Overview

When using Tibero Cluster Manager, Network Heartbeat and TAC block information (Cache Fusion) are shared between nodes via the Interconnect.

If the Interconnect is not configured properly, issues with consistency in the TAC environment may occur, and in severe cases, a TAC Split Brain phenomenon can arise.

This article describes recommended environmental settings for Interconnect configuration.

Method

Interconnect Configuration

Recommended Bandwidth

• Recommended bandwidth: Minimum 1G, Recommended 10G

It can be configured with a minimum of 1G, but if a large amount of block information (Cache Fusion) is transferred between TAC nodes, performance degradation may occur. Therefore, it is recommended to use 10G bandwidth for initial configuration.

Cross Cable

• Cross cable configuration is not supported in the Tibero Cluster Manager environment.
• When using a cross cable, the network cable is directly connected between servers.
• If physical damage occurs to the cross cable, the network of all connected servers will be affected.
• As a result, if a cross cable is configured in the TAC environment, any issue with the cross cable will impact all nodes, including healthy ones.
• This can cause a Split Brain phenomenon, impacting proper database consistency and potentially causing database corruption.

[Cross Cable Not Supported]

• When configuring the network, you must use a switch for cable configuration.

[Network Configuration via Switch Required]

Interconnect NIC Redundancy

Tibero Cluster Manager does not provide its own Interconnect redundancy feature.

Therefore, you must configure and use NIC redundancy provided by the OS.

Note

Only the Linux bonding feature is described.

Linux Bonding

• Bonding is a technology that combines multiple network interfaces into one logical interface.

• You can use bonding to provide redundancy for the Interconnect IP.

• When using the bonding feature, the same bonding mode must be applied throughout the Server–Switch–Server section.

• mode=3 (broadcast) transmits packets through all NICs configured in the bond and must not be used.

[Source: RHEL9, Various Network Bonding Modes]

Interconnect Switch Redundancy

• If a problem occurs in the Interconnect network, the node with the issue may be forcibly shut down to prevent Split Brain.

• To minimize the impact of physical failures in the Interconnect network, switch redundancy is recommended.