your applications
+ needs, and not to maximize the number of virtualized
+ environments that you can execute within the virtualization
+ host.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Virtualization of the CPU resources is more complex. If your
+ MySQL database and application stack do not have a high CPU
+ load, then consolidating multiple environments onto a single
+ host is often more efficient. You should keep in mind that
+ at peak times your application and database CPU requirement
+ may need to grow beyond your default allocation.
+ </para>
+
+ <para>
+ Some virtualization environments (Xen, Solaris Containers,
+ Solaris LDOMs) you can dedicate CPU or core to a virtual
+ instance. You should use this functionality to improve
+ performance for database or application loads that have a
+ high constant CPU requirement as the performance benefit
+ will outweigh the flexibility of dynamic allocation of the
+ CPU resources.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Contention of resources within the host should be taken into
+ account. In a system with high CPU loads, even when
+ dedicating RAM and CPU resources, the I/O channels and
+ interfaces to storage and networking resources may exceed
+ the capacity of the host. With solutions such as Xen and
+ Solaris LDOMs dedicate specific resources to individual
+ virtual instances, but this will not eliminate the effects
+ of the overall load on the host.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ If your database application is time sensitive, including
+ logging and real-time database applications, or you are
+ using MySQL Cluster, then the effects of virtualization may
+ severely reduce the performance of your application. Because
+ of the way the virtualized instances are executed and shared
+ between CPUs and the effects of load on other resources, the
+ response times for your database or application may be much
+ higher than normal. This is especially true if you are
+ running a large number of virtualized instances on a single
+ host.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Be aware of the limitation of using a single host to run
+ multiple virtualized instances. In the event of a machine or
+ component failure, the problem will affect more than just
+ one database instance. For example, a failure in a storage
+ device could bring down all your virtualized instances.
+ Using a RAID solution that supports fault tolerance (RAID
+ levels 1,3,4,5 or 6) will help protect you from the effects
+ of this.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </section>
+
+ <section id="ha-vm-commonissues-storage">
+
+ <title>Virtualization Storage Issues</title>
+
+ <para>
+ Due to the random I/O nature of any database solution, running
+ MySQL within a virtualized environment places a heavy load on
+ the storage solution you are using. To help keep the performance
+ of your virtualized solution at the highest level you should use
+ the following notes to help configure your systems.
+ </para>
+
+ <itemizedlist>
+
+ <listitem>
+ <para>
+ Some virtualization solutions allow you to use a physical
+ disk directly within your virtual host as if it were a local
+ disk. You should use this whenever possible to ensure that
+ disk contention issues do not affect the performance of your
+ virtual environment.
+ </para>
+
+ <para>
+ When running multiple virtual machines, you should use an
+ individual disk for each virtual instance. Using a single
+ disk and multiple partitions, with each partition dedicated
+ to a virtual host, will lead to the same contention issues.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ If you are using standard file-based storage for your
+ virtualized disks:
+ </para>
+
+ <itemizedlist>
+
+ <listitem>
+ <para>
+ File-based storage is subject to fragmentation on the
+ host disk. To prevent fragmentation, create a fixed-size
+ disk (i.e. one where the entire space for the disk file
+ is preallocated) instead of a dynamic disk that will
+ grow with usage. Also be prepared to defragment the disk
+ hosting the files at regular intervals to reduce the
+ fragmentation.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Use separate disk files for the operating system and
+ database disks, and try to avoid partitioning a disk
+ file as this increases the contention within the file.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Use a high-performance disk solution, such as RAID or
+ SAN to store the disk files for your virtualized
+ environments. This will improve the performance of what
+ is essentially a large single file on a physical device.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ When running a number of different virtualized
+ environments within a single host, do not use the same
+ physical host drive for multiple virtual disks. Instead,
+ spread the virtual disks among multiple physical disks.
+ Even when using a RAID device, be aware that each
+ virtual host is equivalent to increasing the load
+ linearly on the host RAID device.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+ </listitem>
+
+ <listitem>
+ <para></para>
+ </listitem>
+
+ </itemizedlist>
+
+ </section>
+
+ <section id="ha-vm-commonissues-networking">
+
+ <title>Virtualization Networking Issues</title>
+
+ <para>
+ When running multiple virtual machines on a host, you should be
+ aware of the networking implications of each virtualized
+ instance. If your host machine has only one network card, then
+ you will be sharing the networking throughput for all of your
+ machines through only one card, and this may severely limit the
+ performance of your virtual environments.
+ </para>
+
+ <para>
+ If possible, you should use multiple network cards to support
+ your virtualized instances. Depending on the expected load of
+ each instance, you should dedicate or spread the allocation of
+ the virtual network devices across these physical devices to
+ ensure that you do not reach saturation.
+ </para>
+
+ <para>
+ If you are using packaged virtual machines as the basis for
+ deployment of your MySQL database solution, you should make sure
+ that the network interfaces are correctly reconfigured. Some
+ solutions duplicate the hardware MAC address which will cause
+ problems when you start up additional instances of the same
+ virtualized environment.
+ </para>
+
+ </section>
+
+ </section>
+
+<!--
+ <section id="ha-vm-xen">
+
+ <title>Using MySQL within a Xen Host</title>
+
+ </section>
+
+ <section id="ha-vm-solaris-zones">
+
+ <title>Using MySQL within Solaris Containers</title>
+
+ </section>
+
+ <section id="ha-vm-solaris-ldoms">
+
+ <title>Using MySQL within Solaris Logical Domains (LDOMs)</title>
+
+ </section>
+
+ <section id="ha-vm-virtapp">
+
+ <title>Using MySQL within Virtualization Applications</title>
+
+ <para>
+ Virtualization applications include those applications that
+ provide a virtualized environment but which run as a standalone
+ application within an existing operating system. Examples of
+ virtualization applications include VMware Workstatation,
+ Parallels Desktop and Parallels Workstation, Virtual Box and
+ others.
+ </para>
+
+ </section>
+
+-->
+
+ <section id="ha-vm-aws">
+
+ <title>Using MySQL within an Amazon EC2 Instance</title>
+
+ <para>
+ The Amazon Elastic Compute Cloud (EC2) service provides virtual
+ servers that you can build and deploy to run a variety of
+ different applications and services, including MySQL. The EC2
+ service is based around the Xen framework, supporting x86, Linux
+ based, platforms with individual instances of a virtual machine
+ referred to as an Amazon Machine Image (AMI). You have complete
+ (root) access to the AMI instance that you create, allowing to
+ configure and install your AMI in any way you choose.
+ </para>
+
+ <para>
+ To use EC2, you create an AMI based on the configuration and
+ applications that you want to use and upload the AMI to the Amazon
+ Simple Storage Service (S3). From the S3 resource, you can deploy
+ one or more copies of the AMI to run as an instance within the EC2
+ environment. The EC2 environment provides management and control
+ of the instance and contextual information about the instance
+ while it is running.
+ </para>
+
+ <para>
+ Because you can create and control the AMI, the configuration and
+ the applications you can deploy and create any environment you
+ choose. This includes a basic MySQL server in addition to more
+ extensive replication, HA and scalability scenarios that enable
+ you to take advantage of the EC2 environment, and the ability to
+ deploy additional instances as the demand for your MySQL services
+ and applications grow.
+ </para>
+
+ <para>
+ To aid the deployment and distribution of work, three different
+ Amazon EC2 instances are available, small (identified as
+ <literal>m1.small</literal>), large (<literal>m1.large</literal>)
+ and extra large (<literal>m1.xlarge</literal>). The different
+ types provide different levels of computing power measured in EC2
+ computer units (ECU). A summary of the different instance
+ configurations is shown here.
+ </para>
+
+ <informaltable>
+ <tgroup cols="4">
+ <colspec colwidth="25*"/>
+ <colspec colwidth="25*"/>
+ <colspec colwidth="25*"/>
+ <colspec colwidth="25*"/>
+ <thead>
+ <row>
+ <entry/>
+ <entry>Small</entry>
+ <entry>Large</entry>
+ <entry>Extra Large</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>Platform</entry>
+ <entry>32-bit</entry>
+ <entry>64-bit</entry>
+ <entry>64-bit</entry>
+ </row>
+ <row>
+ <entry>CPU cores</entry>
+ <entry>1</entry>
+ <entry>2</entry>
+ <entry>4</entry>
+ </row>
+ <row>
+ <entry>ECUs</entry>
+ <entry>1</entry>
+ <entry>4</entry>
+ <entry>8</entry>
+ </row>
+ <row>
+ <entry>RAM</entry>
+ <entry>1.7GB</entry>
+ <entry>7.5GB</entry>
+ <entry>15GB</entry>
+ </row>
+ <row>
+ <entry>Storage</entry>
+ <entry>150GB</entry>
+ <entry>840GB</entry>
+ <entry>1680GB</entry>
+ </row>
+ <row>
+ <entry>I/O Performance</entry>
+ <entry>Medium</entry>
+ <entry>High</entry>
+ <entry>High</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </informaltable>
+
+ <para>
+ The typical model for deploying and using MySQL within the EC2
+ environment is to create a basic AMI that you can use to hold your
+ database data and application. Once the basic environment for your
+ database and application has been created you can then choose to
+ deploy the AMI to a suitable instance. Here the flexibility of
+ having an AMI that can be re-deployed from the small to the large
+ or extra large EC2 instance makes it easy to upgrade the hardware
+ environment without rebuilding your application or database stack.
+ </para>
+
+ <para>
+ To get started with MySQL on EC2, including information on how to
+ set up and install MySQL within an EC2 installation and how to
+ port and migrate your data to the running instance, see
+ <xref linkend="ha-vm-aws-setup"/>.
+ </para>
+
+ <para>
+ For tips and advice on how to create a scalable EC2 environment
+ using MySQL, including guides on setting up replication, see
+ <xref linkend="ha-vm-aws-deploy"/>.
+ </para>
+
+ <section id="ha-vm-aws-setup">
+
+ <title>Setting Up MySQL on an EC2 AMI</title>
+
+ <para>
+ There are many different ways of setting up an EC2 AMI with
+ MySQL, including using any of the pre-configured AMI supplied by
+ Amazon.
+ </para>
+
+ <para>
+ The default <emphasis>Getting Started</emphasis> AMI provided by
+ Amazon uses Fedora Core 4, and you can install MySQL by using
+ <command>yum</command>:
+ </para>
+
+<programlisting>$ <userinput>yum install mysql</userinput></programlisting>
+
+ <para>
+ This will install both the MySQL server and the Perl DBD::MySQL
+ driver for the Perl DBI API.
+ </para>
+
+ <para>
+ Alternatively, you can use one of the AMIs that include MySQL
+ within the standard installation.
+ </para>
+
+ <para>
+ Finally, you can also install a standard version of MySQL
+ downloaded from the MySQL website. The installation process and
+ instructions are identical to any other installation of MySQL on
+ Linux. See <xref linkend="installing"/>.
+ </para>
+
+ <para>
+ The standard configuration for MySQL places the data files in
+ the default location, <filename>/var/lib/mysql</filename>. The
+ default data directory on an EC2 instance is
+ <filename>/mnt</filename> (although on the large and extra large
+ instance you can alter this configuration). You must edit
+ <filename>/etc/my.cnf</filename> to set the
+ <option>datadir</option> option to point to the larger storage
+ area.
+ </para>
+
+ <important>
+ <para>
+ The first time you use the main storage location within an EC2
+ instance it needs to be initialized. The initialization
+ process starts automatically the first time you write to the
+ device. You can start using the device right away, but the
+ write performance of the new device is significantly lower on
+ the initial writes until the initialization process has
+ finished.
+ </para>
+
+ <para>
+ To avoid this problem when setting up a new instance, you
+ should start the initialization process before populating your
+ MySQL database. One to do this, is to use
+ <command>dd</command> to write to the filesystem:
+ </para>
+
+<programlisting># <userinput>dd if=/dev/zero of=initialize bs=1024M count=50</userinput></programlisting>
+
+ <para>
+ The preceding will create a 50GB on the filesystem and start
+ the initialization process. You should delete the file once
+ the process has finished.
+ </para>
+
+ <para>
+ The initialization process can be time-consuming. On the small
+ instance, initialization will take between two and three
+ hours. For the large and extra large drives, the
+ initialization will be 10 or 20 hours respectively.
+ </para>
+ </important>
+
+ <para>
+ In addition to configuring the correct storage location for your
+ MySQL data files, you should also consider setting the following
+ other settings in your instance before you save the instance
+ configuration for deployment:
+ </para>
+
+ <itemizedlist>
+
+ <listitem>
+ <para>
+ Set the MySQL server ID so that when you use it for
+ replication the ID information is set correctly.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Enabling binary logging so that replication can be
+ initialized without starting and stopping the server.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Set the caching and memory parameters for your storage
+ engines. There are no limitations or restrictions on what
+ storage engines you use in your EC2 environment. Choose a
+ configuration, possibly using one of the standard
+ configurations provided with MySQL appropriate for the
+ instance on which you expect to deploy. The large and extra
+ large instances have RAM that can be dedicated to caching.
+ Be aware that if you choose to install
+ <command>memcached</command> on the servers as part of your
+ application stack you must ensure there is enough memory for
+ both MySQL and <command>memcached</command>.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ <para>
+ Once you have configured your AMI with MySQL and the rest of
+ your application stack, you should save the AMI so that you can
+ deploy and reuse the instance.
+ </para>
+
+ <para>
+ Once you have your application stack configured in an AMI,
+ populating your MySQL database with data should be performed by
+ creating a dump of your database using
+ <literal>mysqldump</literal>, transferring the dump to the EC2
+ instance, and then reloading the information into the EC2
+ instance database.
+ </para>
+
+ <para>
+ Before using your instance with your application in a production
+ situation you should be aware of the limitations of the EC2
+ instance environment. See <xref linkend="ha-vm-aws-instance"/>.
+ To begin using your MySQL AMI, you should consult the notes on
+ deployment. See <xref linkend="ha-vm-aws-deploy"/>.
+ </para>
+
+ </section>
+
+ <section id="ha-vm-aws-instance">
+
+ <title>EC2 Instance Limitations</title>
+
+ <para>
+ There are some limitations of the EC2 instances that you should
+ be aware of before deploying your applications. Although these
+ shouldn't affect your ability to deploy within the Amazon EC2
+ environment, they may alter the way you setup and configure your
+ environment to support your application.
+ </para>
+
+ <itemizedlist>
+
+ <listitem>
+ <para>
+ Data stored within instances is not persistent. If you
+ create an instance and populate the instance with data, then
+ the data will only remain in place while the machine is
+ running. The data will survive a reboot. If you shut down
+ the instance, any data it contained will be lost.
+ </para>
+
+ <para>
+ To ensure that you do not lose information, take regular
+ backups using <command>mysqldump</command>. If the data
+ being stored is critical, consider using replication to keep
+ a 'live' backup of your data in the event of a failure. When
+ creating a backup, write the data to the Amazon S3 service
+ to avoid the transfer charges applied when copying data
+ offsite.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ EC2 instances are not persistent. If the hardware on which
+ an instance is running fails, then the instance will be shut
+ down. This can lead to loss of data or service.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ If you want to use replication with your EC2 instances to a
+ non-EC2 environment, be aware of the transfer costs to and
+ from the EC2 service. Data transfer between different EC2
+ instances is free, so using replication within the EC2
+ environment does not incur additional charges.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Certain HA features are either not directly supported, or
+ have limiting factors or problems that may reduce their
+ utility. For example, using DRBD or MySQL Cluster may not
+ work. The default storage configuration is also not
+ redundant. You can use software-based RAID to improve
+ redundancy, but this implies a further performance hit.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </section>
+
+ <section id="ha-vm-aws-deploy">
+
+ <title>Deploying a MySQL Database Using EC2</title>
+
+ <para>
+ Because you cannot guarantee the uptime and availability of your
+ EC2 instances, when deploying MySQL within the EC2 environment
+ you should use an approach that enables you to easily distribute
+ work among your EC2 instances. There are a number of ways of
+ doing this. Using sharding techniques, where you split the
+ application across multiple servers dedicating specific blocks
+ of your dataset and users to different servers is an effective
+ way of doing this. As a general rule, it is easier to create
+ more EC2 instances to support more users than to upgrade the
+ instance to a larger machine.
+ </para>
+
+ <para>
+ The EC2 architecture means that you should treat the EC2
+ instances as temporary, cache-based solutions, rather than as a
+ long-term, high availability solution. In addition to using
+ multiple machines, you should also take advantage of other
+ services, such as <command>memcached</command> to provide
+ additional caching for your application to help reduce the load
+ on the MySQL server so that it can concentrate on writes. On the
+ large and extra large instances within EC2, the RAM available
+ can be used to provide a large memory cache for data.
+ </para>
+
+ <para>
+ Most types of scale out topology that you would use with your
+ own hardware can be used and applied within the EC2 environment.
+ However, you should be use the limitations and advice already
+ given to ensure that any potential failures do not lose you any
+ data. Also, because the relative power of each EC2 instance is
+ so low, you should be prepared to alter your application to use
+ sharding and add further EC2 instances to improve the
+ performance of your application.
+ </para>
+
+ <para>
+ For example, take the typical scale-out environment shown
+ following, where a single master replicates to one or more
+ slaves (three in this example), with a web server running on
+ each replication slave.
+ </para>
+
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="images/published/ec2fig1.png" format="PNG"/>
+ </imageobject>
+ <textobject>
+ <phrase lang="en">Typical standard scale out
+ structure</phrase>
+ </textobject>
+ </mediaobject>
+
+ <para>
+ You can reproduce this structure completely within the EC2
+ environment, using an EC2 instance for the master, and one
+ instance for each of the web and MySQL slave servers.
+ </para>
+
+ <note>
+ <para>
+ Within the EC2 environment, internal (private) IP addresses
+ used by the EC2 instances are constant. You should always use
+ these internal addresses and names when communicating between
+ instances. Only the public IP addresses when communicating
+ with the outside world - for example, when publicising your
+ application.
+ </para>
+ </note>
+
+ <para>
+ To ensure reliability of your database, you should add at least
+ one replication slave dedicated to providing an active backup
+ and storage to the Amazon S3 facility. You can see an example of
+ this in the following topology.
+ </para>
+
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="images/published/ec2fig2.png" format="PNG"/>
+ </imageobject>
+ <textobject>
+ <phrase lang="en">Typical standard scale out structure with
+ backup using EC2</phrase>
+ </textobject>
+ </mediaobject>
+
+ <para>
+ <emphasis role="bold">Using
+ <command>memcached</command></emphasis> within your EC2
+ instances should provide better performance. The large and extra
+ large instances have a significant amount of RAM. To use
+ <command>memcached</command> in your application, when loading
+ information from the database, first check if the item exists in
+ the cache. If the data you are looking for exists in the cache,
+ use it. If not, reload the data from the database and populate
+ the cache.
+ </para>
+
+ <para>
+ <emphasis role="bold">Sharding</emphasis> divides up data in
+ your entire database by allocating individual machines or
+ machine groups to provide a unique set of data according to an
+ appropriate group. For example, you might put all users with a
+ surname ending in the letters A-D onto a single server. When a
+ user connects to the application and their surname is known,
+ queries can be redirected to the appropriate MySQL server.
+ </para>
+
+ <para>
+ When using sharding with EC2 you should separate the web server
+ and MySQL server into separate EC2 instances, and then apply the
+ sharding decision logic into your application. Once you know
+ which MySQL server you should be using for accessing the data
+ you then distribute queries to the appropriate server. You can
+ see a sample of this in the following illustration.
+ </para>
+
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="images/published/ec2fig3.png" format="PNG"/>
+ </imageobject>
+ <textobject>
+ <phrase lang="en">Using sharding in EC2 to spread the
+ load</phrase>
+ </textobject>
+ </mediaobject>
+
+ <warning>
+ <para>
+ With sharding and EC2 you should be careful that the potential
+ for failure of an instance does not affect your application.
+ If the EC2 instance that provides the MySQL server for a
+ particular shard fails, then all of the data on that shard
+ will be unavailable.
+ </para>
+ </warning>
+
+ </section>
+
+ </section>
+
+ <section id="ha-vm-resources">
+
+ <title>Virtualization Resources</title>
+
+ <para>
+ For more information on virtualization, see the following links:
+ </para>
+
+ <itemizedlist>
+
+ <listitem>
+ <para>
+ <ulink url="http://forums.mysql.com/list.php?149">MySQL
+ Virtualization Forum</ulink>
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ <ulink url="http://aws.amazon.com/ec2">Amazon Elastic Compute
+ Cloud (Amazon EC2)</ulink>
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ <ulink url="http://www.mysql.com/products/enterprise/cloud.html">MySQL
+ and Cloud Computing</ulink>
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ <ulink url="http://www.mysql.com/products/enterprise/ec2.html">MySQL
+ Enterprise for Amazon EC2</ulink>
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </section>
+
+</chapter>
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