This section describes the basics for planning, installing, configuring, and running an NDB Cluster. Whereas the examples in Section 23.3, “Configuration of NDB Cluster” provide more in-depth information on a variety of clustering options and configuration, the result of following the guidelines and procedures outlined here should be a usable NDB Cluster which meets the minimum requirements for availability and safeguarding of data.
For information about upgrading or downgrading an NDB Cluster between release versions, see Section 23.2.7, “Upgrading and Downgrading NDB Cluster”.
This section covers hardware and software requirements; networking issues; installation of NDB Cluster; basic configuration issues; starting, stopping, and restarting the cluster; loading of a sample database; and performing queries.
NDB Cluster also provides the NDB Cluster Auto-Installer (now deprecated), a web-based graphical installer, as part of the NDB Cluster distribution. The Auto-Installer can be used to perform basic installation and setup of an NDB Cluster on one (for testing) or more host computers. See Section 23.2.8, “The NDB Cluster Auto-Installer (No longer supported)”, for more information.
Assumptions. The following sections make a number of assumptions regarding the cluster's physical and network configuration. These assumptions are discussed in the next few paragraphs.
Cluster nodes and host computers. The cluster consists of four nodes, each on a separate host computer, and each with a fixed network address on a typical Ethernet network as shown here:
Table 23.5 Network addresses of nodes in example cluster
This setup is also shown in the following diagram:
Network addressing. In the interest of simplicity (and reliability), this How-To uses only numeric IP addresses. However, if DNS resolution is available on your network, it is possible to use host names in lieu of IP addresses in configuring Cluster. Alternatively, you can use the hosts
file (typically /etc/hosts
for Linux and other Unix-like operating systems, C:\WINDOWS\system32\drivers\etc\hosts
on Windows, or your operating system's equivalent) for providing a means to do host lookup if such is available.
Prior to NDB 8.0.22, all network addresses used for connections to or from data and management nodes must use or be resolvable using IPv4. This includes addresses used by SQL nodes to contact the other nodes. Beginning with NDB 8.0.22, NDB Cluster supports IPv6 for connections between any and all cluster nodes.
Potential hosts file issues. A common problem when trying to use host names for Cluster nodes arises because of the way in which some operating systems (including some Linux distributions) set up the system's own host name in the /etc/hosts
during installation. Consider two machines with the host names ndb1
and ndb2
, both in the cluster
network domain. Red Hat Linux (including some derivatives such as CentOS and Fedora) places the following entries in these machines' /etc/hosts
files:
# ndb1 /etc/hosts
:
127.0.0.1 ndb1.cluster ndb1 localhost.localdomain localhost
# ndb2 /etc/hosts
:
127.0.0.1 ndb2.cluster ndb2 localhost.localdomain localhost
SUSE Linux (including OpenSUSE) places these entries in the machines' /etc/hosts
files:
# ndb1 /etc/hosts
:
127.0.0.1 localhost
127.0.0.2 ndb1.cluster ndb1
# ndb2 /etc/hosts
:
127.0.0.1 localhost
127.0.0.2 ndb2.cluster ndb2
In both instances, ndb1
routes ndb1.cluster
to a loopback IP address, but gets a public IP address from DNS for ndb2.cluster
, while ndb2
routes ndb2.cluster
to a loopback address and obtains a public address for ndb1.cluster
. The result is that each data node connects to the management server, but cannot tell when any other data nodes have connected, and so the data nodes appear to hang while starting.
You cannot mix localhost
and other host names or IP addresses in config.ini
. For these reasons, the solution in such cases (other than to use IP addresses for all config.ini
HostName
entries) is to remove the fully qualified host names from /etc/hosts
and use these in config.ini
for all cluster hosts.
Host computer type. Each host computer in our installation scenario is an Intel-based desktop PC running a supported operating system installed to disk in a standard configuration, and running no unnecessary services. The core operating system with standard TCP/IP networking capabilities should be sufficient. Also for the sake of simplicity, we also assume that the file systems on all hosts are set up identically. In the event that they are not, you should adapt these instructions accordingly.
Network hardware. Standard 100 Mbps or 1 gigabit Ethernet cards are installed on each machine, along with the proper drivers for the cards, and that all four hosts are connected through a standard-issue Ethernet networking appliance such as a switch. (All machines should use network cards with the same throughput. That is, all four machines in the cluster should have 100 Mbps cards or all four machines should have 1 Gbps cards.) NDB Cluster works in a 100 Mbps network; however, gigabit Ethernet provides better performance.
NDB Cluster is not intended for use in a network for which throughput is less than 100 Mbps or which experiences a high degree of latency. For this reason (among others), attempting to run an NDB Cluster over a wide area network such as the Internet is not likely to be successful, and is not supported in production.
Sample data. We use the world
database which is available for download from the MySQL website (see https://dev.mysql.com/doc/index-other.html). We assume that each machine has sufficient memory for running the operating system, required NDB Cluster processes, and (on the data nodes) storing the database.
For general information about installing MySQL, see Chapter 2, Installing and Upgrading MySQL. For information about installation of NDB Cluster on Linux and other Unix-like operating systems, see Section 23.2.1, “Installation of NDB Cluster on Linux”. For information about installation of NDB Cluster on Windows operating systems, see Section 23.2.2, “Installing NDB Cluster on Windows”.
For general information about NDB Cluster hardware, software, and networking requirements, see Section 23.1.3, “NDB Cluster Hardware, Software, and Networking Requirements”.