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Platform Redundancy
The
platforms support 1:1 box level redundancy through the communication paths provided by the external High Availability (HA) Ethernet ports.
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For more information on installing the HA pairs, see Installing SBC Application.
Geographical Redundancy High Availability (GRHA)
HA Network Requirements
The following are the network requirement for Geographical Redundancy High Availability (GRHA) mode:
- 10G/1G bandwidth for direct and not direct cable connections.The network connecting to the SBCs must support ARP monitoringdirect cable connections.
- The network connecting to the SBCs must support ARP monitoring.
platforms are configurable using a CLI action command to support Geographical Redundancy High Availability (GRHA) mode providing enhanced support against network degradation. GRHA mode supports active and standby servers located in two different data-centers. This is performed by changing the bond device monitoring from MII to ARP. ARP monitoring is used to detect issues when SBCs are connected to switches which are connected to each other through a network. GRHA mode protects against data center and network failures. In addition to switching the bond monitoring, a new leadership algorithm is included which changes the decision on which SBC survives split-brain recovery. The change is introduced in a GRHA situation since any HA link loss is primarily due to data center isolation.This feature is not configurable during software installation nor is it changeable during an upgrade.
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GRHA mode is only applicable to platforms. |
Peer Election Algorithm
When network issues prevent the SBCs from communicating, both nodes become active (split-brain recovery). Once the communication is re-established, one of the nodes must be restarted again to become the standby. The GRHA mode introduces a new peer election algorithm. The new algorithm changes how we select which node will survive as active by choosing the node that was promoted to active during the split-brain recovery. The algorithm also performs additional checks to handle situations where a node may restart or start for the first time while communication is interrupted.
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All Nodes must use the same algorithm. The default algorithm is used until new peer election algorithm is configured and available on both the nodes. |
HA Link Delays per HA Pair
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For a depiction of media port interconnectivity inter-connectivity in an HA configuration, see the Management and HA Port Connections diagram on page Connecting SBC 7000 Series Ethernet and Data Cables.
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includes the flag, probeOnStandby, for use in disabling ARP/NUD probing by Link Monitors on standby packet ports in case routers in your network do not respond correctly to the ARP probes. This scenario can lead to Link Monitor declaring itself as failed. The CLI syntax is shown below (default value of
probeOnStandby is 'enabled').
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| Disabling ARP/NUD probing can possibly lead to a toggling situation since we rely only on the physical port health on the standby packet port. |
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% set addressContext <addressContext_name> linkDetectionGroup <LDG_name> linkMonitor <name> probeOnStandby <disabled | enabled>
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For Link Monitor configuration details, see:
EMA: Link Detection Group - Link MonitorCLI: Link Monitor - CLI
SBC 7000 Redundancy Performance
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