We have two policies that we think should overwrite (not merge) – but we’re unsure of the behavior as we’re seeing a merge occur when the policy is applied. The two policies with the same monitor features enabled).

The two policies are setup to monitor Windows services.
One policy - Windows basic - will monitor our basic Windows services
Second policy - Windows Domain Controller - will monitor the basic Windows services and domain controller services.

The documentation does indicate that when possible, the policies will be merged. For example, if there are no conflicts between the policies they will be merged.

https://docs.bmc.com/docs/display/tsim107/Policy+precedence+best+practices

https://docs.bmc.com/docs/TSInfrastructure/110/policy-precedence-best-practices-719679713.html#Policyprecedencebestpractices-Policyprecedencebehavior

https://docs.bmc.com/docs/display/tsim113/Policy%20precedence%20best%20practices?refresh=1537458784690&refresh=1537458827056&focusedCommentId=828118023&refresh=1537458863280#comment-828118023

However, there is an exception when monitoring services via a policy, they behave a little different from other policies.

Service based policies will use the include and exclude criteria rather than the policy precedence when attempting to resolve a conflict which arises when two or more policies have the same details/overlapping details.

The standard policy precedence behavior calls for a merging of the two policies

https://docs.bmc.com/docs/display/tsim107/Policy+precedence+best+practices#Policyprecedencebestpractices-Policyprecedencebehavior

When policies A and B are applied to a PATROL Agent

With Conflict

The Agent resolves the conflict that is related to the /AgentSetup/historyRetentionPeriod variable by evaluating the precedence values of the policies.

Because the precedence value of Policy B (070) is lower than that of Policy A (099), the variable value of Policy B, that is 1, is applied to the Agent.

Remember the rule: Lower the number, higher the precedence.

Without Conflict

The Agent is configured according to the union of policy A and policy B because there are no conflicts. All the Windows services configured in policy A and policy B are monitored.

When using services the precedence is not the primary factor in determining how conflicts are resolved. The policy will use the include/exclude criteria to determine which services will be monitored by the Agent.

 
We will be updating the documentation to include the details regarding how services are handled in regard to order, precedence, etc.. the service policies will merge where they can but will then use the exclude and include criteria which are configured for the services to determine which services are applied.