The following use cases illustrate some of the ways you can use alert and response features:
- Define health rules that apply to specific tiers or nodes. Instead of choosing specific nodes, you can trigger a rule when more than a certain percentage of nodes are unhealthy, say 20%.
- Start a diagnostic action for a business transaction.
- Alert when an app agent stops reporting to the Controller.
Create a node health rule based on the value of the Availability metric reported by the agent. If Availability is less than one, the agent is not reporting.
- Alert when the 95th percentile metrics for specific business transactions reach a certain value. You want to apply this rule only to business transactions with names beginning with User.
- You can generalize a health rule by specifying a relative metric path, rather than a specific metric. The health rule is evaluated for each of the affected business transactions. Use a relative metric path when you need to evaluate a single metric for multiple entities.
- You have a large operation with several development teams, each responsible for a different service. You create a health rule for one service and then copy it. Then create different policies in which you can pair each copy of the health rule to an alert addressed to the appropriate team.
- Start a script to change the size of the connection pool. You have an application that performs well for normal load. However, peak loads can cause the application to slow. During peak load, the AppDynamics not only detects the connection pool contention but also allows you to create a remediation script that can automate increasing or decreasing the size of the connection pool. You can require human approval to run this script or just configure it to automatically execute when it is triggered. Create a runbook and associate it with a policy so that it will fire when the connection pool is exhausted.
- Alert when the available disk volume is low. Use an expression over two metrics—available and used disk space—to be alerted when disk volume is low.