IBM Cloud Orchestrator, Version 2.5.0.6

Configuring the quorum tiebreaker

Set the quorum tiebreaker to Operator if you require to give privilege to end user to decide which node should have quorum in case a tie occurs due to a network or node failure.

By default the EXEC quorum tiebreaker is used for IBM® Cloud Orchestrator high availability. The gateway IP address is used as tiebreaker and it determines which part of the cluster gets quorum and can manage active resources. For more information about quorums and tiebreakers, see Operational quorum.

To verify what node has currently the quorum, run the lssam command and search for the node with IBM.ServiceIP:cs-ip that is in online status. For example, if the following output is displayed, the primaryiconode node has currently the quorum:

Online IBM.ResourceGroup:central-services-rg Nominal=Online
        |- Online IBM.Application:bpm-node
                |- Online IBM.Application:bpm-node:primaryiconode
                '- Online IBM.Application:bpm-node:secondaryiconode
        |- Online IBM.Application:bpm
                |- Online IBM.Application:bpm:primaryiconode
                '- Online IBM.Application:bpm:secondaryiconode
        |- Online IBM.Application:ihs
                |- Online IBM.Application:ihs:primaryiconode
                '- Online IBM.Application:ihs:secondaryiconode
        |- Online IBM.Application:scui
                |- Online IBM.Application:scui:primaryiconode
                '- Online IBM.Application:scui:secondaryiconode
        '- Online IBM.ServiceIP:cs-ip
                |- Online IBM.ServiceIP:cs-ip:primaryiconode
                '- Offline IBM.ServiceIP:cs-ip:secondaryiconode
Online IBM.ResourceGroup:pcg-rg Nominal=Online
        '- Online IBM.Application:pcg
                '- Online IBM.Application:pcg:primaryiconode
Online IBM.Equivalency:cs-network-equ
        |- Online IBM.NetworkInterface:ens192:primaryiconode
        '- Online IBM.NetworkInterface:ens192:secondaryiconode

To set the quorum tiebreaker to Operator, perform the following steps:

Make sure that both IBM Cloud Orchestrator nodes are up and can talk to each other:
Run the following command:
```
chrsrc -c IBM.PeerNode OpQuorumTieBreaker="Operator" 
```
If the command runs successfully, no output is displayed.

You can verify if the quorum definition changed by running the following command:

lsrsrc -c IBM.PeerNode OpQuorumTieBreaker

The following output is displayed, for example:

Resource Class Persistent Attributes for IBM.PeerNode
resource 1:
        OpQuorumTieBreaker = "Operator"

If a tie occurs, run the following command to verify the quorum state:
```
lssrc -ls IBM.RecoveryRM|grep Operational 
```
The following output is displayed if there is a tie:
```
Operational Quorum State: PENDING_QUORUM
```
If there is a node or network failure, there is no automatic failover because the quorum is in PENDING_QUORUM state and the operator input is required.
You can give quorum to a node and make the node as primary by running the following command:
```
runact -c IBM.PeerDomain ResolveOpQuorumTie Ownership=1 
```
The following output is displayed, for example:
```
Resource Class Action Response for ResolveOpQuorumTie
```

If you need to set the quorum tiebreaker to the default EXEC value for the IBM Cloud Orchestrator high availability, perform the following steps:

Run the following command to set the quorum tiebreaker to EXEC:
```
chrsrc -c IBM.PeerNode OpQuorumTieBreaker="cs-network-tiebreaker"
```
If the command runs successfully, no output is displayed.

Verify if the EXEC quorum tiebreaker is configured correctly by running the following command:

lsrsrc -c IBM.PeerNode OpQuorumTieBreaker

The following output is displayed, for example:

Resource Class Persistent Attributes for IBM.PeerNode
resource 1:
        OpQuorumTieBreaker = "cs-network-tiebreaker"

If the quorum tiebreaker is set to EXEC, if there is a tie, the quorum automatically decides which node is active, and failover and failback occur accordingly.