Configuring a redundant network will enable HADB to remain available, even if there is a single network failure. You can configure a redundant network in two ways:
On Solaris 9, by setting up network multipathing.
On all platforms except Windows Server 2003, by configuring a double network.
Before setting up network multipathing, refer to the Administering Network Multipathing section in the IP Network Multipathing Administration Guide on docs.sun.com.
Set network interface failure detection time.
For HADB to properly support multipathing failover, the network interface failure detection time must not exceed one second (1000 milliseconds), as specified by the FAILURE_DETECTION_TIME parameter in /etc/default/mpathd. Edit the file and change the value of this parameter to 1000 if the original value is higher:
To put the change into effect, use this command:
pkill -HUP in.mpathd
Set up IP addresses to use with HADB.
As described in the IP Network Multipathing Administration Guide, multipathing involves grouping physical network interfaces into multipath interface groups. Each physical interface in such a group has two IP addresses associated with it:
a physical interface address used for transmitting data.
a test address for Solaris internal use only.
Specify only one physical interface address from the multipath group when you use hadbm create --hosts.
Suppose there are two host machines named host1 and host2. If they each have two physical network interfaces, then set up the two interfaces as a multipath group. Run ifconfig -a on each host.
The output on host1 is:
bge0: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 5 inet 184.108.40.206 netmask ffffff00 broadcast 220.127.116.11 groupname mp0 bge0:1: flags=9040843<UP,BROADCAST,RUNNING,MULTICAST,DEPRECATED,IPv4,NOFAILOVER> mtu 1500 index 5 inet 18.104.22.168 netmask ffffff00 broadcast 22.214.171.124 bge1: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 6 inet 126.96.36.199 netmask ffffff00 broadcast 188.8.131.52 groupname mp0 bge1:1: flags=9040843<UP,BROADCAST,RUNNING,MULTICAST,DEPRECATED,IPv4,NOFAILOVER> mtu 1500 index 6 inet 184.108.40.206 netmask ff000000 broadcast 220.127.116.11
The output on host2 is:
bge0: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 3 inet 18.104.22.168 netmask ffffff00 broadcast 22.214.171.124 groupname mp0 bge0:1: flags=9040843<UP,BROADCAST,RUNNING,MULTICAST,DEPRECATED,IPv4,NOFAILOVER> mtu 1500 index 3 inet 126.96.36.199 netmask ff000000 broadcast 188.8.131.52 bge1: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 4 inet 184.108.40.206 netmask ffffff00 broadcast 220.127.116.11 groupname mp0 bge1:1: flags=9040843<UP,BROADCAST,RUNNING,MULTICAST,DEPRECATED,IPv4,NOFAILOVER> mtu 1500 index 4 inet 18.104.22.168 netmask ff000000 broadcast 22.214.171.124
In this example, the physical network interfaces on both hosts are listed after bge0 and bge1. Those listed after bge0:1 and bge1:1 are multipath test interfaces (marked DEPRECATED in the ifconfig output), as described in the IP Network Multipathing Administration Guide.
To set up HADB in this environment, select one physical interface address from each host. In this example, HADB uses IP address 126.96.36.199 from host1 and 188.8.131.52 from host2. To create a database with one database node per host, use the command hadbm create --hosts. For example
hadbm create --hosts 184.108.40.206,220.127.116.11
To create a database with two database nodes on each host, use the command:
hadbm create --hosts 18.104.22.168,22.214.171.124, 126.96.36.199,188.8.131.52
In both cases, you must configure the agents on host1 and host2 with separate parameters to specify which interface on the machines the agents should use. So, on host1 use:
And on host2 use:
For information on the ma.server.mainternal.interfaces variable, see Configuration File.
To enable HADB to tolerate single network failures, use IP multipathing if the operating system (for example, Solaris) supports it. Do not configure HADB with double networks on Windows Server 2003—the operating system does not work properly with double networks.
If your operating system is not configured for IP multipathing, and HADB hosts are equipped with two NICs, you can configure HADB to use double networks. For every host, the IP addresses of each of the network interface card (NIC) must be on separate IP subnets.
Within a database, all nodes must be connected to a single network, or all nodes must be connected to two networks.
Routers between the subnets must be configured to forward UDP multicast messages between subnets.
When creating an HADB database, use the –hosts option to specify two IP addresses or host names for each node: one for each NIC IP address. For each node, the first IP address is on net-0 and the second on net-1. The syntax is as follows, with host names for the same node separated by a plus sign (+):
--hosts=node0net0name+node0net1name ,node1net0name+node1net1name ,node2net0name+node2net1name , ...
For example, the following argument creates two nodes, each with two network interfaces. The following host option is used to create these nodes:
Thus, the network addresses
For node0 are 10.10.116.61 and 10.10.124.61
For node1 are 10.10.116.62 and 10.10.124.62
Notice that 10.10.116.61 and 10.10.116.62 are on the same subnet, and 10.10.124.61 and 10.10.124.62 are on the same subnet.
In this example, the management agents must use the same subnet. Thus, the configuration variable ma.server.mainternal.interfaces must be set to, for example, 10.10.116.0/24. This setting can be used on both agents in this example.