Metrics for alerting in advance and preventing trouble can be obtained through the following steps:

1. Identify Relevant Metrics: The first step is to identify the relevant metrics that can be used to monitor and alert for potential issues. These metrics should be chosen based on the specific system and its components, as well as the expected normal behaviour of the system. This could include metrics such as CPU utilization, memory usage, disk space, network latency, etc.

2. Set Up Monitoring: Once the relevant metrics have been identified, the next step is to set up monitoring for these metrics. This could involve using a monitoring tool or manually collecting the metrics. The monitoring should include the ability to set thresholds and alerts based on the metrics.

3. Analyze Trends: Analysis of the collected metrics should be done regularly to identify any trends or patterns. This analysis can help to identify any potential issues before they become a problem.

4. Establish Alerts: Once any trends or patterns have been identified, alerts should be established to notify the appropriate personnel. This should include thresholds that will trigger an alert when they are exceeded.

5. Take Action: Once an alert has been triggered, it is important to take action to address the issue. This could involve troubleshooting the system to identify the root cause of the issue, or implementing a fix or workaround. By following these steps, it is possible to obtain metrics for alerting in advance and preventing trouble. This helps to ensure that any potential issues are identified and addressed before they become a major problem.