Tuesday 27 January 2009

MySQL 5.0 DBA

As I'm a goal oriented person, I tend to take certifications for new products that I'm having to use for work. The certification process gives me a learning structure that forces me not to skip over the things that are less interesting, and hopefully gives me a more rounded knowledge base.

I've recently (3 hours ago ;-) ) completed the MySQL 5.0 DBA certification. To use a footballing cliché it was very definitely a game of two halves. The first exam I found very tricky. Perhaps this was because I still had my Oracle head on, and the concept of multiple pluggable storage engines wasn't sticking, but I really struggled to find the correct answers. The second exam I found much more understandable, lots of questions about EXPLAIN. Both of the MySQL exams are multiple choice format - however, there did seem to be a lot of 'Select all that are correct' questions.

I used this book http://www.mysql.com/certification/studyguides/study-guide-5.0.html to help me along with the incredibly detailed MySQL reference manual.

Tinkering with MySQL Cluster - Part 2 - Getting the software

The next step in my project is probably the most simple - getting hold of the software.

Go to MySQL's website and select to Download MySQL cluster. I chose to do the tar version for Solaris 10 SPARC 64bit, but there is also a package format installer.


Create a mysql user and group on each of the nodes - this user will own the MySQL software.

# mkdir /export/home
# groupadd -g 101 mysql
# useradd -g mysql -u 1001 -s /bin/ksh -d /export/home/mysql -m mysql
# gunzip mysql-cluster-gpl-6.3.20-solaris10-sparc-64bit.tar.gz
# tar xf mysql-cluster-gpl-6.3.20-solaris10-sparc-64bit.tar

Then you copy the directory to /usr/local/bin and create a symbolic link to it

# mkdir /usr/local/bin

# mv mysql-cluster-gpl-6.3.20-solaris10-sparc-64bit /usr/local/bin
# cd /usr/local/bin
# ln -s mysql-cluster-gpl-6.3.20-solaris10-sparc-64bit mysql

You don't actually need the full software directory on every node, but to allow me to repurpose nodes as necessary I'm taking the full software

Change the software owner and group on the MySQL software to help secure the installation

# cd /usr/local/bin
# chown -R mysql mysql
# chgrp -R mysql mysql
Well, that's the software installed on the nodes. As part of this process I noticed that the disk in use for pup3's root partition is heading off to the great computer scrapyard in the sky so this node may no longer be part of the configuration.
Then you copy the directory to /usr/local/bin and create a symbolic link to it

# mkdir /usr/local/bin

# mv mysql-cluster-gpl-6.3.20-solaris10-sparc-64bit /usr/local/bin
# cd /usr/local/bin
# ln -s mysql-cluster-gpl-6.3.20-solaris10-sparc-64bit mysql

You don't actually need the full software directory on every node, but to allow me to repurpose nodes as necessary I'm taking the full software

Change the software owner and group on the MySQL software to help secure the installation

# cd /usr/local/bin
# chown -R mysql mysql
# chgrp -R mysql mysql

Well, that's the software installed on the nodes. As part of this process I noticed that the disk in use for pup3's root partition is heading off to the great computer scrapyard in the sky so this node may no longer be part of the configuration.

Friday 23 January 2009

Tinkering with MySQL Cluster - Part 1 - Preparation

I'm trying to get familiar with MySQL Cluster - though usually most people who work with me use Oracle, I guess the difference in the license cost is making people consider MySQL for their implementations. The concepts are quite different to Oracle RAC, MySQL is based on a 'shared nothing' architecture so there aren't the same requirements for shared disk storage.

Concepts

There are several cluster node types in MySQL

  • Data Nodes - these store and process the data. These ideally with have the most memory and CPU power, as they hold the data in memory, also all data nodes should be the same configuration.
  • Management Nodes - these control the cluster by passing configuration parameters to the data nodes and API nodes. The management software do not require large amounts of memory or CPU.
  • API Nodes - These are nodes which access the MySQL Cluster Data. API nodes include SQL Nodes and nodes running the NDB Native backup and restore (ndb_restore). SQL Nodes run a mysqld process to access the cluster data.

How you split these nodes up amongst the hardware really depends on what you have available. Though you can run multiple data nodes on a single host this is not recommended for resiliency and data availability. However, as the Management node has such a small footprint, you can run a copy of it on each of the SQL nodes if required. The speed of network between the nodes is important, fast and low latency is preferred. As there is no encryption on the cluster traffic, a separate network for the cluster traffic should be used.

Simple Architecture

My Configuration

Sadly I do not have access to 6 separate machines to carry out the configuration. This means that I'm going to make some compromises that are not acceptable in a production environment. I have access to a single v890 for this training exercise, 8 x UltraSPARC IV CPU with 64Gb RAM (very lucky!). To simulate the separate physical nodes I'm going to create Solaris Containers.

Hostname IP-Address Mount Point
CPU Assignment
pup1 10.132.1.185 /pup1 3,19
pup2 10.132.1.186 /pup2 4,20
pup3 10.132.1.187 /pup3 5,21
pup4 10.132.1.188 /pup4 6,22
pup5 10.132.1.189 /pup5 7,23

The CPU assignment isto keep the zones within a single CPU by assigning both cores. You can verify this with the ouput of psrinfo.

# psrinfo -pv

The physical processor has 2 virtual processors (0 16)
UltraSPARC-IV+ (portid 0 impl 0x19 ver 0x22 clock 1500 MHz)
The physical processor has 2 virtual processors (1 17)
UltraSPARC-IV+ (portid 1 impl 0x19 ver 0x22 clock 1500 MHz)
The physical processor has 2 virtual processors (2 18)
UltraSPARC-IV+ (portid 2 impl 0x19 ver 0x22 clock 1500 MHz)
The physical processor has 2 virtual processors (3 19)
UltraSPARC-IV+ (portid 3 impl 0x19 ver 0x22 clock 1500 MHz)
The physical processor has 2 virtual processors (4 20)
UltraSPARC-IV+ (portid 4 impl 0x19 ver 0x22 clock 1500 MHz)
The physical processor has 2 virtual processors (5 21)
UltraSPARC-IV+ (portid 5 impl 0x19 ver 0x22 clock 1500 MHz)
The physical processor has 2 virtual processors (6 22)
UltraSPARC-IV+ (portid 6 impl 0x19 ver 0x22 clock 1500 MHz)
The physical processor has 2 virtual processors (7 23)
UltraSPARC-IV+ (portid 7 impl 0x19 ver 0x22 clock 1500 MHz)

Setting up the Resource Pools

Enable the resource pools feature, using the pooladm(1M) command.

global# pooladm -e

The use of the "global#" prompt throughout this example indicates that a command is run in the global zone.

Save the current configuration to a file by using the pooladm command.

global# pooladm -s

See if any pools already exist on the system, using the pooladm(1M) command.

global# pooladm

Since there are no existing pools configured, there is only an entry for "pool pool_default"

Create the processor sets required. The configuration specifies a minimum of 2 CPUs and a maximum of 2 CPUs for each of the sets.

global# poolcfg -c 'create pset pup1-pset (uint pset.min=2;uint pset.max=2)' global# poolcfg -c 'create pset pup2-pset (uint pset.min=2;uint pset.max=2)' global# poolcfg -c 'create pset pup3-pset (uint pset.min=2;uint pset.max=2)' global# poolcfg -c 'create pset pup4-pset (uint pset.min=2;uint pset.max=2)' global# poolcfg -c 'create pset pup5-pset (uint pset.min=2;uint pset.max=2)' global# poolcfg -c 'transfer to pset pup5-pset (cpu 7;cpu 23)' global# poolcfg -c 'transfer to pset pup4-pset (cpu 6;cpu 22)' global# poolcfg -c 'transfer to pset pup3-pset (cpu 5;cpu 21)' global# poolcfg -c 'transfer to pset pup2-pset (cpu 4;cpu 20)' global# poolcfg -c 'transfer to pset pup1-pset (cpu 3;cpu 19)'

Create the resource pools for the processor sets

global# poolcfg -c 'create pool pup1-pool' global# poolcfg -c 'associate pool pup1-pool (pset pup1-pset)' global# poolcfg -c 'create pool pup2-pool' global# poolcfg -c 'associate pool pup2-pool (pset pup2-pset)' global# poolcfg -c 'create pool pup3-pool' global# poolcfg -c 'associate pool pup3-pool (pset pup3-pset)' global# poolcfg -c 'create pool pup4-pool' global# poolcfg -c 'associate pool pup4-pool (pset pup4-pset)' global# poolcfg -c 'create pool pup5-pool' global# poolcfg -c 'associate pool pup5-pool (pset pup5-pset)'

Activate the configuration

global# pooladm -c

You can view the configuration using the pooladm command<

global# pooladm

system default
string system.comment
int system.version 1
boolean system.bind-default true
string system.poold.objectives wt-load

pool pup5-pool
int pool.sys_id 5
boolean pool.active true
boolean pool.default false
int pool.importance 1
string pool.comment
pset pup5-pset

pool pup4-pool
int pool.sys_id 4
boolean pool.active true
boolean pool.default false
int pool.importance 1
string pool.comment
pset pup4-pset

pool pup1-pool
int pool.sys_id 1
boolean pool.active true
boolean pool.default false
int pool.importance 1
string pool.comment
pset pup1-pset

pool pool_default
int pool.sys_id 0
boolean pool.active true
boolean pool.default true
int pool.importance 1
string pool.comment
pset pset_default

pool pup3-pool
int pool.sys_id 3
boolean pool.active true
boolean pool.default false
int pool.importance 1
string pool.comment
pset pup3-pset

pool pup2-pool
int pool.sys_id 2
boolean pool.active true
boolean pool.default false
int pool.importance 1
string pool.comment
pset pup2-pset

pset pup5-pset
int pset.sys_id 5
boolean pset.default false
uint pset.min 2
uint pset.max 2
string pset.units population
uint pset.load 45
uint pset.size 2
string pset.comment

cpu
int cpu.sys_id 23
string cpu.comment
string cpu.status on-line

cpu
int cpu.sys_id 7
string cpu.comment
string cpu.status on-line

pset pup4-pset
int pset.sys_id 4
boolean pset.default false
uint pset.min 2
uint pset.max 2
string pset.units population
uint pset.load 43
uint pset.size 2
string pset.comment

cpu
int cpu.sys_id 22
string cpu.comment
string cpu.status on-line

cpu
int cpu.sys_id 6
string cpu.comment
string cpu.status on-line

pset pup1-pset
int pset.sys_id 1
boolean pset.default false
uint pset.min 2
uint pset.max 2
string pset.units population
uint pset.load 45
uint pset.size 2
string pset.comment

cpu
int cpu.sys_id 19
string cpu.comment
string cpu.status on-line

cpu
int cpu.sys_id 3
string cpu.comment
string cpu.status on-line

pset pup3-pset
int pset.sys_id 3
boolean pset.default false
uint pset.min 2
uint pset.max 2
string pset.units population
uint pset.load 0
uint pset.size 2
string pset.comment

cpu
int cpu.sys_id 21
string cpu.comment
string cpu.status on-line

cpu
int cpu.sys_id 5
string cpu.comment
string cpu.status on-line

pset pup2-pset
int pset.sys_id 2
boolean pset.default false
uint pset.min 2
uint pset.max 2
string pset.units population
uint pset.load 47
uint pset.size 2
string pset.comment

cpu
int cpu.sys_id 20
string cpu.comment
string cpu.status on-line

cpu
int cpu.sys_id 4
string cpu.comment
string cpu.status on-line

pset pset_default
int pset.sys_id -1
boolean pset.default true
uint pset.min 1
uint pset.max 65536
string pset.units population
uint pset.load 39
uint pset.size 6
string pset.comment

cpu
int cpu.sys_id 17
string cpu.comment
string cpu.status on-line

cpu
int cpu.sys_id 16
string cpu.comment
string cpu.status on-line

cpu
int cpu.sys_id 18
string cpu.comment
string cpu.status on-line

cpu
int cpu.sys_id 1
string cpu.comment
string cpu.status on-line

cpu
int cpu.sys_id 0
string cpu.comment
string cpu.status on-line

cpu
int cpu.sys_id 2
string cpu.comment
string cpu.status on-line

Creating the Zones

You need a directory to hold the zone's root filesystem. On my machine, they are fully separated disks, mounted as /pup[1...x]. The filesystem mountpoint with the permission 700 and owned by root. Within the filesystem you need to create a second directory called 'local' this will be used to hold the /usr/local directory structure. Usually within zones, /usr is a read only filesystem shared from the global zone, and this will prevent the creation of a /usr/local structure on the zone.

Create the first zone

global# zonecfg -z pup2

pup2: No such zone configured
Use 'create' to begin configuring a new zone.
zonecfg:pup2> create
zonecfg:pup2> set zonepath=/pup2
zonecfg:pup2> add net
zonecfg:pup2:net> set address=10.132.1.186
zonecfg:pup2:net> set physical=ce0
zonecfg:pup2:net> end
zonecfg:pup2> set pool=pup2-pool
zonecfg:pup2> add fs
zonecfg:pup2:fs> set dir=/usr/local
zonecfg:pup2:fs> set special=/pup2/local
zonecfg:pup2:fs> set type=lofs
zonecfg:pup2:fs> set options=[rw,nodevices]
zonecfg:pup2:fs> end
zonecfg:pup2> verify
zonecfg:pup2> commit

global #zoneadm -z pup2 install

Preparing to install zone email-zone
Creating list of files to copy from the global zone.
[Some output was omitted here for brevity]
Zone pup2 is initialized.

Boot the zone

global# zoneadm -z pup2 boot

Connect to the Console for the zone. There will be an initial delay while the SMF services are updated. Then you will be prompted to set basic information such as Locale, Hostname for the zone. To exit the console use the ~. keysequence.

global# zlogin -C pup2

Cloning the Zone

Once you have one zone configured, you can quickly create the others. Stop the configured zone

global# zoneadm -z pup2 halt

Copy the zone configuration from pup2

global# zonecfg -z pup2 export > /tmp/pup5.cfg

Edit the file /tmp/pup5.cfg and change the IP Address, disk paths and devices to match pup5. Use this file to create the pup5 zone.

global# zonecfg -z pup5 -f /tmp/pup5.cfg

Clone pup5 from pup2

global# zoneadm -z pup5 clone pup2

Cloning zonepath /pup2...
grep: can't open /a/etc/dumpadm.conf

Boot and login to your new zone. You will need to configure the hostname and locale information.


# zoneadm -z pup5 boot
# zlogin -C pup5

Repeat this procedure for the rest of the zones.