Deployment Configuration: Simple

Description

This is the simplest network configuration. There is no network redundancy so when any failure occurs, there is a good chance that all or part of the cluster will stop functioning. All failover activity is up to the Terracotta software.

In this diagram, the IP addresses are merely examples to demonstrate that the L1s (L1a & L1b) and L2s (TCserverA & TCserverB) can live on different subnets. The actual addressing scheme is specific to your environment. The single switch is a single point of failure.

Additional configuration

There is no additional network or operating-system configuration necessary in this configuration. Each machine needs a proper network configuration (IP address, subnet mask, gateway, DNS, NTP, hostname) and must be plugged into the network.

Test Plan - Network Failures Non-Redundant Network

To determine that your configuration is correct, use the following tests to confirm all failure scenarios behave as expected.

TestID	Failure	Expected Outcome
FS1	Loss of L1a (link or system)	Cluster continues as normal using only L1b
FS2	Loss of L1b (link or system)	Cluster continues as normal using only L1a
FS3	Loss of L1a & L1b	Non-functioning cluster
FS4	Loss of Switch	Non-functioning cluster
FS5	Loss of Active L2 (link or system)	mirror L2 becomes new Active L2, L1s fail over to new Active L2
FS6	Loss of mirror L2	Cluster continues as normal without TC redundancy
FS7	Loss of TCservers A & B	Non-functioning cluster

Test Plan - Network Tests Non-redundant Network

After the network has been configured, you can test your configuration with simple ping tests.

TestID	Host	Action	Expected Outcome
NT1	all	ping every other host	successful ping
NT2	all	pull network cable during continuous ping	ping failure until link restored
NT3	switch	reload	all pings cease until reload complete and links restored