Expected behavior of Patch Management feature when a Neverfail Engine DR Pair is extended to a HA+DR Trio

Expected behavior of Patch Management feature when a Neverfail Engine DR Pair is extended to a HA+DR Trio

Summary

This Knowledgebase article provides details about the expected behavior of Passive Patch Management feature when a Neverfail Engine DR Pair is extended to a HA+DR Trio deployment, by adding a new HA node to the existing binary cluster.

 

More information

Scenario:

  • Neverfail Engine is initially deployed as a DR Pair cluster
  • Secondary DR server is configured for passive node management with a management name and a corresponding IP address
  • Neverfail Engine DR Pair is extended to a Trio HA+DR deployment, by adding a new HA node to the existing binary cluster
    • by design, this operation means that the existing Secondary DR node's Identity is changed to Tertiary DR, and a new Secondary HA node is cloned using the Primary as a source

Result:

  • The new Secondary HA node will be configured with the Management Identity set initially on the old Secondary DR node. This is an expected behavior: Passive Node Management configuration is based on server's Identity, and it is being applied on a given node each time Neverfail Engine service is started.

Possible impact:

  • The new Secondary HA server might get configured with a management IP address which is not valid in the new HA site subnet context, i.e. HA and DR public subnets are different, thus Secondary HA will be configured with a management IP valid in the DR subnet.

Workaround: 

  • reconfigure the Management Identity passive management name and IP address as per new context 

Applies To

Neverfail Continuity Engine v8.5